/* ByteDance Video AIGC — enterprise showcase
   Design system: graphite + warm paper + oxide accent. Sharp edges, mono labels, editorial rhythm. */

:root{
  --ink:#0A0B0D;
  --ink-2:#12141A;
  --ink-3:#1B1E25;
  --paper:#F7F6F3;
  --paper-2:#EEECE7;
  --white:#FFFFFF;
  --text:#14161A;
  --text-2:#4D5259;
  --text-3:#7A8088;
  --on-dark:#F4F3EF;
  --on-dark-2:#A9AEB6;
  --line:rgba(20,22,26,.14);
  --line-2:rgba(20,22,26,.08);
  --line-d:rgba(255,255,255,.16);
  --line-d2:rgba(255,255,255,.08);
  --accent:#C2471F;
  --accent-2:#DB5A2B;
  --accent-soft:#F4E4DC;
  --steel:#6F7B87;
  --max:1240px;
  --gut:clamp(18px,4vw,56px);
  --r:3px;
  --mono:"SFMono-Regular","Cascadia Mono","Consolas","Liberation Mono",monospace;
  --sans:"Inter","Segoe UI Variable Text","Segoe UI","Helvetica Neue",Arial,sans-serif;
}

*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{
  margin:0;background:var(--paper);color:var(--text);
  font-family:var(--sans);font-size:17px;line-height:1.62;
  -webkit-font-smoothing:antialiased;text-rendering:optimizeLegibility;
}
img{display:block;max-width:100%;height:auto}
a{color:inherit}
::selection{background:var(--accent);color:#fff}

/* ---------- layout ---------- */
.wrap{width:100%;max-width:var(--max);margin:0 auto;padding:0 var(--gut)}
.sec{padding:clamp(56px,7vw,104px) 0}
.sec--tight{padding:clamp(36px,4.5vw,64px) 0}
.sec--dark{background:var(--ink);color:var(--on-dark)}
.sec--ink2{background:var(--ink-2);color:var(--on-dark)}
.sec--paper2{background:var(--paper-2)}
.grid{display:grid;gap:clamp(20px,3vw,40px)}
.g2{grid-template-columns:repeat(2,minmax(0,1fr))}
.g3{grid-template-columns:repeat(3,minmax(0,1fr))}
.g4{grid-template-columns:repeat(4,minmax(0,1fr))}
.split{display:grid;grid-template-columns:minmax(0,1.15fr) minmax(0,.85fr);gap:clamp(28px,5vw,72px);align-items:start}
.split--even{grid-template-columns:repeat(2,minmax(0,1fr))}

/* ---------- type ---------- */
.eyebrow{
  font-family:var(--mono);font-size:11px;letter-spacing:.18em;text-transform:uppercase;
  color:var(--text-3);display:flex;align-items:center;gap:10px;margin:0 0 18px;
}
.eyebrow::before{content:"";width:26px;height:1px;background:currentColor;opacity:.6;flex:none}
.sec--dark .eyebrow,.sec--ink2 .eyebrow{color:var(--on-dark-2)}
h1,h2,h3,h4{margin:0;font-weight:650;letter-spacing:-.026em;line-height:1.06;color:inherit}
h1{font-size:clamp(38px,5.4vw,74px);letter-spacing:-.032em;line-height:1.03}
h2{font-size:clamp(28px,3.1vw,44px);line-height:1.1}
h3{font-size:clamp(21px,1.6vw,25px);line-height:1.25;letter-spacing:-.018em}
h4{font-size:17px;line-height:1.35;letter-spacing:-.01em}
.lede{font-size:clamp(18px,1.32vw,21px);line-height:1.55;color:var(--text-2);max-width:64ch;margin:22px 0 0}
.sec--dark .lede,.sec--ink2 .lede{color:var(--on-dark-2)}
p{margin:0 0 1.05em;max-width:74ch}
p:last-child{margin-bottom:0}
.muted{color:var(--text-2)}
.dim{color:var(--text-3)}
.small{font-size:14px;line-height:1.6}
.mono{font-family:var(--mono);font-size:12px;letter-spacing:.06em}
strong{font-weight:650}
em{font-style:normal;color:var(--accent)}

