:root {
  --cream: #fff9ed;
  --paper: #fffdf8;
  --midnight: #101526;
  --ink: #1b2136;
  --muted: #626778;
  --orange: #f5a623;
  --orange-deep: #d86d20;
  --teal: #29b8a6;
  --pink: #ed6f91;
  --violet: #7565dd;
  --blue: #4f7edb;
  --line: rgba(16, 21, 38, .13);
  --shadow: 0 24px 70px rgba(33, 30, 44, .12);
  --radius: 30px;
  --shell: min(1180px, calc(100% - 40px));
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
img, video { display: block; max-width: 100%; }
a { color: inherit; }
button, select, input, textarea { font: inherit; }
.skip-link { position: fixed; left: 16px; top: -80px; z-index: 999; background: #fff; padding: 12px 18px; border-radius: 99px; }
.skip-link:focus { top: 16px; }
.shell { width: var(--shell); margin-inline: auto; }

.site-header {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--paper) 88%, transparent);
  border-bottom: 1px solid rgba(16, 21, 38, .08);
  backdrop-filter: blur(18px);
}
.site-bar { min-height: 76px; display: flex; align-items: center; gap: 30px; }
.brand { display: inline-flex; align-items: center; gap: 11px; text-decoration: none; font-weight: 750; letter-spacing: -.025em; font-size: 1.15rem; }
.brand img { width: 34px; height: 34px; }
.brand small { display: block; color: var(--muted); font-size: .66rem; font-weight: 550; letter-spacing: .1em; text-transform: uppercase; line-height: 1; margin-top: 3px; }
.site-nav { margin-left: auto; display: flex; align-items: center; gap: 4px; }
.site-nav a { color: #3d4459; text-decoration: none; font-weight: 520; font-size: .91rem; padding: 9px 12px; border-radius: 99px; }
.site-nav a:hover, .site-nav a[aria-current="page"] { color: var(--ink); background: #fff; box-shadow: 0 4px 20px rgba(16,21,38,.07); }
.site-nav a[aria-current="page"] { font-weight: 650; }
.site-nav .join { background: var(--orange); color: #382300; font-weight: 680; margin-left: 6px; box-shadow: 0 7px 18px rgba(245,166,35,.2); }
.site-nav .join:hover { background: #efa01f; color: #2f1e00; box-shadow: 0 9px 22px rgba(245,166,35,.28); }
.lang { border: 1px solid var(--line); border-radius: 99px; background: rgba(255,255,255,.4); padding: 8px 10px; color: #3d4459; font-weight: 450; margin-left: 6px; max-width: 92px; }
.menu-toggle { display: none; margin-left: auto; border: 1px solid var(--line); background: #fff; border-radius: 99px; padding: 8px 14px; font-weight: 650; }

.eyebrow { margin: 0 0 18px; font-size: .76rem; font-weight: 900; text-transform: uppercase; letter-spacing: .15em; color: var(--orange-deep); }
h1, h2, h3, p { margin-top: 0; }
h1, h2, h3 { line-height: 1.06; letter-spacing: -.045em; }
h1 { font-size: clamp(3.2rem, 7.5vw, 7.2rem); margin-bottom: 24px; }
h2 { font-size: clamp(2.35rem, 5vw, 4.7rem); margin-bottom: 22px; }
h3 { font-size: clamp(1.25rem, 2vw, 1.75rem); margin-bottom: 11px; }
.lead { font-size: clamp(1.06rem, 1.6vw, 1.36rem); color: var(--muted); max-width: 700px; }
.max-copy { max-width: 730px; }
.center { text-align: center; margin-inline: auto; }
.center .lead { margin-inline: auto; }
.accent { color: var(--orange-deep); }
.accent-teal { color: var(--teal); }
.accent-pink { color: var(--pink); }
.inverse { background: var(--midnight); color: #fff; }
.inverse .lead, .inverse .muted { color: #b8bfd2; }

