@import url('https://fonts.googleapis.com/css2?family=DM+Sans:wght@400;500;600;700&family=Manrope:wght@400;500;600;700;800&display=swap');

:root {
  color-scheme: light;
  --ink: #202522;
  --muted: #79817c;
  --muted-dark: #555f59;
  --paper: #fbfcfa;
  --canvas: #f4f6f3;
  --line: #e7ebe7;
  --line-dark: #d8ded9;
  --green: #63836d;
  --green-dark: #385644;
  --green-pale: #eaf0e9;
  --yellow: #f2ca62;
  --purple: #dcd4f3;
  --sidebar-width: 254px;
  --shadow-soft: 0 14px 40px rgba(42, 53, 46, .055);
  font-family: 'DM Sans', 'Avenir Next', Avenir, sans-serif;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
}

* { box-sizing: border-box; }
html { min-width: 320px; background: var(--canvas); }
body { margin: 0; color: var(--ink); background: var(--canvas); min-height: 100vh; }
button, input, select, textarea { font: inherit; }
button { color: inherit; }
button:focus-visible, a:focus-visible, input:focus-visible, select:focus-visible, textarea:focus-visible, summary:focus-visible { outline: 3px solid rgba(97, 131, 107, .34); outline-offset: 2px; }
button:disabled { cursor: not-allowed; }
::selection { background: #e1eacb; color: #26382b; }

.app-frame { min-height: 100vh; }
.sidebar {
  width: var(--sidebar-width); position: fixed; z-index: 10; inset: 0 auto 0 0;
  display: flex; flex-direction: column; padding: 27px 18px 16px;
  background: #fff; border-right: 1px solid var(--line);
}
.brand { display: inline-flex; align-items: center; gap: 10px; margin: 0 0 43px 7px; color: var(--ink); text-decoration: none; width: fit-content; }
.brand-mark { width: 39px; height: 39px; display: grid; place-items: center; border-radius: 12px; color: #fff; background: #52725c; box-shadow: inset 0 1px 0 rgba(255,255,255,.24); }
.brand-mark svg { width: 33px; height: 33px; }
.brand-copy { display: flex; align-items: baseline; gap: 5px; }
.brand-copy strong { font: 800 22px/1 'Manrope', sans-serif; letter-spacing: -1.4px; }
.brand-copy small { color: #879189; font-size: 9px; line-height: 1; letter-spacing: 1.8px; font-weight: 700; }
.side-label { padding: 0 11px; margin: 0 0 11px; color: #9aa29d; font-size: 9px; font-weight: 700; letter-spacing: 1.45px; }
.side-label-spaced { margin-top: 34px; }
.side-nav { display: grid; gap: 5px; }
.nav-item { min-height: 44px; width: 100%; padding: 0 11px; border: 0; border-radius: 9px; display: flex; align-items: center; gap: 12px; background: transparent; color: #606a64; text-align: left; cursor: pointer; font-size: 13px; font-weight: 600; transition: background .18s, color .18s; }
.nav-item:hover { background: #f5f7f4; color: var(--ink); }
.nav-item.is-active { color: #3a5c46; background: #edf3ec; }
.nav-icon { width: 18px; height: 18px; display: inline-grid; place-items: center; }
.nav-icon svg, .nav-item svg { width: 18px; height: 18px; }
.nav-count { display: inline-grid; place-items: center; min-width: 20px; height: 20px; margin-left: auto; color: #77817a; background: #f1f3f0; border-radius: 6px; font-size: 10px; font-weight: 700; }
.side-note { display: grid; grid-template-columns: 34px 1fr 27px; align-items: start; gap: 9px; padding: 11px 8px 11px 10px; border: 1px solid #e9ede8; border-radius: 11px; }
.side-note-icon { width: 32px; height: 32px; display: grid; place-items: center; border-radius: 9px; background: #fff5d7; color: #b48a2a; }
.side-note-icon svg { width: 16px; height: 16px; }
.side-note strong { display: block; margin: 1px 0 4px; font-size: 11px; font-weight: 700; }
.side-note p { margin: 0; color: #858e87; font-size: 10px; line-height: 1.45; }
.side-note-action { width: 26px; height: 26px; display: grid; place-items: center; border: 0; border-radius: 7px; background: #eff3ed; color: #54735c; cursor: pointer; }
.side-note-action:hover { background: #e0ebdf; }
.side-note-action svg { width: 14px; height: 14px; }
.sidebar-bottom { margin-top: auto; }
.ai-soon-card { margin: 0 1px 18px; padding: 14px 13px 13px; border-radius: 12px; background: #f8f7f0; }
.ai-soon-top { display: flex; justify-content: space-between; align-items: center; margin-bottom: 11px; }
.ai-sparkle { display: grid; place-items: center; width: 23px; height: 23px; color: #8d7744; border-radius: 7px; background: #eee8d5; }
.ai-sparkle svg { width: 14px; height: 14px; }
.soon-pill { color: #8f8059; font-size: 8px; font-weight: 700; letter-spacing: 1px; }
.ai-soon-card > strong { display: block; font: 700 12px 'Manrope', sans-serif; }
.ai-soon-card p { margin: 5px 0 0; color: #7e8277; font-size: 10px; line-height: 1.55; }
.profile-row { display: flex; align-items: center; gap: 9px; padding: 13px 3px 1px; border-top: 1px solid var(--line); }
.avatar { width: 31px; height: 31px; display: grid; place-items: center; flex: none; border-radius: 50%; background: #e5d7c8; color: #76563e; font: 700 12px 'Manrope', sans-serif; }
.profile-copy { display: grid; gap: 3px; }
.profile-copy strong { font-size: 11px; font-weight: 700; }
.profile-copy span { color: #89928b; font-size: 10px; }
.icon-button { display: inline-grid; place-items: center; padding: 0; border: 0; background: transparent; color: #727c75; cursor: pointer; }
.icon-button svg { width: 18px; height: 18px; }
.profile-more { width: 28px; height: 28px; margin-left: auto; border-radius: 7px; }
.profile-more:hover { background: #f0f3f0; }

.main-shell { min-height: 100vh; margin-left: var(--sidebar-width); }
.topbar { position: sticky; z-index: 5; top: 0; display: flex; align-items: center; justify-content: space-between; height: 72px; padding: 0 clamp(24px, 4vw, 60px); border-bottom: 1px solid rgba(224, 230, 224, .78); background: rgba(249, 250, 247, .91); backdrop-filter: blur(16px); }
.breadcrumbs { display: flex; align-items: center; gap: 10px; color: #89918b; font-size: 11px; }
.breadcrumbs strong { color: #47524b; font-weight: 600; }
.crumb-slash { color: #c1c7c1; }
.topbar-actions { display: flex; align-items: center; gap: 14px; }
.search-box { width: 232px; height: 37px; display: flex; align-items: center; gap: 9px; padding: 0 10px; border: 1px solid #e3e8e3; border-radius: 8px; background: #fff; color: #9ba39d; }
.search-box > span { display: grid; place-items: center; }
.search-box svg { width: 15px; height: 15px; }
