/* EduNet — a small, bright laboratory for big discoveries. */
:root {
  color-scheme: light;
  --paper: #f6f8f2;
  --surface: #ffffff;
  --ink: #132d26;
  --muted: #6b7970;
  --line: #dfe6da;
  --green: #204d3a;
  --green-deep: #163f30;
  --lime: #c8f26d;
  --yellow: #f4ce6a;
  --radius: 22px;
  --shadow: 0 12px 32px rgba(30, 57, 36, .045);
  font-family: "Segoe UI", Arial, sans-serif;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 96px; }
body { margin: 0; min-width: 320px; background: var(--paper); color: var(--ink); font-size: 15px; line-height: 1.55; }
button, input, select, textarea { font: inherit; }
button, a, input, select, textarea { -webkit-tap-highlight-color: transparent; }
button { color: inherit; }
button, select, input[type="range"] { cursor: pointer; }
button, input, select, textarea { margin: 0; }
button { border: 0; }
button:disabled { cursor: not-allowed; opacity: .48; }
a { color: inherit; text-decoration: none; }
img, svg { max-width: 100%; }
svg { flex-shrink: 0; }
svg text { font-family: "Segoe UI", Arial, sans-serif; }
h1, h2, h3, h4, p { margin-top: 0; }
h1, h2, h3, h4 { line-height: 1.15; }
p:last-child { margin-bottom: 0; }
::selection { color: var(--ink); background: var(--lime); }
:focus-visible { outline: 3px solid #5b9228; outline-offset: 4px; }
[hidden] { display: none !important; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }

.topbar {
  position: sticky; top: 0; z-index: 30;
  display: flex; align-items: center; justify-content: space-between; gap: 24px;
  min-height: 78px; padding: 0 max(32px, calc((100vw - 1280px) / 2));
  border-bottom: 1px solid var(--line); background: rgba(246,248,242,.96);
  backdrop-filter: blur(16px);
}
.brand { display: inline-flex; align-items: center; gap: 10px; flex-shrink: 0; }
.brand-mark { display: grid; place-items: center; width: 37px; height: 37px; border-radius: 12px; background: var(--green); color: var(--lime); }
.brand-mark svg { width: 25px; height: 25px; }
.brand-word { font-size: 23px; line-height: 1; font-weight: 800; letter-spacing: -.9px; }
.brand-tag { margin-left: 3px; padding: 4px 7px; border: 1px solid #cfdac6; border-radius: 5px; color: #697861; font-size: 9px; font-weight: 800; letter-spacing: 1px; text-transform: uppercase; }
.topnav { display: flex; align-items: center; gap: 5px; margin-left: auto; }
.nav-btn { padding: 9px 15px; border-radius: 9px; background: transparent; color: #677369; font-size: 13px; font-weight: 600; transition: color .18s, background .18s; }
.nav-btn:hover, .nav-btn.active, .nav-btn[aria-current="page"] { background: #e9efdf; color: var(--ink); }
.header-actions { display: flex; align-items: center; gap: 11px; }
.icon-btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; flex: 0 0 auto; width: 38px; height: 38px; border: 1px solid var(--line); border-radius: 11px; background: transparent; color: var(--ink); transition: background .18s, border-color .18s; }
.icon-btn:hover { background: #eaf0e2; border-color: #c4d0ba; }
.icon-btn svg, .button svg, .sidebar-link svg, .nav-btn svg { width: 18px; height: 18px; }
.button { display: inline-flex; align-items: center; justify-content: center; gap: 9px; min-height: 45px; padding: 11px 19px; border: 1px solid transparent; border-radius: 10px; font-size: 13px; font-weight: 700; line-height: 1.25; text-align: center; transition: background .18s, border-color .18s, transform .18s, box-shadow .18s; }
.button-primary { background: var(--green); color: #fff; box-shadow: 0 4px 0 rgba(16,43,31,.06); }
.button-primary:hover { background: #163e2d; transform: translateY(-1px); box-shadow: 0 5px 12px rgba(22,63,48,.12); }
.button-secondary { background: #fff; border-color: #d8e1d1; color: var(--ink); }
.button-secondary:hover { border-color: #a9bc9a; background: #f3f8eb; }
.button-ghost { background: transparent; color: var(--green); }
.button-ghost:hover { background: #e9f0df; }
.button-small { min-height: 36px; padding: 8px 13px; border-radius: 8px; font-size: 12px; }
.button-danger { color: #a04431; background: #fff1eb; border-color: #efd5cc; }
.button-lime { background: var(--lime); color: var(--ink); }
.button-lime:hover { background: #b8e55c; }
.button-wide { width: 100%; }
.mobile-nav { display: none; }

.landing { width: min(1280px, calc(100% - 64px)); margin: 0 auto; }
.hero { position: relative; display: grid; grid-template-columns: 1.02fr 1fr; align-items: center; gap: 55px; min-height: 548px; padding: 61px 0 50px; }
.hero-copy { position: relative; z-index: 2; padding-bottom: 7px; }
.eyebrow { display: inline-flex; align-items: center; gap: 8px; width: fit-content; margin-bottom: 20px; padding: 6px 10px; border: 1px solid #d9e3cc; border-radius: 6px; background: #eff4e7; color: #52703d; font-size: 10px; line-height: 1.3; font-weight: 750; letter-spacing: 1.15px; text-transform: uppercase; }
.status-dot { flex: 0 0 auto; width: 6px; height: 6px; border-radius: 50%; background: #6b913a; box-shadow: 0 0 0 3px rgba(113,152,61,.1); }
.hero-title { max-width: 650px; margin-bottom: 23px; font-size: clamp(38px, 4.25vw, 59px); line-height: 1.055; letter-spacing: -2.6px; font-weight: 750; }
.hero-title em { position: relative; font-style: normal; color: #4b772c; }
.hero-title mark, .hero-title .accent { padding: 0 .1em .025em; background: var(--lime); border-radius: 5px; color: var(--ink); }
.hero-lead { max-width: 480px; margin-bottom: 25px; color: #6b786d; font-size: 15px; line-height: 1.85; }
.hero-actions { display: flex; align-items: center; flex-wrap: wrap; gap: 10px; }
.hero-actions .button { min-height: 46px; padding-inline: 20px; }
.hero-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 9px 17px; margin-top: 23px; color: #7a8477; font-size: 10px; }
.hero-meta > span { display: inline-flex; align-items: center; gap: 5px; }
.hero-meta svg { width: 13px; height: 13px; color: #6d8c4f; }
.hero-art { position: relative; display: flex; align-items: center; justify-content: center; width: 100%; min-width: 0; min-height: 405px; border: 1px solid #dce5d4; border-radius: 25px; background-color: #edf3e5; background-image: linear-gradient(#dce6d380 1px, transparent 1px), linear-gradient(90deg, #dce6d380 1px, transparent 1px); background-size: 24px 24px; box-shadow: inset 0 0 55px 22px #edf3e580; isolation: isolate; }
.hero-art::before { content: ""; position: absolute; inset: 25px; z-index: -1; border: 1px dashed #bccfac; border-radius: 50%; }
.hero-illustration { display: block; width: 100%; max-height: 390px; height: auto; overflow: visible; }
.orbit-label { position: absolute; display: inline-flex; align-items: center; gap: 7px; max-width: calc(100% - 24px); padding: 8px 12px; border: 1px solid #d9e2d2; border-radius: 8px; background: #fff; box-shadow: 0 5px 16px #24401c0a; color: #4c6445; font-size: 10px; font-weight: 650; z-index: 2; }
.orbit-label svg { width: 14px; height: 14px; }
.orbit-label:first-of-type { top: 18px; left: 19px; }
.orbit-label:last-of-type { bottom: 43px; right: 15px; }
.equation-chip { position: absolute; z-index: 2; top: 20px; right: 18px; padding: 9px 14px; border: 1px solid #e2c36c; border-radius: 8px; background: var(--yellow); color: #5b4b23; font-size: 15px; font-style: italic; font-weight: 650; box-shadow: 0 4px 10px #46391209; }
.hero-caption { position: absolute; bottom: 15px; left: 18px; right: 18px; display: flex; justify-content: space-between; align-items: center; gap: 10px; color: #78906b; font-size: 9px; letter-spacing: .2px; }
.hero-caption strong { color: #48653b; font-weight: 650; }