.button-row { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 30px; }
.button { display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-height: 50px; padding: 0 21px; border: 1px solid transparent; border-radius: 99px; background: var(--midnight); color: #fff; text-decoration: none; font-weight: 700; cursor: pointer; }
.button:hover { transform: translateY(-2px); box-shadow: 0 10px 24px rgba(16, 21, 38, .16); }
.button.alt { background: transparent; border-color: var(--line); color: var(--ink); }
.inverse .button { background: #fff; color: var(--midnight); }
.inverse .button.alt { background: transparent; color: #fff; border-color: rgba(255,255,255,.24); }
.text-link { display: inline-flex; align-items: center; gap: 7px; color: var(--orange-deep); font-weight: 850; text-decoration: none; }

section { padding: clamp(78px, 10vw, 150px) 0; }
.hero { overflow: hidden; padding-top: clamp(62px, 8vw, 105px); min-height: calc(100svh - 76px); display: grid; align-items: center; }
.hero-grid { display: grid; grid-template-columns: minmax(0, .9fr) minmax(430px, 1.1fr); gap: clamp(40px, 6vw, 90px); align-items: center; }
.hero-grid h1 { font-size: clamp(3.1rem, 4.6vw, 4.8rem); }
.hero h1 span { display: block; }
.hero h1 .turn { background: linear-gradient(90deg, var(--orange-deep), var(--pink), var(--violet)); background-clip: text; color: transparent; }
.hero-subtitle { margin: -4px 0 22px; color: var(--orange-deep); font-size: clamp(1rem, 1.35vw, 1.2rem); font-weight: 550; letter-spacing: -.015em; }
.hero-visual { position: relative; min-height: 610px; display: grid; place-items: center; }
.orbit-stage { position: absolute; inset: 2% -8%; }
.orbit-stage svg { width: 100%; height: 100%; overflow: visible; }
.orbit-path { fill: none; stroke: rgba(117,101,221,.25); stroke-width: 2; stroke-dasharray: 7 9; }
.orbit-path.hot { stroke: var(--orange); stroke-width: 4; stroke-dasharray: 0; filter: drop-shadow(0 0 10px rgba(245,166,35,.35)); stroke-dasharray: 900; stroke-dashoffset: 900; animation: draw-path 2.8s .3s forwards ease-in-out; }
.orbit-node { transform-box: fill-box; transform-origin: center; animation: breathe 3s infinite ease-in-out; }
.orbit-node:nth-of-type(2) { animation-delay: .5s; }
.orbit-label { font-size: 15px; fill: var(--muted); font-weight: 800; }
.orbit-label.muted-path { fill: #9295a4; }
.hero-question { position: relative; z-index: 3; width: min(330px, 72%); padding: 30px; background: rgba(255,255,255,.92); border: 1px solid rgba(255,255,255,.7); border-radius: 28px; box-shadow: var(--shadow); transform: rotate(-2deg); }
.hero-question b { display: block; font-size: 1.5rem; line-height: 1.15; letter-spacing: -.03em; }
.hero-question small { color: var(--muted); }
@keyframes draw-path { to { stroke-dashoffset: 0; } }
@keyframes breathe { 50% { transform: scale(1.12); } }

.section-intro { display: grid; grid-template-columns: .82fr 1.18fr; gap: clamp(40px, 7vw, 100px); align-items: end; margin-bottom: 55px; }
.section-intro > * { margin-bottom: 0; }
.concept-stage { min-height: 520px; border-radius: var(--radius); background: #fff; color: var(--ink); border: 1px solid var(--line); box-shadow: var(--shadow); padding: clamp(22px, 4vw, 48px); overflow: hidden; }
.path-heading { margin: 0 0 24px; max-width: 760px; }
.path-heading h3 { color: #fff; font-size: clamp(1.65rem, 3vw, 2.45rem); }
.path-heading p { color: #c6ccdd; margin-bottom: 0; font-size: 1.05rem; }
.path-demo { position: relative; min-height: 420px; display: grid; align-items: end; }
.path-demo svg { position: absolute; inset: 0; width: 100%; height: 100%; }
.path-base { fill: none; stroke: #d9dce5; stroke-width: 5; }
.path-route { fill: none; stroke-width: 6; stroke-linecap: round; stroke-dasharray: 700; stroke-dashoffset: 700; animation: draw-path 3s .5s forwards ease; }
.path-route.one { stroke: var(--violet); }
.path-route.two { stroke: var(--orange); animation-delay: 1.2s; }
.path-prompt { position: relative; z-index: 2; justify-self: center; max-width: 560px; display: grid; grid-template-columns: 1fr auto 1fr; gap: 15px; align-items: center; padding-bottom: 14px; }
.prompt-card { border: 2px solid #9ea4b3; border-radius: 20px; background: #fffdf8; color: var(--ink); padding: 16px; font-weight: 800; box-shadow: 0 10px 30px rgba(16,21,38,.08); }
.prompt-card small { display: block; margin-bottom: 5px; color: #666c7d; font-size: .68rem; letter-spacing: .12em; text-transform: uppercase; }
.prompt-card.changed { background: #ffe2bd; border-color: var(--orange-deep); }
.prompt-card.changed small { color: #8c3c12; }
.path-prompt i { font-style: normal; color: var(--orange-deep); font-size: 1.5rem; }
.path-legend { position: absolute; inset: 0; z-index: 1; pointer-events: none; color: var(--ink); font-size: .76rem; font-weight: 900; letter-spacing: .04em; text-transform: uppercase; }
.path-legend span { position: absolute; padding: 5px 9px; border-radius: 99px; background: rgba(255,255,255,.9); border: 1px solid var(--line); }
.path-legend .start { left: 3%; top: 56%; }
.path-legend .branch { left: 41%; top: 38%; }
.path-legend .old-end { right: 3%; bottom: 13%; color: #5e4dc2; }
.path-legend .new-end { right: 3%; top: 12%; color: #a84917; }