.search-box input { min-width: 0; flex: 1; padding: 0; color: var(--ink); border: 0; outline: none; background: transparent; font-size: 11px; }
.search-box input::placeholder { color: #a3aaa5; }
.search-box kbd { padding: 2px 4px; border: 1px solid #e8ebe8; border-radius: 4px; color: #9ba39d; background: #fafbfa; font: 9px 'DM Sans', sans-serif; white-space: nowrap; }
.button { min-height: 38px; display: inline-flex; justify-content: center; align-items: center; gap: 8px; padding: 0 14px; border: 1px solid transparent; border-radius: 8px; cursor: pointer; text-decoration: none; font-size: 11px; font-weight: 700; transition: transform .16s, background .16s, border-color .16s; white-space: nowrap; }
.button:hover { transform: translateY(-1px); }
.button svg { width: 15px; height: 15px; }
.button-dark { background: #27332b; color: #fff; box-shadow: 0 3px 8px rgba(39, 51, 43, .12); }
.button-dark:hover { background: #3a5141; }
.button-light { color: #3d5645; background: #fff; border-color: #e2e9e1; }
.button-light:hover { border-color: #c8d7c9; background: #fbfdfb; }
.button-quiet { color: #5b6b5f; background: transparent; }
.button-quiet:hover { background: #f0f3f0; }
.button-small { min-height: 32px; padding: 0 10px; font-size: 10px; }
.top-avatar { width: 30px; height: 30px; margin-left: 2px; font-size: 11px; }
.mobile-menu { display: none; width: 34px; height: 34px; border-radius: 8px; }
.page-content { width: min(100%, 1460px); margin: 0 auto; padding: 35px clamp(24px, 4vw, 60px) 72px; }

/* Shared page headings */
.page-heading { display: flex; justify-content: space-between; align-items: flex-end; gap: 24px; margin-bottom: 25px; }
.page-heading h1 { margin: 7px 0 7px; font: 700 clamp(25px, 2.7vw, 34px)/1.16 'Manrope', sans-serif; letter-spacing: -1.25px; }
.page-heading p { margin: 0; max-width: 560px; color: #747e77; font-size: 12px; line-height: 1.7; }
.eyebrow { color: #89948b; font-size: 9px; font-weight: 700; letter-spacing: 1.6px; }
.heading-date { display: flex; align-items: center; gap: 7px; padding-bottom: 4px; color: #909992; font-size: 10px; white-space: nowrap; }
.heading-date svg { width: 14px; height: 14px; }

/* Overview */
.welcome-heading { margin-bottom: 24px; }
.welcome-heading h1 span { color: #66806d; }
.welcome-hero { position: relative; min-height: 238px; display: grid; grid-template-columns: minmax(0, 1.25fr) minmax(220px, .75fr); overflow: hidden; border-radius: 17px; background: #e8eddf; isolation: isolate; }
.hero-copy { position: relative; z-index: 1; align-self: center; padding: 31px 38px; }
.hero-label { display: inline-flex; align-items: center; gap: 7px; margin-bottom: 13px; color: #52674f; font-size: 9px; font-weight: 700; letter-spacing: 1.25px; }
.hero-label::before { width: 6px; height: 6px; content: ''; border-radius: 50%; background: #8ca26c; }
.hero-copy h2 { max-width: 475px; margin: 0; color: #25372b; font: 700 clamp(25px, 3vw, 37px)/1.13 'Manrope', sans-serif; letter-spacing: -1.5px; }
.hero-copy p { max-width: 405px; margin: 11px 0 19px; color: #607262; font-size: 12px; line-height: 1.65; }
.hero-actions { display: flex; align-items: center; gap: 8px; }
.hero-actions .button-dark { background: #365340; }
.hero-actions .button-dark:hover { background: #274330; }
.hero-visual { position: relative; min-height: 220px; }
.hero-visual::before { position: absolute; width: 245px; height: 245px; top: 10px; right: 28px; border: 1px solid rgba(91, 120, 82, .15); border-radius: 50%; content: ''; }
.hero-visual::after { position: absolute; width: 182px; height: 182px; top: 41px; right: 60px; border: 1px dashed rgba(91, 120, 82, .22); border-radius: 50%; content: ''; }
.hero-sun { position: absolute; z-index: 1; width: 115px; height: 115px; top: 73px; right: 93px; display: grid; place-items: center; border-radius: 50%; color: #fffbe9; background: #d2aa48; box-shadow: 0 14px 32px rgba(142, 114, 50, .2), inset 7px 5px 14px rgba(255,255,255,.24); }
.hero-sun svg { width: 61px; height: 61px; stroke-width: 1.2; }
.hero-dot { position: absolute; z-index: 2; width: 19px; height: 19px; border: 4px solid #e8eddf; border-radius: 50%; background: #738f69; box-shadow: 0 0 0 1px rgba(61,83,60,.22); }
.hero-dot.dot-one { top: 58px; right: 199px; }
.hero-dot.dot-two { top: 169px; right: 55px; width: 13px; height: 13px; border-width: 3px; background: #9b81b6; }
.hero-dot.dot-three { top: 30px; right: 95px; width: 11px; height: 11px; border-width: 2px; background: #dc8269; }
.hero-atom { position: absolute; z-index: 2; top: 89px; right: 45px; width: 29px; height: 29px; display: grid; place-items: center; border-radius: 50%; color: #fff; background: #63836d; font-size: 10px; font-weight: 700; }
.hero-sticker { position: absolute; z-index: 2; right: 204px; bottom: 28px; display: flex; align-items: center; gap: 7px; padding: 8px 11px; border: 1px solid rgba(76, 105, 74, .1); border-radius: 9px; color: #5a715c; background: rgba(255,255,255,.76); box-shadow: 0 5px 18px rgba(71, 88, 69, .08); font-size: 9px; font-weight: 700; transform: rotate(-5deg); }
.hero-sticker svg { width: 14px; height: 14px; color: #b79745; }
.stats-row { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); margin: 17px 0 36px; padding: 14px 0; border: 1px solid var(--line); border-radius: 11px; background: rgba(255,255,255,.64); }
.stat-item { display: flex; align-items: center; gap: 11px; padding: 2px 21px; border-right: 1px solid var(--line); }
.stat-item:last-child { border-right: 0; }
.stat-icon { width: 32px; height: 32px; display: grid; place-items: center; border-radius: 9px; color: #6d806e; background: #eff3ed; }
.stat-icon svg { width: 16px; height: 16px; }
.stat-copy strong { display: block; color: #37413a; font: 700 16px 'Manrope', sans-serif; }
.stat-copy span { display: block; margin-top: 2px; color: #8a928c; font-size: 9px; }
.section-head { display: flex; align-items: flex-end; justify-content: space-between; gap: 18px; margin-bottom: 14px; }
.section-head h2 { margin: 0; font: 700 17px 'Manrope', sans-serif; letter-spacing: -.45px; }
.section-head p { margin: 5px 0 0; color: #858e87; font-size: 10px; }
.text-link { display: inline-flex; align-items: center; gap: 5px; padding: 5px 0; border: 0; color: #55745d; background: transparent; cursor: pointer; font-size: 10px; font-weight: 700; text-decoration: none; white-space: nowrap; }
