/* Dubseat landing. Concept A "Timeline": Swiss type, black/white, one red accent, two waveforms. */
:root {
  --ink: #111;
  --g1: #5c5c5c;      /* secondary text on white */
  --g2: #8e8e8e;      /* tertiary, timecodes */
  --rule: #d6d6d6;
  --paper: #fff;
  --red: #d7261e;     /* accent on white */
  --red-d: #ff4a3d;   /* accent on black */
  --on-dark: #c9c9c9;
  --font: "Helvetica Neue", Helvetica, Arial, sans-serif;
  --pad: clamp(20px, 5vw, 72px);
  --sec: clamp(80px, 11vw, 152px);
  --hd: 64px;
  --ease: cubic-bezier(.16, 1, .3, 1);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: var(--hd); -webkit-text-size-adjust: 100%; }
body { margin: 0; font: 17px/1.5 var(--font); color: var(--ink); background: var(--paper); -webkit-font-smoothing: antialiased; }
::selection { background: var(--red); color: #fff; }
a { color: inherit; text-underline-offset: .2em; text-decoration-thickness: 1px; }
:focus-visible { outline: 2px solid var(--red); outline-offset: 3px; }
.dark :focus-visible { outline-color: var(--red-d); }
.btn:focus-visible { outline-color: #fff; box-shadow: 0 0 0 5px var(--ink); }
:not(.dark) > .btn:focus-visible { outline-color: var(--ink); box-shadow: none; }
img, svg { display: block; }

.skip { position: absolute; left: 8px; top: -60px; z-index: 100; background: var(--paper); color: var(--ink); padding: 10px 14px; }
.skip:focus { top: 8px; }

/* ---------- type ---------- */
h1, h2, h3 { font-weight: 500; margin: 0; text-wrap: balance; }
h1 { font-size: clamp(36px, 4.6vw, 68px); line-height: 1.03; letter-spacing: -.03em; }
h2 { font-size: clamp(30px, 3.8vw, 52px); line-height: 1.07; letter-spacing: -.02em; }
h3 { font-size: 20px; line-height: 1.25; letter-spacing: -.005em; }
p { margin: 0; max-width: 60ch; text-wrap: pretty; }
.lead { font-size: clamp(18px, 1.5vw, 21px); line-height: 1.45; }
.red { color: var(--red); }
.sub { color: var(--g1); }
.dark .sub { color: var(--g2); }
.tc { font-size: 13px; letter-spacing: .04em; color: var(--g1); font-variant-numeric: tabular-nums; }
.fine { font-size: 14px; color: var(--g2); margin-top: 16px; }

.dark { background: var(--ink); color: #fff; }
.dark .red { color: var(--red-d); }
.dark p { color: var(--on-dark); }

section { padding: var(--sec) var(--pad); }

/* ---------- buttons ---------- */
.btn { display: inline-flex; align-items: center; justify-content: center; min-height: 52px; padding: 0 24px;
  border: 0; border-radius: 0; font: 500 16px/1 var(--font); background: var(--red); color: #fff; text-decoration: none;
  cursor: pointer; white-space: nowrap; transition: background-color .2s; }
.btn:hover { background: #b81f18; }
.btn:active { background: #9f1a14; }
.btn.sm { min-height: 44px; padding: 0 16px; font-size: 14px; }
.btn[aria-busy="true"] { opacity: .7; cursor: progress; }

/* ---------- header ---------- */
.hd { position: sticky; top: 0; z-index: 20; height: var(--hd); display: flex; align-items: center; gap: 32px;
  padding: 0 var(--pad); background: rgba(17, 17, 17, .94); color: #fff; backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); }
.logo { font-weight: 700; font-size: 19px; letter-spacing: .005em; text-decoration: none; }
.hd nav { display: flex; gap: 28px; margin-left: auto; font-size: 15px; }
.hd nav a { color: var(--on-dark); text-decoration: none; padding: 12px 0; }
.hd nav a:hover { color: #fff; }
.hd-end { display: flex; align-items: center; gap: 20px; }
.lang { display: flex; font-size: 14px; }
.lang a { display: inline-flex; align-items: center; min-height: 44px; padding: 0 8px; color: var(--g2); text-decoration: none; }
.lang a:hover { color: #fff; }
.lang a[aria-current="page"] { color: #fff; }