/* ---------- nav ---------- */
.nav{
  position:sticky;top:0;z-index:60;background:rgba(10,11,13,.92);
  backdrop-filter:saturate(160%) blur(14px);border-bottom:1px solid var(--line-d2);
}
.nav__in{max-width:var(--max);margin:0 auto;padding:0 var(--gut);height:64px;display:flex;align-items:center;gap:28px}
.brand{display:flex;align-items:baseline;gap:10px;text-decoration:none;color:var(--on-dark);flex:none}
.brand__bd{font-weight:700;font-size:15px;letter-spacing:-.01em}
.brand__sub{font-family:var(--mono);font-size:10.5px;letter-spacing:.14em;text-transform:uppercase;color:var(--on-dark-2)}
.nav__links{display:flex;gap:26px;margin-left:auto}
.nav__links a{
  font-size:13.5px;color:var(--on-dark-2);text-decoration:none;letter-spacing:.01em;
  padding:6px 0;border-bottom:1px solid transparent;transition:color .18s,border-color .18s;white-space:nowrap;
}
.nav__links a:hover{color:#fff;border-color:var(--accent)}
.nav__links a[aria-current="page"]{color:#fff;border-color:rgba(255,255,255,.5)}
.btn--nav{flex:none;margin-left:26px}
.nav__toggle{display:none}

.btn{
  display:inline-flex;align-items:center;gap:9px;text-decoration:none;cursor:pointer;
  font-family:var(--sans);font-size:14px;font-weight:600;letter-spacing:.005em;
  padding:12px 20px;border-radius:var(--r);border:1px solid transparent;
  transition:transform .18s ease,background .18s,border-color .18s,color .18s;
}
.btn:hover{transform:translateY(-1px)}
.btn--primary{background:var(--accent);color:#fff}
.btn--primary:hover{background:var(--accent-2)}
.btn--ghost{background:transparent;border-color:var(--line-d);color:var(--on-dark)}
.btn--ghost:hover{border-color:rgba(255,255,255,.45);background:rgba(255,255,255,.04)}
.btn--quiet{background:transparent;border-color:var(--line);color:var(--text)}
.btn--quiet:hover{border-color:var(--text);background:var(--white)}
.btn--sm{font-size:12.5px;padding:9px 15px}
.btn__arrow{font-family:var(--mono);font-size:11px;opacity:.8}

/* ---------- hero ---------- */
.hero{position:relative;background:var(--ink);color:var(--on-dark);overflow:hidden}
.hero::after{
  content:"";position:absolute;inset:0;pointer-events:none;
  background:
    radial-gradient(70% 60% at 82% 18%,rgba(194,71,31,.12),transparent 62%),
    radial-gradient(50% 50% at 8% 90%,rgba(111,123,135,.14),transparent 70%);
}
.hero__in{
  position:relative;z-index:2;max-width:var(--max);margin:0 auto;padding:clamp(44px,5.6vw,78px) var(--gut) clamp(34px,3.6vw,54px);
  display:grid;grid-template-columns:minmax(0,1.1fr) minmax(0,1fr);gap:clamp(28px,4vw,56px);align-items:end;
}
.hero__copy{min-width:0}
.hero h1{max-width:20ch;font-size:clamp(34px,4.4vw,62px);line-height:1.05}
.hero__sub{margin:26px 0 0;font-size:clamp(17px,1.2vw,19.5px);line-height:1.55;color:var(--on-dark-2);max-width:52ch}
.hero__cta{display:flex;flex-wrap:wrap;gap:12px;margin-top:34px}
.hero__art{position:relative;min-width:0}
.hero__art img{
  width:100%;border-radius:var(--r);background:#000;aspect-ratio:2/1;
  border:1px solid rgba(255,255,255,.16);object-fit:cover;
}
.hero__art-tag{
  position:absolute;left:14px;top:13px;z-index:3;font-family:var(--mono);font-size:9.5px;
  letter-spacing:.12em;text-transform:uppercase;color:rgba(255,255,255,.55);
}
.hero__art figcaption{
  font-family:var(--mono);font-size:10.5px;letter-spacing:.08em;text-transform:uppercase;
  color:var(--on-dark-2);margin-top:12px;display:flex;justify-content:space-between;gap:12px;
}
.hero__rule{position:relative;z-index:2;max-width:var(--max);margin:0 auto;padding:0 var(--gut)}
.hero__stats{
  position:relative;z-index:2;border-top:1px solid var(--line-d2);
  display:grid;grid-template-columns:repeat(4,minmax(0,1fr));
}
.hero__stats div{padding:22px 0;padding-right:18px}
.hero__stats .k{font-family:var(--mono);font-size:10px;letter-spacing:.14em;text-transform:uppercase;color:var(--on-dark-2);display:block;margin-bottom:7px}
.hero__stats .v{font-size:clamp(20px,1.7vw,26px);font-weight:650;letter-spacing:-.02em;line-height:1.1;display:block}
.hero__stats .n{font-size:12.5px;color:var(--on-dark-2);display:block;margin-top:6px;line-height:1.4}