.text-link:hover { color: #304d39; }
.text-link svg { width: 13px; height: 13px; }
.featured-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 15px; }
.home-bottom-grid { display: grid; grid-template-columns: minmax(0, 1.4fr) minmax(220px, .8fr); gap: 18px; margin-top: 37px; }
.discovery-banner { position: relative; display: flex; align-items: center; justify-content: space-between; gap: 20px; min-height: 119px; padding: 20px 22px; overflow: hidden; border: 1px solid #e9e8dc; border-radius: 13px; background: #fbfaf4; }
.discovery-banner h3 { margin: 0 0 6px; color: #34382f; font: 700 14px 'Manrope', sans-serif; }
.discovery-banner p { max-width: 280px; margin: 0; color: #84877c; font-size: 10px; line-height: 1.55; }
.discovery-banner .banner-decoration { width: 86px; height: 86px; display: grid; place-items: center; flex: none; margin-right: 4px; color: #ab8d45; border-radius: 50%; background: #f1ebd7; }
.discovery-banner .banner-decoration svg { width: 38px; height: 38px; }
.worksheet-promo { min-height: 119px; display: flex; align-items: center; gap: 13px; padding: 17px; border-radius: 13px; background: #f0eaf5; }
.worksheet-promo-icon { width: 42px; height: 42px; display: grid; place-items: center; flex: none; border-radius: 12px; color: #7c648c; background: rgba(255,255,255,.65); }
.worksheet-promo-icon svg { width: 20px; height: 20px; }
.worksheet-promo h3 { margin: 0 0 5px; font: 700 12px 'Manrope', sans-serif; }
.worksheet-promo p { margin: 0 0 8px; color: #857a8d; font-size: 9px; line-height: 1.5; }
.worksheet-promo .text-link { color: #755d86; font-size: 9px; }

/* Experiment cards */
.experiment-card { min-width: 0; overflow: hidden; border: 1px solid #e6eae5; border-radius: 12px; background: #fff; box-shadow: 0 2px 6px rgba(40, 52, 43, .018); transition: transform .2s, box-shadow .2s, border-color .2s; }
.experiment-card:hover { transform: translateY(-3px); border-color: #d9e0d9; box-shadow: 0 12px 27px rgba(41, 53, 44, .075); }
.card-cover { position: relative; height: 137px; display: flex; align-items: center; justify-content: center; overflow: hidden; }
.card-cover.theme-violet { background: #eeeaf5; }
.card-cover.theme-green { background: #e8efe5; }
.card-cover.theme-blue { background: #e4edf1; }
.card-cover.theme-amber { background: #f3eadb; }
.cover-topline { position: absolute; z-index: 2; inset: 11px 11px auto; display: flex; align-items: center; justify-content: space-between; }
.subject-pill { display: inline-flex; align-items: center; gap: 5px; padding: 5px 8px; border: 1px solid rgba(84, 99, 87, .09); border-radius: 6px; color: #5d7061; background: rgba(255,255,255,.76); font-size: 8px; font-weight: 700; }
.subject-pill svg { width: 11px; height: 11px; }
.card-source { color: #657a69; background: rgba(255,255,255,.67); border-radius: 5px; padding: 5px 6px; font-size: 8px; font-weight: 600; }
.favorite-button { width: 27px; height: 27px; display: grid; place-items: center; border: 1px solid rgba(84,99,87,.08); border-radius: 8px; color: #708074; background: rgba(255,255,255,.78); cursor: pointer; transition: color .16s, background .16s; }
.favorite-button:hover, .favorite-button.is-favorite { color: #ae7a2a; background: #fff8e9; }
.favorite-button svg { width: 14px; height: 14px; }
.favorite-button.is-favorite svg { fill: #edca6b; stroke: #ad7c2d; }
.cover-open { position: absolute; inset: 0; border: 0; background: transparent; cursor: pointer; }
.card-title-action { position: relative; z-index: 1; display: block; padding: 13px 14px 5px; border: 0; color: #29332d; background: transparent; cursor: pointer; text-align: left; font: 700 13px 'Manrope', sans-serif; letter-spacing: -.2px; }
.card-title-action:hover { color: #496a53; }
.card-description { display: -webkit-box; min-height: 33px; margin: 0; padding: 0 14px; overflow: hidden; color: #818a83; font-size: 9px; line-height: 1.55; -webkit-line-clamp: 2; -webkit-box-orient: vertical; }
.card-footer { display: flex; align-items: center; justify-content: space-between; margin: 12px 14px 12px; padding-top: 10px; border-top: 1px solid #f0f2ef; }
.card-meta { display: flex; align-items: center; gap: 10px; color: #929a94; font-size: 8px; }
.card-meta span { display: inline-flex; align-items: center; gap: 4px; }
.card-meta svg { width: 11px; height: 11px; }
.card-arrow { width: 24px; height: 24px; display: grid; place-items: center; border: 0; border-radius: 7px; color: #718476; background: #f3f6f2; cursor: pointer; }
.card-arrow:hover { color: #fff; background: #5c7b63; }
.card-arrow svg { width: 13px; height: 13px; }
.card-artwork { position: relative; width: 100%; height: 100%; pointer-events: none; }
/* tiny pendulum artwork */
.mini-orbit { position: absolute; top: 23px; left: calc(50% - 43px); width: 86px; height: 94px; border: 1px dashed rgba(108,94,144,.25); border-radius: 48% 48% 45% 45%; }
.mini-pivot { position: absolute; top: 15px; left: calc(50% - 3px); z-index: 1; width: 7px; height: 7px; border-radius: 50%; background: #8b78ac; }
.mini-string { position: absolute; top: 21px; left: 50%; width: 2px; height: 50px; background: #766893; transform: rotate(22deg); transform-origin: top center; }
.mini-string::after { position: absolute; left: -6px; bottom: -10px; width: 14px; height: 14px; border-radius: 50%; content: ''; background: #c49d54; box-shadow: 0 4px 8px rgba(105,83,53,.2); }
.mini-orbit::after { position: absolute; content: ''; width: 13px; height: 13px; top: 34px; right: -6px; border: 3px solid #eeeaf5; border-radius: 50%; background: #9a83b9; }
/* tiny plant artwork */
.mini-pot { position: absolute; left: calc(50% - 25px); bottom: 25px; width: 50px; height: 34px; border-top: 6px solid #b98f69; border-radius: 3px 3px 13px 13px; background: #d8b18a; transform: perspective(40px) rotateX(-4deg); }
.mini-stem { position: absolute; left: 50%; bottom: 54px; width: 3px; height: 51px; border-radius: 3px; background: #678569; transform: rotate(-3deg); }
.mini-leaf { position: absolute; width: 19px; height: 10px; border-radius: 100% 0 100% 0; background: #88a475; }
.mini-leaf.left { top: 19px; right: 1px; transform: rotate(22deg); }
