/* Wave Young 2026 — shared stylesheet (festival = light, hackathon = dark) */
@font-face { font-family: "Inter"; src: url("../fonts/inter.woff2") format("woff2"); font-weight: 100 900; font-display: swap; }
@font-face { font-family: "Space Grotesk"; src: url("../fonts/spacegrotesk.woff2") format("woff2"); font-weight: 300 700; font-display: swap; }
@font-face { font-family: "JetBrains Mono"; src: url("../fonts/jetbrainsmono.woff2") format("woff2"); font-weight: 100 800; font-display: swap; }

:root {
  --bg: #F7F7F5; --bg2: #FFFFFF; --ink: #111318; --ink2: #2A2E38; --mute: #5B606B; --line: #E3E3DE; --line2: #D2D2CC;
  --blue: #2B6BFF; --violet: #8A3DFF; --cyan: #00C2FF; --pink: #D63CFF;
  --grad: linear-gradient(90deg, var(--cyan) 0%, var(--blue) 40%, var(--violet) 75%, var(--pink) 100%);
  --sans: "Inter", -apple-system, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", system-ui, sans-serif;
  --disp: "Space Grotesk", "Inter", -apple-system, "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  --r: 14px; --r2: 22px; --max: 1180px; --gut: 20px; --nav: 64px;
  --shadow: 0 1px 2px rgba(17,19,24,.04), 0 12px 40px -18px rgba(17,19,24,.18);
}
html[data-theme="dark"] {
  --bg: #0B0F1A; --bg2: #111726; --ink: #F2F4F8; --ink2: #D7DCE6; --mute: #98A2B8; --line: #1E2637; --line2: #2A3448;
  --shadow: 0 1px 2px rgba(0,0,0,.4), 0 16px 48px -20px rgba(0,0,0,.7);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--ink); font-family: var(--sans); font-size: 17px; line-height: 1.55; -webkit-font-smoothing: antialiased; overflow-x: hidden; }
html[lang="zh"] body { font-size: 16px; }
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
h1, h2, h3, h4 { margin: 0; font-weight: 600; letter-spacing: -.02em; line-height: 1.1; }
h1 { font-family: var(--disp); font-size: clamp(44px, 7.4vw, 96px); font-weight: 700; letter-spacing: -.035em; line-height: .98; }
h2 { font-size: clamp(30px, 4.2vw, 48px); }
h3 { font-size: clamp(20px, 2.2vw, 26px); }
p { margin: 0 0 1em; }
p.lead { font-size: clamp(18px, 1.5vw, 21px); color: var(--ink2); max-width: 46ch; }
.mute { color: var(--mute); }
.kicker { display: inline-flex; align-items: center; gap: 10px; font-family: var(--mono); font-size: 12px; letter-spacing: .12em; text-transform: uppercase; color: var(--mute); margin-bottom: 18px; }
.kicker::before { content: ""; width: 22px; height: 2px; background: var(--grad); border-radius: 2px; }
.grad-text { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.wrap { max-width: var(--max); margin: 0 auto; padding: 0 var(--gut); }
section { padding: clamp(72px, 9vw, 130px) 0; }
section + section { border-top: 1px solid var(--line); }
.center { text-align: center; }

/* nav */
.nav { position: sticky; top: 0; z-index: 50; height: var(--nav); background: color-mix(in srgb, var(--bg) 82%, transparent); backdrop-filter: saturate(160%) blur(14px); -webkit-backdrop-filter: saturate(160%) blur(14px); border-bottom: 1px solid var(--line); }
.nav .wrap { height: 100%; display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.brand { display: flex; align-items: center; gap: 10px; font-family: var(--disp); font-weight: 700; letter-spacing: -.01em; font-size: 17px; white-space: nowrap; }
.brand svg { width: 34px; height: 24px; }
.brand small { font-family: var(--mono); font-weight: 500; font-size: 11px; color: var(--mute); letter-spacing: .08em; margin-left: 4px; }
.nav-links { display: flex; gap: 26px; font-size: 14.5px; font-weight: 500; color: var(--ink2); }
.nav-links a:hover { color: var(--ink); }
.nav-right { display: flex; align-items: center; gap: 10px; }
.lang { display: inline-flex; border: 1px solid var(--line2); border-radius: 999px; padding: 3px; font-family: var(--mono); font-size: 12px; }
.lang button { white-space: nowrap; border: 0; background: transparent; color: var(--mute); padding: 5px 10px; border-radius: 999px; cursor: pointer; font: inherit; }
.lang button.active { background: var(--ink); color: var(--bg); }
.burger { display: none; width: 40px; height: 40px; border: 1px solid var(--line2); border-radius: 10px; background: transparent; cursor: pointer; color: var(--ink); }
.burger svg { width: 20px; height: 20px; }
.mobile-menu { display: none; position: fixed; inset: var(--nav) 0 0 0; background: var(--bg); z-index: 49; padding: 24px var(--gut); flex-direction: column; gap: 6px; font-size: 22px; font-weight: 600; }
.mobile-menu a { padding: 12px 0; border-bottom: 1px solid var(--line); }
.mobile-menu.open { display: flex; }

/* buttons */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; height: 50px; padding: 0 22px; border-radius: 999px; font-weight: 600; font-size: 15.5px; border: 1px solid var(--ink); color: var(--ink); background: transparent; cursor: pointer; transition: transform .15s ease, background .15s ease, color .15s ease; white-space: nowrap; font-family: var(--sans); }
.btn:hover { transform: translateY(-1px); }
.btn-primary { background: var(--ink); color: var(--bg); border-color: var(--ink); }
.btn-grad { position: relative; color: #fff; border: 0; background: linear-gradient(90deg, var(--blue), var(--violet)); box-shadow: 0 10px 30px -12px rgba(43,107,255,.6); }
.btn-grad:hover { box-shadow: 0 14px 36px -12px rgba(138,61,255,.7); }
.btn-sm { height: 40px; padding: 0 16px; font-size: 14px; }
.btn[disabled] { opacity: .55; pointer-events: none; }

