/* ===========================================================================
   RheoByte landing — palette mirrors the app (src/constants/theme.ts):
   ink (black/white) as the major colour, green as the minor accent.
   =========================================================================== */

:root {
  --bg: #ffffff;
  --bg-elem: #f6f6f7;
  --bg-selected: #efeff1;
  --text: #0b0b0c;
  --text-2: #6b6b70;
  --text-3: #9a9aa0;
  --tint: #0b0b0c;
  --accent: #16a34a;
  --accent-soft: rgba(22, 163, 74, 0.12);
  --accent-line: rgba(22, 163, 74, 0.32);
  --mobile: #0b0b0c;
  --wifi: #16a34a;
  --border: rgba(11, 11, 12, 0.09);
  --track: rgba(11, 11, 12, 0.07);
  --shadow: 0 1px 2px rgba(11, 11, 12, 0.04), 0 12px 32px rgba(11, 11, 12, 0.06);
  --shadow-lg: 0 30px 80px rgba(11, 11, 12, 0.14);

  --font: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --mono: "JetBrains Mono", ui-monospace, "SF Mono", monospace;
  --maxw: 1120px;
  --radius: 18px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #08080a;
    --bg-elem: #161618;
    --bg-selected: #1e1e20;
    --text: #f5f5f6;
    --text-2: rgba(245, 245, 246, 0.62);
    --text-3: rgba(245, 245, 246, 0.4);
    --tint: #f5f5f6;
    --accent: #22c55e;
    --accent-soft: rgba(34, 197, 94, 0.16);
    --accent-line: rgba(34, 197, 94, 0.4);
    --mobile: #f5f5f6;
    --wifi: #22c55e;
    --border: rgba(245, 245, 246, 0.1);
    --track: rgba(245, 245, 246, 0.1);
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.4), 0 12px 32px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 30px 80px rgba(0, 0, 0, 0.6);
  }
}

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

html { scroll-behavior: smooth; scroll-padding-top: 80px; }

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

h1, h2, h3 { line-height: 1.1; letter-spacing: -0.03em; font-weight: 700; }
a { color: inherit; text-decoration: none; }

/* ---- shared atoms ---- */
.mark {
  width: 30px; height: 30px; flex: none;
  object-fit: contain; display: inline-block;
  margin: -4px 0; /* logo has transparent padding; pull it tight */
}

.eyebrow {
  font-family: var(--mono);
  font-size: 12px; font-weight: 500; letter-spacing: 0.16em;
  color: var(--text-3); text-transform: uppercase;
}
.eyebrow--accent { color: var(--accent); }

.btn {
  display: inline-flex; align-items: center; justify-content: center;
  gap: 8px; font-weight: 600; font-size: 15px;
  padding: 11px 20px; border-radius: 12px;
  background: var(--tint); color: var(--bg);
  border: 1px solid transparent; cursor: pointer;
  transition: transform 0.15s ease, opacity 0.15s ease, box-shadow 0.15s ease;
  white-space: nowrap;
}
.btn:hover { transform: translateY(-2px); box-shadow: var(--shadow); }
.btn:active { transform: translateY(0); }
.btn--lg { padding: 15px 28px; font-size: 16px; border-radius: 14px; }
.btn--sm { padding: 8px 16px; font-size: 14px; }
.btn--ghost {
  background: transparent; color: var(--text);
  border-color: var(--border);
}
.btn--ghost:hover { background: var(--bg-elem); }

/* ---- nav ---- */
.nav {
  position: sticky; top: 0; z-index: 50;
  display: flex; align-items: center; gap: 24px;
  max-width: var(--maxw); margin: 0 auto;
  padding: 16px 24px;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: saturate(180%) blur(16px);
  border-bottom: 1px solid transparent;
}
.nav { width: 100%; }
.nav__brand { display: flex; align-items: center; gap: 9px; font-weight: 700; font-size: 17px; letter-spacing: -0.02em; }
.nav__links { display: flex; gap: 26px; margin-left: auto; font-size: 15px; color: var(--text-2); font-weight: 500; }
.nav__links a:hover { color: var(--text); }
.nav .btn { margin-left: 8px; }

@media (max-width: 760px) {
  .nav__links { display: none; }
  .nav .btn { margin-left: auto; }
}

/* ---- layout ---- */
.section { max-width: var(--maxw); margin: 0 auto; padding: 96px 24px; }
.section__head { max-width: 640px; margin-bottom: 56px; }
.section__head .eyebrow { display: block; margin-bottom: 14px; }
.section__head h2 { font-size: clamp(28px, 4vw, 42px); }

