:root {
  --navy: #062e61;
  --blue: #007eb5;
  --cyan: #08bfd0;
  --aqua: #6fe0eb;
  --coral: #ff6243;
  --orange: #ff8a35;
  --yellow: #ffc61c;
  --paper: #ffffff;
  --mist: #f2fbff;
  --line: #cfeaf3;
  --text: #0a315e;
  --muted: #58708e;
  --shadow: 0 20px 50px rgba(7, 75, 122, .12);
  --font-body: "Tajawal", Tahoma, "Segoe UI", Arial, sans-serif;
  --font-display: "Noto Kufi Arabic", "Tajawal", Tahoma, sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--text);
  background: var(--paper);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
}
body.dialog-open { overflow: hidden; }
button, input { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }
a { color: inherit; }
button { color: inherit; }
:focus-visible { outline: 4px solid rgba(255, 198, 28, .85); outline-offset: 3px; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }
.skip-link { position: fixed; z-index: 100; top: 10px; right: 10px; transform: translateY(-150%); padding: 10px 16px; border-radius: 12px; background: var(--navy); color: #fff; }
.skip-link:focus { transform: none; }

.site-header { position: sticky; top: 0; z-index: 40; background: rgba(255,255,255,.94); border-bottom: 1px solid rgba(7,126,181,.15); backdrop-filter: blur(15px); }
.header-inner { width: min(1500px, 100%); min-height: 88px; margin: auto; padding: 10px clamp(16px, 3vw, 46px); display: grid; grid-template-columns: 230px 1fr minmax(260px, 360px) auto; align-items: center; gap: clamp(15px, 2vw, 34px); }
.brand { display: block; line-height: 0; }
.brand img { width: 205px; height: 65px; object-fit: contain; object-position: right center; }
.main-nav { display: flex; justify-content: center; align-items: center; gap: clamp(18px, 2.2vw, 38px); }
.main-nav a { position: relative; padding: 14px 2px; text-decoration: none; font-weight: 800; white-space: nowrap; }
.main-nav, .header-cta, .primary-button, .launch-button, .category b { font-family: var(--font-display); }
.main-nav a::after { content: ""; position: absolute; right: 50%; bottom: 4px; width: 0; height: 4px; border-radius: 99px; background: var(--cyan); transition: .2s; }
.main-nav a:hover::after, .main-nav a.active::after { right: 0; width: 100%; }
.header-search { height: 50px; display: flex; align-items: center; gap: 8px; padding: 0 15px; border: 1px solid #c9dbe9; border-radius: 18px; background: #f9fbfd; }
.header-search:focus-within { border-color: var(--cyan); box-shadow: 0 0 0 3px rgba(8,191,208,.14); }
.search-icon { font: 700 2rem/1 Arial; transform: rotate(-15deg); }
.header-search input { width: 100%; min-width: 0; border: 0; outline: 0; color: var(--text); background: transparent; }
.header-search input::placeholder { color: #7e8fa4; }
.header-cta, .primary-button { display: inline-flex; align-items: center; justify-content: center; gap: 10px; border-radius: 17px; background: linear-gradient(135deg, var(--coral), var(--orange)); color: #fff; font-weight: 900; text-decoration: none; box-shadow: 0 12px 25px rgba(255,98,67,.24); transition: transform .2s, box-shadow .2s; }
.header-cta { min-height: 50px; padding: 0 20px; white-space: nowrap; }
.header-cta:hover, .primary-button:hover { transform: translateY(-3px); box-shadow: 0 16px 30px rgba(255,98,67,.3); }
.menu-toggle { display: none; width: 46px; height: 44px; padding: 10px; border: 1px solid var(--line); border-radius: 12px; background: #fff; }
.menu-toggle span { display: block; height: 3px; margin: 4px 0; border-radius: 2px; background: var(--navy); }

.hero { position: relative; min-height: 560px; overflow: hidden; display: grid; grid-template-columns: 1.05fr .95fr; align-items: center; gap: clamp(30px, 5vw, 90px); padding: 65px max(5vw, calc((100vw - 1440px)/2)) 100px; background: radial-gradient(circle at 78% 36%, rgba(255,240,139,.8), transparent 24%), linear-gradient(120deg, #f8fdff 0%, #d8f6ff 54%, #9ee9fb 100%); isolation: isolate; }
.hero::before, .hero::after { content: ""; position: absolute; z-index: 0; pointer-events: none; border: 3px solid rgba(8,191,208,.25); border-radius: 50%; transform: rotate(-18deg); }