/* hero */
.hero { position: relative; padding: clamp(56px, 8vw, 110px) 0 clamp(48px, 6vw, 80px); overflow: hidden; }
.hero-grid { display: grid; grid-template-columns: 1.15fr .85fr; gap: clamp(28px, 5vw, 72px); align-items: center; }
.hero h1 .l2 { display: block; }
.hero .meta { display: flex; flex-wrap: wrap; gap: 10px 22px; margin: 26px 0 30px; font-size: 15px; color: var(--ink2); }
.hero .meta span { display: inline-flex; align-items: center; gap: 8px; }
.hero .meta svg { width: 16px; height: 16px; color: var(--mute); }
.hero .ctas { display: flex; flex-wrap: wrap; gap: 12px; }
.hero-media { position: relative; border-radius: var(--r2); overflow: hidden; box-shadow: var(--shadow); aspect-ratio: 4/3.2; }
.hero-media img { width: 100%; height: 100%; object-fit: cover; }
.hero-media .tag { position: absolute; left: 14px; bottom: 14px; background: rgba(255,255,255,.9); color: #111; font-family: var(--mono); font-size: 11px; letter-spacing: .08em; padding: 7px 10px; border-radius: 8px; }
.wave-bg { position: absolute; left: 50%; top: 0; width: 1600px; transform: translateX(-50%); pointer-events: none; opacity: .9; z-index: 0; }
.hero .wrap { position: relative; z-index: 1; }

/* countdown + stats */
.strip { border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); background: var(--bg2); }
.strip .wrap { display: grid; grid-template-columns: auto 1fr; gap: 32px; align-items: center; padding-top: 22px; padding-bottom: 22px; }
.cd { display: flex; gap: 18px; font-family: var(--disp); }
.cd div { display: flex; flex-direction: column; align-items: center; min-width: 54px; }
.cd b { font-size: 34px; font-weight: 700; letter-spacing: -.03em; line-height: 1; font-variant-numeric: tabular-nums; }
.cd small { font-family: var(--mono); font-size: 10.5px; letter-spacing: .1em; text-transform: uppercase; color: var(--mute); margin-top: 6px; }
.stats { display: flex; justify-content: flex-end; gap: clamp(18px, 4vw, 56px); flex-wrap: wrap; }
.stats div { display: flex; flex-direction: column; }
.stats b { font-family: var(--disp); font-size: 28px; font-weight: 700; letter-spacing: -.03em; line-height: 1; }
.stats small { color: var(--mute); font-size: 13px; margin-top: 5px; }

/* story: building */
.story { padding-top: clamp(64px, 8vw, 110px); }
.story-head { max-width: 62ch; margin-bottom: clamp(36px, 5vw, 70px); }
.story-grid { display: grid; grid-template-columns: minmax(300px, 40%) 1fr; gap: clamp(28px, 6vw, 96px); align-items: start; }
.building-wrap { position: sticky; top: calc(var(--nav) + 24px); }
.building { width: 100%; height: auto; display: block; }
.building .ln { fill: none; stroke: var(--ink); stroke-width: 1.4; stroke-linecap: round; stroke-linejoin: round; }
.building .thin { fill: none; stroke: var(--ink); stroke-width: .8; opacity: .55; }
.building .glass { fill: var(--bg2); stroke: var(--ink); stroke-width: .8; opacity: .9; }
.building .floor-hl { fill: url(#gradFill); opacity: 0; transition: opacity .5s ease; }
.building .floor-edge { fill: none; stroke: url(#gradStroke); stroke-width: 2.4; opacity: 0; transition: opacity .5s ease; }
.building g.active .floor-hl { opacity: .28; }
.building g.active .floor-edge { opacity: 1; }
.building .ground { stroke: var(--ink); stroke-width: 1.6; }
.floor-legend { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 8px; margin-top: 18px; }
.floor-legend div { padding: 10px 12px; border: 1px solid var(--line); border-radius: 10px; font-size: 13px; color: var(--mute); transition: all .3s ease; }
.floor-legend div b { display: block; font-family: var(--mono); font-size: 11px; letter-spacing: .1em; color: var(--mute); margin-bottom: 2px; }
.floor-legend div.active { color: var(--ink); border-color: transparent; background: linear-gradient(var(--bg2), var(--bg2)) padding-box, var(--grad) border-box; border: 1px solid transparent; }
.floor-legend div.active b { color: var(--blue); }
.floors { display: flex; flex-direction: column; }
.floor { min-height: 78vh; display: flex; flex-direction: column; justify-content: center; padding: 6vh 0; border-top: 1px solid var(--line); }
.floor:first-child { border-top: 0; }
.floor .tag { font-family: var(--mono); font-size: 12px; letter-spacing: .12em; text-transform: uppercase; color: var(--blue); margin-bottom: 14px; }
.floor h3 { font-size: clamp(28px, 3.4vw, 40px); margin-bottom: 18px; }
.floor p { max-width: 56ch; color: var(--ink2); }
.pills { display: flex; flex-wrap: wrap; gap: 8px; margin: 10px 0 0; padding: 0; list-style: none; }
.pills li { border: 1px solid var(--line2); border-radius: 999px; padding: 7px 13px; font-size: 13.5px; color: var(--ink2); background: var(--bg2); }
.pills.chips li { font-family: var(--mono); font-size: 12px; }
.sub-h { font-family: var(--mono); font-size: 11.5px; letter-spacing: .12em; text-transform: uppercase; color: var(--mute); margin: 26px 0 10px; }
.checks { list-style: none; padding: 0; margin: 14px 0 0; display: grid; gap: 8px; }
.checks li { display: flex; gap: 10px; align-items: flex-start; color: var(--ink2); }
.checks li::before { content: ""; flex: 0 0 18px; height: 18px; margin-top: 4px; border-radius: 50%; background: var(--grad); -webkit-mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='black' stroke-width='3' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M20 6 9 17l-5-5'/%3E%3C/svg%3E") center/70% no-repeat; mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='black' stroke-width='3' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M20 6 9 17l-5-5'/%3E%3C/svg%3E") center/70% no-repeat; }
.day-list { display: grid; gap: 10px; margin-top: 10px; }
.day-list div { border: 1px solid var(--line); background: var(--bg2); border-radius: var(--r); padding: 14px 16px; }
.day-list b { display: block; font-family: var(--mono); font-size: 11.5px; letter-spacing: .1em; color: var(--blue); text-transform: uppercase; margin-bottom: 4px; }
.day-list strong { display: block; font-weight: 600; }
.day-list small { color: var(--mute); }
.hack-card { margin-top: 26px; border-radius: var(--r2); padding: 26px; color: #fff; background: #0B0F1A; position: relative; overflow: hidden; box-shadow: var(--shadow); }
.hack-card::after { content: ""; position: absolute; inset: auto -20% -60% -20%; height: 120%; background: radial-gradient(60% 60% at 50% 60%, rgba(43,107,255,.55), rgba(138,61,255,.25) 50%, transparent 75%); pointer-events: none; }
.hack-card > * { position: relative; z-index: 1; }
.hack-card .k { font-family: var(--mono); font-size: 11.5px; letter-spacing: .12em; text-transform: uppercase; color: #9FB4FF; }
.hack-card h4 { font-family: var(--disp); font-size: clamp(22px, 2.6vw, 30px); margin: 8px 0 8px; letter-spacing: -.02em; }
.hack-card p { color: #C9D1E3; max-width: 52ch; margin-bottom: 18px; }
.hack-card .btn { border-color: #fff; color: #fff; }
.hack-card .btn:hover { background: #fff; color: #0B0F1A; }