.mini-leaf.right { top: 30px; left: 2px; transform: rotate(193deg); }
.mini-leaf.top { top: -4px; left: -9px; width: 14px; height: 8px; transform: rotate(-27deg); }
.mini-sun { position: absolute; top: 39px; right: calc(50% - 54px); width: 21px; height: 21px; border-radius: 50%; background: #e7c776; box-shadow: 0 0 0 6px rgba(231,199,118,.13); }
/* tiny circuit artwork */
.mini-circuit { position: relative; width: 139px; height: 79px; border: 2px solid #709298; border-radius: 14px; opacity: .95; }
.mini-circuit::before { position: absolute; top: -7px; left: 39px; width: 17px; height: 13px; content: ''; border-radius: 8px 8px 0 0; border: 2px solid #709298; border-bottom: 0; background: transparent; }
.mini-circuit::after { position: absolute; top: 29px; right: -8px; width: 31px; height: 20px; content: ''; border-top: 2px solid #709298; border-bottom: 2px solid #709298; background: #e4edf1; }
.mini-bulb { position: absolute; z-index: 2; top: 24px; right: 1px; width: 26px; height: 26px; border: 2px solid #709298; border-radius: 50%; background: #f4d98e; box-shadow: 0 0 13px rgba(231,190,94,.48); }
.mini-resistor { position: absolute; top: 31px; left: 62px; z-index: 2; width: 25px; height: 15px; border: 2px solid #709298; border-radius: 4px; background: #e9f0e8; }
.mini-battery { position: absolute; left: 21px; top: 27px; z-index: 2; width: 17px; height: 22px; border: 2px solid #709298; border-radius: 3px; background: #f4f8f6; }
.mini-battery::after { position: absolute; left: 5px; top: -7px; width: 3px; height: 5px; content: ''; background: #709298; }

/* Explore / personal lab */
.filter-row { display: flex; align-items: center; justify-content: space-between; gap: 15px; margin: 24px 0 17px; }
.filter-chips { display: flex; align-items: center; flex-wrap: wrap; gap: 7px; }
.filter-chip { min-height: 30px; padding: 0 11px; border: 1px solid #e5e9e4; border-radius: 20px; color: #717a73; background: #fff; cursor: pointer; font-size: 9px; font-weight: 600; transition: all .16s; }
.filter-chip:hover { border-color: #cbd8ca; color: #46624e; }
.filter-chip.is-active { border-color: #dce8db; color: #45634c; background: #eaf1e8; }
.results-label { color: #909992; font-size: 9px; white-space: nowrap; }
.catalog-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 16px; }
.empty-state { display: grid; justify-items: center; padding: 56px 18px; border: 1px dashed #dce3dc; border-radius: 13px; background: rgba(255,255,255,.54); text-align: center; }
.empty-state-icon { width: 51px; height: 51px; display: grid; place-items: center; margin-bottom: 13px; border-radius: 15px; color: #69816c; background: #eaf0e8; }
.empty-state-icon svg { width: 24px; height: 24px; }
.empty-state h2 { margin: 0 0 6px; font: 700 15px 'Manrope', sans-serif; }
.empty-state p { max-width: 340px; margin: 0 0 17px; color: #818b84; font-size: 10px; line-height: 1.6; }

/* Worksheet index */
.worksheet-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 15px; }
.worksheet-card { position: relative; min-height: 191px; padding: 16px; overflow: hidden; border: 1px solid #e6eae5; border-radius: 12px; background: #fff; cursor: pointer; text-align: left; transition: transform .2s, box-shadow .2s, border-color .2s; }
.worksheet-card:hover { transform: translateY(-3px); border-color: #d6dfd5; box-shadow: 0 12px 25px rgba(41,53,44,.065); }
.worksheet-card::after { position: absolute; right: -21px; bottom: -31px; width: 105px; height: 105px; content: ''; border: 1px solid #eee6d9; border-radius: 50%; box-shadow: 0 0 0 9px #faf8f2, 0 0 0 10px #f0ecdf; }
.worksheet-card-top { display: flex; align-items: center; justify-content: space-between; margin-bottom: 24px; }
.sheet-icon { width: 39px; height: 39px; display: grid; place-items: center; border-radius: 11px; color: #837098; background: #f1edf5; }
.sheet-icon svg { width: 18px; height: 18px; }
.sheet-count { color: #929b94; font-size: 9px; }
.worksheet-card h3 { position: relative; z-index: 1; max-width: 230px; margin: 0 0 7px; font: 700 13px/1.45 'Manrope', sans-serif; }
.worksheet-card p { position: relative; z-index: 1; max-width: 240px; margin: 0; color: #818b84; font-size: 9px; line-height: 1.55; }
.worksheet-card-footer { position: absolute; z-index: 1; left: 16px; right: 16px; bottom: 14px; display: flex; justify-content: space-between; align-items: center; }
.worksheet-card-footer span { color: #92a095; font-size: 8px; }
.worksheet-card-footer svg { width: 14px; height: 14px; color: #718477; }
.worksheet-card.is-custom .sheet-icon { color: #65816a; background: #edf3e9; }

/* Experiment detail */
.detail-return { display: flex; align-items: center; justify-content: space-between; margin-bottom: 20px; }
.detail-return button { display: inline-flex; align-items: center; gap: 7px; padding: 5px 0; border: 0; color: #748077; background: transparent; cursor: pointer; font-size: 10px; font-weight: 600; }
.detail-return button:hover { color: #3d6448; }
.detail-return svg { width: 14px; height: 14px; }
.detail-actions { display: flex; align-items: center; gap: 8px; }
.detail-head { display: flex; align-items: flex-end; justify-content: space-between; gap: 30px; margin-bottom: 21px; }
.detail-head h1 { max-width: 720px; margin: 8px 0 9px; font: 700 clamp(26px, 3.2vw, 38px)/1.13 'Manrope', sans-serif; letter-spacing: -1.35px; }
.detail-head p { max-width: 630px; margin: 0; color: #737d76; font-size: 11px; line-height: 1.7; }
.detail-tags { display: flex; align-items: center; flex-wrap: wrap; gap: 7px; }
.detail-tag { display: inline-flex; align-items: center; gap: 5px; padding: 5px 8px; border: 1px solid #e5eae4; border-radius: 6px; color: #68756a; background: #fff; font-size: 8px; font-weight: 600; }
.detail-tag svg { width: 11px; height: 11px; }
.detail-head-side { display: flex; align-items: center; gap: 8px; flex: none; padding-bottom: 3px; }
.detail-tabs { display: flex; gap: 19px; padding: 0 0 1px; border-bottom: 1px solid #e2e7e2; }
.tab-button { position: relative; min-height: 38px; padding: 0 2px; border: 0; color: #89928b; background: transparent; cursor: pointer; font-size: 10px; font-weight: 600; }
.tab-button::after { position: absolute; right: 0; bottom: -1px; left: 0; height: 2px; content: ''; border-radius: 3px 3px 0 0; background: transparent; }