.hero::before { width: 540px; height: 180px; left: -130px; bottom: 70px; }
.hero::after { width: 410px; height: 120px; right: 12%; top: 60px; border-color: rgba(255,198,28,.35); }
.hero-copy { position: relative; z-index: 5; max-width: 720px; }
.eyebrow, .section-kicker { margin: 0 0 8px; color: var(--blue); font-weight: 900; }
.eyebrow { display: flex; align-items: center; gap: 10px; }
.eyebrow span { width: 34px; height: 5px; border-radius: 99px; background: var(--yellow); transform: rotate(-10deg); }
.hero h1 { margin: 0; color: var(--navy); font-size: clamp(3rem, 6vw, 6.5rem); line-height: 1.08; letter-spacing: -3px; }
.hero h1, .section-heading h2, .activities-section h2, .about-section h2, .card-body h3, .dialog-shell h2 { font-family: var(--font-display); }
.hero h1 em { position: relative; z-index: 0; isolation: isolate; display: inline-block; color: var(--coral); font-style: normal; }
.hero h1 em::after { content: ""; position: absolute; z-index: -1; right: 0; bottom: -9px; width: 100%; height: 10px; border-radius: 50%; background: var(--yellow); transform: rotate(-2deg); }
.hero-copy > p:not(.eyebrow):not(.hero-author) { position: relative; z-index: 2; max-width: 680px; margin: 28px 0 10px; padding: 10px 14px; border-radius: 14px; background: rgba(255,255,255,.62); color: #234c73; font-size: clamp(1.05rem, 1.6vw, 1.35rem); font-weight: 600; box-shadow: 0 8px 24px rgba(6,46,97,.06); backdrop-filter: blur(4px); }
.hero-author { position: relative; z-index: 2; width: max-content; max-width: 100%; margin: 0 14px 24px; color: var(--navy); font-size: 1rem; font-weight: 700; }
.hero-author strong { color: var(--coral); font-family: "Noto Kufi Arabic", "Tajawal", sans-serif; }
.visit-summary { display: inline-flex; align-items: center; gap: 8px; margin: 0 14px 18px; padding: 5px 14px; border-radius: 999px; background: #fff; color: var(--navy); font-weight: 800; box-shadow: 0 5px 16px rgba(6,46,97,.08); }
.visit-summary[hidden] { display: none; }
.hero-actions { display: flex; align-items: center; gap: 22px; flex-wrap: wrap; }
.primary-button { min-height: 58px; padding: 0 28px; }
.text-button { color: var(--navy); font-weight: 900; text-underline-offset: 7px; }
.hero-visual { position: relative; z-index: 1; min-height: 420px; display: grid; place-items: center; }
.visual-halo { position: absolute; width: min(37vw, 520px); aspect-ratio: 1; border-radius: 50%; background: rgba(255,255,255,.52); box-shadow: inset 0 0 0 28px rgba(255,255,255,.3), 0 30px 70px rgba(0,126,181,.14); }
.hero-visual img { position: relative; z-index: 2; width: min(43vw, 620px); max-height: 350px; object-fit: contain; filter: drop-shadow(0 24px 24px rgba(3,57,96,.15)); }
.science-chip { position: absolute; z-index: 3; padding: 8px 15px; border: 2px solid #fff; border-radius: 14px; color: #fff; font-weight: 900; box-shadow: 0 10px 24px rgba(3,57,96,.15); }
.chip-one { top: 14%; right: 1%; background: var(--coral); transform: rotate(7deg); }
.chip-two { left: 4%; top: 23%; background: var(--blue); transform: rotate(-6deg); }
.chip-three { left: 16%; bottom: 8%; background: #13a56f; transform: rotate(5deg); }
.hero-spark { position: absolute; z-index: 2; color: var(--yellow); font-size: 2.4rem; }
.spark-one { top: 16%; left: 47%; }
.spark-two { right: 3%; bottom: 25%; }
.wave { position: absolute; z-index: 0; pointer-events: none; right: -5%; bottom: -90px; width: 110%; height: 170px; border-radius: 50% 50% 0 0; background: rgba(255,255,255,.88); box-shadow: 0 -25px 0 rgba(26,178,224,.17), 0 -52px 0 rgba(9,149,204,.11); }

.catalog-section { width: min(1450px, calc(100% - 32px)); margin: auto; padding: 78px 0 95px; }
.section-heading { display: flex; align-items: end; justify-content: space-between; gap: 25px; margin-bottom: 28px; }
.section-heading h2, .activities-section h2, .about-section h2 { margin: 0; color: var(--navy); font-size: clamp(2rem, 4vw, 3.7rem); line-height: 1.25; }