/* agenda */
.tabs { display: inline-flex; gap: 4px; border: 1px solid var(--line2); border-radius: 999px; padding: 4px; margin: 6px 0 26px; }
.tabs button { border: 0; background: transparent; font: inherit; font-weight: 600; font-size: 14px; padding: 9px 16px; border-radius: 999px; cursor: pointer; color: var(--mute); }
.tabs button.active { background: var(--ink); color: var(--bg); }
.agenda { display: grid; gap: 0; border: 1px solid var(--line); border-radius: var(--r2); overflow: hidden; background: var(--bg2); }
.agenda .row { display: grid; grid-template-columns: 110px 1fr auto; gap: 18px; padding: 16px 20px; border-top: 1px solid var(--line); align-items: baseline; }
.agenda .row:first-child { border-top: 0; }
.agenda .t { font-family: var(--mono); font-size: 13px; color: var(--mute); letter-spacing: .04em; }
.agenda .w { font-family: var(--mono); font-size: 11px; color: var(--blue); letter-spacing: .1em; }
.note { font-size: 13.5px; color: var(--mute); margin-top: 14px; }

/* venue */
.venue-grid { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(24px, 4vw, 56px); align-items: center; }
.gallery { display: grid; grid-template-columns: 2fr 1fr; grid-template-rows: 1fr 1fr; gap: 10px; }
.gallery img { width: 100%; height: 100%; object-fit: cover; border-radius: var(--r); }
.gallery img:first-child { grid-row: 1 / 3; }
.facts { display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px; margin: 24px 0; }
.facts div { border: 1px solid var(--line); border-radius: 12px; padding: 14px; background: var(--bg2); }
.facts b { display: block; font-family: var(--disp); font-size: 22px; letter-spacing: -.02em; }
.facts small { color: var(--mute); font-size: 12.5px; }
.addr { display: grid; gap: 6px; margin: 10px 0 18px; }
.addr b { font-family: var(--mono); font-size: 11px; letter-spacing: .12em; text-transform: uppercase; color: var(--mute); }
.addr .zh { font-size: 15px; color: var(--ink2); }
.links { display: flex; flex-wrap: wrap; gap: 10px; }

/* partners */
.pgroup { margin-top: 26px; }
.pgroup h4 { font-family: var(--mono); font-size: 11.5px; letter-spacing: .12em; text-transform: uppercase; color: var(--mute); margin-bottom: 10px; }
.wall { display: flex; flex-wrap: wrap; gap: 8px; }
.wall span { border: 1px solid var(--line); background: var(--bg2); border-radius: 10px; padding: 9px 13px; font-size: 14px; color: var(--ink2); }
.wall.big span { font-size: 16px; font-weight: 600; padding: 14px 18px; }

/* cards */
.cards3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
.card { border: 1px solid var(--line); background: var(--bg2); border-radius: var(--r2); padding: 26px; display: flex; flex-direction: column; gap: 10px; box-shadow: var(--shadow); }
.card h3 { font-size: 22px; }
.card p { color: var(--ink2); flex: 1; }
.card .n { font-family: var(--mono); font-size: 12px; color: var(--blue); letter-spacing: .12em; }