/* ---------- page head (inner pages) ---------- */
.pagehead{background:var(--ink);color:var(--on-dark);padding:clamp(48px,6vw,84px) 0 clamp(36px,4vw,56px);
  background-image:linear-gradient(180deg,rgba(255,255,255,.03),transparent 70%)}
.pagehead h1{max-width:24ch}
.pagehead .lede{max-width:70ch}

/* ---------- cards & blocks ---------- */
.card{background:var(--white);border:1px solid var(--line);border-radius:var(--r);padding:clamp(22px,2.4vw,32px)}
.card--flush{padding:0;overflow:hidden}
.card--dark{background:var(--ink-2);border-color:rgba(255,255,255,.1);color:var(--on-dark)}
.num{
  font-family:var(--mono);font-size:11px;letter-spacing:.14em;color:var(--text-3);
  display:block;margin-bottom:14px;
}
.card--dark .num{color:var(--on-dark-2)}
.card h3{margin-bottom:10px}
.card p{font-size:15.5px;line-height:1.6;color:var(--text-2);margin-bottom:0}
.card--dark p{color:var(--on-dark-2)}
.card__link{
  display:inline-flex;align-items:center;gap:8px;margin-top:20px;font-family:var(--mono);
  font-size:11.5px;letter-spacing:.08em;text-transform:uppercase;color:var(--accent);text-decoration:none;
  border-bottom:1px solid transparent;padding-bottom:2px;
}
.card__link:hover{border-color:var(--accent)}
.card--dark .card__link{color:#F0A184}

.vtline{
  display:inline-flex;align-items:center;gap:8px;font-family:var(--mono);font-size:10.5px;
  letter-spacing:.1em;text-transform:uppercase;color:#2F6B4F;
  background:#E8F1EC;border:1px solid #CFE1D8;border-radius:2px;padding:4px 8px;
}
.vtline--dark{color:#8FD3AE;background:rgba(47,107,79,.16);border-color:rgba(143,211,174,.28)}

/* ---------- capability block ---------- */
.cap{display:grid;grid-template-columns:56px minmax(0,1.15fr) minmax(0,1fr);gap:clamp(18px,3vw,44px);
  padding:clamp(30px,3.6vw,46px) 0;border-top:1px solid var(--line)}
.cap:first-of-type{border-top:0}
.cap__n{font-family:var(--mono);font-size:12px;letter-spacing:.1em;color:var(--accent);padding-top:4px}
.cap__title h3{font-size:clamp(22px,2.1vw,30px);margin-bottom:12px}
.cap__body p{font-size:15.5px;line-height:1.62;color:var(--text-2);margin-bottom:12px}
.cap__meta{border-left:1px solid var(--line);padding-left:clamp(18px,2.4vw,32px)}
.cap__meta dl{margin:0;display:grid;gap:14px}
.cap__meta dt{font-family:var(--mono);font-size:10px;letter-spacing:.14em;text-transform:uppercase;color:var(--text-3);margin-bottom:4px}
.cap__meta dd{margin:0;font-size:14px;line-height:1.5;color:var(--text)}
.cap__src{font-size:12px;color:var(--text-3);line-height:1.5}

