/* ============================================================
   BUD AI — Design System
   科技感 + 專業感 + 信任感
   純 CSS，無 framework 依賴
   ============================================================ */

/* ----------------------------------------------------------
   1. Design Tokens (CSS Variables)
   ---------------------------------------------------------- */
:root {
  /* Brand Colors */
  --color-primary: #1a365d;        /* 深藍 — 專業、信任 */
  --color-primary-dark: #102a43;
  --color-primary-light: #2c5282;
  --color-accent: #3182ce;         /* 亮藍 — 科技、活力 */
  --color-accent-dark: #2c5282;
  --color-accent-light: #4299e1;

  /* Neutrals */
  --color-bg: #f7fafc;             /* 淺灰背景 */
  --color-surface: #ffffff;        /* 卡片白 */
  --color-surface-alt: #edf2f7;    /* 區塊分隔 */
  --color-border: #e2e8f0;         /* 細邊框 */
  --color-border-strong: #cbd5e0;

  /* Text */
  --color-text: #2d3748;           /* 主文字 — 深灰 */
  --color-text-muted: #718096;     /* 次要文字 */
  --color-text-light: #a0aec0;     /* 輔助文字 */
  --color-text-inverse: #ffffff;   /* 深底反白 */

  /* Status */
  --color-success: #2f855a;
  --color-success-bg: #f0fff4;
  --color-warning: #c05621;        /* 用橙唔用黃，較專業 */
  --color-warning-bg: #fffaf0;
  --color-danger: #c53030;
  --color-danger-bg: #fff5f5;
  --color-info: #2b6cb0;
  --color-info-bg: #ebf8ff;

  /* Typography */
  --font-sans: 'Noto Sans TC', 'PingFang TC', 'Microsoft JhengHei',
               -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'SF Mono', 'Cascadia Code', 'Roboto Mono',
               ui-monospace, monospace;

  --fs-xs: 0.75rem;     /* 12px */
  --fs-sm: 0.875rem;    /* 14px */
  --fs-base: 1rem;      /* 16px */
  --fs-lg: 1.125rem;    /* 18px */
  --fs-xl: 1.375rem;    /* 22px */
  --fs-2xl: 1.75rem;    /* 28px */
  --fs-3xl: 2.25rem;    /* 36px */
  --fs-4xl: 3rem;       /* 48px */

  --lh-tight: 1.2;
  --lh-normal: 1.5;
  --lh-relaxed: 1.7;

  --fw-regular: 400;
  --fw-medium: 500;
  --fw-semibold: 600;
  --fw-bold: 700;

  /* Spacing Scale (4px base) */
  --space-1: 0.25rem;   /* 4px */
  --space-2: 0.5rem;    /* 8px */
  --space-3: 0.75rem;   /* 12px */
  --space-4: 1rem;      /* 16px */
  --space-5: 1.5rem;    /* 24px */
  --space-6: 2rem;      /* 32px */
  --space-7: 3rem;      /* 48px */
  --space-8: 4rem;      /* 64px */
  --space-9: 6rem;      /* 96px */

  /* Radius — 4px 系，唔用大圓角 */
  --radius-sm: 2px;
  --radius: 4px;
  --radius-lg: 6px;

  /* Shadow — 微妙、專業 */
  --shadow-sm: 0 1px 2px 0 rgba(16, 42, 67, 0.05);
  --shadow: 0 1px 3px 0 rgba(16, 42, 67, 0.08), 0 1px 2px 0 rgba(16, 42, 67, 0.04);
  --shadow-md: 0 4px 6px -1px rgba(16, 42, 67, 0.08), 0 2px 4px -1px rgba(16, 42, 67, 0.04);
  --shadow-lg: 0 10px 15px -3px rgba(16, 42, 67, 0.08), 0 4px 6px -2px rgba(16, 42, 67, 0.04);

  /* Layout */
  --container-max: 1200px;
  --container-narrow: 760px;
  --nav-height: 60px;

  /* Transition */
  --transition-fast: 120ms ease-out;
  --transition: 180ms ease-out;
}

/* ----------------------------------------------------------
   2. Reset & Base
   ---------------------------------------------------------- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-height) + var(--space-4));
}

body {
  font-family: var(--font-sans);
  font-size: var(--fs-base);
  line-height: var(--lh-normal);
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Sticky footer pattern */
main {
  flex: 1 0 auto;
}

img, svg, video {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--transition-fast);
}
a:hover { color: var(--color-accent-dark); }

ul, ol { list-style: none; }

button, input, select, textarea {
  font: inherit;
  color: inherit;
}

/* ----------------------------------------------------------
   3. Typography
   ---------------------------------------------------------- */
h1, h2, h3, h4, h5, h6 {
  font-weight: var(--fw-semibold);
  line-height: var(--lh-tight);
  color: var(--color-primary);
  letter-spacing: -0.01em;
}

h1 { font-size: var(--fs-3xl); }
h2 { font-size: var(--fs-2xl); }
h3 { font-size: var(--fs-xl); }
h4 { font-size: var(--fs-lg); }

p { line-height: var(--lh-relaxed); }

strong { font-weight: var(--fw-semibold); }

/* Monospace 標籤 — 科技感 */
.mono {
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  letter-spacing: 0.02em;
}