.section { padding: 35px 0 38px; }
.section-head { display: flex; justify-content: space-between; align-items: flex-end; gap: 24px; margin-bottom: 24px; }
.section-kicker { display: block; margin-bottom: 8px; color: #7f8b73; font-size: 9px; font-weight: 800; letter-spacing: 1.8px; text-transform: uppercase; }
.section-title { margin-bottom: 7px; font-size: 29px; line-height: 1.15; letter-spacing: -1.1px; font-weight: 750; }
.section-copy { max-width: 510px; margin-bottom: 0; color: var(--muted); font-size: 12px; line-height: 1.7; }
.section-head > .button { flex-shrink: 0; margin-bottom: 3px; }
.steps-grid { display: grid; grid-template-columns: repeat(3, minmax(0,1fr)); gap: 15px; margin-bottom: 10px; }
.step-card { position: relative; display: grid; grid-template-columns: 39px 1fr; align-items: start; gap: 15px; padding: 23px 20px; border-top: 1px solid #cfdac5; }
.step-number { display: flex; align-items: center; justify-content: center; width: 36px; height: 36px; border: 1px solid #d3dfc7; border-radius: 50%; background: #edf3e5; color: #5b7747; font-size: 12px; font-weight: 700; }
.step-card h3 { margin: 2px 0 9px; font-size: 14px; font-weight: 700; letter-spacing: -.2px; }
.step-card p { color: var(--muted); font-size: 11px; line-height: 1.75; }
.template-grid { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 20px; }
.template-card { display: flex; flex-direction: column; min-width: 0; overflow: hidden; border: 1px solid var(--line); border-radius: 17px; background: #fff; box-shadow: var(--shadow); transition: border-color .2s, transform .2s, box-shadow .2s; }
.template-card:hover { transform: translateY(-3px); border-color: #bfd0ad; box-shadow: 0 14px 34px #1f421311; }
.template-card.selected { border-color: #789f4a; box-shadow: 0 0 0 2px #c8f26d80; }
.template-visual { position: relative; display: flex; align-items: center; justify-content: center; height: 188px; overflow: hidden; border-bottom: 1px solid #e1e8da; background-color: #edf3e5; background-image: radial-gradient(#c8d5bc 1px,transparent 1px); background-size: 15px 15px; }
.template-card:nth-child(2) .template-visual { background-color: #f7f1dc; background-image: radial-gradient(#dfd5b2 1px,transparent 1px); border-bottom-color: #e9e1c5; }
.template-card:nth-child(3) .template-visual { background-color: #e9f1ef; background-image: radial-gradient(#c5d9d1 1px,transparent 1px); border-bottom-color: #d5e2dd; }
.template-visual > svg { display: block; width: 100%; height: 100%; }
.template-visual .pill { position: absolute; z-index: 2; top: 13px; left: 13px; background: #ffffffd9; border-color: #d7dfd1; color: #65765a; }
.template-body { display: flex; flex: 1; flex-direction: column; padding: 20px 21px 18px; }
.template-body h3 { margin-bottom: 10px; font-size: 19px; font-weight: 750; letter-spacing: -.6px; }
.template-body > p { margin-bottom: 17px; color: #7a8377; font-size: 11px; line-height: 1.8; }
.template-tags { display: flex; flex-wrap: wrap; align-items: center; gap: 5px; margin-bottom: 21px; }
.pill { display: inline-flex; align-items: center; justify-content: center; gap: 4px; min-height: 22px; padding: 3px 7px; border: 1px solid #e3e8dd; border-radius: 5px; background: #f3f6ee; color: #6e7b63; font-size: 9px; line-height: 1.4; font-weight: 600; white-space: nowrap; }
.pill-green { border-color: #d4e4c5; background: #edf6e4; color: #5a7c3d; }
.pill-yellow { border-color: #e9dcae; background: #faf4df; color: #8a7743; }
.card-footer { display: flex; justify-content: space-between; align-items: center; gap: 10px; margin-top: auto; padding-top: 14px; border-top: 1px solid #edf0e7; color: #7f897a; font-size: 10px; }
.card-footer > span { display: inline-flex; align-items: center; gap: 5px; }
.arrow-button { display: flex; align-items: center; justify-content: center; width: 30px; height: 30px; border: 1px solid #dce5d3; border-radius: 8px; background: #f3f7ed; color: #47693a; }
.arrow-button:hover { border-color: #a8c18f; background: var(--lime); }
.arrow-button svg { width: 15px; height: 15px; }
.footer { display: flex; align-items: center; justify-content: space-between; gap: 20px; max-width: 1280px; margin: 38px auto 0; padding: 24px 0; border-top: 1px solid var(--line); color: #8b9384; font-size: 10px; }
.footer .brand { gap: 6px; }
.footer .brand-word { font-size: 16px; color: #58704b; letter-spacing: -.5px; }
.footer .brand-mark { width: 24px; height: 24px; border-radius: 7px; }
.footer .brand-mark svg { width: 17px; height: 17px; }
.footer-links { display: flex; gap: 20px; }
.footer a:hover { color: var(--green); }

.workspace { display: grid; grid-template-columns: 213px minmax(0,1fr); width: min(1360px,100%); min-height: 740px; margin: 0 auto; }
.workspace-sidebar { display: flex; flex-direction: column; align-items: stretch; gap: 6px; padding: 26px 15px 20px; background: var(--green-deep); color: #dfebd7; }
.sidebar-brand { margin-bottom: 24px; padding: 0 12px; color: #a7bea1; font-size: 10px; font-weight: 650; text-transform: uppercase; letter-spacing: 1.2px; }
.sidebar-link { display: flex; align-items: center; gap: 10px; width: 100%; min-height: 43px; padding: 10px 12px; border: 1px solid transparent; border-radius: 9px; background: transparent; color: #b7ccb0; font-size: 12px; font-weight: 600; text-align: left; transition: color .18s, background .18s; }
.sidebar-link:hover { background: #ffffff0c; color: #fff; }
.sidebar-link.active, .sidebar-link[aria-current="page"] { background: var(--lime); color: #25452a; }
.sidebar-link svg { width: 17px; height: 17px; }
.sidebar-link .count { margin-left: auto; min-width: 19px; padding: 0 4px; border-radius: 4px; background: #0000000d; font-size: 10px; text-align: center; }
.sidebar-note { position: relative; margin-top: auto; padding: 19px 12px 6px; border-top: 1px solid #ffffff1c; color: #9bb492; font-size: 10px; line-height: 1.8; }
.sidebar-note strong { display: block; margin: 7px 0 5px; color: #d5e8c7; font-size: 11px; font-weight: 650; }
.sidebar-note svg { color: #c6e699; }
.workspace-main { min-width: 0; padding: 31px 35px 45px; }
.workspace-heading { display: flex; align-items: flex-start; justify-content: space-between; gap: 24px; margin-bottom: 27px; }
.workspace-heading h1 { margin-bottom: 8px; font-size: 30px; letter-spacing: -1.2px; font-weight: 750; }
.workspace-heading p { max-width: 570px; margin-bottom: 0; color: var(--muted); font-size: 12px; line-height: 1.7; }
.workspace-heading .section-kicker { margin-bottom: 9px; }
.workspace-heading > .button { flex-shrink: 0; margin-top: 4px; }
.workspace-tools { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 12px; margin-bottom: 21px; }
.workspace-tools .input { width: 240px; }
.workspace-tools .select { width: auto; min-width: 160px; }
.workspace-tools > div { display: flex; gap: 8px; }
.stats-grid { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 14px; margin-bottom: 28px; }
.stat-card { position: relative; padding: 20px 20px 18px; border: 1px solid var(--line); border-radius: 13px; background: #fff; }
.stat-card:nth-child(2) { background: #edf3e5; }
.stat-card:nth-child(3) { background: #faf4e2; }
.stat-card > svg { position: absolute; top: 21px; right: 18px; width: 19px; height: 19px; color: #8ba578; }
.stat-value { display: block; margin-bottom: 7px; font-size: 29px; font-weight: 750; line-height: 1; letter-spacing: -1px; }
.stat-label { color: #7e8975; font-size: 10px; }
.empty-state { padding: 61px 25px 57px; border: 1px dashed #cbd9bd; border-radius: 18px; background: #f0f4e9; text-align: center; }
.empty-state > svg, .empty-icon { width: 48px; height: 48px; margin: 0 auto 19px; color: #7b9a5e; }
.empty-state h2, .empty-state h3 { margin-bottom: 11px; font-size: 21px; letter-spacing: -.5px; }
.empty-state p { max-width: 390px; margin: 0 auto 21px; color: #7d8974; font-size: 12px; line-height: 1.8; }
.library-list { overflow: hidden; border: 1px solid var(--line); border-radius: 15px; background: #fff; }
.lesson-row { display: flex; align-items: center; gap: 17px; padding: 21px; border-bottom: 1px solid #e8ede1; }
.lesson-row:last-child { border-bottom: 0; }
.lesson-icon { display: flex; justify-content: center; align-items: center; flex: 0 0 auto; width: 49px; height: 49px; border: 1px solid #dbe7cf; border-radius: 12px; background: #eff5e6; color: #608343; }
.lesson-icon svg { width: 25px; height: 25px; }
.lesson-row > div:nth-child(2) { min-width: 0; }
.lesson-title { display: block; margin-bottom: 6px; font-size: 14px; font-weight: 700; letter-spacing: -.25px; overflow-wrap: anywhere; }
.lesson-meta { display: flex; align-items: center; flex-wrap: wrap; gap: 7px; color: #88917f; font-size: 10px; }
.lesson-actions { display: flex; align-items: center; justify-content: flex-end; flex-wrap: wrap; gap: 6px; margin-left: auto; flex-shrink: 0; }
.lesson-actions .icon-btn { width: 32px; height: 32px; border-radius: 8px; }
.lesson-actions .icon-btn svg { width: 15px; height: 15px; }