/* ---------- video cards ---------- */
.vgrid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:clamp(18px,2.4vw,30px)}
.vcard{display:flex;flex-direction:column;text-decoration:none;color:inherit;background:transparent}
.vcard__frame{
  position:relative;aspect-ratio:16/9;border-radius:var(--r);overflow:hidden;background:var(--ink);
  border:1px solid rgba(255,255,255,.12);display:flex;align-items:center;justify-content:center;
  transition:border-color .2s,transform .25s ease;
}
.vcard__frame::before{
  content:"";position:absolute;inset:0;
  background:
    repeating-linear-gradient(115deg,rgba(255,255,255,.035) 0 1px,transparent 1px 7px),
    radial-gradient(120% 90% at 20% 110%,rgba(194,71,31,.20),transparent 62%),
    radial-gradient(80% 70% at 90% -10%,rgba(111,123,135,.22),transparent 60%);
}
.vcard__idx{
  position:absolute;left:14px;top:12px;font-family:var(--mono);font-size:10.5px;letter-spacing:.12em;
  color:rgba(255,255,255,.55);
}
.vcard__frame::after{
  content:"";position:absolute;inset:0;z-index:1;pointer-events:none;
  background:radial-gradient(130% 105% at 10% -5%,var(--tint,rgba(194,71,31,.18)),transparent 62%);
}
.vcard[data-cat="cinematic"]{--tint:rgba(194,71,31,.28)}
.vcard[data-cat="control"]{--tint:rgba(76,114,132,.28)}
.vcard[data-cat="continuity"]{--tint:rgba(104,126,84,.24)}
.vcard[data-cat="multimodal"]{--tint:rgba(148,118,84,.24)}
.vcard[data-cat="auto"]{--tint:rgba(178,140,64,.24)}
.vcard[data-cat="iteration"]{--tint:rgba(96,104,126,.26)}
.vcard__cat{
  position:absolute;left:14px;bottom:12px;z-index:2;font-family:var(--mono);font-size:9.5px;
  letter-spacing:.1em;text-transform:uppercase;color:rgba(255,255,255,.48);
}
.vcard__tag{
  position:absolute;right:14px;top:12px;font-family:var(--mono);font-size:9.5px;letter-spacing:.1em;
  text-transform:uppercase;color:rgba(255,255,255,.62);text-align:right;max-width:58%;line-height:1.5;
}
.vcard__play{
  position:relative;z-index:2;width:54px;height:54px;border-radius:50%;
  border:1px solid rgba(255,255,255,.45);display:grid;place-items:center;
  transition:background .2s,border-color .2s,transform .2s;
}
.vcard__play svg{width:15px;height:15px;fill:#fff;margin-left:2px}
.vcard:hover .vcard__frame{border-color:rgba(194,71,31,.55);transform:translateY(-2px)}
.vcard:hover .vcard__play{background:var(--accent);border-color:var(--accent);transform:scale(1.04)}
.vcard__body{padding:14px 0 0}
.vcard__title{font-size:15px;font-weight:640;line-height:1.32;letter-spacing:-.012em;margin:0 0 8px}
.vcard__meta{font-family:var(--mono);font-size:10px;line-height:1.55;letter-spacing:.09em;text-transform:uppercase;color:var(--text-3);margin:0 0 8px}


.vcard__note{font-size:12.5px;color:var(--text-2);line-height:1.5;margin-top:8px}

/* ---------- chips / filters ---------- */
.chips{display:flex;flex-wrap:wrap;gap:9px;margin:0 0 clamp(26px,3vw,38px)}
.chip{
  font-family:var(--mono);font-size:10.5px;letter-spacing:.1em;text-transform:uppercase;
  padding:9px 13px;border:1px solid var(--line);background:transparent;color:var(--text-2);
  border-radius:2px;cursor:pointer;transition:all .16s;
}
.chip:hover{border-color:var(--text);color:var(--text)}
.chip[aria-pressed="true"]{background:var(--ink);border-color:var(--ink);color:#fff}