.section-heading > p { max-width: 460px; margin: 0 0 8px; color: var(--muted); }
.category-bar { display: grid; grid-template-columns: repeat(5, minmax(0, 1fr)); gap: 18px; }
.filter-step-heading { margin: 0 0 12px; color: var(--navy); font-weight: 900; font-size: 1rem; }
.filter-step-heading span, .curriculum-heading span { display: inline-grid; place-items: center; margin-left: 7px; padding: 6px 10px; border-radius: 9px; background: var(--yellow); color: var(--navy); font-size: .78rem; }
.category { position: relative; min-width: 0; overflow: hidden; padding: 0; border: 3px solid transparent; border-radius: 25px; background: #fff; text-align: right; cursor: pointer; box-shadow: 0 14px 35px rgba(7,75,122,.11); transition: transform .24s, border-color .24s, box-shadow .24s; }
.category:hover { transform: translateY(-6px); box-shadow: 0 22px 45px rgba(7,75,122,.17); }
.category:focus-visible { outline: 4px solid rgba(8,191,208,.3); outline-offset: 3px; }
.category.active { border-color: var(--cyan); box-shadow: 0 22px 50px rgba(7,75,122,.2); }
.category.active::after { content: "✓"; position: absolute; top: 12px; left: 12px; width: 38px; height: 38px; display: grid; place-items: center; border-radius: 50%; background: var(--yellow); color: var(--navy); font-weight: 900; box-shadow: 0 7px 18px rgba(3,57,96,.2); }
.category-visual { display: block; aspect-ratio: 16 / 9; overflow: hidden; background: #eaf7fb; }
.category-visual img { width: 100%; height: 100%; display: block; object-fit: cover; transition: transform .35s; }
.category:hover .category-visual img, .category.active .category-visual img { transform: scale(1.045); }
.category-copy { display: block; padding: 17px 19px 19px; }
.category b, .category small { display: block; }
.category b { color: var(--navy); font-size: 1.3rem; }
.category small { margin-top: 3px; color: var(--muted); font-size: .88rem; }
.filter-or { display: flex; align-items: center; gap: 12px; margin: 22px 0; color: var(--blue); font-weight: 900; }
.filter-or::before, .filter-or::after { content: ''; height: 1px; flex: 1; background: var(--line); }
.filter-or span { display: grid; width: 42px; height: 42px; place-items: center; border-radius: 50%; background: #fff; box-shadow: 0 7px 18px rgba(7,75,122,.1); }
.curriculum-filters { display: grid; grid-template-columns: 1.15fr .85fr; gap: 18px; padding: 20px; border: 1px solid var(--line); border-radius: 25px; background: linear-gradient(135deg, #f4fbff, #fffdf2); box-shadow: 0 12px 32px rgba(7,75,122,.07); }
.curriculum-filters[hidden] { display: none; }
.curriculum-heading { grid-column: 1 / -1; display: flex; align-items: center; color: var(--navy); }
.filter-group { min-width: 0; margin: 0; padding: 0; border: 0; }
.filter-group legend { margin-bottom: 12px; color: var(--navy); font-weight: 900; font-size: 1rem; }
.filter-group legend span { width: 29px; height: 29px; display: inline-grid; place-items: center; margin-left: 7px; border-radius: 9px; background: var(--yellow); color: var(--navy); }
.filter-options { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 10px; }
.term-options { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.filter-button { min-height: 68px; padding: 10px 13px; border: 2px solid transparent; border-radius: 17px; background: #fff; color: var(--navy); text-align: center; cursor: pointer; box-shadow: 0 7px 18px rgba(7,75,122,.07); transition: transform .2s, border-color .2s, background .2s; }
.filter-button:hover { transform: translateY(-3px); }
.filter-button:focus-visible { outline: 3px solid rgba(8,191,208,.3); outline-offset: 2px; }
.filter-button.active { border-color: var(--cyan); background: #eafcff; box-shadow: 0 9px 23px rgba(8,191,208,.14); }
.filter-button b, .filter-button small { display: block; }
.filter-button b { font-size: 1rem; }
.filter-button small { margin-top: 2px; color: var(--muted); font-size: .78rem; }
.result-line { min-height: 46px; display: flex; align-items: center; justify-content: space-between; margin: 20px 3px 9px; color: var(--muted); font-size: .92rem; }