/* ---- hero ---- */
.hero {
  max-width: var(--maxw); margin: 0 auto;
  padding: 64px 24px 80px;
  display: grid; grid-template-columns: 1.05fr 0.95fr;
  gap: 56px; align-items: center;
}
.hero__copy .eyebrow { display: block; margin-bottom: 18px; }
.hero h1 { font-size: clamp(38px, 6vw, 62px); font-weight: 800; }
.lede { margin-top: 22px; font-size: clamp(17px, 2vw, 20px); color: var(--text-2); max-width: 30ch; }
.hero__cta { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 34px; }
.trust {
  list-style: none; display: flex; flex-wrap: wrap; gap: 10px 22px;
  margin-top: 34px; font-size: 14px; color: var(--text-2); font-weight: 500;
}
.trust li { display: inline-flex; align-items: center; gap: 7px; }
.trust svg { width: 16px; height: 16px; color: var(--accent); }

@media (max-width: 880px) {
  .hero { grid-template-columns: 1fr; padding-top: 40px; gap: 48px; }
  .hero__device { order: -1; }
  .lede { max-width: none; }
}

/* ---- phone mockup ---- */
.hero__device { display: flex; justify-content: center; }
.phone {
  width: 300px; max-width: 80vw;
  background: var(--bg); border: 1px solid var(--border);
  border-radius: 40px; padding: 12px;
  box-shadow: var(--shadow-lg);
  position: relative;
}
.phone__notch {
  position: absolute; top: 14px; left: 50%; transform: translateX(-50%);
  width: 110px; height: 22px; border-radius: 0 0 14px 14px;
  background: var(--bg-elem);
}
.phone__screen {
  background: var(--bg-elem);
  border-radius: 30px; padding: 40px 18px 22px;
  display: flex; flex-direction: column; gap: 18px;
}
.screen-eyebrow { font-family: var(--mono); font-size: 9px; letter-spacing: 0.14em; color: var(--text-3); text-align: center; }

.ring { position: relative; width: 200px; height: 200px; margin: 4px auto 0; }
.ring__svg { transform: rotate(-90deg); width: 100%; height: 100%; }
.ring__svg circle { fill: none; stroke-width: 17; stroke-linecap: round; }
.ring__track { stroke: var(--track); }
.ring__wifi {
  stroke: var(--wifi); stroke-dasharray: 528; stroke-dashoffset: 339; /* ~36% */
}
.ring__mobile {
  stroke: var(--mobile); stroke-dasharray: 528; stroke-dashoffset: 528;
  animation: ring-fill 1.4s cubic-bezier(0.22, 1, 0.36, 1) 0.3s forwards;
}
@keyframes ring-fill { to { stroke-dashoffset: 198; } } /* ~62% */
.ring__center {
  position: absolute; inset: 0; display: flex; flex-direction: column;
  align-items: center; justify-content: center; text-align: center;
}
.ring__label { font-family: var(--mono); font-size: 9px; letter-spacing: 0.12em; text-transform: uppercase; color: var(--text-3); }
.ring__value { font-size: 40px; font-weight: 700; letter-spacing: -0.04em; font-variant-numeric: tabular-nums; }
.ring__value small { font-size: 15px; font-weight: 600; color: var(--text-2); margin-left: 2px; }
.ring__sub { font-size: 11px; color: var(--text-2); margin-top: 4px; }

.split { display: flex; gap: 10px; }
.split__item {
  flex: 1; background: var(--bg); border: 1px solid var(--border);
  border-radius: 12px; padding: 10px 12px; display: grid;
  grid-template-columns: auto 1fr; gap: 2px 7px; align-items: center;
}
.split__k { font-size: 11px; color: var(--text-2); }
.split__v { grid-column: 2; font-size: 15px; font-weight: 700; font-variant-numeric: tabular-nums; }
.dot { width: 8px; height: 8px; border-radius: 50%; grid-row: span 2; }
.dot--mobile { background: var(--mobile); }
.dot--wifi { background: var(--wifi); }

.limit { background: var(--bg); border: 1px solid var(--border); border-radius: 12px; padding: 12px; display: flex; flex-direction: column; gap: 8px; }
.limit__head { display: flex; justify-content: space-between; font-family: var(--mono); font-size: 9px; letter-spacing: 0.1em; color: var(--text-3); }
.limit__status { color: var(--accent); font-weight: 500; }
.limit__bar { height: 8px; border-radius: 6px; background: var(--track); overflow: hidden; }
.limit__bar span { display: block; height: 100%; background: var(--accent); border-radius: 6px; }
.limit__ticks { display: flex; justify-content: space-between; font-family: var(--mono); font-size: 10px; color: var(--text-3); font-variant-numeric: tabular-nums; }

/* ---- features grid ---- */
.grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px;
}
.card {
  background: var(--bg-elem); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 28px;
  transition: transform 0.2s ease, border-color 0.2s ease;
}
.card:hover { transform: translateY(-4px); border-color: var(--accent-line); }
.card__icon {
  width: 46px; height: 46px; border-radius: 13px;
  background: var(--accent-soft); color: var(--accent);
  display: grid; place-items: center; margin-bottom: 18px;
}
.card__icon svg { width: 22px; height: 22px; }
.card h3 { font-size: 19px; margin-bottom: 8px; }
.card p { color: var(--text-2); font-size: 15px; }