.world-stage { border-radius: var(--radius); overflow: hidden; min-height: 680px; position: relative; display:grid; grid-template-columns:54% 46%; background: #151c33; color: #fff; box-shadow: var(--shadow); }
.world-stage::after { content: ""; position: absolute; inset: 0; background: linear-gradient(90deg, rgba(8,12,24,.38) 43%, rgba(8,12,24,.08) 72%, transparent 100%); pointer-events: none; }
.world-image { position: relative; inset: auto; grid-column:2; grid-row:1; width: 100%; height: 100%; min-height:680px; object-fit: cover; object-position: center; }
.world-grid { position: absolute; inset: 0; opacity: .46; background-image: linear-gradient(rgba(255,255,255,.06) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,.06) 1px, transparent 1px); background-size: 42px 42px; transform: perspective(500px) rotateX(58deg) scale(1.5) translateY(20%); }
.world-orb { position: absolute; border-radius: 50%; filter: blur(2px); }
.world-orb.one { width: 280px; height: 280px; right: 13%; top: 17%; background: radial-gradient(circle at 35% 30%, #fff3b8, var(--orange) 10%, #ec644b 38%, rgba(236,100,75,.08) 72%); box-shadow: 0 0 90px rgba(245,166,35,.4); }
.world-orb.two { width: 110px; height: 110px; right: 8%; bottom: 16%; background: radial-gradient(circle at 35% 30%, white, var(--teal) 30%, rgba(41,184,166,.1) 72%); }
.world-copy { position: relative; z-index: 3; grid-column:1; grid-row:1; max-width: 690px; padding: clamp(38px, 6vw, 76px); }
.world-copy h2 { font-size: clamp(2.5rem, 4.5vw, 4.7rem); }
.world-lead { max-width: 610px; color: #eef1fb; font-size: clamp(1.02rem, 1.5vw, 1.22rem); }
.world-steps { display: grid; gap: 11px; margin: 28px 0; }
.world-steps > span { display: grid; grid-template-columns: 112px 1fr; align-items: start; gap: 13px; color: #e3e7f3; }
.world-steps b { display: block; padding: 4px 8px; background: rgba(255,255,255,.13); border: 1px solid rgba(255,255,255,.18); border-radius: 9px; color: #fff; font-size: .72rem; letter-spacing: .08em; text-transform: uppercase; text-align: center; }
.world-note { max-width: 610px; color: #b8bfd2; font-size: .91rem; margin: 24px 0 28px; }

.course-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 22px; }
.course-card { min-height: 660px; border-radius: var(--radius); overflow: hidden; position: relative; color: #fff; text-decoration: none; display: flex; flex-direction: column; box-shadow: var(--shadow); }
.course-card .media { position: absolute; inset: 0; }
.course-card .media img { width: 100%; height: 100%; object-fit: cover; transition: transform .6s ease; }
.course-card:hover .media img { transform: scale(1.035); }
.course-card .media::after { content:""; position:absolute; inset:0; background:linear-gradient(180deg, rgba(12,16,28,.05) 20%, rgba(12,16,28,.88) 88%); }
.course-card .card-copy { position: relative; z-index: 2; margin-top: auto; padding: clamp(28px, 4vw, 48px); }
.course-card h3 { font-size: clamp(2.1rem, 4vw, 4rem); }
.course-card p { color: #eef0f8; max-width: 530px; font-size: 1.08rem; }
.tags { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 18px; }
.tag { padding: 5px 10px; border-radius: 99px; border: 1px solid rgba(255,255,255,.38); font-size: .75rem; font-weight: 850; letter-spacing: .05em; }
.newton-art { background: radial-gradient(circle at 60% 15%, #566ba8, transparent 35%), linear-gradient(145deg,#171d36,#27244c 58%,#913f45); }
.newton-art::before { content:"☾"; position:absolute; right:10%; top:7%; color:#fff6ca; font-size:12rem; line-height:1; filter:drop-shadow(0 0 30px rgba(255,246,202,.35)); }
.newton-art::after { content:"Could the pull that makes an apple fall also keep the Moon in orbit?"; position:absolute; right:8%; top:34%; width:45%; padding:20px; border:1px solid rgba(255,255,255,.26); border-radius:20px; background:rgba(11,16,35,.68); backdrop-filter:blur(12px); font-weight:800; font-size:clamp(1rem,2vw,1.5rem); }