/* forms */
form { display: grid; gap: 14px; }
.f2 { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
label.f { display: grid; gap: 6px; font-size: 13px; color: var(--mute); font-weight: 500; }
input, select, textarea { width: 100%; font: inherit; font-size: 16px; color: var(--ink); background: var(--bg2); border: 1px solid var(--line2); border-radius: 12px; padding: 12px 14px; outline: none; transition: border-color .15s ease, box-shadow .15s ease; }
input:focus, select:focus, textarea:focus { border-color: var(--blue); box-shadow: 0 0 0 4px rgba(43,107,255,.15); }
textarea { min-height: 96px; resize: vertical; }
.check { display: flex; gap: 10px; align-items: flex-start; font-size: 14.5px; color: var(--ink2); }
.check input { width: 18px; height: 18px; margin-top: 3px; flex: 0 0 auto; accent-color: var(--blue); }
.seg { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.seg label { border: 1px solid var(--line2); border-radius: 12px; padding: 12px 14px; cursor: pointer; display: flex; gap: 10px; align-items: center; font-size: 15px; background: var(--bg2); }
.seg label:has(input:checked) { border-color: var(--blue); box-shadow: 0 0 0 3px rgba(43,107,255,.15); }
.seg input { width: auto; accent-color: var(--blue); }
.days-check { display: flex; gap: 8px; flex-wrap: wrap; }
.days-check label { border: 1px solid var(--line2); border-radius: 999px; padding: 9px 14px; display: inline-flex; gap: 8px; align-items: center; cursor: pointer; background: var(--bg2); font-size: 14.5px; }
.days-check label:has(input:checked) { border-color: var(--blue); background: rgba(43,107,255,.08); }
.days-check input { width: auto; accent-color: var(--blue); }
.form-wrap { max-width: 720px; }
.form-card { border: 1px solid var(--line); background: var(--bg2); border-radius: var(--r2); padding: clamp(22px, 3vw, 36px); box-shadow: var(--shadow); }
.form-msg { display: none; padding: 26px; border-radius: var(--r); background: var(--bg2); border: 1px solid var(--line); }
.form-msg.show { display: block; }
.form-msg h3 { margin-bottom: 8px; }
.form-err { display: none; color: #C2262E; font-size: 14px; }
.form-err.show { display: block; }
.hidden { display: none !important; }

/* faq */
.faq { display: grid; gap: 0; border-top: 1px solid var(--line); }
.faq details { border-bottom: 1px solid var(--line); }
.faq summary { cursor: pointer; padding: 18px 0; font-weight: 600; font-size: 17px; list-style: none; display: flex; justify-content: space-between; gap: 16px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; font-family: var(--mono); color: var(--mute); flex: 0 0 auto; }
.faq details[open] summary::after { content: "–"; }
.faq p { color: var(--ink2); padding-bottom: 18px; max-width: 70ch; }

/* footer */
footer { border-top: 1px solid var(--line); padding: 48px 0 32px; font-size: 14px; color: var(--mute); }
footer .grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 28px; margin-bottom: 26px; }
footer h4 { font-family: var(--mono); font-size: 11px; letter-spacing: .12em; text-transform: uppercase; color: var(--mute); margin-bottom: 10px; }
footer a { color: var(--ink2); }
footer .line { border-top: 1px solid var(--line); padding-top: 18px; font-size: 12.5px; }
.qr { width: 96px; height: 96px; border: 1px dashed var(--line2); border-radius: 10px; display: grid; place-items: center; font-family: var(--mono); font-size: 10px; color: var(--mute); text-align: center; padding: 6px; }

/* hackathon specifics */
.h-hero { position: relative; padding: clamp(64px, 9vw, 130px) 0 clamp(40px, 5vw, 70px); overflow: hidden; }
.h-hero h1 { max-width: 14ch; }
.h-hero h1 .l2 { display: block; }
.h-hero .grid-bg { position: absolute; inset: 0; background-image: linear-gradient(var(--line) 1px, transparent 1px), linear-gradient(90deg, var(--line) 1px, transparent 1px); background-size: 48px 48px; -webkit-mask-image: radial-gradient(70% 70% at 50% 30%, #000 20%, transparent 100%); mask-image: radial-gradient(70% 70% at 50% 30%, #000 20%, transparent 100%); opacity: .5; }
.h-hero .glow { position: absolute; width: 900px; height: 600px; left: 50%; top: -240px; transform: translateX(-50%); background: radial-gradient(50% 50% at 50% 50%, rgba(43,107,255,.35), rgba(138,61,255,.18) 45%, transparent 70%); filter: blur(20px); pointer-events: none; }
.manifesto { display: flex; flex-wrap: wrap; gap: 8px; margin: 22px 0 8px; }
.manifesto span { font-family: var(--mono); font-size: 12.5px; letter-spacing: .06em; border: 1px solid var(--line2); border-radius: 999px; padding: 7px 12px; color: var(--ink2); }
.manifesto span::before { content: "✓ "; color: var(--cyan); }
.facts6 { display: grid; grid-template-columns: repeat(6, 1fr); gap: 10px; }
.facts6 div { border: 1px solid var(--line); background: var(--bg2); border-radius: 12px; padding: 16px 14px; }
.facts6 b { display: block; font-family: var(--disp); font-size: 26px; letter-spacing: -.02em; }
.facts6 small { color: var(--mute); font-size: 12.5px; }
.prizes { display: grid; grid-template-columns: 1.3fr 1fr 1fr; gap: 12px; }
.prize { border: 1px solid var(--line); background: var(--bg2); border-radius: var(--r2); padding: 26px; position: relative; overflow: hidden; }
.prize.first { background: linear-gradient(var(--bg2), var(--bg2)) padding-box, var(--grad) border-box; border: 1px solid transparent; }
.prize .r { font-family: var(--mono); font-size: 12px; letter-spacing: .12em; color: var(--mute); text-transform: uppercase; }
.prize .v { font-family: var(--disp); font-size: clamp(38px, 5vw, 64px); font-weight: 700; letter-spacing: -.04em; margin-top: 8px; line-height: 1; }
.prize.first .v { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.steps { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; counter-reset: s; }
.step { border: 1px solid var(--line); background: var(--bg2); border-radius: var(--r2); padding: 22px; }
.step .n { font-family: var(--mono); font-size: 12px; color: var(--blue); letter-spacing: .12em; margin-bottom: 10px; }
.step h3 { font-size: 19px; margin-bottom: 8px; }
.step p { color: var(--mute); font-size: 15px; margin: 0; }
.sched { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.sched .day { border: 1px solid var(--line); background: var(--bg2); border-radius: var(--r2); overflow: hidden; }
.sched .day h3 { font-family: var(--mono); font-weight: 500; font-size: 13px; letter-spacing: .1em; text-transform: uppercase; padding: 16px 20px; border-bottom: 1px solid var(--line); color: var(--mute); }
.term { font-family: var(--mono); font-size: 12px; color: var(--mute); }
.term::before { content: "$ "; color: var(--cyan); }
.two { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(24px, 4vw, 56px); align-items: start; }
.logi { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.logi div { border: 1px solid var(--line); background: var(--bg2); border-radius: var(--r); padding: 16px; }
.logi b { display: block; margin-bottom: 4px; }
.logi p { margin: 0; color: var(--mute); font-size: 14.5px; }