@media (max-width: 880px) { .grid { grid-template-columns: 1fr 1fr; } }
@media (max-width: 560px) { .grid { grid-template-columns: 1fr; } }

/* ---- steps ---- */
.steps { list-style: none; display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; counter-reset: step; }
.step { background: var(--bg-elem); border: 1px solid var(--border); border-radius: var(--radius); padding: 28px; }
.step__n {
  display: grid; place-items: center; width: 38px; height: 38px;
  border-radius: 11px; background: var(--tint); color: var(--bg);
  font-weight: 700; font-size: 17px; margin-bottom: 16px;
}
.step h3 { font-size: 18px; margin-bottom: 6px; }
.step p { color: var(--text-2); font-size: 15px; }
@media (max-width: 760px) { .steps { grid-template-columns: 1fr; } }

/* ---- privacy band ---- */
.privacy {
  max-width: var(--maxw); margin: 0 auto; padding: 72px 40px;
  width: calc(100% - 48px);
  background: var(--bg-elem); border: 1px solid var(--border);
  border-radius: 28px; text-align: center;
}
.privacy .eyebrow { display: block; margin-bottom: 16px; }
.privacy h2 { font-size: clamp(26px, 4vw, 40px); }
.privacy p { max-width: 62ch; margin: 20px auto 0; color: var(--text-2); font-size: 17px; }
.privacy__chips { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; margin-top: 28px; }
.privacy__chips span {
  font-family: var(--mono); font-size: 12px; letter-spacing: 0.04em;
  padding: 8px 14px; border-radius: 999px;
  background: var(--accent-soft); color: var(--accent);
  border: 1px solid var(--accent-line);
}

/* ---- faq ---- */
.faq { max-width: 760px; }
.faq details {
  border-bottom: 1px solid var(--border); padding: 4px 0;
}
.faq summary {
  cursor: pointer; list-style: none; padding: 18px 0;
  font-weight: 600; font-size: 17px; display: flex; justify-content: space-between; align-items: center; gap: 16px;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "+"; font-weight: 400; font-size: 24px; color: var(--text-3);
  transition: transform 0.2s ease; line-height: 1;
}
.faq details[open] summary::after { transform: rotate(45deg); }
.faq details p { color: var(--text-2); padding: 0 0 20px; font-size: 16px; max-width: 64ch; }

/* ---- final cta ---- */
.cta {
  max-width: var(--maxw); margin: 40px auto 0; padding: 88px 24px 110px;
  text-align: center;
}
.cta h2 { font-size: clamp(30px, 5vw, 50px); }
.cta p { color: var(--text-2); font-size: 19px; margin: 16px 0 32px; }
.cta__note { display: block; margin-top: 18px; font-family: var(--mono); font-size: 12px; letter-spacing: 0.06em; color: var(--text-3); }

/* ---- footer ---- */
.footer {
  border-top: 1px solid var(--border);
  text-align: center; padding: 48px 24px;
  display: flex; flex-direction: column; align-items: center; gap: 8px;
}
.footer__brand { display: flex; align-items: center; gap: 9px; font-weight: 700; font-size: 16px; }
.footer__meta { font-size: 13px; color: var(--text-3); }
.footer__copy { font-size: 13px; color: var(--text-3); margin-top: 8px; }

/* ---- legal / privacy page ---- */
.legal { max-width: 740px; margin: 0 auto; padding: 64px 24px 96px; }
.legal__back { font-size: 14px; color: var(--text-2); font-weight: 500; }
.legal__back:hover { color: var(--text); }
.legal .eyebrow { display: block; margin: 32px 0 14px; }
.legal h1 { font-size: clamp(34px, 6vw, 52px); font-weight: 800; }
.legal__updated { font-family: var(--mono); font-size: 13px; color: var(--text-3); margin-top: 12px; }
.legal__lead { font-size: 18px; color: var(--text-2); margin-top: 28px; }
.legal h2 { font-size: 22px; margin-top: 44px; }
.legal p { color: var(--text-2); font-size: 16px; margin-top: 14px; }
.legal ul { color: var(--text-2); font-size: 16px; margin: 14px 0 0; padding-left: 22px; }
.legal li { margin-top: 8px; }
.legal strong { color: var(--text); font-weight: 600; }
.legal a { color: var(--accent); font-weight: 500; }
.legal a:hover { text-decoration: underline; }
.footer a { color: var(--text-2); }
.footer a:hover { color: var(--text); }

/* ---- reveal on scroll ---- */
.reveal { opacity: 0; transform: translateY(20px); transition: opacity 0.7s ease, transform 0.7s ease; }
.reveal.in { opacity: 1; transform: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal { opacity: 1; transform: none; transition: none; }
  .ring__mobile { animation: none; stroke-dashoffset: 198; }
  .btn:hover, .card:hover { transform: none; }
}