.builder-grid { display: grid; grid-template-columns: minmax(0,1fr) minmax(0,1.04fr); align-items: start; gap: 23px; }
.panel { min-width: 0; padding: 23px; border: 1px solid var(--line); border-radius: 16px; background: #fff; box-shadow: var(--shadow); }
.panel-heading { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin-bottom: 22px; padding-bottom: 15px; border-bottom: 1px solid #e9eee2; }
.panel-heading h2, .panel-heading h3 { margin: 0; font-size: 15px; letter-spacing: -.35px; font-weight: 750; }
.panel-heading .pill { font-size: 8px; }
.field { display: flex; flex-direction: column; gap: 7px; min-width: 0; margin-bottom: 18px; }
.field > label, .field > .field-label { display: block; color: #4a6042; font-size: 11px; font-weight: 700; }
.field label > span { margin-left: 3px; color: #8a977c; font-weight: 400; }
.field-row { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 13px; }
.input, .select, .textarea { width: 100%; min-height: 42px; padding: 10px 12px; border: 1px solid #dfe6d7; border-radius: 8px; background: #fbfcf8; color: #3c5436; font-size: 12px; line-height: 1.5; transition: border-color .18s, box-shadow .18s; }
.input::placeholder, .textarea::placeholder { color: #a0a992; }
.input:hover, .select:hover, .textarea:hover { border-color: #bdcda9; }
.input:focus, .select:focus, .textarea:focus { outline: none; border-color: #87a65b; box-shadow: 0 0 0 3px #c8f26d33; }
.textarea { min-height: 98px; resize: vertical; }
.select { padding-right: 27px; }
.segmented { display: flex; gap: 3px; padding: 4px; border: 1px solid #e0e7d8; border-radius: 9px; background: #f3f6ee; }
.segmented button { flex: 1; min-height: 32px; padding: 6px 8px; border: 1px solid transparent; border-radius: 6px; background: transparent; color: #849075; font-size: 10px; font-weight: 650; }
.segmented button.active, .segmented button[aria-pressed="true"], .segmented button[aria-selected="true"] { border-color: #dce5d2; background: #fff; color: #416331; box-shadow: 0 2px 4px #24421206; }
.segmented button:hover { color: #3d652c; }
.helper { margin: 0; color: #8d9681; font-size: 9px; line-height: 1.75; }
.notice { display: flex; align-items: flex-start; gap: 9px; margin: 16px 0; padding: 12px 13px; border: 1px solid #e4ddb9; border-radius: 8px; background: #faf6e6; color: #8e7d44; font-size: 10px; line-height: 1.75; }
.notice svg { width: 15px; height: 15px; margin-top: 1px; }
.notice.success { border-color: #cbe0b5; background: #edf7e6; color: #517239; }
.notice.error { border-color: #edcbc0; background: #fff2eb; color: #995e46; }
.form-actions { display: flex; align-items: center; flex-wrap: wrap; justify-content: flex-end; gap: 8px; margin-top: 22px; padding-top: 19px; border-top: 1px solid #e8eee0; }
.form-actions > .helper { margin-right: auto; }
.scenario-card { padding: 17px; border: 1px solid #e3eadb; border-radius: 11px; background: #f8faf4; }
.scenario-card + .scenario-card { margin-top: 13px; }
.scenario-card h3, .scenario-card h4 { margin: 0 0 8px; font-size: 13px; letter-spacing: -.2px; }
.scenario-card p { color: #7d8972; font-size: 10px; line-height: 1.8; }
.scenario-list { display: flex; flex-direction: column; gap: 10px; margin: 17px 0 0; padding: 0; list-style: none; }
.scenario-item { display: flex; align-items: flex-start; gap: 11px; padding: 12px 13px; border: 1px solid #e6ecde; border-radius: 9px; background: #fff; font-size: 11px; }
.scenario-item > span:first-child { display: grid; place-items: center; flex: 0 0 auto; width: 22px; height: 22px; border-radius: 6px; background: #e9f2de; color: #628249; font-size: 9px; font-weight: 700; }
.scenario-item strong { display: block; margin: 1px 0 4px; color: #4b623e; font-size: 11px; }
.scenario-item p { margin: 0; color: #88937d; font-size: 10px; line-height: 1.7; }

.play-layout { display: grid; grid-template-columns: minmax(0,1fr) 314px; align-items: start; gap: 22px; }
.play-main, .play-aside { min-width: 0; }
.simulation { overflow: hidden; border: 1px solid #d7e2cc; border-radius: 15px; background: #fff; }
.simulation-stage { position: relative; display: flex; align-items: center; justify-content: center; min-height: 305px; overflow: hidden; border-bottom: 1px solid #dce5d3; background-color: #eff4e8; background-image: linear-gradient(#dce6d380 1px,transparent 1px),linear-gradient(90deg,#dce6d380 1px,transparent 1px); background-size: 22px 22px; }
.simulation-stage > svg { display: block; width: 100%; height: auto; min-height: 260px; max-height: 340px; }
.simulation-stage > .pill { position: absolute; top: 13px; left: 13px; z-index: 2; background: #fff; }
.simulation-controls { padding: 18px 21px 20px; }
.simulation-controls > .button { margin-bottom: 16px; }
.simulation-control-head { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin-bottom: 18px; }
.simulation-control-head strong { color: #557347; font-size: 11px; }
.control-actions { display: flex; flex-wrap: wrap; gap: 7px; }
.range-field { margin-bottom: 18px; }
.range-field:last-child { margin-bottom: 0; }
.range-label { display: flex; align-items: center; justify-content: space-between; gap: 15px; margin-bottom: 8px; color: #6c7b60; font-size: 10px; font-weight: 600; }
.range-label output, .range-label strong { min-width: 52px; padding: 3px 7px; border: 1px solid #dfe7d4; border-radius: 5px; background: #f4f8ed; color: #4b6c37; text-align: center; font-size: 10px; font-weight: 700; }
input[type="range"] { display: block; width: 100%; height: 5px; margin: 12px 0; border: 0; border-radius: 4px; background: #e0e8d5; accent-color: #6e923f; -webkit-appearance: none; appearance: none; }
input[type="range"]::-webkit-slider-thumb { width: 16px; height: 16px; border: 3px solid #fff; border-radius: 50%; background: #6d903d; box-shadow: 0 0 0 1px #89a264,0 2px 4px #30501126; -webkit-appearance: none; appearance: none; }
input[type="range"]::-moz-range-thumb { width: 11px; height: 11px; border: 3px solid #fff; border-radius: 50%; background: #6d903d; box-shadow: 0 0 0 1px #89a264; }
input[type="range"]:focus-visible { outline-offset: 8px; }
.readout-grid { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 10px; margin: 15px 0; }
.readout { padding: 13px 10px; border: 1px solid #e0e7d7; border-radius: 9px; background: #fbfcf8; text-align: center; }
.readout span, .readout small { display: block; margin-bottom: 4px; color: #8b967e; font-size: 9px; }
.readout strong { color: #46633b; font-size: 17px; font-weight: 750; }
.readout strong small { display: inline; color: #6e805e; font-size: 10px; font-weight: 500; }
.question-card { padding: 22px; border: 1px solid var(--line); border-radius: 15px; background: #fff; box-shadow: var(--shadow); }
.question-counter { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin-bottom: 13px; color: #8b967d; font-size: 9px; font-weight: 700; letter-spacing: .5px; text-transform: uppercase; }
.question-card h2, .question-card h3 { margin: 18px 0 11px; font-size: 18px; line-height: 1.35; font-weight: 750; letter-spacing: -.5px; }
.question-card p { margin-bottom: 18px; color: #7e8c73; font-size: 11px; line-height: 1.8; }
.choice { display: flex; align-items: center; gap: 9px; width: 100%; min-height: 44px; margin: 8px 0; padding: 11px 12px; border: 1px solid #e0e7d7; border-radius: 8px; background: #fbfcf9; color: #607154; font-size: 11px; line-height: 1.5; text-align: left; transition: background .15s, border-color .15s; }
.choice:hover { border-color: #aec494; background: #f0f6e6; }
.choice > span:first-child { display: grid; place-items: center; flex: 0 0 auto; min-width: 21px; height: 21px; border: 1px solid #dce4d1; border-radius: 5px; background: #fff; color: #8a987c; font-size: 9px; }
.choice.selected { border-color: #94b365; background: #eff6e3; color: #46682e; }
.choice.correct { border-color: #9abf75; background: #eaf5e0; color: #4e7933; }
.choice.wrong { border-color: #e6bba8; background: #fff1e9; color: #a47159; }
.feedback { margin: 14px 0; padding: 11px 12px; border: 1px solid #d2e3bf; border-radius: 8px; background: #eff7e6; color: #64844a; font-size: 10px; line-height: 1.75; }
.feedback.wrong { border-color: #edd6b5; background: #fff7e8; color: #9a7f4e; }
.question-card > .button { width: 100%; margin-top: 13px; }
.progress-track { height: 5px; overflow: hidden; border-radius: 4px; background: #e7eddf; }
.progress-fill { height: 100%; border-radius: 4px; background: #a9cb6c; transition: width .3s ease; }
.result-card { padding: 37px 28px; border: 1px solid #d5e2c8; border-radius: 17px; background: #fff; text-align: center; }
.result-card > svg { width: 57px; height: 57px; margin-bottom: 17px; color: #8cad52; }
.result-card h2 { margin-bottom: 13px; font-size: 26px; letter-spacing: -.8px; }
.result-card p { max-width: 440px; margin: 0 auto 20px; color: #7a8970; font-size: 12px; line-height: 1.8; }
.result-score { margin: 20px 0; color: #547637; font-size: 46px; font-weight: 750; line-height: 1; letter-spacing: -2px; }
.result-card .form-actions { justify-content: center; }
.play-aside .notice { margin-top: 13px; }
.play-aside .panel { margin-top: 15px; padding: 18px; }
.play-aside .panel h3 { margin-bottom: 10px; font-size: 13px; }
.play-aside .panel p { color: #8b957f; font-size: 10px; line-height: 1.8; }