/* reveal */
.rv { opacity: 0; transform: translateY(14px); transition: opacity .6s ease, transform .6s ease; }
.rv.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) { .rv { opacity: 1; transform: none; transition: none; } html { scroll-behavior: auto; } }

/* responsive */
@media (max-width: 980px) {
  .hero-grid { grid-template-columns: 1fr; }
  .hero-media { aspect-ratio: 16/10; }
  .story-grid { grid-template-columns: 1fr; gap: 0; }
  .building-wrap { position: sticky; top: var(--nav); z-index: 5; background: var(--bg); padding: 12px 0 10px; border-bottom: 1px solid var(--line); display: grid; grid-template-columns: 96px 1fr; gap: 14px; align-items: center; }
  .building { width: 96px; }
  .floor-legend { margin-top: 0; grid-template-columns: 1fr 1fr 1fr; gap: 6px; }
  .floor-legend div { padding: 8px 8px; font-size: 11.5px; }
  .floor { min-height: 0; padding: 48px 0; }
  .venue-grid, .two, .sched { grid-template-columns: 1fr; }
  .cards3, .steps { grid-template-columns: 1fr 1fr; }
  .facts6 { grid-template-columns: repeat(3, 1fr); }
  .prizes { grid-template-columns: 1fr; }
  footer .grid { grid-template-columns: 1fr 1fr; }
  .strip .wrap { grid-template-columns: 1fr; gap: 18px; }
  .stats { justify-content: flex-start; }
}
@media (max-width: 720px) {
  .nav-links { display: none; }
  .nav .nav-right .btn { display: none; }
  .brand small { display: none; }
  .lang button { padding: 5px 8px; }
  .wave-bg { width: 1000px; }
  .burger { display: inline-grid; place-items: center; }
  .cards3, .steps, .facts, .logi, .f2, .seg { grid-template-columns: 1fr; }
  .facts { grid-template-columns: 1fr 1fr; }
  .facts6 { grid-template-columns: 1fr 1fr; }
  .agenda .row { grid-template-columns: 1fr; gap: 4px; }
  .gallery { grid-template-columns: 1fr; grid-template-rows: auto; }
  .gallery img:first-child { grid-row: auto; }
  .gallery img { aspect-ratio: 16/10; }
  footer .grid { grid-template-columns: 1fr; }
  .cd b { font-size: 28px; }
  .cd { gap: 12px; }
  .hero .ctas .btn { width: 100%; }
  .floor-legend div b { font-size: 10px; }
  .floor-legend div span { display: none; }
}

/* official logo + split hero (2026-09-23 v2) */
.logo-nav { height: 30px; width: auto; }
.lockup { width: min(520px, 78vw); height: auto; margin: 0 0 8px -2%; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.hero-top { max-width: 720px; }
.hero-top .meta { margin: 8px 0 18px; }
.split { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-top: 34px; }
.panel { border-radius: var(--r2); border: 1px solid var(--line); background: var(--bg2); overflow: hidden; display: flex; flex-direction: column; box-shadow: var(--shadow); }
.panel .k { font-family: var(--mono); font-size: 11.5px; letter-spacing: .12em; text-transform: uppercase; color: #9FB4FF; margin-bottom: 12px; }
.panel h2 { font-family: var(--disp); font-size: clamp(26px, 2.8vw, 36px); letter-spacing: -.025em; margin-bottom: 12px; }
.panel p { color: var(--ink2); max-width: 46ch; }
.panel .ctas { display: flex; flex-wrap: wrap; gap: 10px; margin-top: auto; padding-top: 18px; }
.panel .pills { margin-bottom: 6px; }
.panel-hack { padding: 30px; position: relative; background: linear-gradient(var(--bg2), var(--bg2)) padding-box, var(--grad) border-box; border: 1px solid transparent; }
.panel-hack::after { content: ""; position: absolute; inset: auto -20% -50% -20%; height: 110%; background: radial-gradient(60% 60% at 50% 60%, rgba(43,107,255,.45), rgba(138,61,255,.2) 50%, transparent 75%); pointer-events: none; }
.panel-hack > * { position: relative; z-index: 1; }
.panel-fest img { width: 100%; aspect-ratio: 16/8; object-fit: cover; }
.panel-body { padding: 26px 30px 30px; display: flex; flex-direction: column; flex: 1; }
.hack-card { border: 1px solid var(--line); }
@media (max-width: 980px) { .split { grid-template-columns: 1fr; } }
@media (max-width: 720px) { .panel-hack, .panel-body { padding: 22px; } .panel .ctas .btn { width: 100%; } .hero-top .meta b, .hero-top .meta span { font-size: 14px; } }

