/* =============================================
   NUROL site — global styles
   Visual Identity Guidelines · December 2025
   ============================================= */

:root {
  /* Brand palette — exact values from brand kit */
  --bg: #1C1E21;            /* Matte Black */
  --bg-2: #15171a;          /* deeper matte */
  --ink: #FFFFFF;           /* White */
  --ink-dim: #E0D6B0;       /* Wheat (warm soft neutral) */
  --ink-mute: #B5BB89;      /* Ecru (green-tinted neutral) */
  --ink-faint: #6e7456;     /* darker ecru */
  --rule: #2a2d31;          /* matte-black tinted */
  --rule-2: #3a3d42;

  --forest: #1B6435;        /* Hunter Green */
  --forest-deep: #0e3a1f;
  --forest-ring: #2a8c4a;
  --mint: #4dba6e;          /* tighter mint derived from Hunter */

  --gold: #9D8300;          /* Dark Yellow */
  --gold-dim: #6b5a00;
  --gold-bright: #c9a82c;   /* slightly brighter for hover/highlight */

  /* Typography — rounded modern wordmark vibe. CJK falls back to Noto TC. */
  --sans: 'Sora', 'DM Sans', 'Noto Sans TC', system-ui, sans-serif;
  --body: 'DM Sans', 'Noto Sans TC', system-ui, sans-serif;
  --serif: 'Instrument Serif', 'Noto Serif TC', Georgia, serif;
  --mono: 'IBM Plex Mono', 'Noto Sans TC', ui-monospace, monospace;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; background: var(--bg); color: var(--ink); font-family: var(--body); -webkit-font-smoothing: antialiased; }
body { min-height: 100vh; line-height: 1.5; }

a { color: inherit; text-decoration: none; }
button { font: inherit; cursor: pointer; }
img { max-width: 100%; display: block; }

/* page wrapper -- atmospheric gradient as background */
.page {
  position: relative;
  min-height: 100vh;
  background:
    radial-gradient(ellipse 80% 60% at 20% 0%, rgba(27,100,53,0.22) 0%, rgba(28,30,33,0) 60%),
    radial-gradient(ellipse 60% 50% at 90% 30%, rgba(27,100,53,0.12) 0%, rgba(28,30,33,0) 60%),
    var(--bg);
  overflow-x: clip;
}

/* hero variant: deeper gradient */
.page-hero-bg {
  background:
    radial-gradient(ellipse 100% 70% at 20% 50%, rgba(27,100,53,0.26) 0%, rgba(28,30,33,0) 60%),
    radial-gradient(ellipse 60% 50% at 90% 30%, rgba(77,186,110,0.06) 0%, rgba(28,30,33,0) 60%),
    var(--bg);
}

/* nav */
.nav {
  position: sticky; top: 0; z-index: 50;
  display: flex; align-items: center; justify-content: space-between;
  padding: 22px 56px;
  background: rgba(28,30,33,0.72);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--rule);
}
.nav-brand { display: flex; align-items: center; gap: 12px; }
.nav-logo { height: 30px; width: auto; display: block; }
.nav-brand-name { font-family: var(--sans); font-size: 17px; font-weight: 700; letter-spacing: 0.18em; }
.nav-links { display: flex; gap: 32px; font-size: 14px; font-weight: 500; color: var(--ink-mute); }
.nav-links a { transition: color 120ms; }
.nav-links a:hover { color: var(--ink); }
.nav-links a.active { color: var(--ink); }
.nav-cta {
  font-size: 13px; font-weight: 600;
  color: var(--bg); padding: 11px 22px;
  background: var(--gold); border-radius: 999px;
  transition: background 120ms, transform 120ms;
  white-space: nowrap;
}
.nav-cta:hover { background: var(--gold-bright); transform: translateY(-1px); }

/* containers */
.container { max-width: 1280px; margin: 0 auto; padding: 0 56px; }
.container-narrow { max-width: 880px; margin: 0 auto; padding: 0 56px; }
.container-wide { max-width: 1440px; margin: 0 auto; padding: 0 56px; }

/* typography */
.eyebrow {
  font-family: var(--mono);
  font-size: 11px; letter-spacing: 0.3em;
  color: var(--gold);
  text-transform: uppercase;
}
.eyebrow-mute {
  font-family: var(--mono);
  font-size: 11px; letter-spacing: 0.22em;
  color: var(--forest-ring);
  text-transform: uppercase;
}
.h1 {
  font-family: var(--sans);
  font-size: clamp(56px, 7vw, 108px);
  line-height: 0.92;
  font-weight: 600;
  letter-spacing: -0.035em;
  margin: 0;
}
.h1 .italic-mint {
  font-family: var(--serif);
  font-style: italic;
  font-weight: 400;
  color: var(--mint);
}
.h2 {
  font-family: var(--sans);
  font-size: clamp(36px, 4.4vw, 64px);
  line-height: 1.0;
  font-weight: 600;
  letter-spacing: -0.025em;
  margin: 0;
}
.h2 .italic { font-family: var(--serif); font-style: italic; font-weight: 400; }
.h3 {
  font-family: var(--sans);
  font-size: clamp(22px, 2.4vw, 32px);
  line-height: 1.15;
  font-weight: 600;
  letter-spacing: -0.015em;
  margin: 0;
}
.lede {
  font-size: clamp(17px, 1.4vw, 21px);
  line-height: 1.5;
  color: var(--ink-dim);
  font-weight: 400;
}
.prose { color: var(--ink-dim); line-height: 1.7; font-size: 16px; }
.prose p { margin: 0 0 18px; }
.prose strong { color: var(--ink); font-weight: 600; }

