/* =============================================================
   TwinC AI Design System – Colors & Type
   -------------------------------------------------------------
   Brand: 雙生雲科技 · TwinC AI Limited
   Concept: "雙生雲" (twin cloud) — twin clouds in blue + green,
   symbolising human × AI partnership, on-prem × cloud, dual LLM
   (OpenAI + in-house). Warm orange accents pulled from brand
   imagery (exhibition / hero banner).
   ============================================================= */

/* ---------- Webfonts ------------------------------------------
   TwinC's live site uses Wix defaults (Poppins + Noto Sans TC).
   We load the closest Google Font matches. ❗️If the brand has
   official font files, drop them in /fonts and update here. */

@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@300;400;500;600;700;800&family=Noto+Sans+TC:wght@300;400;500;700;900&family=Noto+Serif+TC:wght@400;500;700&family=JetBrains+Mono:wght@400;500;600&display=swap');

:root {
  /* ---------- Brand Colors ---------- */
  /* Primary — Twin Cloud duo */
  --brand-cloud-blue:    #4FC3DC;   /* left cloud — softer, supportive */
  --brand-cloud-blue-d:  #2FA3BE;
  --brand-cloud-blue-l:  #A8E1EE;

  --brand-leaf-green:    #5EB947;   /* right cloud — primary brand */
  --brand-leaf-green-d:  #3F9B2C;
  --brand-leaf-green-l:  #B4DFA6;

  /* Accent — Orange (exhibition / hero imagery) */
  --brand-amber:         #F59338;
  --brand-amber-d:       #D6731A;
  --brand-amber-l:       #FDC890;

  /* Deep tech navy (technical/architecture pages) */
  --brand-navy:          #0F2C4A;
  --brand-navy-l:        #1B3E67;

  /* ---------- Neutrals ---------- */
  --n-0:    #FFFFFF;
  --n-50:   #FAFBFC;
  --n-100:  #F3F5F7;
  --n-200:  #E6EAEE;
  --n-300:  #CED5DC;
  --n-400:  #9AA4AE;
  --n-500:  #6B7680;
  --n-600:  #4A525B;
  --n-700:  #2F353C;
  --n-800:  #1C2025;
  --n-900:  #0B0E11;

  /* ---------- Semantic FG / BG ---------- */
  --fg-1: var(--n-800);   /* primary text */
  --fg-2: var(--n-600);   /* secondary text */
  --fg-3: var(--n-500);   /* tertiary / captions */
  --fg-inv: var(--n-0);   /* text on dark */

  --bg-1: var(--n-0);     /* page */
  --bg-2: var(--n-50);    /* sunken / section alt */
  --bg-3: var(--n-100);   /* card alt */
  --bg-dark: var(--brand-navy);

  /* ---------- Status ---------- */
  --ok:     #2FA83B;
  --warn:   #E8A322;
  --error:  #D84B3C;
  --info:   var(--brand-cloud-blue);

  /* ---------- Border ---------- */
  --border-1: var(--n-200);
  --border-2: var(--n-300);
  --border-strong: var(--n-700);

  /* ---------- Type families ---------- */
  --font-sans: "Poppins", "Noto Sans TC", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-display: "Poppins", "Noto Sans TC", system-ui, sans-serif;
  --font-zh: "Noto Sans TC", "PingFang TC", "Microsoft JhengHei", sans-serif;
  --font-serif: "Noto Serif TC", Georgia, serif;
  --font-mono: "JetBrains Mono", "SF Mono", Consolas, monospace;

  /* ---------- Type scale (desktop default) ---------- */
  --fs-display: 68px;
  --fs-h1: 48px;
  --fs-h2: 36px;
  --fs-h3: 28px;
  --fs-h4: 22px;
  --fs-h5: 18px;
  --fs-body: 16px;
  --fs-body-lg: 18px;
  --fs-small: 14px;
  --fs-caption: 12px;

  --lh-tight: 1.15;
  --lh-snug: 1.3;
  --lh-normal: 1.55;
  --lh-loose: 1.75;

  --fw-light: 300;
  --fw-regular: 400;
  --fw-medium: 500;
  --fw-semibold: 600;
  --fw-bold: 700;
  --fw-black: 900;