.tab-button.is-active { color: #425e49; }
.tab-button.is-active::after { background: #64816a; }
.tab-badge { display: inline-grid; place-items: center; min-width: 16px; height: 16px; margin-left: 5px; padding: 0 4px; border-radius: 5px; color: #748077; background: #eff2ef; font-size: 8px; }
.experiment-workspace { display: grid; grid-template-columns: minmax(0, 1.45fr) minmax(255px, .75fr); gap: 15px; margin-top: 16px; align-items: start; }
.left-lab-column { display: grid; gap: 13px; }
.simulator-card, .control-card, .guide-card, .observation-card { border: 1px solid #e4e9e3; border-radius: 12px; background: #fff; }
.simulator-card { overflow: hidden; }
.simulator-head { min-height: 48px; display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 0 15px; border-bottom: 1px solid #eff1ee; }
.simulator-head h2 { display: flex; align-items: center; gap: 8px; margin: 0; font: 700 11px 'Manrope', sans-serif; }
.simulator-head h2 > span { width: 25px; height: 25px; display: grid; place-items: center; border-radius: 7px; color: #66816b; background: #edf3ec; }
.simulator-head h2 svg { width: 13px; height: 13px; }
.live-badge { display: inline-flex; align-items: center; gap: 5px; padding: 5px 7px; border-radius: 5px; color: #64806a; background: #eff5ed; font-size: 8px; font-weight: 700; letter-spacing: .35px; }
.live-badge::before { width: 5px; height: 5px; content: ''; border-radius: 50%; background: #78a26f; box-shadow: 0 0 0 3px rgba(120,162,111,.12); }
.sim-visual { position: relative; height: 278px; display: grid; place-items: center; overflow: hidden; background-color: #f7f8f5; background-image: radial-gradient(#dfe5de 0.7px, transparent .7px); background-size: 16px 16px; }
.sim-visual::before { position: absolute; inset: 0; content: ''; pointer-events: none; background: linear-gradient(90deg, rgba(249,250,247,.33), transparent 20%, transparent 80%, rgba(249,250,247,.33)); }
.sim-stage-label { position: absolute; z-index: 2; top: 12px; left: 14px; right: 14px; display: flex; justify-content: space-between; color: #a0a9a1; font-size: 8px; font-weight: 700; letter-spacing: .8px; }
.sim-stage-label span:last-child { color: #8d9a8f; font-size: 7px; letter-spacing: 1px; }
.pendulum-svg { width: min(86%, 390px); height: 228px; overflow: visible; }
.pendulum-swing-group { transform-box: view-box; transform-origin: 50% 19.2%; animation: pendulum-swing var(--swing-duration, 2.2s) ease-in-out infinite; }
@keyframes pendulum-swing { 0%, 100% { transform: rotate(-24deg); } 50% { transform: rotate(24deg); } }
.pendulum-svg .support { stroke: #bec9bd; stroke-width: 7; stroke-linecap: round; }
.pendulum-svg .arm { stroke: #6c826d; stroke-width: 3; stroke-linecap: round; }
.pendulum-svg .arc { fill: none; stroke: #cdd9cb; stroke-width: 1.5; stroke-dasharray: 4 5; }
.pendulum-svg .pivot { fill: #52745a; }
.pendulum-svg .bob { fill: #d3a951; stroke: #b28a3c; stroke-width: 2; filter: drop-shadow(0 5px 4px rgba(63,64,48,.17)); }
.sim-caption { position: absolute; bottom: 11px; left: 0; right: 0; display: flex; justify-content: center; color: #8b958d; font-size: 9px; }
.plant-scene { position: relative; width: 240px; height: 208px; display: flex; align-items: flex-end; justify-content: center; margin-top: 18px; }
.plant-sun { position: absolute; top: 28px; right: 25px; width: 35px; height: 35px; border-radius: 50%; background: #f0d581; box-shadow: 0 0 0 9px rgba(240,213,129,.16), 0 0 25px rgba(240,213,129,.26); }
.plant-sun::after { position: absolute; inset: -8px; content: ''; border: 1px dashed rgba(220,183,94,.45); border-radius: 50%; }
.plant-stem { position: absolute; bottom: 53px; left: calc(50% - 2px); width: 4px; height: var(--plant-height, 100px); border-radius: 4px 4px 0 0; background: linear-gradient(#77956a, #5f805f); transform-origin: bottom center; transition: height .35s ease; }
.plant-leaf { position: absolute; z-index: 1; width: 38px; height: 19px; border-radius: 100% 0 100% 0; background: #87a878; box-shadow: inset 4px 0 rgba(255,255,255,.12); transition: all .3s ease; }
.plant-leaf::after { position: absolute; top: 9px; left: 4px; width: 27px; height: 1px; content: ''; background: rgba(60,102,67,.35); transform: rotate(-9deg); }
.plant-leaf.left { top: 22px; right: 0; transform: rotate(21deg); transform-origin: left center; }
.plant-leaf.right { top: 50px; left: -35px; transform: rotate(193deg); transform-origin: right center; }
.plant-leaf.top { top: -14px; left: -17px; width: 31px; height: 17px; transform: rotate(-25deg); }
.plant-pot { position: absolute; bottom: 24px; left: calc(50% - 31px); width: 62px; height: 39px; border-top: 7px solid #bd956f; border-radius: 3px 3px 13px 13px; background: linear-gradient(90deg,#d0a985,#ddb894 50%,#c99f7b); box-shadow: 0 7px 13px rgba(112,85,57,.12); clip-path: polygon(0 0,100% 0,87% 100%,13% 100%); }
.plant-soil { position: absolute; bottom: 54px; left: calc(50% - 27px); width: 54px; height: 7px; border-radius: 50%; background: #795c43; }
.plant-ground { position: absolute; bottom: 23px; width: 190px; height: 1px; background: #d9e0d7; }
.plant-height-label { position: absolute; bottom: 68px; left: calc(50% + 45px); color: #778c76; font-size: 9px; font-weight: 700; }
.circuit-svg { width: min(86%, 440px); height: 230px; overflow: visible; }
.circuit-svg .wire { fill: none; stroke: #78979a; stroke-width: 4; stroke-linejoin: round; stroke-linecap: round; }
.circuit-svg .battery { fill: #f8fbf8; stroke: #78979a; stroke-width: 3; }
.circuit-svg .battery-line { stroke: #66868b; stroke-width: 3; stroke-linecap: round; }
.circuit-svg .resistor { fill: #f6f3e9; stroke: #78979a; stroke-width: 3; }
.circuit-svg .bulb { fill: #f2d482; stroke: #b79950; stroke-width: 3; filter: drop-shadow(0 0 11px rgba(229,189,89,.62)); transition: fill .2s, filter .2s; }
.circuit-svg .bulb-off { fill: #e4e8e3; stroke: #9ca9a1; filter: none; }
.circuit-svg .flow { fill: none; stroke: #e0b953; stroke-width: 3; stroke-dasharray: 2 13; stroke-linecap: round; animation: current-flow 1s linear infinite; }
@keyframes current-flow { to { stroke-dashoffset: -30; } }
.sim-readouts { display: grid; grid-template-columns: repeat(3, 1fr); border-top: 1px solid #edf0ed; background: #fff; }
