/* Heightmark site — brand tokens mirror the iOS app's dark palette. */
:root {
  --ink: #111619;
  --surface: #181f25;
  --elevated: #1f282f;
  --line: rgba(255, 255, 255, 0.09);
  --snow: #eef3f2;
  --mist: #93a1a8;
  --faint: #5c6770;
  --accent: #ff7a45;
  --accent-deep: #e25b22;
  --rare: #6fd0c2;
  --uncommon: #8fa8ff;
  --max: 1080px;
  --radius: 20px;
  font-synthesis: none;
  -webkit-font-smoothing: antialiased;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  background:
    radial-gradient(1200px 600px at 50% -10%, rgba(255, 122, 69, 0.10), transparent 60%),
    var(--ink);
  color: var(--snow);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.6;
  min-height: 100vh;
}

.mono {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

a { color: inherit; text-decoration: none; }

.wrap { max-width: var(--max); margin: 0 auto; padding: 0 24px; }

/* lang visibility: body.lang-en shows .en, hides .zh and vice versa */
body.lang-zh .en { display: none; }
body.lang-en .zh { display: none; }

/* ---------- header ---------- */
header.nav {
  position: sticky; top: 0; z-index: 50;
  backdrop-filter: blur(18px);
  background: rgba(17, 22, 25, 0.72);
  border-bottom: 1px solid var(--line);
}
.nav .wrap { display: flex; align-items: center; justify-content: space-between; height: 60px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 600; letter-spacing: 1.5px; font-size: 14px; }
.brand .dot { width: 22px; height: 22px; }
.nav-links { display: flex; align-items: center; gap: 22px; font-size: 14px; color: var(--mist); }
.nav-links a:hover { color: var(--snow); }
.lang-toggle {
  border: 1px solid var(--line); background: var(--elevated); color: var(--snow);
  border-radius: 999px; padding: 6px 14px; font-size: 12px; cursor: pointer;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace; letter-spacing: 0.5px;
  transition: border-color .2s, background .2s;
}
.lang-toggle:hover { border-color: var(--accent); }
@media (max-width: 640px) { .nav-links .hide-sm { display: none; } }

/* ---------- hero ---------- */
.hero { padding: 84px 0 60px; }
.hero .wrap { display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 48px; align-items: center; }
.eyebrow { color: var(--accent); font-size: 12px; letter-spacing: 2px; margin-bottom: 18px; }
h1 { font-size: clamp(34px, 5vw, 52px); line-height: 1.12; font-weight: 700; letter-spacing: -0.5px; }
.lede { color: var(--mist); font-size: 17px; margin: 20px 0 30px; max-width: 30em; }
.cta-row { display: flex; gap: 14px; flex-wrap: wrap; }
.btn {
  display: inline-flex; align-items: center; gap: 9px; height: 52px; padding: 0 24px;
  border-radius: 14px; font-weight: 600; font-size: 16px; cursor: pointer; border: none;
  transition: transform .15s, filter .2s;
}
.btn:active { transform: scale(0.98); }
.btn-primary { background: linear-gradient(180deg, var(--accent), var(--accent-deep)); color: #1a0d07; }
.btn-primary:hover { filter: brightness(1.06); }
.btn[aria-disabled="true"] { cursor: not-allowed; opacity: 0.58; pointer-events: none; }
.btn-ghost { background: transparent; color: var(--snow); border: 1px solid var(--line); }
.btn-ghost:hover { border-color: var(--accent); }
.hero-note { color: var(--faint); font-size: 12.5px; margin-top: 16px; }

/* dial visual */
.dial-card {
  aspect-ratio: 1; max-width: 360px; margin-left: auto;
  border-radius: 28px; border: 1px solid var(--line);
  background: linear-gradient(180deg, var(--elevated), var(--surface));
  display: grid; place-items: center; position: relative; overflow: hidden;
}
.dial-card svg { width: 100%; height: 100%; position: absolute; inset: 0; }
.dial-center { position: relative; text-align: center; }
.dial-center .big { font-size: 64px; font-weight: 600; letter-spacing: -1px; }
.dial-center .unit { color: var(--mist); font-size: 13px; letter-spacing: 2px; }
@media (max-width: 820px) {
  .hero .wrap { grid-template-columns: 1fr; }
  .dial-card { margin: 8px auto 0; }
}

