/* ============================================================
   苔青 · taiqing.org  —— modern minimal light
   Accent: celadon / moss green (苔青)
   ============================================================ */

:root {
  --paper:      #fbfbf8;   /* warm paper background */
  --paper-2:    #ffffff;   /* cards */
  --ink:        #1c1d1a;   /* primary text */
  --ink-soft:   #52544e;   /* secondary text */
  --ink-faint:  #8a8c85;   /* tertiary / meta */
  --line:       #e8e8e2;   /* hairline borders */
  --line-soft:  #f0f0ea;
  --celadon:    #5c7d68;   /* accent — moss/celadon */
  --celadon-dk: #445f4e;
  --celadon-bg: #eef3ee;   /* accent tint */

  --radius:     18px;
  --radius-sm:  10px;
  --shadow:     0 1px 2px rgba(28,29,26,.04), 0 8px 24px rgba(28,29,26,.05);
  --shadow-lg:  0 2px 6px rgba(28,29,26,.06), 0 20px 48px rgba(28,29,26,.09);

  --font-serif: "Noto Serif SC", Georgia, "Songti SC", serif;
  --font-sans:  "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI",
                "PingFang SC", "Microsoft YaHei", sans-serif;

  --maxw: 1080px;
}

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

html { scroll-behavior: smooth; }

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

/* subtle paper grain */
.grain {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  opacity: .5;
  background-image: radial-gradient(rgba(92,125,104,.05) 1px, transparent 1px);
  background-size: 4px 4px;
}

a { color: inherit; text-decoration: none; }
em { font-style: normal; color: var(--celadon-dk); font-weight: 500; }

/* ---------------------------- header ---------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px clamp(20px, 5vw, 56px);
  background: rgba(251,251,248,.78);
  backdrop-filter: saturate(160%) blur(12px);
  -webkit-backdrop-filter: saturate(160%) blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color .3s;
}
.site-header:hover { border-color: var(--line-soft); }

.brand { display: flex; align-items: baseline; gap: 10px; }
.brand-seal {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 22px;
  letter-spacing: .12em;
  color: var(--ink);
}
.brand-latin {
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--ink-faint);
  text-transform: uppercase;
}

.site-nav { display: flex; gap: 28px; }
.site-nav a {
  font-size: 14px;
  color: var(--ink-soft);
  position: relative;
  transition: color .2s;
}
.site-nav a::after {
  content: "";
  position: absolute;
  left: 0; bottom: -4px;
  width: 0; height: 1.5px;
  background: var(--celadon);
  transition: width .25s ease;
}
.site-nav a:hover { color: var(--ink); }
.site-nav a:hover::after { width: 100%; }

/* ---------------------------- layout ---------------------------- */
main { position: relative; z-index: 1; }
section { padding-inline: clamp(20px, 5vw, 56px); }
.hero, .apps, .about { max-width: var(--maxw); margin-inline: auto; }

/* ---------------------------- hero ---------------------------- */
.hero {
  padding-top: clamp(64px, 12vh, 140px);
  padding-bottom: clamp(56px, 10vh, 120px);
}
.hero-eyebrow {
  font-size: 13px;
  letter-spacing: .34em;
  color: var(--celadon);
  text-transform: uppercase;
  margin-bottom: 24px;
}
.hero-title {
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(38px, 7vw, 76px);
  line-height: 1.18;
  letter-spacing: .02em;
  color: var(--ink);
  margin-bottom: 28px;
}
.hero-sub {
  max-width: 40ch;
  font-size: clamp(15px, 1.6vw, 18px);
  color: var(--ink-soft);
  margin-bottom: 40px;
}
.hero-note { color: var(--ink-faint); font-size: .82em; }

.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; }

.btn {
  display: inline-flex;
  align-items: center;
  font-size: 15px;
  font-weight: 500;
  padding: 13px 26px;
  border-radius: 999px;
  transition: transform .2s ease, background .2s, box-shadow .2s, color .2s;
}
.btn-primary {
  background: var(--celadon);
  color: #fff;
  box-shadow: 0 6px 18px rgba(92,125,104,.28);
}
.btn-primary:hover { background: var(--celadon-dk); transform: translateY(-2px); }
.btn-ghost { color: var(--ink-soft); }
.btn-ghost:hover { color: var(--ink); background: var(--celadon-bg); }