.dialog, dialog { width: min(540px,calc(100% - 32px)); max-height: min(82vh,800px); overflow-y: auto; padding: 27px; border: 1px solid #d7e2cd; border-radius: 18px; background: #fff; color: var(--ink); box-shadow: 0 25px 90px #122c2640; scrollbar-width: thin; scrollbar-color: #cad9bb #f3f7ed; }
dialog::backdrop { background: rgba(22,43,30,.38); backdrop-filter: blur(4px); }
.modal-heading { display: flex; justify-content: space-between; align-items: flex-start; gap: 18px; margin-bottom: 22px; }
.modal-heading h2 { margin: 1px 0 7px; font-size: 23px; letter-spacing: -.8px; }
.modal-heading p { max-width: 390px; margin-bottom: 0; color: #859078; font-size: 11px; line-height: 1.7; }
.modal-heading .icon-btn { width: 30px; height: 30px; border: 0; background: #f1f5eb; }
.modal-heading .icon-btn svg { width: 16px; height: 16px; }
.modal-actions { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 8px; margin-top: 22px; padding-top: 18px; border-top: 1px solid #e5ecdc; }
.share-url { width: 100%; margin-top: 8px; padding: 13px; border: 1px solid #dce6d2; border-radius: 8px; background: #f6f9f0; color: #627b4f; font-size: 11px; overflow-wrap: anywhere; word-break: break-word; }
.toast { position: fixed; z-index: 100; left: 50%; bottom: 25px; display: flex; align-items: center; gap: 9px; width: max-content; max-width: calc(100% - 32px); padding: 13px 19px; border: 1px solid #437153; border-radius: 11px; background: var(--green-deep); color: #f4faec; box-shadow: 0 9px 30px #122e3024; font-size: 12px; text-align: center; transform: translate(-50%,15px); opacity: 0; pointer-events: none; transition: transform .2s, opacity .2s; }
.toast.show { transform: translate(-50%,0); opacity: 1; }
.toast svg { width: 16px; height: 16px; color: var(--lime); }
.install-tip { display: flex; align-items: flex-start; gap: 12px; margin: 22px 0; padding: 16px 18px; border: 1px solid #d6e2c9; border-radius: 11px; background: #edf5e3; color: #6b8257; font-size: 11px; line-height: 1.8; }
.install-tip > svg { width: 21px; height: 21px; margin-top: 2px; }
.install-tip strong { display: block; margin-bottom: 3px; color: #4f6d3b; }
.install-tip .button { margin-left: auto; flex-shrink: 0; }
.loading { display: flex; align-items: center; gap: 8px; }
.loading::before { content: ""; width: 12px; height: 12px; border: 2px solid currentColor; border-right-color: transparent; border-radius: 50%; animation: spin .7s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }

@media (min-width: 1500px) {
  .hero { min-height: 590px; }
  .workspace { margin-top: 24px; margin-bottom: 24px; overflow: hidden; border: 1px solid var(--line); border-radius: 18px; }
}

@media (max-width: 1150px) {
  .topbar { padding-inline: 26px; gap: 17px; }
  .brand-tag { display: none; }
  .landing { width: calc(100% - 52px); }
  .hero { gap: 32px; min-height: 510px; }
  .hero-title { font-size: 45px; letter-spacing: -2px; }
  .hero-art { min-height: 367px; }
  .hero-lead { font-size: 13px; }
  .hero-meta { gap: 7px 12px; font-size: 9px; }
  .workspace { grid-template-columns: 180px minmax(0,1fr); }
  .workspace-sidebar { padding-inline: 10px; }
  .workspace-main { padding: 28px 25px 40px; }
  .builder-grid { gap: 16px; }
  .panel { padding: 18px; }
  .play-layout { grid-template-columns: minmax(0,1fr) 280px; gap: 16px; }
  .question-card { padding: 18px; }
  .lesson-actions .button { font-size: 10px; padding-inline: 10px; }
  .template-body { padding: 18px; }
  .step-card { padding-inline: 12px; gap: 12px; }
}

@media (max-width: 900px) {
  .topbar { min-height: 72px; }
  .brand-word { font-size: 22px; }
  .nav-btn { padding-inline: 10px; font-size: 12px; }
  .header-actions { gap: 6px; }
  .header-actions .button { padding-inline: 12px; font-size: 11px; }
  .hero { gap: 24px; min-height: 460px; padding-top: 43px; }
  .hero-title { font-size: 39px; letter-spacing: -1.7px; }
  .hero-lead { font-size: 12px; margin-bottom: 21px; }
  .hero-art { min-height: 326px; border-radius: 20px; }
  .hero-actions .button { min-height: 40px; padding: 10px 13px; font-size: 11px; }
  .eyebrow { margin-bottom: 17px; font-size: 8px; letter-spacing: .8px; }
  .orbit-label { padding: 7px 8px; font-size: 8px; }
  .equation-chip { padding: 7px 10px; font-size: 12px; }
  .hero-caption { font-size: 8px; }
  .template-grid { gap: 13px; }
  .template-visual { height: 154px; }
  .template-body { padding: 17px 15px 14px; }
  .template-body h3 { font-size: 17px; }
  .template-body > p { font-size: 10px; }
  .template-tags { margin-bottom: 15px; }
  .card-footer { font-size: 9px; }
  .step-card { grid-template-columns: 30px 1fr; gap: 10px; padding: 19px 7px; }
  .step-number { width: 29px; height: 29px; font-size: 10px; }
  .step-card h3 { font-size: 12px; }
  .step-card p { font-size: 10px; }
  .workspace { grid-template-columns: 166px minmax(0,1fr); }
  .workspace-main { padding: 26px 21px 35px; }
  .workspace-heading { gap: 12px; }
  .workspace-heading h1 { font-size: 26px; }
  .workspace-heading p { font-size: 11px; }
  .workspace-heading > .button { padding-inline: 11px; font-size: 11px; }
  .sidebar-link { padding-inline: 9px; gap: 8px; font-size: 11px; }
  .builder-grid { grid-template-columns: minmax(0,1fr); }
  .play-layout { grid-template-columns: minmax(0,1fr); }
  .play-aside { display: grid; grid-template-columns: minmax(0,1.3fr) minmax(0,1fr); gap: 15px; align-items: start; }
  .play-aside .notice { margin: 0; }
  .play-aside .panel { margin-top: 0; }
  .play-aside .question-card { grid-row: span 2; }
  .lesson-row { padding: 17px; gap: 12px; flex-wrap: wrap; }
  .lesson-actions { width: 100%; padding-left: 61px; justify-content: flex-start; }
  .stats-grid { gap: 9px; }
  .stat-card { padding: 18px 14px; }
  .stat-card > svg { top: 17px; right: 12px; width: 15px; height: 15px; }
  .stat-value { font-size: 26px; }
  .stat-label { font-size: 9px; }
}