/* ================= v3 (2026-09-23): fonts, sizes, video hero, podium, logos, VIP ================= */
@font-face { font-family: "WY Display"; src: url("../fonts/chakrapetch-700.woff2") format("woff2"); font-weight: 700 900; font-display: swap; }
@font-face { font-family: "WY Display"; src: url("../fonts/chakrapetch-600.woff2") format("woff2"); font-weight: 500 600; font-display: swap; }
@font-face { font-family: "DM Sans"; src: url("../fonts/dmsans.woff2") format("woff2"); font-weight: 100 1000; font-display: swap; }
:root { --sans: "DM Sans", -apple-system, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans CJK SC", system-ui, sans-serif; --disp: "WY Display", "DM Sans", -apple-system, "PingFang SC", "Microsoft YaHei", system-ui, sans-serif; --r: 12px; --r2: 18px; }
body { font-size: 18px; line-height: 1.5; }
html[lang="zh"] body { font-size: 17px; }
h1, h2, h3, h4 { font-family: var(--disp); font-weight: 800; letter-spacing: 0; line-height: 1.02; text-transform: uppercase; }
h2 { font-size: clamp(30px, 3.6vw, 46px); }
h3 { font-size: clamp(20px, 2vw, 26px); }
html[lang="zh"] h1, html[lang="zh"] h2, html[lang="zh"] h3, html[lang="zh"] h4 { font-family: var(--sans); font-weight: 800; letter-spacing: -.01em; }
p.lead { font-size: clamp(19px, 1.5vw, 22px); }
.kicker { font-family: var(--disp); font-weight: 700; font-size: 13px; letter-spacing: .14em; }
.sub-h, .day-list b, .prize .r, .step .n, .card .n, .agenda .t, .agenda .w, .floor .tag, .panel .k, .hack-card .k, .cd small, .addr b, .pgroup h4, footer h4, .hero-media .tag, .term, .manifesto span { font-family: var(--disp); font-weight: 700; font-size: 12.5px; letter-spacing: .12em; }
.agenda .t { font-family: var(--mono); font-weight: 500; font-size: 14px; letter-spacing: .04em; }
.floor .tag { font-size: 13px; }
.brand { font-family: var(--disp); font-weight: 800; font-size: 15px; letter-spacing: .04em; text-transform: uppercase; }
.brand small { font-family: var(--disp); font-size: 11px; letter-spacing: .14em; }
.nav-links { gap: 6px; font-size: 15.5px; font-weight: 600; }
.nav-links a { padding: 8px 12px; border: 1px solid transparent; border-radius: 6px; transition: border-color .15s ease; }
.nav-links a:hover { border-color: var(--ink); color: var(--ink); }
.lang { border-radius: 8px; padding: 3px; font-family: var(--disp); font-weight: 700; font-size: 12px; }
.lang button { border-radius: 5px; }
.btn { border-radius: 8px; height: 54px; padding: 0 24px; font-size: 16.5px; font-weight: 700; }
.btn-sm { height: 42px; padding: 0 16px; font-size: 14.5px; }
.tabs { border-radius: 8px; padding: 4px; gap: 4px; }
.tabs button { border-radius: 5px; font-size: 15px; font-family: var(--disp); font-weight: 700; letter-spacing: .02em; }
.pills li, .wall span { border-radius: 8px; font-size: 15px; }
.pills.chips li { font-family: var(--disp); font-weight: 600; font-size: 13px; letter-spacing: .04em; }
.stats b, .cd b, .facts b, .facts6 b, .prize .v { font-family: var(--disp); font-weight: 800; }
.stats small, .facts small, .facts6 small { font-size: 14px; }
.days-check label, .seg label, input, select, textarea { border-radius: 8px; }
.floor-legend div, .floor-legend a { display: block; border-radius: 8px; font-size: 14px; color: var(--mute); }
.floor-legend a { padding: 10px 12px; border: 1px solid var(--line); transition: all .3s ease; }
.floor-legend a b { display: block; font-family: var(--disp); font-weight: 700; font-size: 12px; letter-spacing: .12em; color: var(--mute); margin-bottom: 2px; }
.floor-legend a.active { color: var(--ink); border: 1px solid transparent; background: linear-gradient(var(--bg2), var(--bg2)) padding-box, var(--grad) border-box; }
.floor-legend a.active b { color: var(--blue); }
.floor-legend a:hover { border-color: var(--ink2); }
.floor-cta { margin-top: 22px; align-self: flex-start; }
.link { font-weight: 600; color: var(--ink2); padding: 12px 4px; }
.link:hover { color: var(--ink); }