/* ---------------------------- section head ---------------------------- */
.section-head { margin-bottom: 36px; }
.section-head h2 {
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: clamp(26px, 3.4vw, 36px);
  letter-spacing: .06em;
  color: var(--ink);
  margin-bottom: 8px;
}
.section-head p { color: var(--ink-faint); font-size: 15px; }

/* ---------------------------- apps grid ---------------------------- */
.apps { padding-bottom: clamp(48px, 8vh, 96px); }

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 20px;
}

.card {
  position: relative;
  display: flex;
  flex-direction: column;
  background: var(--paper-2);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 26px 26px 24px;
  min-height: 210px;
  box-shadow: var(--shadow);
  transition: transform .28s cubic-bezier(.2,.7,.3,1),
              box-shadow .28s, border-color .28s;
}
.card:not(.is-soon):not(.is-placeholder):hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
  border-color: #dfe6df;
}

.card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 20px;
}
.card-glyph {
  display: grid;
  place-items: center;
  width: 46px; height: 46px;
  border-radius: 12px;
  background: var(--celadon-bg);
  color: var(--celadon-dk);
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 24px;
}

.card-title {
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 22px;
  letter-spacing: .04em;
  margin-bottom: 8px;
  color: var(--ink);
}
.card-desc {
  font-size: 14.5px;
  color: var(--ink-soft);
  flex-grow: 1;
  margin-bottom: 18px;
}
.card-link {
  font-size: 13px;
  color: var(--celadon);
  letter-spacing: .02em;
  font-weight: 500;
  transition: gap .2s;
}
.card:hover .card-link { color: var(--celadon-dk); }

/* badges */
.badge {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: .08em;
  padding: 4px 10px;
  border-radius: 999px;
}
.badge-live { background: var(--celadon-bg); color: var(--celadon-dk); }
.badge-soon { background: #f3f0e8; color: #9a8a5f; }

/* soon / placeholder states */
.card.is-soon, .card.is-placeholder { cursor: default; }
.card.is-soon .card-glyph { background: #f3f0e8; color: #9a8a5f; }
.card.is-soon .card-link { color: var(--ink-faint); }

.card.is-placeholder {
  background: transparent;
  border-style: dashed;
  border-color: #dcdcd4;
  box-shadow: none;
}
.card.is-placeholder .card-glyph {
  background: transparent;
  border: 1px dashed #cfcfc6;
  color: var(--ink-faint);
  font-size: 20px;
}
.card.is-placeholder .card-title,
.card.is-placeholder .card-desc { color: var(--ink-faint); }
.card.is-placeholder .card-link { color: var(--ink-faint); }

/* ---------------------------- about ---------------------------- */
.about {
  padding-top: clamp(40px, 7vh, 80px);
  padding-bottom: clamp(56px, 10vh, 110px);
  border-top: 1px solid var(--line);
}
.about-body { max-width: 56ch; }
.about-body p { font-size: clamp(15px, 1.6vw, 18px); color: var(--ink-soft); margin-bottom: 16px; }
.about-body strong { color: var(--ink); font-weight: 600; }
.about-muted { color: var(--ink-faint) !important; font-size: 14px !important; }

/* ---------------------------- footer ---------------------------- */
.site-footer {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
  padding: 32px 20px 44px;
  font-size: 13px;
  color: var(--ink-faint);
  letter-spacing: .04em;
}
.footer-dot { opacity: .5; }

/* ---------------------------- responsive ---------------------------- */
.br-mobile { display: none; }
@media (max-width: 640px) {
  .br-mobile { display: inline; }
  .site-nav { gap: 18px; }
  .hero-title { letter-spacing: 0; }
}

/* respect reduced motion */
@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; scroll-behavior: auto !important; }
}