/* ---------- flow ---------- */
.flow{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:0;border:1px solid var(--line);background:var(--white);border-radius:var(--r);overflow:hidden}
.flow__step{padding:clamp(18px,2.2vw,26px);border-right:1px solid var(--line);position:relative}
.flow__step:last-child{border-right:0}
.flow__n{font-family:var(--mono);font-size:10px;letter-spacing:.14em;color:var(--accent);display:block;margin-bottom:10px}
.flow__h{font-size:14.5px;font-weight:650;letter-spacing:-.012em;margin-bottom:7px}
.flow__p{font-size:12.5px;line-height:1.5;color:var(--text-2)}
.flow__role{font-family:var(--mono);font-size:9.5px;letter-spacing:.08em;text-transform:uppercase;color:var(--steel);display:block;margin-top:12px}

/* ---------- stats band ---------- */
.statband{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:0;border-top:1px solid var(--line)}
.statband>div{padding:26px 0 0;padding-right:20px}
.statband .v{font-size:clamp(28px,2.6vw,38px);font-weight:650;letter-spacing:-.03em;line-height:1;display:block}
.statband .k{font-family:var(--mono);font-size:10px;letter-spacing:.12em;text-transform:uppercase;color:var(--text-3);display:block;margin-top:10px}
.statband .n{font-size:12.5px;color:var(--text-2);display:block;margin-top:7px;line-height:1.45}

/* ---------- table ---------- */
.twrap{overflow-x:auto;border:1px solid var(--line);border-radius:var(--r);background:var(--white)}
table{border-collapse:collapse;width:100%;min-width:720px;font-size:14px}
th,td{text-align:left;vertical-align:top;padding:14px 16px;border-bottom:1px solid var(--line-2)}
th{font-family:var(--mono);font-size:10px;letter-spacing:.12em;text-transform:uppercase;color:var(--text-3);
  font-weight:500;background:var(--paper-2);position:sticky;top:0;white-space:nowrap}
td.strong{font-weight:640}
tr:last-child td{border-bottom:0}

/* ---------- gallery ---------- */
.gallery{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:clamp(16px,2.4vw,26px)}
.fig{margin:0}
.fig img{border-radius:var(--r);border:1px solid var(--line);background:#000}
.fig figcaption{font-size:12.5px;line-height:1.5;color:var(--text-2);margin-top:10px}
.fig figcaption b{display:block;font-family:var(--mono);font-size:10px;letter-spacing:.1em;text-transform:uppercase;color:var(--text-3);margin-bottom:5px;font-weight:500}

/* ---------- cta band ---------- */
.ctaband{background:var(--ink);color:var(--on-dark);padding:clamp(52px,6vw,88px) 0}
.ctaband__grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:1px;background:rgba(255,255,255,.12);border:1px solid rgba(255,255,255,.12);margin-top:clamp(30px,4vw,48px)}
.ctaband__cell{background:var(--ink);padding:clamp(22px,2.8vw,34px);display:flex;flex-direction:column;gap:12px}
.ctaband__cell h3{font-size:18px}
.ctaband__cell p{font-size:14px;color:var(--on-dark-2);line-height:1.55;margin:0}
.ctaband__cell .btn{margin-top:auto;align-self:flex-start}

/* ---------- footer ---------- */
.foot{background:#07080A;color:var(--on-dark-2);padding:clamp(40px,5vw,64px) 0 30px;font-size:13px}
.foot__grid{display:grid;grid-template-columns:1.4fr 1fr 1fr;gap:clamp(24px,4vw,56px)}
.foot h4{font-size:13px;color:var(--on-dark);margin-bottom:14px;font-weight:600}
.foot a{color:var(--on-dark-2);text-decoration:none;display:block;padding:4px 0}
.foot a:hover{color:#fff}
.foot__note{border-top:1px solid rgba(255,255,255,.1);margin-top:clamp(28px,4vw,44px);padding-top:20px;
  font-size:11.5px;line-height:1.6;color:#6E747C;max-width:92ch}
.foot__brand{display:flex;align-items:baseline;gap:9px;margin-bottom:14px}
.foot__brand .brand__bd{color:#fff}