/* ---------- sections ---------- */
section { padding: 56px 0; }
.section-head { text-align: center; max-width: 36em; margin: 0 auto 40px; }
.section-head .kicker { color: var(--accent); font-size: 12px; letter-spacing: 2px; margin-bottom: 10px; }
.section-head h2 { font-size: clamp(26px, 3.4vw, 34px); font-weight: 700; letter-spacing: -0.3px; }
.section-head p { color: var(--mist); margin-top: 12px; }

.grid { display: grid; gap: 16px; grid-template-columns: repeat(2, 1fr); }
@media (max-width: 720px) { .grid { grid-template-columns: 1fr; } }
.card {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 24px;
}
.card .ic {
  width: 44px; height: 44px; border-radius: 12px; display: grid; place-items: center;
  background: rgba(255, 122, 69, 0.13); color: var(--accent); margin-bottom: 16px;
}
.card h3 { font-size: 17px; font-weight: 600; margin-bottom: 8px; }
.card p { color: var(--mist); font-size: 14.5px; }

/* steps */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; counter-reset: s; }
@media (max-width: 720px) { .steps { grid-template-columns: 1fr; } }
.step { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; }
.step .n {
  font-family: ui-monospace, monospace; color: var(--accent); font-size: 13px;
  border: 1px solid var(--line); border-radius: 999px; width: 30px; height: 30px;
  display: grid; place-items: center; margin-bottom: 14px;
}
.step h3 { font-size: 16px; margin-bottom: 6px; }
.step p { color: var(--mist); font-size: 14px; }

/* landmark strip */
.ladder { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; }
.chip {
  border: 1px solid var(--line); background: var(--surface); border-radius: 999px;
  padding: 8px 14px; font-size: 13px; color: var(--mist);
}
.chip b { color: var(--snow); font-family: ui-monospace, monospace; }

/* faq */
.faq { max-width: 760px; margin: 0 auto; }
details {
  border: 1px solid var(--line); border-radius: 14px; background: var(--surface);
  padding: 4px 20px; margin-bottom: 12px;
}
details[open] { border-color: rgba(255, 122, 69, 0.4); }
summary {
  cursor: pointer; list-style: none; padding: 16px 0; font-weight: 600; font-size: 16px;
  display: flex; justify-content: space-between; align-items: center; gap: 16px;
}
summary::-webkit-details-marker { display: none; }
summary::after { content: "+"; color: var(--accent); font-size: 22px; font-weight: 400; }
details[open] summary::after { content: "−"; }
details .a { color: var(--mist); padding: 0 0 18px; font-size: 14.5px; }

/* cta band */
.band {
  text-align: center; background: linear-gradient(180deg, var(--elevated), var(--surface));
  border: 1px solid var(--line); border-radius: 28px; padding: 48px 24px; margin: 24px 0;
}
.band h2 { font-size: 28px; margin-bottom: 12px; }
.band p { color: var(--mist); margin-bottom: 24px; }

/* footer */
footer { border-top: 1px solid var(--line); padding: 40px 0 60px; color: var(--faint); font-size: 13px; }
footer .wrap { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 16px; }
footer a { color: var(--mist); }
footer a:hover { color: var(--snow); }
.foot-links { display: flex; gap: 22px; flex-wrap: wrap; }

/* legal page */
.legal { max-width: 760px; margin: 0 auto; padding: 40px 0 20px; }
.legal h1 { font-size: 34px; margin-bottom: 6px; }
.legal .updated { color: var(--faint); font-size: 13px; margin-bottom: 32px; }
.legal h2 { font-size: 19px; margin: 30px 0 10px; }
.legal p, .legal li { color: var(--mist); font-size: 15px; }
.legal ul { padding-left: 22px; margin: 8px 0; }
.legal a { color: var(--accent); }
.back { display: inline-block; margin-bottom: 28px; color: var(--mist); font-size: 14px; }