.timeline { position: fixed; inset: 0 0 auto; height: 2px; z-index: 30; pointer-events: none; }
.timeline i { display: block; height: 100%; width: 100%; background: var(--red-d); transform-origin: 0 50%; transform: scaleX(0); }

/* ---------- phone (dark app UI) ---------- */
.phone { --w: 290px; width: var(--w); aspect-ratio: 9 / 18; margin: 0; flex: none;
  background: #1a1a1a; border: 1px solid #3a3a3a; border-radius: calc(var(--w) * .155); padding: calc(var(--w) * .034); }
.phone .scr { position: relative; height: 100%; background: #000; border-radius: calc(var(--w) * .125);
  padding: calc(var(--w) * .21) calc(var(--w) * .08) calc(var(--w) * .09); color: #fff; display: flex; flex-direction: column; overflow: hidden; }
.phone .scr::before { content: ""; position: absolute; top: calc(var(--w) * .04); left: 50%; width: 32%; height: calc(var(--w) * .088);
  transform: translateX(-50%); background: #1a1a1a; border-radius: 99px; }
.scr .mute { color: #6e6e6e; font-size: 12px; }
.scr .dim { color: #a0a0a0; font-size: 12px; }
.scr .title { font-size: 20px; font-weight: 500; margin: 6px 0 4px; }
.scr .center-t { margin-top: 40%; }
.scr hr { border: 0; border-top: 1px solid #2a2a2a; margin: 16px 0; width: 100%; }
.scr .gap-t { margin-top: 20px; }
.scr .foot { margin-top: auto; text-align: center; }
.chip { display: flex; justify-content: space-between; align-items: center; padding: 11px 13px; border-radius: 10px; background: #1c1c1c; font-size: 14px; margin-top: 8px; }
.chip.on { background: var(--red); font-weight: 500; }
.chip small { font-size: 11px; opacity: .85; font-weight: 400; }
.pill { margin-top: auto; height: 44px; border-radius: 22px; background: #fff; color: #000; display: flex; align-items: center; justify-content: center; font-weight: 500; font-size: 14px; }
.state { display: flex; align-items: center; gap: 8px; font-size: 14px; font-weight: 500; color: #a0a0a0; margin-top: 32px; transition: color .4s; }
.state i { width: 8px; height: 8px; border-radius: 50%; background: #6e6e6e; transition: background-color .4s; }
.synced .state { color: var(--red-d); }
.synced .state i { background: var(--red-d); }
.clock { font-size: calc(var(--w) * .15); font-weight: 500; letter-spacing: -.02em; font-variant-numeric: tabular-nums; margin: 6px 0 16px; }
.tune { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; margin-top: 10px; }
.tune span { background: #1c1c1c; border-radius: 10px; text-align: center; padding: 11px 0; font-size: 14px; }

/* ---------- waveforms: rolling, the dub lane catches up with the hall lane ---------- */
.waves { position: relative; height: 64px; overflow: hidden; }
.lane { position: absolute; inset: 0; }
.roll { display: flex; width: 200%; height: 100%; animation: roll 10s linear infinite; }
.roll svg { width: 50%; height: 100%; flex: none; }
@keyframes roll { to { transform: translateX(-50%); } }
.lane.dub { transform: translateX(22%); opacity: .55; transition: transform 1.4s var(--ease), opacity .6s; }
.synced .lane.dub { transform: none; opacity: 1; }
.waves.ph::after { content: ""; position: absolute; left: 50%; top: -4px; bottom: -4px; width: 1px; background: #fff; opacity: .7; }
.paused .roll { animation-play-state: paused; }

/* ---------- 1. hero ---------- */
.hero { display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: clamp(32px, 6vw, 112px); align-items: center;
  min-height: calc(100svh - var(--hd) - 72px); padding-top: clamp(40px, 6vw, 80px); padding-bottom: clamp(40px, 6vw, 80px); }
.hero .lead { margin-top: 28px; }
.hero .btn { margin-top: 40px; }
.hero-phone { --w: clamp(240px, calc((100svh - var(--hd) - 72px - 2 * clamp(40px, 6vw, 80px)) * 9 / 18), 290px); }

.strip { display: grid; grid-template-columns: auto 1fr auto; align-items: center; gap: 24px; padding: 20px var(--pad);
  border-top: 1px solid #262626; font-size: 13px; color: var(--g2); }
.strip-waves { position: relative; height: 32px; }
.strip-waves > div { position: absolute; inset: 0; overflow: hidden; }
.strip-waves .roll { animation-duration: 30s; }