/* ---------- misc ---------- */
.note{
  border-left:2px solid var(--accent);padding:2px 0 2px 18px;font-size:13.5px;line-height:1.6;color:var(--text-2);
}
.note--dark{border-color:var(--accent-2);color:var(--on-dark-2)}
.src{font-size:11.5px;line-height:1.6;color:var(--text-3);margin-top:14px}
.src a{color:inherit;text-decoration:underline;text-underline-offset:2px}
.rule{height:1px;background:var(--line);border:0;margin:0}
.badge{
  display:inline-block;font-family:var(--mono);font-size:9.5px;letter-spacing:.1em;text-transform:uppercase;
  padding:3px 7px;border-radius:2px;border:1px solid var(--line);color:var(--text-2);
}
.badge--case{background:#F0EFEA;border-color:#DAD8D1;color:#3D4148}
.badge--pub{background:#EAF0F3;border-color:#D3DEE4;color:#3A5566}
.badge--ref{background:#F3EDE9;border-color:#E3D5CD;color:#7A4B36}
.hide{display:none !important}
.anchor{scroll-margin-top:88px}

/* ---------- responsive ---------- */
@media (max-width:1080px){
  .hero__in{grid-template-columns:1fr;align-items:start}
  .hero__art{margin-top:32px}
  .hero h1{max-width:22ch}
  .vgrid,.gallery{grid-template-columns:repeat(2,minmax(0,1fr))}
  .flow{grid-template-columns:repeat(2,minmax(0,1fr))}
  .flow__step{border-bottom:1px solid var(--line)}
  .flow__step:nth-child(2n){border-right:0}
  .cap{grid-template-columns:44px minmax(0,1fr);row-gap:22px}
  .cap__meta{grid-column:2;border-left:0;padding-left:0;border-top:1px solid var(--line);padding-top:18px}
  .g4{grid-template-columns:repeat(2,minmax(0,1fr))}
  .statband,.hero__stats{grid-template-columns:repeat(2,minmax(0,1fr))}
  .font{}
}
@media (max-width:860px){
  .nav__links{display:none}
  .nav__toggle{display:inline-flex;margin-left:auto;background:none;border:1px solid var(--line-d);
    color:var(--on-dark);width:40px;height:36px;border-radius:2px;align-items:center;justify-content:center;cursor:pointer}
  .btn--nav{display:none}
  .g3,.g2,.split,.split--even,.ctaband__grid,.foot__grid{grid-template-columns:1fr}
  .vgrid,.gallery{grid-template-columns:1fr}
  .flow{grid-template-columns:1fr}
  .flow__step{border-right:0;border-bottom:1px solid var(--line)}
  .hero__stats,.statband{grid-template-columns:1fr 1fr}
  p{max-width:none}
  table{min-width:640px}
}
@media (max-width:620px){
  body{font-size:16px}
  h1{font-size:clamp(30px,8.6vw,42px)}
  .sec{padding:44px 0}
  .hero__in{padding-top:34px}
  .hero__stats,.statband{grid-template-columns:1fr}
  .hero__stats div,.statband>div{border-bottom:1px solid var(--line-d2);padding-bottom:16px}
  .hero__stats div:last-child,.statband>div:last-child{border-bottom:0}
  .btn{width:100%;justify-content:center}
  .hero__cta{flex-direction:column;align-items:stretch}
}

/* drawer */
.drawer{
  position:fixed;inset:64px 0 0;background:var(--ink);z-index:55;padding:22px var(--gut) 40px;
  transform:translateY(-6px);opacity:0;pointer-events:none;transition:opacity .22s,transform .22s;
}
.drawer[data-open="true"]{opacity:1;transform:none;pointer-events:auto}
.drawer a{display:block;color:var(--on-dark);text-decoration:none;font-size:16px;padding:14px 0;border-bottom:1px solid var(--line-d2)}
.drawer .btn{margin-top:22px}

@media (prefers-reduced-motion:reduce){
  *{transition:none !important;animation:none !important}
}
:focus-visible{outline:2px solid var(--accent);outline-offset:3px}