@media (max-width: 700px) {
  html { scroll-padding-top: 82px; }
  .topbar { min-height: 68px; padding: 0 20px; gap: 12px; }
  .brand { gap: 8px; }
  .brand-mark { width: 32px; height: 32px; border-radius: 10px; }
  .brand-mark svg { width: 23px; height: 23px; }
  .brand-word { font-size: 21px; }
  .topnav { gap: 0; }
  .nav-btn { padding: 8px; font-size: 10px; }
  .header-actions .button { min-height: 34px; padding: 7px 10px; font-size: 10px; }
  .header-actions .icon-btn { width: 33px; height: 33px; border-radius: 9px; }
  .landing { width: calc(100% - 40px); }
  .hero { grid-template-columns: minmax(0,1fr); gap: 28px; padding: 36px 0 26px; }
  .hero-copy { padding-bottom: 0; }
  .hero-title { max-width: 560px; margin-bottom: 19px; font-size: clamp(35px,6.7vw,47px); line-height: 1.08; letter-spacing: -1.7px; }
  .eyebrow { margin-bottom: 18px; font-size: 9px; }
  .hero-lead { max-width: 490px; margin-bottom: 23px; font-size: 13px; line-height: 1.85; }
  .hero-actions .button { min-height: 43px; padding-inline: 17px; font-size: 12px; }
  .hero-meta { margin-top: 19px; font-size: 9px; }
  .hero-art { min-height: 310px; max-width: 550px; margin: 0 auto; }
  .hero-illustration { max-height: 310px; }
  .orbit-label { font-size: 9px; }
  .equation-chip { font-size: 14px; }
  .section { padding: 30px 0 24px; }
  .section-title { font-size: 27px; letter-spacing: -.9px; }
  .section-head { gap: 13px; margin-bottom: 20px; }
  .section-head > .button { font-size: 10px; padding-inline: 10px; }
  .section-copy { font-size: 11px; }
  .steps-grid { grid-template-columns: minmax(0,1fr); gap: 0; }
  .step-card { grid-template-columns: 34px 1fr; gap: 13px; padding: 19px 4px; }
  .step-number { width: 32px; height: 32px; }
  .step-card h3 { margin: 1px 0 6px; font-size: 14px; }
  .step-card p { max-width: 440px; margin: 0; font-size: 11px; line-height: 1.7; }
  .template-grid { grid-template-columns: minmax(0,1fr); gap: 17px; }
  .template-card { display: grid; grid-template-columns: 38% minmax(0,1fr); border-radius: 15px; }
  .template-visual { min-height: 210px; height: 100%; border-bottom: 0; border-right: 1px solid #e1e8da; }
  .template-visual .pill { top: 10px; left: 10px; font-size: 8px; }
  .template-body { padding: 19px 17px 16px; }
  .template-body h3 { font-size: 18px; }
  .template-body > p { font-size: 11px; margin-bottom: 12px; }
  .template-tags { margin-bottom: 13px; }
  .footer { flex-wrap: wrap; justify-content: flex-start; gap: 14px 20px; margin-top: 23px; padding: 22px 0; font-size: 9px; }
  .footer > p { margin: 0 0 0 auto; }
  .footer-links { gap: 13px; margin-left: auto; }
  .workspace { grid-template-columns: minmax(0,1fr); min-height: calc(100vh - 68px); }
  .workspace-sidebar { flex-direction: row; align-items: center; gap: 6px; overflow-x: auto; padding: 11px 20px; scrollbar-width: none; }
  .workspace-sidebar::-webkit-scrollbar { display: none; }
  .sidebar-brand, .sidebar-note { display: none; }
  .sidebar-link { justify-content: center; flex: 0 0 auto; width: auto; min-height: 36px; padding: 8px 12px; border-radius: 8px; font-size: 10px; white-space: nowrap; }
  .sidebar-link svg { width: 15px; height: 15px; }
  .workspace-main { padding: 26px 20px 35px; }
  .workspace-heading { margin-bottom: 23px; }
  .workspace-heading h1 { font-size: 27px; }
  .workspace-heading p { max-width: 400px; font-size: 11px; }
  .workspace-tools .input { width: 100%; }
  .workspace-tools > .field, .workspace-tools > .input { flex: 1; }
  .workspace-tools .select { min-width: 130px; }
  .stats-grid { gap: 10px; margin-bottom: 23px; }
  .stat-card { padding: 18px 16px 15px; }
  .stat-value { font-size: 27px; }
  .lesson-row { flex-wrap: nowrap; padding: 18px 16px; }
  .lesson-actions { width: auto; margin-left: auto; padding: 0; }
  .lesson-actions .button { display: none; }
  .lesson-title { font-size: 12px; }
  .lesson-meta { font-size: 9px; gap: 5px; }
  .lesson-icon { width: 41px; height: 41px; border-radius: 10px; }
  .lesson-icon svg { width: 22px; height: 22px; }
  .play-aside { grid-template-columns: minmax(0,1.2fr) minmax(0,1fr); }
  .dialog, dialog { padding: 23px; }
}

@media (max-width: 480px) {
  .topbar { min-height: 64px; padding-inline: 17px; gap: 9px; }
  .topnav { display: none; }
  .header-actions { margin-left: auto; }
  .header-actions .button { min-height: 33px; padding-inline: 11px; font-size: 10px; }
  .header-actions .button svg { width: 14px; height: 14px; }
  .header-actions .icon-btn { width: 32px; height: 32px; }
  .brand-word { font-size: 21px; }
  .landing { width: calc(100% - 34px); }
  .hero { gap: 28px; padding: 31px 0 18px; }
  .hero-title { font-size: 36px; letter-spacing: -1.55px; }
  .hero-lead { font-size: 12px; line-height: 1.85; }
  .hero-meta { gap: 7px 12px; font-size: 8px; }
  .hero-actions { gap: 8px; }
  .hero-actions .button { min-height: 42px; padding-inline: 13px; font-size: 11px; }
  .hero-art { min-height: 276px; border-radius: 17px; background-size: 20px 20px; }
  .hero-art::before { inset: 22px; }
  .hero-illustration { max-height: 276px; }
  .orbit-label { padding: 6px 8px; font-size: 8px; border-radius: 6px; }
  .orbit-label:first-of-type { top: 13px; left: 12px; }
  .orbit-label:last-of-type { right: 11px; bottom: 36px; }
  .equation-chip { top: 12px; right: 11px; padding: 6px 9px; font-size: 12px; }
  .hero-caption { left: 12px; right: 12px; bottom: 11px; font-size: 7px; }
  .section { padding-top: 28px; }
  .section-title { font-size: 25px; }
  .section-kicker { font-size: 8px; letter-spacing: 1.5px; }
  .section-head { align-items: flex-start; }
  .section-head > .button { align-self: flex-end; min-height: 31px; padding: 6px 0 6px 8px; font-size: 9px; white-space: nowrap; }
  .section-head > .button svg { width: 13px; height: 13px; }
  .template-card { display: flex; }
  .template-visual { height: 173px; min-height: 0; border-right: 0; border-bottom: 1px solid #e1e8da; }
  .template-visual .pill { top: 12px; left: 12px; }
  .template-body { padding: 20px; }
  .template-body h3 { font-size: 21px; }
  .template-body > p { font-size: 12px; }
  .template-tags { margin-bottom: 17px; }
  .pill { font-size: 9px; }
  .card-footer { font-size: 10px; padding-top: 15px; }
  .arrow-button { width: 32px; height: 32px; }
  .footer { gap: 13px; }
  .footer > p { margin-left: auto; font-size: 8px; }
  .footer-links { width: 100%; margin-left: 0; }
  .workspace { min-height: calc(100vh - 64px); }
  .workspace-sidebar { padding: 10px 17px; gap: 4px; }
  .sidebar-link { min-height: 34px; padding-inline: 11px; font-size: 10px; gap: 6px; }
  .workspace-main { padding: 24px 17px 32px; }
  .workspace-heading { flex-wrap: wrap; gap: 13px; margin-bottom: 22px; }
  .workspace-heading h1 { font-size: 27px; }
  .workspace-heading p { font-size: 11px; }
  .workspace-heading > .button { margin-top: 0; min-height: 37px; padding: 9px 13px; }
  .workspace-tools { gap: 9px; }
  .workspace-tools > .input { flex-basis: 100%; }
  .workspace-tools .select { min-width: 0; }
  .workspace-tools > div { width: 100%; }
  .stats-grid { gap: 7px; }
  .stat-card { padding: 17px 11px 13px; border-radius: 10px; }
  .stat-card > svg { display: none; }
  .stat-value { margin-bottom: 7px; font-size: 25px; }
  .stat-label { font-size: 8px; }
  .empty-state { padding: 42px 20px; }
  .empty-state h2, .empty-state h3 { font-size: 20px; }
  .empty-state p { font-size: 11px; }
  .lesson-row { gap: 10px; padding: 16px 13px; flex-wrap: wrap; }
  .lesson-row > div:nth-child(2) { flex: 1; }
  .lesson-actions { width: 100%; padding-left: 51px; gap: 6px; }
  .lesson-actions .button { display: inline-flex; }
  .lesson-title { font-size: 13px; }
  .lesson-meta { font-size: 8px; }
  .lesson-actions .icon-btn { width: 29px; height: 29px; }
  .builder-grid { gap: 16px; }
  .panel { padding: 18px; border-radius: 13px; }
  .panel-heading { margin-bottom: 19px; gap: 8px; }
  .panel-heading h2, .panel-heading h3 { font-size: 14px; }
  .panel-heading .pill { font-size: 7px; padding-inline: 5px; }
  .field-row { gap: 10px; }
  .field { margin-bottom: 16px; }
  .field > label, .field > .field-label { font-size: 10px; }
  .input, .select, .textarea { min-height: 41px; padding: 10px; font-size: 11px; }
  .textarea { min-height: 96px; }
  .segmented button { font-size: 9px; padding-inline: 6px; }
  .notice { padding: 11px; font-size: 9px; }
  .form-actions { gap: 7px; margin-top: 18px; padding-top: 16px; }
  .form-actions .button { flex: 1; min-height: 40px; padding-inline: 11px; font-size: 11px; }
  .form-actions > .helper { flex-basis: 100%; }
  .scenario-card { padding: 14px; }
  .scenario-item { padding: 11px; gap: 8px; }
  .play-layout { gap: 15px; }
  .play-aside { display: block; }
  .play-aside .notice, .play-aside .panel { margin-top: 13px; }
  .simulation-stage { min-height: 242px; background-size: 19px 19px; }
  .simulation-stage > svg { min-height: 225px; max-height: 280px; }
  .simulation-controls { padding: 17px; }
  .simulation-control-head { flex-wrap: wrap; margin-bottom: 15px; }
  .readout-grid { gap: 7px; margin: 13px 0; }
  .readout { padding: 12px 7px; }
  .readout strong { font-size: 15px; }
  .readout span, .readout small { font-size: 8px; }
  .question-card { padding: 20px; }
  .question-card h2, .question-card h3 { font-size: 19px; }
  .question-card p { font-size: 12px; }
  .choice { min-height: 47px; padding: 11px 12px; font-size: 12px; }
  .feedback { font-size: 11px; }
  .result-card { padding: 30px 21px; }
  .result-card h2 { font-size: 24px; }
  .result-card p { font-size: 11px; }
  .dialog, dialog { width: calc(100% - 26px); max-height: 88vh; padding: 22px 19px; border-radius: 15px; }
  .modal-heading h2 { font-size: 21px; }
  .modal-heading p { font-size: 10px; }
  .modal-actions { gap: 7px; }
  .modal-actions .button { flex: 1; min-height: 40px; padding-inline: 10px; font-size: 11px; }
  .share-url { font-size: 10px; }
  .toast { bottom: 17px; padding: 12px 15px; font-size: 11px; }
  .install-tip { flex-wrap: wrap; gap: 9px; padding: 14px; font-size: 10px; }
  .install-tip > div { flex: 1; }
  .install-tip .button { flex-basis: 100%; margin-left: 0; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
}