  /* ---------- Spacing scale (4 px base) ---------- */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 20px;
  --space-6: 24px;
  --space-8: 32px;
  --space-10: 40px;
  --space-12: 48px;
  --space-16: 64px;
  --space-20: 80px;
  --space-24: 96px;

  /* ---------- Radius ---------- */
  --r-xs: 4px;
  --r-sm: 8px;
  --r-md: 12px;
  --r-lg: 20px;
  --r-xl: 28px;
  --r-pill: 999px;
  --r-cloud: 28px;  /* signature cloud-like soft corners */

  /* ---------- Shadows ---------- */
  --shadow-sm:   0 1px 2px rgba(15, 44, 74, 0.06),
                 0 1px 3px rgba(15, 44, 74, 0.04);
  --shadow-md:   0 4px 8px rgba(15, 44, 74, 0.06),
                 0 8px 24px rgba(15, 44, 74, 0.08);
  --shadow-lg:   0 12px 24px rgba(15, 44, 74, 0.10),
                 0 24px 48px rgba(15, 44, 74, 0.12);
  --shadow-glow-green: 0 8px 32px rgba(94, 185, 71, 0.28);
  --shadow-glow-blue:  0 8px 32px rgba(79, 195, 220, 0.32);
  --shadow-glow-amber: 0 10px 40px rgba(245, 147, 56, 0.32);

  /* ---------- Motion ---------- */
  --ease-out: cubic-bezier(.22, .9, .3, 1);
  --ease-in-out: cubic-bezier(.6, 0, .3, 1);
  --dur-quick: 140ms;
  --dur-base: 240ms;
  --dur-slow: 480ms;

  /* ---------- Signature gradients ---------- */
  --grad-twin: linear-gradient(110deg, var(--brand-cloud-blue) 0%, var(--brand-leaf-green) 100%);
  --grad-amber-glow: radial-gradient(120% 80% at 50% 0%, #FFD79A 0%, #F59338 45%, #C15A12 100%);
  --grad-hero-wash: linear-gradient(180deg, rgba(79,195,220,0.10) 0%, rgba(94,185,71,0.06) 60%, transparent 100%);
  --grad-navy-deep: linear-gradient(180deg, #0F2C4A 0%, #071A30 100%);
}

/* ---------- Semantic element defaults ---------- */
html { -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; }

body {
  font-family: var(--font-sans);
  font-size: var(--fs-body);
  line-height: var(--lh-normal);
  color: var(--fg-1);
  background: var(--bg-1);
  font-weight: var(--fw-regular);
}

h1, .h1 {
  font-family: var(--font-display);
  font-size: var(--fs-h1);
  line-height: var(--lh-tight);
  font-weight: var(--fw-bold);
  letter-spacing: -0.01em;
  color: var(--fg-1);
  margin: 0;
}

h2, .h2 {
  font-family: var(--font-display);
  font-size: var(--fs-h2);
  line-height: var(--lh-snug);
  font-weight: var(--fw-semibold);
  letter-spacing: -0.005em;
  margin: 0;
}

h3, .h3 {
  font-family: var(--font-display);
  font-size: var(--fs-h3);
  line-height: var(--lh-snug);
  font-weight: var(--fw-semibold);
  margin: 0;
}

h4, .h4 {
  font-family: var(--font-display);
  font-size: var(--fs-h4);
  line-height: var(--lh-snug);
  font-weight: var(--fw-semibold);
  margin: 0;
}

h5, .h5 {
  font-family: var(--font-sans);
  font-size: var(--fs-h5);
  line-height: var(--lh-normal);
  font-weight: var(--fw-semibold);
  margin: 0;
}

.lead  { font-size: var(--fs-body-lg); color: var(--fg-2); line-height: var(--lh-loose); }
.small { font-size: var(--fs-small); color: var(--fg-2); }
.caption { font-size: var(--fs-caption); color: var(--fg-3); letter-spacing: 0.02em; text-transform: uppercase; }

code, pre, .mono { font-family: var(--font-mono); font-size: 0.92em; }

.eyebrow {
  font-family: var(--font-sans);
  font-size: var(--fs-caption);
  font-weight: var(--fw-semibold);
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--brand-leaf-green-d);
}

.zh { font-family: var(--font-zh); }