.clear-search { border: 0; background: transparent; color: var(--blue); font-weight: 800; text-decoration: underline; cursor: pointer; }
.cards-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 24px; }
.cards-grid[hidden] { display: none; }
.sim-card { grid-column: span 1; min-width: 0; overflow: hidden; border: 1px solid var(--line); border-radius: 25px; background: #fff; box-shadow: var(--shadow); transition: transform .25s, box-shadow .25s; }
.sim-card:hover { transform: translateY(-7px); box-shadow: 0 26px 55px rgba(7,75,122,.18); }
.card-visual { position: relative; min-height: 250px; display: grid; place-items: center; overflow: hidden; }
.earth-card { background: radial-gradient(circle at 50% 48%, #fff7c8 0 12%, transparent 13%), linear-gradient(145deg, #c6f3ff, #eefcff 55%, #dff8e6); }
.biology-card { background: radial-gradient(circle at 20% 20%, rgba(255,255,255,.9), transparent 25%), linear-gradient(145deg, #e8e2ff, #f6f3ff 55%, #dff9f2); }
.chemistry-card { background: radial-gradient(circle at 80% 20%, rgba(255,255,255,.85), transparent 24%), linear-gradient(145deg, #fff0cf, #fff9e9 55%, #dff6ff); }
.card-visual::before, .card-visual::after { content: ""; position: absolute; width: 380px; height: 110px; border: 4px solid rgba(0,126,181,.25); border-radius: 50%; transform: rotate(-15deg); }
.card-visual::after { width: 320px; height: 90px; border-color: rgba(255,198,28,.5); transform: rotate(21deg); }
.card-badge { position: absolute; z-index: 2; top: 16px; right: 16px; padding: 5px 13px; border-radius: 99px; background: rgba(255,255,255,.9); color: #17825a; font-size: .8rem; font-weight: 900; box-shadow: 0 6px 15px rgba(7,75,122,.08); }
.card-symbols { position: relative; z-index: 1; width: 250px; height: 190px; }
.card-symbols span { position: absolute; filter: drop-shadow(0 10px 10px rgba(3,57,96,.15)); }
.card-symbols .main-symbol { inset: 28px auto auto 72px; font-size: 5.8rem; }
.card-symbols .symbol-one { right: 7px; bottom: 9px; font-size: 2.8rem; }
.card-symbols .symbol-two { left: 7px; top: 20px; font-size: 2.4rem; }
.card-symbols .symbol-three { right: 20px; top: 0; font-size: 2.3rem; }
.card-body { padding: 22px; }
.card-meta { display: flex; justify-content: space-between; gap: 10px; color: var(--blue); font-size: .78rem; font-weight: 800; }
.card-body h3 { margin: 8px 0 6px; color: var(--navy); font-size: 1.45rem; }
.card-body p { min-height: 80px; margin: 0 0 18px; color: var(--muted); font-size: .95rem; }
.card-body .card-stats { min-height: 0; margin: -5px 0 13px; color: var(--blue); font-size: .9rem; font-weight: 800; }
.card-stats:empty { display: none; }
.card-footer { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.launch-button { min-height: 46px; padding: 0 20px; border: 0; border-radius: 14px; background: linear-gradient(135deg, var(--coral), var(--orange)); color: #fff; font-weight: 900; cursor: pointer; }
.interactive-label { white-space: nowrap; color: #17825a; font-size: .82rem; font-weight: 800; }
.interactive-label i { display: inline-block; width: 8px; height: 8px; margin-left: 4px; border-radius: 50%; background: #25b875; box-shadow: 0 0 0 5px rgba(37,184,117,.12); }
.empty-search { padding: 55px 20px; border: 2px dashed var(--line); border-radius: 25px; text-align: center; }
.empty-search > span { font-size: 2.7rem; }
.empty-search h3 { margin: 8px 0 0; }
.empty-search p { margin: 3px 0 0; color: var(--muted); }

.activities-section { width: min(1450px, calc(100% - 32px)); margin: 0 auto 90px; padding: clamp(32px, 6vw, 75px); border-radius: 34px; background: linear-gradient(125deg, #062e61, #07538a); color: #fff; overflow: hidden; position: relative; }
.activities-section::after { content: ""; position: absolute; width: 480px; height: 480px; left: -160px; bottom: -300px; border: 2px solid rgba(111,224,235,.25); border-radius: 50%; box-shadow: 0 0 0 35px rgba(111,224,235,.08), 0 0 0 70px rgba(111,224,235,.05); }
.activities-section .section-kicker { color: var(--aqua); }