.demo-frame { margin: 0; border-radius: var(--radius); overflow: hidden; background: #fff; color: var(--ink); box-shadow: var(--shadow); border: 1px solid var(--line); }
.demo-frame.inverse { background: #0b1020; border-color: rgba(255,255,255,.12); color: #fff; }
.demo-media { position: relative; min-height: 460px; overflow: hidden; }
.demo-media > img, .demo-media > video { width: 100%; height: 100%; object-fit: cover; position: absolute; inset: 0; }
.demo-caption { padding: 22px 25px; display: flex; justify-content: space-between; gap: 24px; align-items: center; border-top: 1px solid var(--line); }
.inverse .demo-caption { border-top-color: rgba(255,255,255,.12); }
.demo-caption strong { display:block; font-size:1.08rem; }
.demo-caption span { color:var(--muted); font-size:.9rem; }
.inverse .demo-caption span { color:#aeb6cf; }
.demo-controls { display:flex; gap:8px; }
.demo-controls button { border:1px solid var(--line); background:transparent; border-radius:99px; padding:8px 12px; font-weight:800; cursor:pointer; }
.inverse .demo-controls button { color:#fff; border-color:rgba(255,255,255,.25); }

.newton-interface { background:#0b1020; color:#eef1ff; min-height:560px; display:grid; grid-template-columns:1fr 1.08fr; }
.newton-scene { position:relative; overflow:hidden; padding:38px; background: radial-gradient(circle at 70% 24%, rgba(117,101,221,.48), transparent 30%), linear-gradient(#171d37,#0e1429); }
.newton-scene .moon { position:absolute; width:130px; height:130px; border-radius:50%; right:13%; top:12%; background:radial-gradient(circle at 36% 32%,#fff,#d8d4ba 48%,#96927f); box-shadow:0 0 45px rgba(255,255,255,.19); }
.newton-scene .apple { position:absolute; left:48%; bottom:24%; font-size:4.2rem; animation:apple-fall 2.8s infinite ease-in; }
.newton-scene .ground { position:absolute; inset:auto 0 0; height:34%; background:linear-gradient(175deg,#263a43,#16242b); clip-path:polygon(0 30%,100% 0,100% 100%,0 100%); }
.newton-scene blockquote { position:absolute; left:8%; top:16%; z-index:2; width:50%; margin:0; font-size:clamp(1.3rem,2.4vw,2.25rem); line-height:1.12; font-weight:850; letter-spacing:-.04em; }
@keyframes apple-fall { 0% { transform:translateY(-120px) rotate(-8deg); opacity:0; } 18% { opacity:1; } 75%,100% { transform:translateY(90px) rotate(10deg); opacity:1; } }
.thinking-panel { padding:28px; display:flex; flex-direction:column; gap:17px; }
.thinking-tabs { display:flex; flex-wrap:wrap; gap:8px; }
.thinking-tab { border:1px solid rgba(255,255,255,.16); background:rgba(255,255,255,.05); color:#cfd4e8; padding:8px 12px; border-radius:99px; cursor:pointer; font-size:.82rem; font-weight:850; }
.thinking-tab.active { background:var(--orange); color:#26170a; border-color:var(--orange); }
.thinking-card { padding:20px; border:1px solid rgba(255,255,255,.13); background:rgba(255,255,255,.055); border-radius:18px; }
.thinking-card small { color:#969fbd; text-transform:uppercase; letter-spacing:.13em; font-weight:850; }
.thinking-card p { margin:8px 0 0; font-size:1.02rem; }
.thinking-card.changed { border-color:rgba(245,166,35,.54); background:rgba(245,166,35,.09); }
.thinking-trail { margin-top:auto; display:grid; grid-template-columns:repeat(3,1fr); gap:7px; }
.thinking-trail span { height:6px; border-radius:99px; background:rgba(255,255,255,.13); }
.thinking-trail span.on { background:var(--orange); }