@media print {
  .topbar, .workspace-sidebar, .header-actions, .form-actions, .toast, .mobile-nav, .footer, .lesson-actions { display: none !important; }
  body { color: #132d26; background: #fff; }
  .workspace, .builder-grid, .play-layout { display: block; }
  .workspace-main { padding: 0; }
  .panel, .simulation, .question-card { break-inside: avoid; margin-bottom: 20px; box-shadow: none; }
}

/* Screen-specific composition and native form elements. */
.skip-link { position: fixed; top: 10px; left: 16px; z-index: 150; padding: 10px 15px; border-radius: 8px; background: var(--green); color: #fff; font-size: 12px; transform: translateY(-150%); }
.skip-link:focus { transform: translateY(0); }
.brand-mark { position: relative; display: inline-flex; align-items: center; justify-content: center; padding-bottom: 3px; font-family: Arial,sans-serif; font-size: 30px; line-height: 1; font-weight: 750; letter-spacing: -2px; }
.brand-mark > span { position: absolute; top: 7px; right: 5px; font-size: 13px; line-height: 1; }
.footer .brand-mark { padding-bottom: 2px; font-size: 21px; }
.footer .brand-mark > span { top: 4px; right: 3px; font-size: 9px; }
.footer .brand > span:last-child { color: #58704b; font-size: 16px; font-weight: 750; letter-spacing: -.5px; }
.footer { width: min(1280px,calc(100% - 64px)); }
.hero-title > span { color: #5b803c; }
.equation-chip { display: flex; flex-direction: column; gap: 4px; top: auto; right: 18px; bottom: 37px; width: 237px; padding: 13px 16px; border-color: #d5bd6d; background: #f7d77f; font-style: normal; transform: rotate(-3deg); }
.equation-chip small { color: #8b763a; font-size: 7px; font-weight: 750; letter-spacing: 1.3px; }
.equation-chip strong { color: #3d4329; font-size: 24px; font-weight: 650; letter-spacing: -.4px; }
.equation-chip > span { color: #8d793f; font-size: 8px; font-weight: 400; }
.hero-caption { right: auto; bottom: 17px; color: #738b61; font-size: 8px; }
.how-section { padding: 31px 0 17px; }
#examples { padding: 27px 0 36px; }
.step-number { grid-row: 1 / span 2; }
.step-card { row-gap: 0; }
.step-card > h3, .step-card > p { grid-column: 2; }
.step-card > p { margin-bottom: 0; }
.template-tags { justify-content: space-between; margin-bottom: 11px; color: #89937c; font-size: 8px; letter-spacing: .4px; }
.template-tags > span:first-child { color: #748565; font-weight: 700; text-transform: uppercase; }
.template-card .card-footer .button { min-height: 29px; margin-left: -7px; padding: 6px 7px; font-size: 10px; }
.bottom-cta { display: flex; align-items: center; justify-content: space-between; gap: 25px; margin: 5px 0 13px; padding: 34px 37px; border-color: #dbe5cd; background: #eaf2dd; box-shadow: none; }
.bottom-cta h2 { margin: 0 0 12px; font-size: 30px; line-height: 1.13; letter-spacing: -1.2px; }
.bottom-cta p { color: #82936f; font-size: 11px; }
.bottom-cta .button { flex-shrink: 0; }
.sidebar-brand { font-size: 8px; line-height: 1.8; }
.sidebar-brand strong { display: block; margin-top: 5px; color: #e1edda; font-size: 17px; font-weight: 650; letter-spacing: -.4px; text-transform: none; }
.sidebar-link > span { margin-left: auto; min-width: 18px; padding: 1px 4px; border-radius: 4px; background: #0000000a; font-size: 9px; text-align: center; }
.stat-card .stat-label { display: block; margin-bottom: 14px; }
.stat-card .stat-value { margin-bottom: 9px; }
.stat-card > span:last-child { color: #8a967e; font-size: 9px; }
.search-field { margin-left: auto; }
.storage-note { margin-top: 16px; }
.empty-icon { display: grid; place-items: center; border: 1px solid #d5e2c8; border-radius: 14px; background: #e4edd8; }
.empty-icon svg { width: 25px; height: 25px; }
.lesson-title { margin: 0; }
.lesson-title h3 { margin: 0 0 7px; font-size: 14px; font-weight: 700; letter-spacing: -.25px; }
.lesson-meta { font-weight: 400; }
.lesson-row > .pill { margin-left: auto; }
.lesson-row .lesson-actions { margin-left: 0; }
.panel-heading { justify-content: flex-start; }
.panel-heading > .step-number { width: 27px; height: 27px; font-size: 9px; }
.panel-heading > .pill { margin-left: auto; }
.field { color: #4a6042; font-size: 11px; font-weight: 650; }
fieldset.field { min-inline-size: 0; padding: 0; border: 0; }
.field legend { margin-bottom: 7px; padding: 0; font-size: 11px; font-weight: 700; }
.field .input, .field .select, .field .textarea { font-weight: 400; }
.scenario-list { margin-top: 3px; }
.scenario-item { cursor: pointer; align-items: flex-start; }
.scenario-item input[type="radio"] { flex: 0 0 auto; width: 14px; height: 14px; margin: 3px 0 0; accent-color: #648839; }
.scenario-item:has(input:checked) { border-color: #b4cb94; background: #f1f7e8; }
.scenario-item small { display: block; color: #859275; font-size: 9px; font-weight: 400; line-height: 1.7; }
.editor-question { min-inline-size: 0; margin: 20px 0 0; padding: 15px 0 2px; border: 0; border-top: 1px solid #e5ecdc; }
.editor-question legend { padding: 0 9px 0 0; color: #6b8452; font-size: 10px; font-weight: 750; }
.editor-question .textarea { min-height: 73px; font-size: 11px; line-height: 1.6; }
.editor-question .field { gap: 7px; margin-bottom: 11px; }
.editor-choices { display: grid; grid-template-columns: minmax(0,1fr); gap: 7px; margin-bottom: 13px; }
.editor-choices label { display: flex; align-items: center; gap: 9px; min-width: 0; }
.editor-choices input[type="radio"] { flex: 0 0 auto; width: 14px; height: 14px; accent-color: #6e913f; }
.editor-choices .input { min-height: 34px; padding: 7px 10px; font-size: 10px; }
.approval-field { display: flex; align-items: flex-start; gap: 9px; margin-top: 14px; padding: 13px; border: 1px solid #d6e3c7; border-radius: 9px; background: #f1f7e9; color: #6b8256; font-size: 10px; line-height: 1.7; cursor: pointer; }
.approval-field input { width: 14px; height: 14px; margin-top: 2px; accent-color: #6e913f; flex-shrink: 0; }
.player-page { width: min(1180px,calc(100% - 64px)); margin: 0 auto; padding: 28px 0 45px; }
.back-link { display: inline-flex; align-items: center; gap: 7px; margin-bottom: 18px; color: #829374; font-size: 10px; }
.back-link svg { width: 14px; height: 14px; }
.back-link:hover { color: var(--green); }
.player-page > .workspace-heading { margin-bottom: 24px; }
.player-page > .workspace-heading > .pill { margin-top: 36px; }
.simulation > .panel-heading { min-height: 56px; margin: 0; padding: 15px 20px; border: 0; }
.simulation .readout-grid { margin: 17px 21px 4px; }
.simulation > .helper { margin: 0 21px 20px; padding-top: 13px; border-top: 1px solid #e8eee0; color: #7a8b6b; }
.range-field { display: block; }
.range-label output { min-width: 0; padding: 0; border: 0; border-radius: 0; background: transparent; }
.range-label strong { white-space: nowrap; }
.play-aside .question-card { margin-top: 0; }
.question-card > .helper { margin-top: 18px; }
.choice:disabled { opacity: 1; cursor: default; }
.choice > svg:last-child { width: 15px; height: 15px; margin-left: auto; }
.feedback strong { display: block; margin-bottom: 5px; }
.feedback p { margin: 0; color: inherit; font-size: inherit; line-height: inherit; }
.feedback-wrong { border-color: #ead7b9; background: #fff8e9; color: #907a4a; }
.result-symbol { display: grid; place-items: center; width: 54px; height: 54px; margin: 0 auto 20px; border-radius: 50%; background: #ecf5df; color: #759b45; }
.result-symbol svg { width: 28px; height: 28px; }
.result-card > .progress-track { margin-bottom: 20px; }
.result-card > .button { width: 100%; margin: 5px 0; }
.result-card > .helper { margin-top: 16px; font-size: 9px; }
.review-question { margin-top: 20px; padding-top: 17px; border-top: 1px solid #e5ecdc; }
.review-question h3 { margin-bottom: 12px; font-size: 13px; line-height: 1.6; }
.review-question p { color: #7a8b6a; font-size: 11px; line-height: 1.8; }
.review-question p strong { color: #598039; font-weight: 650; }
.dialog > p { color: #7a8970; font-size: 12px; line-height: 1.8; }
.dialog .install-tip { display: block; }
.dialog .install-tip p { margin: 0; }