/* hero v3: hackathon | video | festival */
.wrap.wide { max-width: 1440px; }
.hero3 { padding: clamp(28px, 4vw, 56px) 0 clamp(36px, 5vw, 64px); position: relative; overflow: hidden; }
.hero-glow { position: absolute; left: 50%; top: 10%; width: 1200px; height: 700px; transform: translateX(-50%); background: radial-gradient(45% 45% at 50% 50%, rgba(43,107,255,.28), rgba(138,61,255,.14) 50%, transparent 72%); filter: blur(30px); pointer-events: none; }
.hero3 .wrap { position: relative; }
.hero-head { display: flex; align-items: flex-end; justify-content: space-between; gap: 24px; flex-wrap: wrap; margin-bottom: clamp(18px, 3vw, 36px); }
.hero-head .lockup { width: min(320px, 60vw); margin: 0; }
.hero-head .meta { display: flex; flex-wrap: wrap; gap: 6px 22px; font-size: 16px; color: var(--ink2); padding-bottom: 8px; }
.hero-head .meta b { color: var(--ink); }
.hero-grid3 { display: grid; grid-template-columns: minmax(280px, 1fr) minmax(0, 1.9fr) minmax(280px, 1fr); gap: clamp(20px, 3vw, 48px); align-items: center; }
.hcol { display: flex; flex-direction: column; }
.hcol h2 { font-size: clamp(24px, 2.2vw, 32px); margin-bottom: 14px; }
.hcol p { color: var(--ink2); font-size: 16.5px; }
.hcol .checks { margin: 4px 0 0; font-size: 16px; }
.hcol .ctas { display: flex; flex-direction: column; align-items: flex-start; gap: 6px; margin-top: 22px; }
.hcol-fest { text-align: left; }
.hero-video { position: relative; border-radius: var(--r2); overflow: hidden; aspect-ratio: 16/9; background: #05070d; box-shadow: 0 40px 120px -40px rgba(43,107,255,.55), 0 10px 40px -20px rgba(0,0,0,.8); }
.hero-video::before { content: ""; position: absolute; inset: 0; z-index: 2; pointer-events: none; box-shadow: inset 0 0 80px 30px rgba(11,15,26,.45); }
.hero-video video { width: 100%; height: 100%; object-fit: cover; display: block; }
.organizer { font-size: 14px; margin-top: 26px; text-align: center; }
/* podium */
.podium { display: grid; grid-template-columns: 1fr 1.15fr 1fr; gap: 6px; align-items: end; margin: 6px 0 16px; height: 128px; }
.podium .step { border-radius: 8px 8px 4px 4px; background: var(--bg2); border: 1px solid var(--line); display: flex; flex-direction: column; justify-content: flex-end; padding: 10px 10px 10px; text-align: center; }
.podium .step b { font-family: var(--disp); font-weight: 800; font-size: 18px; letter-spacing: -.01em; }
.podium .step span { font-family: var(--disp); font-weight: 700; font-size: 11px; letter-spacing: .14em; color: var(--mute); margin-top: 3px; text-transform: uppercase; }
.podium .s1 { height: 100%; background: linear-gradient(var(--bg2), var(--bg2)) padding-box, var(--grad) border-box; border: 1px solid transparent; }
.podium .s1 b { font-size: 22px; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.podium .s2 { height: 74%; }
.podium .s3 { height: 56%; }
/* logos */
.logos { display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: 10px; }
.logo { background: #fff; border-radius: 8px; height: 68px; display: grid; place-items: center; padding: 10px 14px; }
.logo img { max-height: 46px; max-width: 100%; width: auto; object-fit: contain; }
/* section spacing tighter */
section { padding: clamp(64px, 8vw, 112px) 0; }
@media (max-width: 1100px) {
  .hero-grid3 { grid-template-columns: 1fr 1fr; }
  .hero-video { grid-column: 1 / -1; grid-row: 1; }
}
@media (max-width: 720px) {
  .hero-grid3 { grid-template-columns: 1fr; }
  .hero-video { grid-column: auto; grid-row: auto; border-radius: 12px; }
  .hero-head { flex-direction: column; align-items: flex-start; }
  .hcol .ctas .btn { width: 100%; }
  .logos { grid-template-columns: repeat(2, 1fr); }
  .podium { height: 110px; }
}

/* v3.1 hero compaction */
.hero3 { padding-top: clamp(20px, 2.6vw, 34px); }
.hero-head { margin-bottom: clamp(10px, 1.6vw, 20px); align-items: center; }
.hero-head .lockup { width: min(230px, 50vw); }
.hero-head .meta { padding-bottom: 0; }
.hero-grid3 { grid-template-columns: minmax(260px, .9fr) minmax(0, 2fr) minmax(260px, .9fr); }
.hcol h2 { font-size: clamp(22px, 1.9vw, 28px); }
.hcol p, .hcol .checks { font-size: 15.5px; }
.podium { height: 108px; margin-bottom: 12px; }
.hcol .ctas { margin-top: 16px; }
.organizer { margin-top: 18px; }
/* v3.2 responsive overrides (must stay last) */
@media (max-width: 1100px) { .hero-grid3 { grid-template-columns: 1fr 1fr; } .hero-video { grid-column: 1 / -1; grid-row: 1; } }
@media (max-width: 720px) { .hero-grid3 { grid-template-columns: 1fr; gap: 28px; } .hero-video { grid-column: auto; grid-row: auto; } .hcol h2 { font-size: 24px; } .podium { height: 104px; } .podium .step b { font-size: 16px; } .podium .s1 b { font-size: 19px; } }

/* v4: Chakra Petch display, no hero header, central video with faded sides */
h1, h2, h3, h4 { font-weight: 700; letter-spacing: .01em; }
h2 { font-size: clamp(34px, 4.2vw, 56px); }
.kicker, .sub-h, .day-list b, .prize .r, .step .n, .card .n, .floor .tag, .panel .k, .hack-card .k, .cd small, .addr b, .pgroup h4, footer h4, .term, .manifesto span, .brand, .brand small, .lang, .tabs button, .pills.chips li, .floor-legend a b, .podium .step span { font-weight: 700; letter-spacing: .1em; }
.brand { font-size: 17px; letter-spacing: .06em; }
.hero3 { padding-top: clamp(22px, 3vw, 40px); }
.hero-head { display: none; }
.hero-grid3 { grid-template-columns: minmax(240px, .8fr) minmax(0, 2.6fr) minmax(240px, .8fr); gap: clamp(8px, 1.5vw, 24px); align-items: center; }
.hero-video { border-radius: 0; box-shadow: none; -webkit-mask-image: linear-gradient(90deg, transparent 0%, #000 14%, #000 86%, transparent 100%); mask-image: linear-gradient(90deg, transparent 0%, #000 14%, #000 86%, transparent 100%); }
.hero-video::before { box-shadow: inset 0 0 60px 20px rgba(11,15,26,.35); }
.hero-ambient { position: absolute; inset: -10% -5%; background: url("../video/hero-poster.jpg") center/cover no-repeat; filter: blur(60px) saturate(1.2); opacity: .32; pointer-events: none; }
.hero3 .wrap { position: relative; z-index: 1; }
.hcol h2 { font-size: clamp(26px, 2.4vw, 36px); }
.hcol-hack { padding-left: 4px; }
.hcol-fest { padding-right: 4px; }
.video-cap { grid-column: 2; text-align: center; font-family: var(--disp); font-weight: 600; font-size: 13px; letter-spacing: .12em; text-transform: uppercase; color: var(--mute); margin-top: -6px; }
.video-cap b { color: var(--ink2); font-weight: 700; }
@media (max-width: 1100px) { .hero-grid3 { grid-template-columns: 1fr 1fr; gap: 24px; } .hero-video { grid-column: 1 / -1; grid-row: 1; -webkit-mask-image: none; mask-image: none; border-radius: var(--r2); } .video-cap { grid-column: 1 / -1; } }
@media (max-width: 720px) { .hero-grid3 { grid-template-columns: 1fr; } .hero-video { grid-column: auto; grid-row: auto; } .video-cap { grid-column: auto; } }