/* AI Explorer Lab: a preview that opens the existing Newton inquiry in place. */
.newton-launcher { background:#0b1020; }
.newton-preview { min-height:560px; display:grid; grid-template-columns:.9fr 1.1fr; background:#0b1020; }
.newton-preview-scene { position:relative; min-height:560px; overflow:hidden; background:radial-gradient(circle at 58% 26%,rgba(117,101,221,.5),transparent 31%),linear-gradient(155deg,#18203c,#0b1020 72%); }
.newton-preview-label { position:absolute; z-index:4; left:30px; top:28px; padding:7px 11px; border:1px solid rgba(255,255,255,.24); border-radius:99px; color:#fff3d7; font-size:.68rem; font-weight:900; letter-spacing:.15em; }
.newton-earth { position:absolute; width:520px; height:520px; left:-220px; bottom:-300px; border-radius:50%; background:radial-gradient(circle at 65% 24%,#56c5b4 0 8%,#4f7edb 9% 32%,#1d315d 62%,#121a33 78%); box-shadow:0 0 80px rgba(79,126,219,.32); }
.newton-orbit { position:absolute; width:430px; height:275px; left:11%; top:24%; border:2px solid rgba(255,255,255,.23); border-left-color:rgba(245,166,35,.82); border-radius:50%; transform:rotate(-18deg); }
.newton-moon { position:absolute; width:68px; height:68px; right:15px; top:24px; border-radius:50%; background:radial-gradient(circle at 34% 30%,#fff,#dad7c5 47%,#827f72); box-shadow:0 0 34px rgba(255,255,255,.24); }
.newton-apple { position:absolute; z-index:3; left:34%; top:42%; width:22px; height:22px; border-radius:50%; background:var(--orange); color:transparent; box-shadow:0 0 20px rgba(245,166,35,.58); animation:newton-drop 3.2s infinite ease-in; }
.fall-line { position:absolute; left:calc(34% + 10px); top:45%; height:165px; border-left:1px dashed rgba(245,166,35,.58); }
@keyframes newton-drop { 0%,12% { transform:translateY(-35px); opacity:.25; } 45%,75% { transform:translateY(108px); opacity:1; } 100% { transform:translateY(108px); opacity:0; } }
.newton-preview-thinking { padding:clamp(25px,4vw,48px); display:flex; flex-direction:column; justify-content:center; gap:13px; background:linear-gradient(145deg,#10162b,#151b34); }
.newton-concept { position:relative; padding:17px 19px 17px 24px; border:1px solid rgba(255,255,255,.13); border-radius:17px; background:rgba(255,255,255,.045); }
.newton-concept::before { content:""; position:absolute; left:0; top:15px; bottom:15px; width:4px; border-radius:0 5px 5px 0; background:#929bb7; }
.newton-concept.question { border-color:rgba(245,166,35,.42); background:rgba(245,166,35,.08); }
.newton-concept.question::before { background:var(--orange); }
.newton-concept.reframe { border-color:rgba(41,184,166,.42); background:rgba(41,184,166,.07); }
.newton-concept.reframe::before { background:var(--teal); }
.newton-concept small { color:#aeb6cf; font-size:.69rem; font-weight:900; letter-spacing:.14em; text-transform:uppercase; }
.newton-concept p { margin:5px 0 0; color:#f3f5fb; font-weight:720; line-height:1.38; }
.newton-role-note { margin:5px 1px 0; color:#aeb6cf; font-size:.86rem; }
.newton-role-note b { color:#fff; }
.newton-launch-button { white-space:nowrap; background:var(--orange) !important; border-color:var(--orange) !important; color:#271708 !important; padding:11px 17px !important; }
.newton-preview[hidden], .newton-interface[hidden], .newton-live[hidden], .newton-launcher .demo-caption[hidden] { display:none; }
.newton-live-toolbar { min-height:52px; padding:8px 13px; display:flex; align-items:center; justify-content:space-between; gap:12px; border-bottom:1px solid rgba(255,255,255,.12); background:#11172b; }
.newton-live-toolbar button, .newton-live-toolbar a { border:0; background:transparent; color:#e6e9f5; font-size:.8rem; font-weight:800; text-decoration:none; cursor:pointer; }
.newton-live-toolbar button:hover, .newton-live-toolbar a:hover { color:var(--orange); }
.newton-live iframe { display:block; width:100%; height:clamp(580px,75vh,760px); border:0; background:#f7f7f7; }