/* ---------- 2. problem ---------- */
.problem { display: grid; grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr); gap: clamp(32px, 6vw, 96px); align-items: end; }
.problem .lead { color: var(--g1); }

/* ---------- 3. how ---------- */
.how { border-top: 1px solid var(--rule); }
.steps { list-style: none; margin: 72px 0 0; padding: 0; display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: clamp(24px, 4vw, 56px); }
.step { border-top: 1px solid var(--ink); padding-top: 16px; display: flex; flex-direction: column; }
.step h3 { margin: 8px 0 8px; }
.step p { color: var(--g1); font-size: 16px; }
.phone.sm { --w: 240px; aspect-ratio: 9 / 19.5; }
.step .phone.sm { margin-top: 32px; }
.steps { align-items: stretch; }
.step p { min-height: 3em; }
.step .phone.sm { align-self: flex-start; }

/* ---------- 4. features ---------- */
.features { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.4fr); gap: clamp(32px, 6vw, 96px); align-items: start; }
.features h2 { position: sticky; top: calc(var(--hd) + 40px); }
.feat { margin: 0; display: grid; grid-template-columns: 1fr 1fr; gap: 48px clamp(24px, 4vw, 56px); }
.feat div { border-top: 1px solid #3a3a3a; padding-top: 16px; }
.feat dt { font-size: 20px; font-weight: 500; margin-bottom: 8px; }
.feat dd { margin: 0; color: var(--on-dark); }

/* ---------- 5. need ---------- */
.need { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.25fr); gap: clamp(32px, 6vw, 96px); align-items: center; }
.need-list { list-style: none; margin: 40px 0 32px; padding: 0; }
.need-list li { display: grid; grid-template-columns: 140px 1fr; gap: 16px; padding: 16px 0; border-top: 1px solid var(--rule); font-size: 18px; }
.need-list li:last-child { border-bottom: 1px solid var(--rule); }
.need-list b { font-weight: 500; }
.need-list span { color: var(--g1); }
.need p { color: var(--g1); }
.hall-fig { margin: 0; }
.hall { width: 100%; height: auto; aspect-ratio: 900 / 340; }

/* ---------- 6. beta ---------- */
.beta { display: grid; grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr); gap: clamp(32px, 6vw, 96px); align-items: end; }
.beta .btn { margin-top: 32px; }

/* ---------- 7. faq ---------- */
.faq { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 2fr); gap: clamp(32px, 6vw, 96px); align-items: start; }
.faq-list details { border-top: 1px solid var(--rule); }
.faq-list details:last-child { border-bottom: 1px solid var(--rule); }
.faq-list summary { list-style: none; cursor: pointer; display: flex; justify-content: space-between; align-items: center; gap: 24px;
  padding: 22px 0; font-size: 19px; font-weight: 500; }
.faq-list summary::-webkit-details-marker { display: none; }
.faq-list summary::after { content: ""; flex: none; width: 14px; height: 14px; background:
  linear-gradient(currentColor, currentColor) center / 14px 1.5px no-repeat,
  linear-gradient(currentColor, currentColor) center / 1.5px 14px no-repeat; transition: transform .3s var(--ease); }
.faq-list details[open] summary::after { transform: rotate(45deg); }
.faq-list summary:hover { text-decoration: underline; text-underline-offset: .25em; }
.faq-list details p { padding: 0 0 24px; color: var(--g1); }
.faq-more { margin-top: 32px; color: var(--g1); }
.faq-more a { color: var(--ink); }

/* ---------- 8. join ---------- */
.join .lead { margin-top: 24px; }
.wl { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr) auto; gap: 12px; align-items: end; max-width: 880px; margin-top: 48px; }
.wl label { display: flex; flex-direction: column; gap: 8px; font-size: 14px; color: var(--on-dark); }
.wl input { height: 52px; min-width: 0; padding: 0 16px; font: 17px var(--font); color: #fff; background: transparent; border: 1px solid #7a7a7a; border-radius: 0; transition: border-color .2s; }
.wl input::placeholder { color: #8e8e8e; }
.wl input:hover { border-color: #888; }
.wl input:focus { border-color: #fff; outline: none; }
.wl input[aria-invalid="true"] { border-color: var(--red-d); }
.form-msg { grid-column: 1 / -1; min-height: 1.5em; font-size: 15px; }
.form-msg.err { color: var(--red-d); }
.form-msg.ok { color: #fff; }
.wl.done label, .wl.done button { display: none; }
.form-msg:focus { outline: none; }
.wl .h-captcha { grid-column: 1 / -1; min-height: 78px; }
.wl.done .h-captcha { display: none; }
.wl .hp { position: absolute; left: -9999px; width: 1px; height: 1px; opacity: 0; }
.fine a { color: var(--on-dark); }
.wl.done .form-msg { font-size: clamp(20px, 2vw, 26px); }

