/* nook4.me landing page.
   Three brand colours (ink, lime, pink) plus paper, following Sunny's note
   to converge the palette. Paper and lime are the MRD/spec palette, ink and
   the bright pink come from Tony's intro video (2026-10-30), and --emph is
   the wordmark pink in Tony's projects UI. Swap them here when the brand kit
   lands. No inline styles anywhere: the CSP only allows this stylesheet. */

:root {
  --ink: #14201e;
  --paper: #f4f6f2;
  --lime: #ddf79f;
  --pink: #ff479f;

  --bg: var(--paper);
  --fg: var(--ink);
  --muted: #4a5753;
  --card: #ffffff;
  --line: #dde4da;
  --emph: #d6197a; /* 4.5:1 on paper, so it also works for small text */
  --pill-bg: var(--ink);
  --pill-fg: var(--paper);
  --pill-num-bg: var(--lime);
  --pill-num-fg: var(--ink);
  --btn-bg: var(--ink);
  --btn-fg: var(--paper);
  --blob-a: rgba(221, 247, 159, 0.75);
  --blob-b: rgba(255, 71, 159, 0.14);
  --phone-ring: rgba(20, 32, 30, 0.35);

  --font: ui-rounded, "SF Pro Rounded", system-ui, -apple-system, "Segoe UI",
    "PingFang TC", "Noto Sans TC", "Microsoft JhengHei", sans-serif;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: var(--ink);
    --fg: #eef3ec;
    --muted: #a9b6b1;
    --card: #1c2a27;
    --line: #2b3b37;
    --emph: var(--pink);
    --pill-bg: var(--lime);
    --pill-fg: var(--ink);
    --pill-num-bg: var(--ink);
    --pill-num-fg: var(--lime);
    --btn-bg: var(--lime);
    --btn-fg: var(--ink);
    --blob-a: rgba(221, 247, 159, 0.09);
    --blob-b: rgba(255, 71, 159, 0.12);
    --phone-ring: rgba(221, 247, 159, 0.18);
  }
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font);
  font-size: 1.0625rem;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a {
  color: inherit;
}

a:focus-visible,
video:focus-visible {
  outline: 3px solid var(--pink);
  outline-offset: 3px;
}

em {
  font-style: normal;
  color: var(--emph);
}

.wrap {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 20px;
}

.skip {
  position: absolute;
  left: -999px;
}

.skip:focus {
  left: 16px;
  top: 12px;
  background: var(--card);
  padding: 8px 14px;
  border-radius: 8px;
}

/* header */

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding-top: 20px;
  padding-bottom: 8px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  font-size: 1.4rem;
  letter-spacing: -0.01em;
  text-decoration: none;
}

.brand svg {
  width: 36px;
  height: 36px;
  flex: none;
}

.brand .four {
  color: var(--emph);
}

.site-nav {
  display: flex;
  gap: 18px;
  font-weight: 600;
  font-size: 0.95rem;
}

.site-nav a {
  text-decoration: none;
}

.site-nav a:hover {
  text-decoration: underline;
}

/* hero */

.hero {
  display: grid;
  gap: 40px;
  align-items: center;
  padding-top: 28px;
  padding-bottom: 56px;
  background:
    radial-gradient(circle at 6% 22%, var(--blob-a) 0 150px, transparent 151px),
    radial-gradient(circle at 96% 82%, var(--blob-b) 0 190px, transparent 191px);
}

@media (min-width: 860px) {
  .hero {
    grid-template-columns: 1.15fr 0.85fr;
    padding-top: 48px;
  }
}

.eyebrow {
  display: inline-block;
  font-family: var(--mono);
  font-size: 0.85rem;
  background: var(--pill-bg);
  color: var(--pill-fg);
  padding: 5px 14px;
  border-radius: 999px;
}

h1 {
  font-size: clamp(2.5rem, 6.4vw, 4.25rem);
  line-height: 1.04;
  letter-spacing: -0.025em;
  font-weight: 800;
  margin: 20px 0 16px;
}

h1,
h2,
h3 {
  text-wrap: balance;
}

/* CJK headlines read heavier and wrap per character, so keep them smaller
   than the English ones to avoid a lone 來。 on its own line. */
:lang(zh) h1 {
  font-size: clamp(2.1rem, 5.6vw, 3.6rem);
  line-height: 1.15;
}