.curriculum-section { background:#fff9ed; }
.curriculum-intro { align-items:start; }
.curriculum-grid { display:grid; grid-template-columns:repeat(3,minmax(0,1fr)); gap:16px; }
.curriculum-card { --card-accent:var(--violet); min-height:320px; padding:28px; display:flex; flex-direction:column; border:1px solid var(--line); border-radius:24px; background:#fff; box-shadow:0 16px 40px rgba(16,21,38,.07); position:relative; overflow:hidden; }
.curriculum-card::before { content:""; position:absolute; inset:0 0 auto; height:5px; background:var(--card-accent); }
.curriculum-card:nth-child(2), .curriculum-card:nth-child(5) { --card-accent:var(--orange); }
.curriculum-card:nth-child(3), .curriculum-card:nth-child(6) { --card-accent:var(--teal); }
.curriculum-card h3 { font-size:clamp(1.45rem,2vw,1.9rem); }
.curriculum-card > p:not(.curriculum-kicker) { color:var(--muted); line-height:1.52; }
.curriculum-kicker { margin:0 0 22px; color:var(--card-accent); font-size:.68rem; font-weight:900; letter-spacing:.12em; text-transform:uppercase; }
.concept-tags { margin-top:auto; padding-top:20px; display:flex; flex-wrap:wrap; gap:7px; }
.concept-tags span { padding:5px 9px; border-radius:99px; background:#f3f2f8; color:#555b70; font-size:.7rem; font-weight:800; }
.example-investigations { margin:32px 0 0; padding:22px 25px; border:1px solid var(--line); border-radius:20px; background:rgba(255,255,255,.68); color:var(--muted); }
.example-investigations b { color:var(--ink); }
.course-format { margin-top:20px; padding:30px; display:grid; grid-template-columns:.45fr 1fr 1.25fr; gap:24px; align-items:start; border-radius:24px; background:var(--midnight); color:#fff; }
.course-format .eyebrow, .course-format h3, .course-format p { margin-bottom:0; }
.course-format h3 { font-size:1.45rem; }
.course-format > p:last-child { color:#b8bfd2; }
.sequence { display:grid; grid-template-columns:repeat(7,1fr); gap:9px; margin-top:45px; }
.sequence span { min-height:100px; border-radius:18px; padding:13px 9px; background:#fff; border:1px solid var(--line); display:grid; place-items:center; text-align:center; font-weight:850; position:relative; }
.sequence span:not(:last-child)::after { content:"→"; position:absolute; right:-10px; z-index:2; color:var(--orange-deep); }
/* Must follow .sequence: same specificity, so the later rule is the one that wins. */
.inquiry-sequence { grid-template-columns:repeat(5,1fr); }
.split { display:grid; grid-template-columns:1fr 1fr; gap:clamp(28px,6vw,85px); align-items:center; }
.tile-grid { display:grid; grid-template-columns:repeat(3,1fr); gap:16px; }
.tile { border:1px solid var(--line); border-radius:22px; padding:24px; background:#fff; }
.tile[href] { color:var(--ink); text-decoration:none; transition:transform .2s ease, box-shadow .2s ease; }
.tile[href]:hover { transform:translateY(-3px); box-shadow:0 18px 45px rgba(16,21,38,.11); }
.tile .num { color:var(--orange-deep); font-weight:900; font-size:.75rem; letter-spacing:.12em; }
.tile p { margin-bottom:0; color:var(--muted); }
.tile strong { display:block; margin-top:20px; color:var(--orange-deep); }
.experience-grid .experience-featured { grid-column:1/-1; justify-self:center; width:calc((100% - 32px) / 3); }
.modes .tile { position: relative; min-height: 210px; padding-top: 64px; }
.mode-symbol { position: absolute; left: 24px; top: 20px; display: grid; place-items: center; width: 34px; height: 34px; border-radius: 50%; background: #fff0d6; color: var(--orange-deep); font-weight: 900; }
.gallery-strip { display:grid; grid-template-columns:1.2fr .8fr .8fr; gap:12px; }
.gallery-strip figure { margin:0; border-radius:22px; overflow:hidden; min-height:380px; position:relative; background:#ddd; }
.gallery-strip img { width:100%; height:100%; object-fit:cover; position:absolute; }
.gallery-strip figcaption { position:absolute; z-index:2; inset:auto 10px 10px; padding:10px 12px; border-radius:14px; background:rgba(10,14,28,.75); backdrop-filter:blur(10px); color:#fff; font-weight:750; font-size:.85rem; }