.activities-section h2 { color: #fff; }
.activity-heading { position: relative; z-index: 1; max-width: 780px; margin-bottom: 28px; }
.activity-heading > p:last-child { color: #cbe3f4; font-size: 1.05rem; }
.activity-status { position: relative; z-index: 1; min-height: 150px; display: flex; align-items: center; justify-content: center; gap: 18px; padding: 28px; border: 1px solid rgba(255,255,255,.25); border-radius: 26px; background: rgba(255,255,255,.1); backdrop-filter: blur(10px); }
.activity-mark { width: 70px; height: 70px; display: grid; place-items: center; flex: 0 0 auto; border-radius: 22px; background: var(--yellow); color: var(--navy); font-size: 2rem; font-weight: 900; }
.activity-status strong, .activity-status small { display: block; }
.activity-status strong { font-size: 1.15rem; }
.activity-status small { color: #cbe3f4; }
.activities-grid { position: relative; z-index: 1; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 18px; margin-top: 30px; }
.activities-grid:not([hidden]) { display: grid; }
.activity-card { display: flex; flex-direction: column; min-width: 0; padding: 24px; border: 1px solid rgba(255,255,255,.32); border-radius: 24px; background: rgba(255,255,255,.97); color: var(--text); box-shadow: 0 18px 36px rgba(0,23,55,.18); }
.activity-card-top { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.pdf-label { padding: 5px 10px; border-radius: 99px; background: #ffe9e4; color: #bf351d; font-size: .77rem; font-weight: 900; }
.activity-card-top small { color: var(--muted); font-weight: 700; }
.activity-card h3 { margin: 17px 0 7px; font-family: var(--font-display); font-size: 1.1rem; line-height: 1.55; }
.activity-card > p { margin: 0 0 14px; color: var(--muted); }
.activity-reference { margin-top: auto; padding: 12px; border-radius: 14px; background: var(--mist); color: var(--navy); font-size: .88rem; }
.activity-reference strong { display: block; color: var(--blue); }
.activity-actions { display: grid; grid-template-columns: 1fr 1fr; gap: 9px; margin-top: 15px; }
.activity-actions a, .activity-help { min-height: 44px; display: grid; place-items: center; padding: 8px 12px; border: 0; border-radius: 13px; text-decoration: none; font-weight: 900; cursor: pointer; }
.activity-actions a { background: linear-gradient(135deg, var(--coral), var(--orange)); color: #fff; }
.activity-help { background: #e1f7fb; color: var(--navy); }

.about-section { width: min(1200px, calc(100% - 32px)); margin: 0 auto 90px; display: grid; grid-template-columns: 210px 1fr auto; align-items: center; gap: 40px; padding: 36px; border: 1px solid var(--line); border-radius: 30px; background: #f8fdff; }
.about-section img { width: 210px; height: 130px; object-fit: contain; }
.about-section > div > p:last-child { margin-bottom: 0; color: var(--muted); }
.author { min-width: 190px; padding: 17px 20px; border-right: 5px solid var(--coral); border-radius: 12px; background: #fff; color: var(--muted); }
.author strong { color: var(--navy); }
footer { min-height: 105px; display: flex; align-items: center; justify-content: space-between; gap: 20px; padding: 20px max(5vw, calc((100vw - 1440px)/2)); border-top: 1px solid var(--line); background: #f7fcff; color: var(--muted); }
footer img { width: 160px; height: 65px; object-fit: contain; }
footer a { color: var(--blue); font-weight: 800; }

.simulation-dialog { width: 100vw; max-width: none; height: 100vh; max-height: none; margin: 0; padding: 12px; border: 0; background: rgba(2,25,53,.84); }
.simulation-dialog::backdrop { background: rgba(2,25,53,.84); }
.dialog-shell { width: 100%; height: 100%; display: grid; grid-template-rows: auto 1fr; overflow: hidden; border-radius: 22px; background: #fff; box-shadow: 0 30px 80px rgba(0,0,0,.3); }
.dialog-shell > header { display: flex; align-items: center; justify-content: space-between; gap: 15px; padding: 10px 16px 10px 22px; border-bottom: 1px solid var(--line); background: #f8fdff; }
.dialog-shell header span { color: var(--blue); font-size: .74rem; font-weight: 900; }