.readout-item { padding: 11px 12px; border-right: 1px solid #edf0ed; text-align: center; }
.readout-item:last-child { border-right: 0; }
.readout-item span { display: block; margin-bottom: 4px; color: #9ba39c; font-size: 8px; }
.readout-item strong { display: block; color: #455549; font: 700 13px 'Manrope', sans-serif; }
.control-card { padding: 15px; }
.control-card-title { display: flex; align-items: flex-start; justify-content: space-between; gap: 8px; padding-bottom: 12px; border-bottom: 1px solid #eff1ef; }
.control-card-title h2 { margin: 0 0 4px; font: 700 11px 'Manrope', sans-serif; }
.control-card-title p { margin: 0; color: #959d96; font-size: 9px; }
.reset-button { display: inline-flex; align-items: center; gap: 5px; padding: 4px 0; border: 0; color: #8b958d; background: transparent; cursor: pointer; font-size: 8px; }
.reset-button:hover { color: #47644d; }
.reset-button svg { width: 12px; height: 12px; }
.control-slider { padding: 13px 0 11px; border-bottom: 1px solid #f0f2ef; }
.control-slider:last-child { border-bottom: 0; padding-bottom: 1px; }
.control-line { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin-bottom: 9px; }
.control-line label { color: #59645c; font-size: 9px; font-weight: 600; }
.control-value { min-width: 44px; padding: 4px 6px; border-radius: 5px; color: #5e755f; background: #f0f5ed; text-align: center; font-size: 9px; font-weight: 700; }
input[type=range] { width: 100%; height: 4px; margin: 0; accent-color: #6f8b72; cursor: pointer; }
.range-ends { display: flex; justify-content: space-between; margin-top: 5px; color: #adb4ad; font-size: 7px; }
.observation-card { margin-top: 12px; padding: 14px; background: #faf9f2; border-color: #efeddf; }
.observation-card label { display: flex; align-items: center; gap: 7px; margin-bottom: 8px; color: #5b5f50; font-size: 9px; font-weight: 700; }
.observation-card label svg { width: 13px; height: 13px; color: #9b8b52; }
.observation-card textarea { width: 100%; min-height: 71px; padding: 8px; resize: vertical; border: 1px solid #eae8dc; border-radius: 7px; color: #475046; background: rgba(255,255,255,.76); outline: none; font-size: 9px; line-height: 1.5; }
.observation-card textarea::placeholder { color: #b0b3a8; }
.autosave-note { display: flex; align-items: center; gap: 5px; margin-top: 6px; color: #9b9e91; font-size: 8px; }
.autosave-note svg { width: 10px; height: 10px; }
.guide-card { display: flex; align-items: flex-start; gap: 12px; padding: 14px 15px; }
.guide-icon { width: 29px; height: 29px; display: grid; place-items: center; flex: none; border-radius: 9px; color: #75875f; background: #f0f3e9; }
.guide-icon svg { width: 15px; height: 15px; }
.guide-body { min-width: 0; }
.guide-body h3 { margin: 1px 0 7px; font: 700 10px 'Manrope', sans-serif; }
.guide-body ol { display: grid; gap: 5px; margin: 0; padding-left: 15px; color: #778079; font-size: 9px; line-height: 1.5; }
.guide-body li::marker { color: #91a08f; font-weight: 700; }
.detail-worksheet { margin-top: 18px; }
.worksheet-intro-card { display: flex; align-items: center; justify-content: space-between; gap: 20px; padding: 20px; border: 1px solid #e5e9e2; border-radius: 12px; background: linear-gradient(110deg,#f1f4ea,#f7f5ee); }
.worksheet-intro-card h2 { margin: 0 0 7px; font: 700 18px 'Manrope', sans-serif; letter-spacing: -.4px; }
.worksheet-intro-card p { max-width: 600px; margin: 0; color: #727d70; font-size: 10px; line-height: 1.65; }
.worksheet-question-list { display: grid; gap: 11px; margin-top: 14px; }
.worksheet-question { padding: 15px 16px; border: 1px solid #e6eae4; border-radius: 10px; background: #fff; }
.question-number { display: inline-grid; place-items: center; width: 23px; height: 23px; margin-right: 7px; border-radius: 7px; color: #68816b; background: #eef3ec; font-size: 9px; font-weight: 700; vertical-align: middle; }
.worksheet-question label { display: block; margin-bottom: 9px; color: #4d5950; font-size: 10px; font-weight: 600; line-height: 1.55; }
.worksheet-question textarea { width: 100%; min-height: 72px; padding: 9px 10px; resize: vertical; border: 1px solid #e8ece7; border-radius: 7px; color: #465047; background: #fcfdfb; font-size: 10px; line-height: 1.55; }
.worksheet-question textarea::placeholder { color: #b0b8b1; }
.worksheet-save-note { display: flex; align-items: center; justify-content: flex-end; gap: 5px; margin-top: 9px; color: #8d998e; font-size: 8px; }
.worksheet-save-note svg { width: 12px; height: 12px; }
.worksheet-empty { display: grid; justify-items: center; padding: 48px 20px; text-align: center; border: 1px dashed #dce3dc; border-radius: 12px; background: #fcfdfb; }
.worksheet-empty h2 { margin: 12px 0 7px; font: 700 15px 'Manrope', sans-serif; }
.worksheet-empty p { max-width: 340px; margin: 0 0 15px; color: #838c84; font-size: 10px; line-height: 1.6; }

/* Worksheet reader */
.reader-top { display: flex; align-items: flex-start; justify-content: space-between; gap: 18px; margin-bottom: 20px; }
.reader-top h1 { margin: 7px 0 7px; font: 700 clamp(24px,3vw,34px)/1.15 'Manrope', sans-serif; letter-spacing: -1.2px; }
.reader-top p { margin: 0; color: #79837b; font-size: 10px; line-height: 1.6; }
.reader-back { display: inline-flex; align-items: center; gap: 6px; margin-bottom: 14px; padding: 0; border: 0; color: #738078; background: transparent; cursor: pointer; font-size: 9px; font-weight: 600; }
.reader-back:hover { color: #3d6448; }
.reader-back svg { width: 13px; height: 13px; }
.worksheet-paper { max-width: 825px; margin: 0 auto; padding: clamp(20px,4vw,38px); border: 1px solid #e8e9df; border-radius: 13px; background: #fffefa; box-shadow: var(--shadow-soft); }
.paper-top { display: flex; align-items: flex-start; justify-content: space-between; gap: 20px; padding-bottom: 20px; border-bottom: 1px solid #e9e9df; }
.paper-title-group { max-width: 570px; }
.paper-kicker { margin-bottom: 7px; color: #9a8b62; font-size: 8px; font-weight: 700; letter-spacing: 1.35px; }
.paper-top h2 { margin: 0 0 7px; color: #333a32; font: 700 21px 'Manrope', sans-serif; letter-spacing: -.55px; }
.paper-top p { margin: 0; color: #7d8276; font-size: 10px; line-height: 1.6; }