/* ---------- footer ---------- */
.ft { display: flex; flex-wrap: wrap; align-items: center; gap: 12px 32px; padding: 32px var(--pad) calc(32px + env(safe-area-inset-bottom));
  background: var(--ink); color: var(--g2); font-size: 14px; border-top: 1px solid #262626; }
.ft .logo { color: #fff; margin-right: auto; }
.ft a { color: var(--on-dark); padding: 12px 0; }

/* ---------- responsive ---------- */
@media (max-width: 960px) {
  .hd nav { display: none; }
  .hd-end { margin-left: auto; }
  .hero, .problem, .features, .need, .beta, .faq { grid-template-columns: 1fr; }
  .hero { min-height: 0; }
  .hero-phone { justify-self: center; --w: min(280px, 72vw); }
  .features h2 { position: static; }
  .steps { grid-template-columns: 1fr; gap: 64px; }
  .step { display: flex; flex-direction: column; }
  .step p { min-height: 0; }
  .step .phone.sm { align-self: center; }
  .wl { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
  .wl .btn { grid-column: 1 / -1; justify-self: start; }
}
@media (max-width: 640px) {
  body { font-size: 16px; }
  .hd { gap: 12px; }
  .hd-end { gap: 8px; }
  .feat { grid-template-columns: 1fr; gap: 32px; }
  .need-list li { grid-template-columns: 1fr; gap: 2px; }
  .wl { grid-template-columns: 1fr; }
  .phone.sm { --w: 220px; }
  .phone.sm .scr .title { font-size: 16px; white-space: nowrap; }
  .steps { gap: 48px; }
  .hall { aspect-ratio: 4 / 3; height: auto; }
  .wl .btn { width: 100%; }
  .strip { grid-template-columns: 1fr; gap: 8px; }
  .strip > span:last-child { justify-self: end; }
  .faq-list summary { font-size: 17px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .roll { animation: none; }
  .lane.dub, .state, .state i, .faq-list summary::after { transition: none; }
}

/* ---------- legal document (privacy) ---------- */
.legal .hd .hd-end { margin-left: auto; }
.doc { max-width: 760px; margin: 0 auto; padding: clamp(48px, 7vw, 96px) var(--pad) clamp(64px, 9vw, 120px); }
.doc h1 { font-size: clamp(30px, 3.6vw, 44px); line-height: 1.1; margin-bottom: 40px; }
.doc h2 { font-size: 22px; line-height: 1.3; letter-spacing: -.005em; margin: 48px 0 16px; }
.doc p, .doc li { font-size: 16px; line-height: 1.6; color: #2a2a2a; max-width: 72ch; }
.doc p + p { margin-top: 12px; }
.doc ul { margin: 8px 0 12px; padding-left: 1.2em; }
.doc li { margin-bottom: 8px; }
.doc li::marker { content: "— "; color: var(--g2); }
.doc a { color: var(--ink); }
.doc table { border-collapse: collapse; width: 100%; font-size: 16px; line-height: 1.5; }
.doc th, .doc td { text-align: left; vertical-align: top; padding: 12px 0; border-top: 1px solid var(--rule); }
.doc tr:last-child th, .doc tr:last-child td { border-bottom: 1px solid var(--rule); }
.doc th { font-weight: 500; width: 36%; padding-right: 24px; }
@media (max-width: 640px) { .doc th, .doc td { display: block; width: auto; padding: 4px 0; } .doc th { padding-top: 12px; } .doc td { border-top: 0; padding-bottom: 12px; } }
.doc .doc-meta { color: var(--g1); margin-bottom: 16px; }
.doc mark { background: #fff2a8; color: var(--ink); padding: 0 .2em; }