.compare { display:grid; grid-template-columns:1fr auto 1fr; gap:20px; align-items:center; }
.compare-card { min-height:350px; border-radius:var(--radius); padding:35px; border:1px solid var(--line); background:#fff; color:var(--ink); }
.compare-card.trail { background:var(--midnight); color:#fff; }
.compare-card ul { list-style:none; padding:0; margin:30px 0 0; display:grid; gap:10px; }
.compare-card li { padding:10px 0; border-bottom:1px solid var(--line); }
.compare-card.trail li { border-color:rgba(255,255,255,.13); }
.compare-arrow { font-size:2rem; color:var(--orange-deep); }
.human-ai { display:grid; grid-template-columns:1fr 1fr; border-radius:var(--radius); overflow:hidden; box-shadow:var(--shadow); }
.human-ai > div { padding:clamp(28px,5vw,60px); }
.human-ai .human { background:#fff3dc; color:var(--ink); }
.human-ai .ai { background:#1c2340; color:#fff; }
.human-ai ul { padding-left:18px; columns:2; }
.human-ai .flow { margin-top:25px; height:4px; background:linear-gradient(90deg,var(--orange),var(--pink),var(--violet),var(--teal)); border-radius:9px; position:relative; }
.human-ai .flow::after { content:"›"; position:absolute; right:-4px; top:-23px; font-size:2rem; color:var(--teal); }
.real-world-copy { max-width:900px; margin:34px auto 0; color:#c5cbdd; font-size:1.05rem; }
.real-world-copy p:last-child { margin-bottom:0; }

.callout { border-radius:var(--radius); padding:clamp(34px,6vw,72px); background:#fff1d7; color:var(--ink); display:flex; align-items:center; justify-content:space-between; gap:30px; }
.callout h2 { max-width:700px; margin-bottom:0; }
.inverse .callout .button { background:var(--midnight); color:#fff; }
.site-footer { background:var(--midnight); color:#fff; padding:70px 0 30px; }
.footer-grid { display:grid; grid-template-columns:1.3fr repeat(3,1fr); gap:45px; }
.footer-grid h3 { font-size:1rem; letter-spacing:0; }
.footer-grid a { display:block; color:#bac1d5; text-decoration:none; margin:9px 0; }
.footer-grid a:hover { color:#fff; }
.footer-brand p { color:#aeb6ca; max-width:330px; }
.footer-bottom { display:flex; justify-content:space-between; gap:20px; padding-top:34px; margin-top:42px; border-top:1px solid rgba(255,255,255,.12); color:#929bb3; font-size:.85rem; }

@media (max-width: 920px) {
  .menu-toggle { display:block; }
  .site-nav { display:none; position:absolute; top:69px; left:20px; right:20px; padding:14px; background:#fff; border:1px solid var(--line); border-radius:22px; box-shadow:var(--shadow); flex-direction:column; align-items:stretch; }
  .site-nav.open { display:flex; }
  .site-nav a { padding:11px 13px; }
  .site-nav .join { margin-left:0; text-align:center; }
  .lang { margin:7px 0 0; max-width:none; }
  .hero-grid, .section-intro, .split { grid-template-columns:1fr; }
  .hero { min-height:auto; }
  .hero-visual { min-height:500px; }
  .course-grid { grid-template-columns:1fr; }
  .course-card { min-height:560px; }
  .newton-interface { grid-template-columns:1fr; }
  .newton-scene { min-height:360px; }
  .curriculum-grid { grid-template-columns:1fr 1fr; }
  .course-format { grid-template-columns:1fr; gap:12px; }
  .sequence { grid-template-columns:repeat(4,1fr); }
  .inquiry-sequence { grid-template-columns:repeat(3,1fr); }
  .sequence span:not(:last-child)::after { display:none; }
  .tile-grid { grid-template-columns:1fr 1fr; }
  .experience-grid .experience-featured { width:calc((100% - 16px) / 2); }
  .gallery-strip { grid-template-columns:1fr 1fr; }
  .gallery-strip figure:first-child { grid-column:1/-1; }
  .compare { grid-template-columns:1fr; }
  .compare-arrow { transform:rotate(90deg); justify-self:center; }
  .footer-grid { grid-template-columns:1fr 1fr; }
}

/* Laptop and split-pane windows need the whole opening thought at once. */
@media (min-width: 921px) and (max-height: 820px) {
  .hero {
    min-height: calc(100svh - 76px);
    padding-top: 34px;
    padding-bottom: 34px;
  }
  .hero-grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(350px, .85fr);
    gap: clamp(28px, 4vw, 54px);
  }
  .hero h1 {
    font-size: clamp(3.35rem, 5vw, 4rem);
    margin-bottom: 18px;
  }
  .hero .lead { font-size: 1.05rem; }
  .hero .button-row { margin-top: 22px; }
  .hero-visual { min-height: 500px; }
}