.paper-experiment-link { display: flex; align-items: center; gap: 6px; max-width: 180px; padding: 7px 9px; border: 1px solid #e9ede7; border-radius: 7px; color: #657768; background: #f7f9f5; font-size: 8px; text-align: left; cursor: pointer; }
.paper-experiment-link:hover { border-color: #cad9c9; }
.paper-experiment-link svg { width: 12px; height: 12px; flex: none; }
.student-lines { display: grid; grid-template-columns: 1fr 1fr; gap: 15px; margin: 19px 0 24px; }
.student-lines label { display: flex; align-items: center; gap: 8px; color: #94978b; font-size: 9px; }
.student-lines input { flex: 1; min-width: 0; height: 20px; padding: 0 2px; border: 0; border-bottom: 1px solid #ddded4; border-radius: 0; color: #596257; background: transparent; outline: none; font-size: 9px; }
.student-lines input:focus { border-bottom-color: #80987b; }
.student-lines span { flex: 1; height: 17px; border-bottom: 1px solid #ddded4; }
.paper-question { padding: 0 0 19px; margin-bottom: 18px; border-bottom: 1px dashed #dedfd5; }
.paper-question:last-child { margin-bottom: 0; padding-bottom: 0; border-bottom: 0; }
.paper-q-title { display: flex; gap: 10px; align-items: flex-start; margin: 0 0 11px; color: #484e45; font-size: 10px; font-weight: 600; line-height: 1.6; }
.paper-q-title .question-number { flex: none; margin: 0; }
.paper-question textarea { width: 100%; min-height: 88px; resize: vertical; padding: 10px; border: 1px solid #ecece3; border-radius: 7px; color: #465047; background: rgba(255,255,255,.68); font-size: 10px; line-height: 1.55; }
.paper-question textarea::placeholder { color: #b3b4aa; }
.paper-footer { display: flex; align-items: center; justify-content: space-between; gap: 14px; margin-top: 22px; padding-top: 14px; border-top: 1px solid #e9e9df; color: #92958a; font-size: 8px; }
.paper-footer strong { color: #677d69; font-size: 8px; font-weight: 600; }

/* Dialogs, toast, utilities */
.modal { width: min(590px, calc(100vw - 28px)); max-height: min(91vh, 850px); padding: 0; overflow: auto; border: 1px solid #e5e9e3; border-radius: 15px; color: var(--ink); background: #fff; box-shadow: 0 30px 90px rgba(32, 43, 35, .24); }
.modal::backdrop { background: rgba(29, 39, 32, .37); backdrop-filter: blur(3px); }
.modal-head { position: sticky; z-index: 2; top: 0; display: flex; align-items: flex-start; justify-content: space-between; gap: 18px; padding: 22px 24px 17px; border-bottom: 1px solid #edf0ec; background: rgba(255,255,255,.97); backdrop-filter: blur(10px); }
.modal-head .eyebrow { margin: 1px 0 7px; font-size: 8px; }
.modal-head h2 { margin: 0 0 5px; font: 700 20px 'Manrope', sans-serif; letter-spacing: -.5px; }
.modal-head p { margin: 0; color: #838d85; font-size: 10px; line-height: 1.5; }
.modal-close { width: 30px; height: 30px; flex: none; border-radius: 8px; background: #f5f7f4; }
.modal-close:hover { color: #354d3a; background: #edf3eb; }
.modal-form { padding: 19px 24px 22px; }
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 14px 12px; }
.field { min-width: 0; display: grid; gap: 6px; color: #525f55; font-size: 9px; font-weight: 700; }
.field > span { display: flex; align-items: baseline; gap: 5px; }
.field i { color: #bf7162; font-style: normal; }
.field small { color: #9aa39b; font-size: 8px; font-weight: 400; }
.field-wide { grid-column: 1 / -1; }
.field input, .field select, .field textarea { width: 100%; min-width: 0; padding: 9px 10px; border: 1px solid #e2e8e2; border-radius: 7px; outline: none; color: #3b463e; background: #fcfdfb; font-size: 10px; font-weight: 400; }
.field input, .field select { height: 36px; }
.field textarea { min-height: 67px; resize: vertical; line-height: 1.5; }
.field input:focus, .field select:focus, .field textarea:focus { border-color: #98b197; box-shadow: 0 0 0 3px rgba(115,150,115,.1); }
.field input::placeholder, .field textarea::placeholder { color: #a8b0a9; }
.worksheet-add-on { margin-top: 16px; padding: 11px 12px; border: 1px solid #e7ebe5; border-radius: 8px; background: #fafbf9; }
.worksheet-add-on summary { display: flex; align-items: center; gap: 8px; color: #667269; cursor: pointer; list-style: none; font-size: 9px; font-weight: 600; }
.worksheet-add-on summary::-webkit-details-marker { display: none; }
.summary-plus { width: 20px; height: 20px; display: grid; place-items: center; border-radius: 6px; color: #63816a; background: #edf3eb; }
.summary-plus svg { width: 12px; height: 12px; transition: transform .2s; }
.worksheet-add-on[open] .summary-plus svg { transform: rotate(45deg); }
.optional-tag { margin-left: auto; color: #a0a89f; font-size: 7px; letter-spacing: .8px; }
.worksheet-fields { display: grid; gap: 12px; margin-top: 13px; padding-top: 13px; border-top: 1px solid #ecefeb; }
.modal-foot { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-top: 19px; padding-top: 15px; border-top: 1px solid #edf0ec; }
.form-footnote { display: inline-flex; align-items: center; gap: 5px; color: #929b93; font-size: 8px; }
.form-footnote svg { width: 12px; height: 12px; color: #839385; }
.toast { position: fixed; z-index: 30; right: 24px; bottom: 24px; max-width: min(370px, calc(100vw - 40px)); padding: 12px 15px; border: 1px solid rgba(255,255,255,.1); border-radius: 9px; color: #fff; background: #29372d; box-shadow: 0 12px 28px rgba(29,44,33,.2); font-size: 10px; opacity: 0; pointer-events: none; transform: translateY(8px); transition: opacity .2s, transform .2s; }
.toast.is-visible { opacity: 1; transform: translateY(0); }
.mobile-scrim { display: none; }

@media (min-width: 1500px) {
  .welcome-hero { min-height: 260px; }
  .hero-visual::before { right: 50px; }
  .hero-visual::after { right: 82px; }
  .hero-sun { right: 115px; }
  .hero-dot.dot-one { right: 220px; }
  .hero-dot.dot-two { right: 77px; }
  .hero-dot.dot-three { right: 117px; }
  .hero-atom { right: 67px; }
  .hero-sticker { right: 225px; }
}
@media (max-width: 1180px) {
  :root { --sidebar-width: 226px; }
  .sidebar { padding-right: 14px; padding-left: 14px; }
  .page-content { padding-right: 30px; padding-left: 30px; }
  .topbar { padding-right: 30px; padding-left: 30px; }
  .experiment-workspace { grid-template-columns: minmax(0, 1.2fr) minmax(238px, .8fr); }
  .home-bottom-grid { grid-template-columns: 1.2fr .8fr; }
}
@media (max-width: 950px) {
  :root { --sidebar-width: 215px; }