@media (max-width: 1150px) {
  .equation-chip { right: 17px; bottom: 35px; width: 214px; padding: 11px 14px; }
  .equation-chip strong { font-size: 21px; }
  .equation-chip > span { font-size: 7px; }
  .bottom-cta { padding: 29px; }
  .player-page { width: calc(100% - 52px); }
  .workspace .template-visual { height: 147px; }
  .workspace .template-body { padding: 17px 15px; }
  .workspace .template-body h3 { font-size: 17px; }
}
@media (max-width: 900px) {
  .equation-chip { right: 12px; bottom: 32px; width: 195px; padding: 10px 12px; }
  .equation-chip strong { font-size: 19px; }
  .equation-chip small { font-size: 6px; }
  .equation-chip > span { font-size: 6px; }
  .hero-caption { font-size: 7px; }
  .bottom-cta h2 { font-size: 27px; }
  .bottom-cta .button { font-size: 11px; padding-inline: 13px; }
  .workspace .template-grid { grid-template-columns: minmax(0,1fr); }
  .workspace .template-card { display: grid; grid-template-columns: 39% minmax(0,1fr); }
  .workspace .template-visual { height: 100%; min-height: 205px; border-right: 1px solid #dce5d3; border-bottom: 0; }
  .workspace .template-body { padding: 20px; }
  .workspace .template-body h3 { font-size: 19px; }
  .search-field { flex: 1; margin-left: 0; }
  .search-field .input { width: 100%; }
  .lesson-row > .pill { margin-left: auto; }
  .lesson-row .lesson-actions { padding-left: 61px; }
  .play-aside { display: block; }
  .question-card h2 { font-size: 18px; }
}
@media (max-width: 700px) {
  .footer { width: calc(100% - 40px); }
  .footer > span:nth-child(2) { margin-left: auto; font-size: 8px; }
  .footer > span:last-child { width: 100%; font-size: 8px; }
  .hero-caption { font-size: 8px; }
  .equation-chip { right: 17px; bottom: 36px; width: 210px; padding: 10px 13px; }
  .equation-chip strong { font-size: 22px; }
  .equation-chip small { font-size: 7px; }
  .equation-chip > span { font-size: 7px; }
  .how-section { padding-top: 25px; }
  #examples { padding-top: 21px; }
  .bottom-cta { padding: 27px; }
  .bottom-cta h2 { font-size: 27px; }
  .bottom-cta p { max-width: 250px; font-size: 10px; }
  .workspace .template-card { grid-template-columns: 37% minmax(0,1fr); }
  .workspace .template-visual { min-height: 210px; }
  .stat-card .stat-label { margin-bottom: 12px; }
  .stat-card > span:last-child { font-size: 8px; }
  .lesson-row .lesson-actions { width: auto; padding: 0; }
  .lesson-row > .pill { margin-left: 0; font-size: 8px; }
  .lesson-title h3 { font-size: 12px; }
  .player-page { width: calc(100% - 40px); padding-top: 25px; }
  .player-page > .workspace-heading > .pill { margin-top: 34px; }
}
@media (max-width: 620px) {
  .topnav { display: none; }
}
@media (max-width: 480px) {
  .brand-mark { font-size: 27px; }
  .brand-mark > span { top: 6px; right: 4px; font-size: 12px; }
  .install-button span { display: none; }
  .header-actions .install-button { width: 31px; padding-inline: 0; }
  .hero-caption { bottom: 12px; font-size: 7px; }
  .equation-chip { width: 184px; right: 12px; bottom: 32px; padding: 9px 11px; }
  .equation-chip strong { font-size: 19px; }
  .equation-chip small, .equation-chip > span { font-size: 6px; }
  .section-head:has(.section-copy) { flex-direction: column; gap: 11px; }
  .section-head .section-copy { max-width: 300px; }
  .how-section { padding-top: 29px; padding-bottom: 7px; }
  .template-tags { font-size: 8px; }
  .template-card .card-footer .button { font-size: 11px; }
  .bottom-cta { flex-direction: column; align-items: flex-start; gap: 20px; padding: 25px 23px; }
  .bottom-cta h2 { font-size: 27px; }
  .bottom-cta p { max-width: 250px; font-size: 11px; }
  .bottom-cta .button { min-height: 41px; padding-inline: 15px; font-size: 11px; }
  .footer { width: calc(100% - 34px); }
  .footer > span:nth-child(2) { max-width: 175px; text-align: right; }
  .workspace .template-card { display: flex; }
  .workspace .template-visual { height: 173px; min-height: 0; border-right: 0; border-bottom: 1px solid #dce5d3; }
  .workspace .template-body h3 { font-size: 21px; }
  .stat-card .stat-label { margin-bottom: 12px; font-size: 8px; }
  .stat-card > span:last-child { display: block; max-width: 70px; font-size: 7px; line-height: 1.6; }
  .workspace-tools > .segmented { width: 100%; }
  .workspace-tools .search-field { min-width: 0; }
  .workspace-tools .search-field .input { font-size: 11px; }
  .lesson-title h3 { font-size: 12px; }
  .lesson-row .lesson-actions { width: 100%; padding-left: 51px; }
  .lesson-row > .pill { margin-left: 51px; margin-top: -3px; }
  .panel-heading > .step-number { width: 25px; height: 25px; font-size: 8px; }
  .field { font-size: 10px; }
  .field legend { font-size: 10px; }
  .scenario-item small { font-size: 9px; }
  .editor-question { margin-top: 20px; }
  .editor-question .textarea { min-height: 81px; }
  .editor-choices { gap: 8px; }
  .editor-choices .input { min-height: 38px; font-size: 11px; }
  .approval-field { font-size: 10px; }
  .player-page { width: calc(100% - 34px); padding-top: 23px; }
  .player-page > .workspace-heading { gap: 12px; }
  .player-page > .workspace-heading > .pill { margin-top: 0; }
  .back-link { margin-bottom: 16px; }
  .simulation > .panel-heading { min-height: 52px; padding: 13px 16px; gap: 8px; }
  .simulation > .panel-heading h2 { font-size: 13px; }
  .simulation > .panel-heading .pill { font-size: 7px; }
  .simulation .readout-grid { margin: 15px 16px 3px; }
  .simulation > .helper { margin: 0 17px 18px; font-size: 9px; }
  .question-card h2 { font-size: 18px; }
  .choice { font-size: 11px; }
  .feedback { font-size: 10px; }
  .feedback p { font-size: 10px; }
}