@media (max-width: 600px) {
  :root { --shell: min(100% - 26px, 1180px); --radius:22px; }
  .brand small { display:none; }
  .hero-grid { gap:15px; }
  .hero-visual { min-height:390px; }
  .hero-question { padding:22px; }
  .path-prompt { grid-template-columns:1fr; }
  .path-prompt i { transform:rotate(90deg); justify-self:center; }
  .world-stage { min-height:0; display:flex; flex-direction:column; background:#0a0e1c; }
  .world-stage::after { display:none; }
  .world-image { position:relative; inset:auto; height:240px; min-height:0; flex:none; object-position:center; }
  .world-copy { padding: 34px 24px; max-width:none; }
  .world-steps > span { grid-template-columns: 1fr; gap: 6px; }
  .world-steps b { justify-self: start; }
  .path-legend { display: none; }
  .world-orb.one { width:190px; height:190px; right:-10%; top:45%; }
  .world-orb.two { bottom:7%; }
  .course-card { min-height:520px; }
  .demo-media { min-height:400px; }
  .demo-caption { align-items:flex-start; flex-direction:column; }
  .newton-preview { min-height:0; grid-template-columns:1fr; }
  .newton-preview-scene { min-height:245px; }
  .newton-preview-label { left:18px; top:17px; }
  .newton-earth { width:350px; height:350px; left:-170px; bottom:-225px; }
  .newton-orbit { width:285px; height:165px; left:13%; top:24%; }
  .newton-moon { width:48px; height:48px; }
  .newton-apple { top:38%; }
  .fall-line { top:41%; height:95px; }
  .newton-preview-thinking { padding:20px; gap:9px; }
  .newton-concept { padding:13px 14px 13px 19px; }
  .newton-concept p { font-size:.89rem; }
  .newton-role-note { font-size:.78rem; }
  .newton-launch-button { white-space:normal; }
  .newton-live-toolbar { align-items:flex-start; flex-direction:column; }
  .newton-live iframe { height:560px; }
  .curriculum-grid { grid-template-columns:1fr; }
  .curriculum-card { min-height:0; padding:24px; }
  .example-investigations { padding:19px; font-size:.9rem; }
  .course-format { padding:24px; }
  .thinking-trail { grid-template-columns:repeat(3,1fr); }
  .sequence { grid-template-columns:1fr 1fr; }
  .real-world-flow { grid-template-columns:1fr !important; }
  .tile-grid, .gallery-strip, .human-ai, .footer-grid { grid-template-columns:1fr; }
  .experience-grid .experience-featured { grid-column:auto; width:100%; }
  .gallery-strip figure:first-child { grid-column:auto; }
  .gallery-strip figure { min-height:300px; }
  .human-ai ul { columns:1; }
  .callout { align-items:flex-start; flex-direction:column; }
  .footer-bottom { flex-direction:column; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior:auto; }
  *, *::before, *::after { animation-duration:.001ms !important; animation-iteration-count:1 !important; transition-duration:.001ms !important; }
  .path-route, .orbit-path.hot { stroke-dashoffset:0; }
  .newton-scene .apple { transform:translateY(90px); }
}

/* ── Intro deck on the approach page ───────────────────────────────────────
   The deck ships its own stylesheet (intro/intro.css), written for the older
   site's tokens and for a standalone dark page. Two things to bridge here:
   the handful of tokens reform.css does not define, and <html>, which
   intro.css paints dark for its own page — on a bright reform page the deck
   is one section, so the page keeps its own ground until presenting starts. */
html { background: var(--paper); }
body.presenting { background: #100d22; }

body[data-page="approach"] {
  --surface: #ffffff;
  --ink-soft: #443c63;
  --gold-ink: #a4650a;
  --program-story-opening-background:
    radial-gradient(circle at 78% 18%, rgba(117, 101, 221, .12), transparent 34%),
    radial-gradient(circle at 12% 82%, rgba(245, 166, 35, .12), transparent 30%),
    linear-gradient(145deg, #fffdf8 0%, #fff7eb 55%, #f7f2ff 100%);
}

body[data-page="approach"] .site-header { z-index: 110; }

/* reform.css loads after intro.css, so the site's underlined link style would
   otherwise reach the switch bar's tabs. */
.program-story-switch a { text-decoration: none; }

/* Presenting is fullscreen: the page chrome would sit on top of the slide
   (the deck is fixed at z-index 100 and the header above it at 110), so the
   approach page hands the whole viewport to the deck. Exit is the deck's own
   button, or Esc. */
body[data-page="approach"].presenting .site-header,
body[data-page="approach"].presenting .program-story-switch { display: none; }