  .topbar { gap: 15px; }
  .breadcrumbs { display: none; }
  .topbar-actions { width: 100%; justify-content: flex-end; }
  .search-box { margin-right: auto; }
  .welcome-hero { grid-template-columns: 1.35fr .65fr; }
  .hero-copy { padding-left: 28px; }
  .hero-visual::before { right: -8px; }
  .hero-visual::after { right: 24px; }
  .hero-sun { right: 56px; }
  .hero-dot.dot-one { right: 140px; }
  .hero-dot.dot-two { right: 20px; }
  .hero-dot.dot-three { right: 61px; }
  .hero-atom { right: 1px; }
  .hero-sticker { right: 130px; }
  .featured-grid, .catalog-grid, .worksheet-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .featured-grid .experiment-card:last-child { display: none; }
  .experiment-workspace { grid-template-columns: 1fr; }
  .control-column { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; align-items: start; }
  .observation-card { margin-top: 0; }
  .home-bottom-grid { grid-template-columns: 1fr; }
}
@media (max-width: 700px) {
  :root { --sidebar-width: 264px; }
  .sidebar { z-index: 20; transform: translateX(-102%); transition: transform .23s ease; box-shadow: 18px 0 50px rgba(22,35,25,.12); }
  .sidebar.is-open { transform: translateX(0); }
  .mobile-scrim.is-visible { position: fixed; z-index: 15; inset: 0; display: block; background: rgba(31,43,34,.28); }
  .main-shell { margin-left: 0; }
  .topbar { height: 62px; padding: 0 17px; }
  .mobile-menu { display: inline-grid; flex: none; }
  .topbar-actions { gap: 9px; }
  .search-box { width: auto; flex: 1; height: 35px; padding: 0 8px; }
  .search-box kbd { display: none; }
  .search-box input { font-size: 10px; }
  .top-create { width: 35px; min-width: 35px; height: 35px; min-height: 35px; padding: 0; border-radius: 8px; }
  .top-create span:last-child { display: none; }
  .top-create svg { width: 16px; height: 16px; }
  .top-avatar { display: none; }
  .page-content { padding: 25px 17px 48px; }
  .page-heading { align-items: flex-start; margin-bottom: 19px; }
  .page-heading h1 { font-size: 27px; }
  .heading-date { display: none; }
  .welcome-heading { margin-bottom: 18px; }
  .welcome-hero { min-height: 300px; grid-template-columns: 1fr; }
  .hero-copy { align-self: start; padding: 24px 22px; }
  .hero-copy h2 { max-width: 420px; font-size: 29px; }
  .hero-copy p { max-width: 350px; margin: 8px 0 14px; font-size: 10px; }
  .hero-visual { position: absolute; width: 205px; height: 160px; right: 0; bottom: -18px; opacity: .85; transform: scale(.75); transform-origin: right bottom; }
  .hero-visual::before { right: 3px; }
  .hero-visual::after { right: 35px; }
  .hero-sun { right: 67px; }
  .hero-dot.dot-one { right: 152px; }
  .hero-dot.dot-two { right: 35px; }
  .hero-dot.dot-three { right: 73px; }
  .hero-atom { right: 16px; }
  .hero-sticker { right: 140px; }
  .hero-copy { padding-bottom: 116px; }
  .stats-row { margin: 12px 0 29px; padding: 10px 0; }
  .stat-item { justify-content: center; gap: 7px; padding: 0 5px; }
  .stat-icon { display: none; }
  .stat-copy strong { font-size: 14px; }
  .stat-copy span { font-size: 8px; }
  .section-head { align-items: center; }
  .section-head h2 { font-size: 15px; }
  .featured-grid { grid-template-columns: 1fr; }
  .featured-grid .experiment-card:last-child { display: block; }
  .card-cover { height: 155px; }
  .home-bottom-grid { margin-top: 29px; }
  .discovery-banner { min-height: 116px; padding: 15px; }
  .discovery-banner .banner-decoration { width: 63px; height: 63px; }
  .discovery-banner .banner-decoration svg { width: 30px; height: 30px; }
  .worksheet-promo { min-height: 105px; }
  .filter-row { align-items: flex-start; flex-direction: column; margin-top: 19px; }
  .filter-chips { gap: 6px; }
  .filter-chip { padding: 0 9px; }
  .catalog-grid, .worksheet-grid { grid-template-columns: 1fr; }
  .catalog-grid .card-cover { height: 150px; }
  .detail-return { align-items: flex-start; }
  .detail-actions { gap: 4px; }
  .detail-actions .button { min-height: 32px; padding: 0 9px; font-size: 9px; }
  .detail-actions .button svg { width: 13px; height: 13px; }
  .detail-head { display: block; margin-bottom: 18px; }
  .detail-head h1 { font-size: 29px; }
  .detail-head-side { margin-top: 15px; }
  .experiment-workspace { margin-top: 12px; }
  .control-column { grid-template-columns: 1fr; }
  .observation-card { margin-top: 12px; }
  .sim-visual { height: 248px; }
  .worksheet-intro-card { align-items: flex-start; flex-direction: column; padding: 16px; }
  .worksheet-intro-card h2 { font-size: 16px; }
  .reader-top { flex-direction: column; }
  .paper-top { flex-direction: column; }
  .student-lines { grid-template-columns: 1fr; gap: 10px; }
  .worksheet-paper { padding: 19px 15px; }
  .paper-top h2 { font-size: 18px; }
  .modal { max-height: 94vh; }
  .modal-head { padding: 18px 17px 14px; }
  .modal-form { padding: 16px 17px 18px; }
  .form-grid { grid-template-columns: 1fr; gap: 12px; }
  .field-wide { grid-column: auto; }
  .modal-foot { align-items: flex-start; flex-direction: column; }
  .modal-foot .button { align-self: stretch; }
  .toast { right: 14px; bottom: 14px; }
}
@media (max-width: 390px) {
  .page-content { padding-right: 13px; padding-left: 13px; }
  .topbar { padding-right: 12px; padding-left: 12px; }
  .topbar-actions { gap: 6px; }
  .search-box { gap: 6px; }
  .hero-actions { flex-wrap: wrap; }
  .hero-actions .button { padding: 0 10px; font-size: 10px; }
  .stats-row { grid-template-columns: repeat(3, 1fr); }
  .stat-copy span { max-width: 76px; line-height: 1.2; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
}
@media print {
  body, html { background: #fff !important; }
  .sidebar, .topbar, .reader-back, .reader-top > button, .paper-experiment-link, .toast { display: none !important; }
  .main-shell { margin-left: 0 !important; }
  .page-content { width: 100%; max-width: none; padding: 0; }
  .reader-top { margin-bottom: 12px; }
  .worksheet-paper { max-width: none; padding: 0; border: 0; box-shadow: none; }
  .paper-question textarea { min-height: 98px; border: 0; border-bottom: 1px solid #bbb !important; border-radius: 0; }
  .student-lines input { border: 0; border-bottom: 1px solid #aaa; background: transparent; }
  .paper-footer { margin-top: 10px; }
}