/* buttons */
.btn {
  display: inline-flex; align-items: center; gap: 10px;
  font-size: 14px; font-weight: 600;
  padding: 14px 26px; border-radius: 999px;
  transition: transform 120ms, background 120ms, border-color 120ms;
  cursor: pointer; border: 1px solid transparent;
}
.btn-primary { background: var(--gold); color: var(--bg); }
.btn-primary:hover { background: var(--gold-bright); transform: translateY(-1px); }
.btn-ghost { border-color: var(--forest-ring); color: var(--ink); background: transparent; }
.btn-ghost:hover { background: rgba(27,100,53,0.18); }
.btn-arrow { font-family: var(--mono); font-size: 12px; letter-spacing: 0.16em; color: var(--ink-mute); padding: 14px 0; }
.btn-arrow:hover { color: var(--mint); }

/* sections */
section { padding: 96px 0; }
section.tight { padding: 64px 0; }
section.loose { padding: 140px 0; }

/* hairline */
.hr { height: 1px; background: var(--rule); border: 0; margin: 0; }
.hr-dim { height: 1px; background: var(--rule-2); border: 0; margin: 0; }

/* card */
.card {
  background: linear-gradient(180deg, rgba(27,100,53,0.08) 0%, rgba(28,30,33,0) 100%);
  border: 1px solid var(--rule-2);
  padding: 32px;
  border-radius: 4px;
  transition: border-color 200ms, background 200ms;
}
.card:hover { border-color: var(--forest-ring); }

/* footer */
.footer {
  border-top: 1px solid var(--rule);
  padding: 64px 0 32px;
  background: var(--bg-2);
}
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 64px; margin-bottom: 56px; }
.footer h4 {
  font-family: var(--mono);
  font-size: 10px; letter-spacing: 0.22em;
  color: var(--forest-ring);
  margin: 0 0 18px;
  text-transform: uppercase;
}
.footer ul { list-style: none; padding: 0; margin: 0; }
.footer li { margin-bottom: 10px; font-size: 14px; color: var(--ink-mute); }
.footer li a:hover { color: var(--ink); }
.footer-bottom {
  display: flex; justify-content: space-between; align-items: center;
  padding-top: 24px; border-top: 1px solid var(--rule);
  font-family: var(--mono); font-size: 10px; letter-spacing: 0.18em;
  color: var(--ink-faint);
}

/* utility grids */
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }
.hero-grid {
  display: grid; grid-template-columns: 1.05fr 1fr;
  gap: 60px; align-items: center;
  padding-top: 80px; padding-bottom: 120px;
}

/* numbered list */
.numbered { counter-reset: num; list-style: none; padding: 0; margin: 0; }
.numbered > li {
  counter-increment: num;
  display: grid; grid-template-columns: 64px 1fr; gap: 24px;
  padding: 32px 0; border-top: 1px solid var(--rule);
}
.numbered > li:last-child { border-bottom: 1px solid var(--rule); }
.numbered > li::before {
  content: "0" counter(num);
  font-family: var(--mono); font-size: 12px;
  color: var(--gold); letter-spacing: 0.16em;
}

/* tag */
.tag {
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--mono); font-size: 10px;
  letter-spacing: 0.2em; color: var(--forest-ring);
  border: 1px solid var(--forest-deep);
  padding: 5px 10px; border-radius: 999px;
  text-transform: uppercase;
}
.tag-gold { color: var(--gold); border-color: var(--gold-dim); }

/* horizon line for hero */
.horizon {
  position: absolute; left: 0; right: 0; height: 1px;
  background: linear-gradient(90deg, transparent, var(--forest-deep) 25%, var(--forest-deep) 75%, transparent);
}

/* form */
.field { display: flex; flex-direction: column; gap: 8px; margin-bottom: 22px; }
.field label {
  font-family: var(--mono); font-size: 10px;
  letter-spacing: 0.2em; color: var(--forest-ring);
  text-transform: uppercase;
}
.field input, .field textarea, .field select {
  background: rgba(255,255,255,0.02);
  border: 1px solid var(--rule-2);
  color: var(--ink);
  padding: 14px 16px;
  font: 15px/1.4 var(--body);
  border-radius: 4px;
  outline: none;
  transition: border-color 120ms, background 120ms;
}
.field input:focus, .field textarea:focus, .field select:focus {
  border-color: var(--forest-ring);
  background: rgba(27,100,53,0.06);
}
.field textarea { min-height: 140px; resize: vertical; }
.field-row { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.field-note { font-size: 12px; color: var(--ink-faint); margin-top: -10px; }