.dialog-shell h2 { margin: -3px 0 0; font-size: 1.12rem; }
.dialog-actions { display: flex; align-items: center; gap: 10px; }
.dialog-actions a { color: var(--blue); font-size: .84rem; font-weight: 800; }
.dialog-actions button { width: 44px; height: 44px; border: 0; border-radius: 13px; background: var(--navy); color: #fff; font-size: 1.8rem; line-height: 1; cursor: pointer; }
.dialog-rating { display: flex; align-items: center; gap: 10px; color: var(--navy); font-weight: 800; }
.dialog-rating[hidden] { display: none; }
.dialog-rating #dialog-stats { color: var(--navy); font-size: .88rem; }
.rating-stars { display: flex; direction: ltr; gap: 2px; }
.dialog-actions .rating-stars button { width: 30px; height: 32px; padding: 0; border: 0; border-radius: 6px; background: transparent; color: #9caab8; font-size: 1.5rem; line-height: 1; }
.dialog-actions .rating-stars button:hover, .dialog-actions .rating-stars button.selected { color: #e2a500; }
.dialog-shell iframe { width: 100%; height: 100%; border: 0; background: #fff; }

@media (max-width: 1100px) {
  .header-inner { grid-template-columns: 190px 1fr auto; }
  .brand img { width: 180px; }
  .header-search { grid-row: 2; grid-column: 1 / -1; margin-bottom: 3px; }
  .hero { grid-template-columns: 1fr 1fr; }
  .cards-grid { grid-template-columns: repeat(2, 1fr); }
  .activities-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .category-bar { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .about-section { grid-template-columns: 160px 1fr; }
  .about-section img { width: 160px; }
  .author { grid-column: 2; margin: 0; }
}

@media (max-width: 760px) {
  .site-header { position: relative; }
  .header-inner { min-height: 78px; grid-template-columns: 1fr auto auto; padding: 8px 14px; gap: 10px; }
  .brand img { width: 165px; height: 58px; }
  .menu-toggle { display: block; }
  .header-cta { min-height: 44px; padding: 0 13px; font-size: .82rem; }
  .main-nav { position: absolute; top: 76px; right: 12px; left: 12px; display: none; align-items: stretch; padding: 12px; border: 1px solid var(--line); border-radius: 18px; background: #fff; box-shadow: var(--shadow); }
  .main-nav.open { display: grid; }
  .main-nav a { padding: 11px; }
  .header-search { grid-row: 2; grid-column: 1 / -1; }
  .hero { min-height: auto; grid-template-columns: 1fr; padding: 52px 20px 105px; text-align: center; }
  .eyebrow, .hero-actions { justify-content: center; }
  .hero h1 { font-size: clamp(3.2rem, 15vw, 5.2rem); letter-spacing: -2px; }
  .hero-visual { min-height: 280px; }
  .hero-visual img { width: min(92vw, 560px); max-height: 250px; }
  .visual-halo { width: 300px; }
  .science-chip { font-size: .78rem; }
  .section-heading { display: block; }
  .section-heading > p { margin-top: 10px; }
  .catalog-section { padding-top: 58px; }
  .category-bar { grid-template-columns: 1fr; gap: 14px; }
  .category { display: grid; grid-template-columns: 42% 1fr; align-items: stretch; border-radius: 21px; }
  .category-visual { height: 100%; aspect-ratio: auto; min-height: 130px; }
  .category-copy { align-self: center; padding: 18px; }
  .curriculum-filters { grid-template-columns: 1fr; padding: 16px; }
  .filter-options { gap: 7px; }
  .filter-button { min-height: 64px; padding: 8px; }
  .cards-grid { grid-template-columns: 1fr; }
  .sim-card { max-width: 560px; width: 100%; margin: auto; }
  .activities-section { padding: 38px 24px; }
  .activities-grid { grid-template-columns: 1fr; }
  .about-section { grid-template-columns: 1fr; text-align: center; }
  .about-section img { margin: auto; }
  .author { grid-column: auto; text-align: right; }
  footer { flex-direction: column; text-align: center; }
  .simulation-dialog { padding: 0; }
  .dialog-shell { border-radius: 0; }
  .dialog-shell > header { flex-wrap: wrap; }
  .dialog-rating { flex-wrap: wrap; gap: 2px 8px; }
  .dialog-rating #dialog-stats { font-size: .78rem; }
  .dialog-actions a { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition: none !important; }
}