.tag {
  font-size: 1.3rem;
  font-weight: 700;
  margin: 0 0 10px;
}

.lead {
  color: var(--muted);
  font-size: 1.125rem;
  max-width: 34em;
  margin: 0;
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.btn {
  display: inline-block;
  padding: 13px 22px;
  border-radius: 999px;
  font-weight: 700;
  text-decoration: none;
  border: 2px solid var(--btn-bg);
}

.btn-primary {
  background: var(--btn-bg);
  color: var(--btn-fg);
}

.btn-secondary {
  color: var(--fg);
  border-color: currentColor;
}

.btn:hover {
  transform: translateY(-1px);
}

@media (prefers-reduced-motion: reduce) {
  .btn:hover {
    transform: none;
  }
}

/* video in a phone frame: the intro is vertical (1080x1920) */

.hero-media {
  margin: 0;
}

.phone {
  width: min(100%, 330px);
  margin: 0 auto;
  border: 10px solid #0b1311;
  border-radius: 42px;
  background: #0b1311;
  overflow: hidden;
  box-shadow: 0 0 0 1px var(--line), 0 30px 60px -24px var(--phone-ring);
}

.phone video {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 9 / 16;
  background: var(--ink);
}

.hero-media figcaption {
  text-align: center;
  font-size: 0.9rem;
  color: var(--muted);
  margin: 14px auto 0;
  max-width: 330px;
}

/* sections */

.section {
  padding-top: 48px;
  padding-bottom: 48px;
}

h2 {
  font-size: clamp(1.9rem, 4.4vw, 2.75rem);
  line-height: 1.1;
  letter-spacing: -0.02em;
  font-weight: 800;
  margin: 0 0 14px;
}

.section > .lead {
  margin-bottom: 28px;
}

.steps {
  display: grid;
  gap: 18px;
  margin-top: 28px;
}

@media (min-width: 760px) {
  .steps {
    grid-template-columns: repeat(3, 1fr);
  }
}

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 22px;
  padding: 22px;
  min-width: 0;
}

.soon .card {
  background: transparent;
  border-style: dashed;
}

.card h3 {
  font-size: 1.4rem;
  line-height: 1.2;
  letter-spacing: -0.01em;
  font-weight: 800;
  margin: 16px 0 8px;
}

.card p {
  margin: 0;
  color: var(--muted);
}

.pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--mono);
  font-size: 0.8rem;
  background: var(--pill-bg);
  color: var(--pill-fg);
  border-radius: 999px;
  padding: 4px 12px 4px 4px;
}

.pill b {
  display: inline-grid;
  place-items: center;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: var(--pill-num-bg);
  color: var(--pill-num-fg);
}

.url-chip {
  display: inline-flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 16px;
  max-width: 100%;
  font-family: var(--mono);
  font-size: 0.85rem;
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 6px 6px 6px 14px;
  overflow-wrap: anywhere;
}

.badge {
  background: var(--lime);
  color: var(--ink);
  border-radius: 999px;
  padding: 2px 10px;
  font-size: 0.75rem;
  font-weight: 700;
}

.notes ul {
  margin: 20px 0 0;
  padding-left: 1.2em;
  max-width: 40em;
}

.notes li {
  margin: 10px 0;
}

.invite {
  background: var(--ink);
  color: var(--paper);
  border-radius: 28px;
  padding: 36px 28px;
  margin-top: 24px;
  margin-bottom: 24px;
  /* In light mode the card is ink, the default button color. */
  --btn-bg: var(--lime);
  --btn-fg: var(--ink);
}

.invite em {
  color: var(--lime);
}

.invite p {
  color: #cfd9d4;
  max-width: 38em;
  margin: 0;
}

.invite .fine {
  margin-top: 20px;
  font-size: 0.85rem;
}

@media (prefers-color-scheme: dark) {
  .invite {
    background: var(--card);
    border: 1px solid var(--line);
  }
}

/* footer */

.site-footer {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 22px;
  padding-top: 28px;
  padding-bottom: 48px;
  color: var(--muted);
  font-size: 0.9rem;
}

/* 404 */

.not-found {
  padding-top: 64px;
  padding-bottom: 96px;
}