/* v4.1: hero = exactly one screen, columns pinned top and bottom */
.hero3 { padding: 0; min-height: calc(100vh - var(--nav)); display: flex; }
.hero3 .wrap.wide { display: flex; flex-direction: column; width: 100%; padding-top: 26px; padding-bottom: 26px; }
.hero-grid3 { flex: 1; align-items: stretch; margin-top: 0; }
.hcol { justify-content: space-between; }
.hcol .ctas { margin-top: auto; padding-top: 18px; }
.hcol .checks { margin-bottom: 6px; }
.hero-video { align-self: center; width: 100%; }
.vcap { position: absolute; left: 0; right: 0; bottom: 14px; z-index: 3; text-align: center; font-family: var(--disp); font-weight: 600; font-size: 12.5px; letter-spacing: .12em; text-transform: uppercase; color: rgba(255,255,255,.72); text-shadow: 0 1px 8px rgba(0,0,0,.8); }
.vcap b { color: #fff; font-weight: 700; }
@media (max-height: 760px) { .hcol h2 { font-size: clamp(22px, 2vw, 28px); } .podium { height: 92px; } .hcol p, .hcol .checks { font-size: 15px; } }
@media (max-width: 1100px) { .hero3 { min-height: 0; } .hero3 .wrap.wide { padding-top: 24px; padding-bottom: 40px; } .hcol { justify-content: flex-start; } .hcol .ctas { margin-top: 20px; } .vcap { font-size: 11px; } }

/* v4.2: video fills the full hero height, no caption */
.hero-video { align-self: stretch; aspect-ratio: auto; height: auto; min-height: 0; margin: -26px 0; }
.hero-video video { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }
.vcap { display: none; }
@media (max-width: 1100px) { .hero-video { margin: 0; aspect-ratio: 16/9; align-self: auto; } .hero-video video { position: static; } }

/* v4.3: big column titles, matching buttons, centred countdown, floor verbs */
.hcol h2.big { font-size: clamp(30px, 2.9vw, 44px); line-height: .98; margin-bottom: 10px; }
.hcol .sub { font-family: var(--disp); font-weight: 600; font-size: clamp(15px, 1.2vw, 18px); letter-spacing: .04em; text-transform: uppercase; color: var(--ink2); margin-bottom: 16px; }
.hcol .ctas .btn { min-width: 250px; }
.cdstrip { background: var(--bg); border-top: 1px solid transparent; border-bottom: 1px solid transparent; background: linear-gradient(var(--bg), var(--bg)) padding-box, linear-gradient(90deg, transparent, rgba(43,107,255,.7), rgba(138,61,255,.7), transparent) border-box; position: relative; }
.cdstrip .wrap { display: flex; flex-direction: column; align-items: center; gap: 10px; padding: 36px var(--gut) 34px; }
.cd-head, .cd-foot { font-family: var(--disp); font-weight: 700; font-size: 12.5px; letter-spacing: .16em; text-transform: uppercase; color: var(--mute); }
.cd-foot { color: var(--ink2); }
.cdstrip .cd { display: flex; align-items: baseline; gap: 14px; }
.cdstrip .cd div { min-width: 96px; }
.cdstrip .cd b { font-size: clamp(48px, 6vw, 84px); font-weight: 700; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; line-height: 1; }
.cdstrip .cd small { font-size: 12px; letter-spacing: .18em; margin-top: 8px; }
.cdstrip .cd i { font-style: normal; font-family: var(--disp); font-weight: 700; font-size: clamp(36px, 4.5vw, 64px); color: var(--line2); transform: translateY(-6px); }
@media (max-width: 720px) { .cdstrip .cd { gap: 6px; } .cdstrip .cd div { min-width: 64px; } .cdstrip .cd b { font-size: 40px; } .cdstrip .cd i { font-size: 30px; } }

/* v5: honor prize block, form block */
.honor { margin-top: 18px; border-radius: var(--r2); padding: 24px 26px; border: 1px solid transparent; background: linear-gradient(var(--bg2), var(--bg2)) padding-box, var(--grad) border-box; }
.honor .k { font-family: var(--disp); font-weight: 700; font-size: 12.5px; letter-spacing: .14em; text-transform: uppercase; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; margin-bottom: 8px; }
.honor h3 { margin-bottom: 8px; }
.honor p { color: var(--ink2); max-width: 64ch; margin-bottom: 12px; }
.form-block { border: 1px dashed var(--line2); border-radius: var(--r); padding: 14px 16px 16px; display: grid; gap: 12px; }