/* Learner portal and experiment tabs share the existing green visual system. */
.mobile-nav { display: none; }
.portal-page { width: min(1180px,calc(100% - 64px)); margin: 0 auto; padding: 35px 0 0; }
.portal-intro { display: grid; grid-template-columns: 1.35fr 1fr; align-items: center; gap: 45px; min-height: 310px; padding: 44px 48px; overflow: hidden; border-radius: 25px; background: #173d31; color: #f5f8eb; }
.portal-intro .section-kicker { margin-bottom: 18px; color: #c8e79a; }
.portal-intro h1 { margin: 0 0 18px; font-size: clamp(33px,4vw,49px); line-height: 1.1; letter-spacing: -1.9px; }
.portal-intro p { max-width: 490px; margin: 0; color: #c2d3c7; font-size: 14px; line-height: 1.85; }
.portal-notation { display: grid; grid-template-columns: repeat(3,1fr); align-items: center; gap: 10px; transform: rotate(-4deg); }
.portal-notation > span { display: grid; place-items: center; min-height: 115px; border: 1px solid #b6cfaf50; border-radius: 20px; color: #e3edc9; font-family: Georgia,serif; font-size: 40px; font-style: italic; }
.portal-notation > span:nth-child(2) { background: #c8f26d; color: #183e2e; transform: translateY(-15px); }
.portal-notation > span:last-of-type { background: #f4ce6a; color: #183e2e; transform: translateY(12px); }
.portal-notation small { grid-column: 1/-1; padding-top: 11px; color: #bed0ba; font-size: 10px; text-align: center; letter-spacing: .5px; }
.portal-section-head { display: flex; align-items: center; justify-content: space-between; gap: 20px; padding: 38px 0 23px; }
.portal-section-head h2 { margin: 0; font-size: 28px; letter-spacing: -.9px; }
.portal-count { color: #809075; font-family: ui-monospace,monospace; font-size: 13px; }
.game-actions { gap: 4px; }
.game-actions .button { padding-inline: 11px; }
.game-actions .button svg { width: 14px; height: 14px; }
.portal-teacher { display: flex; align-items: center; gap: 21px; margin-top: 28px; padding: 25px 28px; border: 1px solid #dbe5ce; border-radius: 17px; background: #eef4e6; }
.portal-teacher-icon { display: grid; place-items: center; flex: 0 0 48px; width: 48px; height: 48px; border: 1px solid #d6e1c7; border-radius: 13px; background: #fff; color: #5b7b41; }
.portal-teacher-icon svg { width: 23px; height: 23px; }
.portal-teacher h2 { margin: 0 0 8px; font-size: 19px; letter-spacing: -.5px; }
.portal-teacher p { max-width: 570px; margin: 0; color: #677b59; font-size: 12px; line-height: 1.7; }
.portal-teacher > .button { flex-shrink: 0; margin-left: auto; }
.portal-footnote { max-width: 760px; margin: 20px 0 0; color: #778470; font-size: 11px; line-height: 1.8; }
.experiment-switcher { margin-bottom: 30px; }
.experiment-tabs { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 10px; padding: 7px; border: 1px solid #dce5d2; border-radius: 18px; background: #edf2e5; }
.experiment-tab { display: flex; align-items: center; gap: 12px; min-height: 77px; padding: 14px 17px; border: 1px solid transparent; border-radius: 12px; background: transparent; color: #66775b; text-align: left; }
.experiment-tab:hover { border-color: #c3d2ae; background: #f6f9f0; }
.experiment-tab[aria-selected="true"] { border-color: #b7d575; background: #c8f26d; color: #24482b; box-shadow: 0 4px 12px #294e1f0a; }
.experiment-tab:focus-visible { outline: 3px solid #557b2c; outline-offset: 3px; }
.experiment-number { display: grid; place-items: center; flex: 0 0 31px; width: 31px; height: 31px; border: 1px solid currentColor; border-radius: 50%; font-family: ui-monospace,monospace; font-size: 10px; opacity: .65; }
.experiment-tab strong { display: block; margin-bottom: 5px; font-size: 14px; font-weight: 750; letter-spacing: -.2px; }
.experiment-tab small { display: block; font-size: 10px; opacity: .8; }
.experiment-tab > svg { width: 16px; height: 16px; margin-left: auto; flex-shrink: 0; }
.experiment-tabs-hint { margin: 11px 4px 0; color: #7c8973; font-size: 10px; line-height: 1.65; }
.game-panel > .workspace-heading { margin-bottom: 24px; }
.game-panel > .workspace-heading > .pill { margin-top: 36px; }
.game-panel .back-link { margin-bottom: 14px; }
@media (max-width: 1000px) {
  .portal-intro { grid-template-columns: 1.3fr 1fr; gap: 25px; padding: 35px; }
  .portal-notation > span { min-height: 88px; font-size: 30px; }
  .portal-page .template-grid { gap: 13px; }
  .portal-page .template-body { padding-inline: 16px; }
  .game-actions { flex-wrap: wrap; gap: 7px; }
  .experiment-tab { gap: 9px; padding-inline: 12px; }
  .experiment-tab > svg { display: none; }
}
@media (max-width: 820px) {
  body { padding-bottom: calc(76px + env(safe-area-inset-bottom)); }
  .topnav { display: none; }
  .mobile-nav { position: fixed; z-index: 80; right: 0; bottom: 0; left: 0; display: grid; grid-template-columns: repeat(4,1fr); padding: 8px 9px calc(8px + env(safe-area-inset-bottom)); border-top: 1px solid #dbe4d0; background: #fcfdf8f5; backdrop-filter: blur(15px); }
  .mobile-nav a { display: flex; align-items: center; justify-content: center; flex-direction: column; gap: 5px; min-height: 49px; border-radius: 10px; color: #7b8a70; font-size: 9px; font-weight: 650; }
  .mobile-nav a > svg { width: 20px; height: 20px; }
  .mobile-nav a[aria-current="page"] { background: #eaf2de; color: #3c622d; }
  .toast { bottom: calc(91px + env(safe-area-inset-bottom)); }
  .portal-page { width: calc(100% - 40px); padding-top: 24px; }
  .portal-intro { min-height: 0; grid-template-columns: 1fr; padding: 31px; }
  .portal-intro h1 { font-size: 38px; }
  .portal-notation { display: none; }
  .portal-page .template-grid { grid-template-columns: 1fr; }
  .portal-page .template-card { display: grid; grid-template-columns: .85fr 1fr; }
  .portal-page .template-visual { height: 100%; min-height: 220px; border-right: 1px solid #dce5d3; border-bottom: 0; }
  .portal-page .template-body { padding: 24px; }
  .portal-page .game-actions { flex-wrap: nowrap; }
  .portal-teacher { flex-wrap: wrap; padding: 22px; }
  .portal-teacher > div { flex: 1; }
  .portal-teacher > .button { margin-left: 69px; }
  .experiment-tab { justify-content: center; min-height: 68px; padding: 11px 7px; }
  .experiment-number { display: none; }
  .experiment-tab strong { font-size: 13px; }
  .experiment-tab small { max-width: 140px; font-size: 9px; }
}
@media (max-width: 480px) {
  .portal-page { width: calc(100% - 34px); padding-top: 19px; }
  .portal-intro { padding: 28px 24px; border-radius: 19px; }
  .portal-intro h1 { font-size: 32px; letter-spacing: -1.2px; }
  .portal-intro .section-kicker { font-size: 8px; letter-spacing: 1px; }
  .portal-intro p { font-size: 12px; }
  .portal-section-head { padding-top: 29px; }
  .portal-section-head h2 { font-size: 24px; }
  .portal-section-head .section-kicker { font-size: 8px; }
  .portal-page .template-card { display: flex; }
  .portal-page .template-visual { min-height: 0; height: 185px; border-right: 0; border-bottom: 1px solid #dce5d3; }
  .portal-page .template-body { padding: 23px; }
  .portal-page .game-actions .button { min-height: 42px; }
  .portal-teacher { gap: 15px; }
  .portal-teacher-icon { flex-basis: 38px; width: 38px; height: 38px; border-radius: 10px; }
  .portal-teacher h2 { font-size: 17px; }
  .portal-teacher p { font-size: 11px; }
  .portal-teacher > .button { margin-left: 0; width: 100%; }
  .experiment-switcher { margin-bottom: 24px; }
  .experiment-tabs { gap: 4px; padding: 4px; border-radius: 13px; }
  .experiment-tab { min-height: 58px; border-radius: 9px; }
  .experiment-tab strong { margin-bottom: 0; font-size: 11px; }
  .experiment-tab small { display: none; }
  .experiment-tabs-hint { font-size: 9px; }
  .game-panel > .workspace-heading > .pill { margin-top: 0; }
}