/* responsive */
@media (max-width: 900px) {
  .nav { padding: 18px 24px; }
  .nav-links { display: none; }
  .container, .container-narrow, .container-wide { padding: 0 24px; }
  .hero-grid { grid-template-columns: 1fr; padding-top: 48px; padding-bottom: 80px; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; gap: 24px; }
  .glance-grid { grid-template-columns: 1fr !important; }
  .stat-grid { grid-template-columns: 1fr 1fr !important; gap: 28px 24px !important; }
  .grounded-grid { grid-template-columns: 1fr !important; gap: 32px !important; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 32px; }
  section { padding: 64px 0; }
  .field-row { grid-template-columns: 1fr; }
}

/* =============================================
   i18n — language switch + Traditional-Chinese tuning
   ============================================= */
.nav-actions { display: flex; align-items: center; gap: 18px; }
.lang-select {
  background: transparent;
  border: 1px solid var(--rule-2); border-radius: 999px;
  color: var(--ink-mute);
  font-family: var(--mono); font-size: 11px; letter-spacing: 0.1em;
  padding: 7px 13px 7px 13px;
  cursor: pointer; outline: none;
  appearance: none; -webkit-appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='9' height='5' fill='none'%3E%3Cpath d='M1 1l3.5 3L8 1' stroke='%236e7456' stroke-width='1.4' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 10px center;
  padding-right: 26px;
  transition: color 120ms, border-color 120ms;
}
.lang-select:hover { color: var(--ink); border-color: var(--ink-mute); }
.lang-select option { background: #1C1E21; color: #FFFFFF; }
@media (max-width: 900px) { .nav-actions { gap: 12px; } .nav-cta { padding: 9px 16px; } }

/* CJK reads better with relaxed leading and no negative tracking */
html[lang="zh-Hant"] .h1,
html[lang="zh-Hant"] .h2 { letter-spacing: 0; line-height: 1.2; }
html[lang="zh-Hant"] .h3 { letter-spacing: 0; line-height: 1.4; }
html[lang="zh-Hant"] .lede { line-height: 1.7; }
html[lang="zh-Hant"] .prose { line-height: 1.85; }
/* italic serif is a Latin device — render CJK emphasis upright, in mint */
html[lang="zh-Hant"] .italic-mint { font-family: var(--sans); font-style: normal; }
html[lang="zh-Hant"] .h1 .italic,
html[lang="zh-Hant"] .h2 .italic,
html[lang="zh-Hant"] .h3 .italic { font-family: var(--sans); font-style: normal; color: var(--mint); }

/* =============================================
   Mobile nav — hamburger + full-screen overlay
   ============================================= */
.nav-hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  background: none;
  border: 1px solid var(--rule-2);
  border-radius: 6px;
  padding: 8px 10px;
  cursor: pointer;
}
.nav-hamburger span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--ink);
  border-radius: 2px;
  transition: opacity 200ms;
}

.mobile-nav {
  position: fixed;
  inset: 0;
  z-index: 100;
  background: rgba(13, 15, 17, 0.97);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 24px;
  padding: 40px 32px;
}
.mobile-nav a:not(.btn) {
  font-family: var(--sans);
  font-size: 30px;
  font-weight: 600;
  color: var(--ink-dim);
  letter-spacing: -0.01em;
  transition: color 120ms;
}
.mobile-nav a:not(.btn):hover,
.mobile-nav a:not(.btn).active { color: var(--ink); }
.mobile-nav-close {
  position: absolute;
  top: 24px;
  right: 24px;
  background: none;
  border: 1px solid var(--rule-2);
  border-radius: 6px;
  color: var(--ink-mute);
  font-size: 18px;
  line-height: 1;
  padding: 8px 13px;
  cursor: pointer;
  transition: color 120ms, border-color 120ms;
}
.mobile-nav-close:hover { color: var(--ink); border-color: var(--ink-mute); }

@media (max-width: 900px) {
  .nav-hamburger { display: flex; }
  /* Collapse section-level grids with inline styles (CSS classes can't override inline) */
  section [style*="grid-template-columns"]:not(.stat-grid) {
    grid-template-columns: 1fr !important;
    gap: 32px !important;
  }
}

@media (max-width: 480px) {
  .nav-cta { display: none; }         /* appears in mobile overlay instead */
  .stat-grid { grid-template-columns: 1fr !important; }
  .footer-grid { grid-template-columns: 1fr !important; }
  .footer-bottom { flex-direction: column; gap: 8px; text-align: center; }
}