.eyebrow {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-accent);
  font-weight: var(--fw-medium);
  margin-bottom: var(--space-2);
  display: block;
}

.text-muted { color: var(--color-text-muted); }
.text-light { color: var(--color-text-light); }
.text-primary { color: var(--color-primary); }
.text-accent { color: var(--color-accent); }
.text-center { text-align: center; }

/* ----------------------------------------------------------
   4. Layout — Container & Section
   ---------------------------------------------------------- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--space-4);
}

.container-narrow {
  max-width: var(--container-narrow);
}

.section {
  padding-block: var(--space-8);
}

.section-sm {
  padding-block: var(--space-7);
}

.section-alt {
  background-color: var(--color-surface-alt);
}

.section-primary {
  background-color: var(--color-primary);
  color: var(--color-text-inverse);
}
.section-primary h1,
.section-primary h2,
.section-primary h3,
.section-primary h4 { color: var(--color-text-inverse); }

/* Section header — numbered layout */
.section-header {
  max-width: 640px;
  margin-bottom: var(--space-7);
}
.section-header.center {
  margin-inline: auto;
  text-align: center;
}
.section-number {
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  color: var(--color-accent);
  font-weight: var(--fw-medium);
  display: inline-block;
  margin-bottom: var(--space-2);
}
.section-title {
  font-size: var(--fs-2xl);
  margin-bottom: var(--space-3);
}
.section-subtitle {
  color: var(--color-text-muted);
  font-size: var(--fs-lg);
  line-height: var(--lh-relaxed);
}

/* ----------------------------------------------------------
   5. Navigation — Sticky Top Bar
   ---------------------------------------------------------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-height);
  background-color: var(--color-primary);
  border-bottom: 1px solid var(--color-primary-dark);
  box-shadow: var(--shadow-sm);
}

.nav-inner {
  height: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--space-4);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  color: var(--color-text-inverse);
  font-weight: var(--fw-bold);
  font-size: var(--fs-lg);
  letter-spacing: -0.01em;
}
.nav-brand:hover { color: var(--color-text-inverse); opacity: 0.9; }

.nav-brand-icon {
  width: 28px;
  height: 28px;
  flex-shrink: 0;
}

.nav-links {
  display: none;            /* mobile 隱藏，用 toggle */
  align-items: center;
  gap: var(--space-1);
}

.nav-link {
  display: block;
  padding: var(--space-2) var(--space-3);
  color: rgba(255, 255, 255, 0.85);
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  border-radius: var(--radius);
  transition: background var(--transition-fast), color var(--transition-fast);
}
.nav-link:hover {
  color: #fff;
  background-color: rgba(255, 255, 255, 0.08);
}
.nav-link.active {
  color: #fff;
  background-color: rgba(255, 255, 255, 0.12);
}

.nav-cta {
  margin-left: var(--space-2);
}

/* Mobile hamburger */
.nav-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: var(--radius);
  cursor: pointer;
  color: #fff;
  transition: background var(--transition-fast);
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
  position: relative;
  z-index: 1001;
}
.nav-toggle:hover { background-color: rgba(255, 255, 255, 0.08); }
.nav-toggle svg { width: 20px; height: 20px; }

/* Mobile dropdown menu */
.nav-mobile {
  display: none;
  position: absolute;
  top: var(--nav-height);
  left: 0;
  right: 0;
  background-color: var(--color-primary);
  border-bottom: 1px solid var(--color-primary-dark);
  box-shadow: var(--shadow-lg);
  padding: var(--space-3);
  z-index: 1000;
}
.nav-mobile.open {
  display: block;
}
.nav-mobile .nav-link {
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius);
  font-size: var(--fs-base);
}
.nav-mobile .nav-link:hover,
.nav-mobile .nav-link.active {
  background-color: rgba(255, 255, 255, 0.1);
}
.nav-mobile .nav-cta {
  margin: var(--space-3) 0 0;
  width: 100%;
  text-align: center;
}

/* ----------------------------------------------------------
   6. Buttons — 4px radius, 唔用 pill
   ---------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-5);
  font-size: var(--fs-sm);
  font-weight: var(--fw-semibold);
  font-family: var(--font-sans);
  line-height: 1;
  border: 1px solid transparent;
  border-radius: var(--radius);
  cursor: pointer;
  text-decoration: none;
  white-space: nowrap;
  transition: all var(--transition-fast);
  user-select: none;
}
.btn:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}
.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-primary {
  background-color: var(--color-accent);
  color: #fff;
  border-color: var(--color-accent);
}
.btn-primary:hover {
  background-color: var(--color-accent-dark);
  border-color: var(--color-accent-dark);
  color: #fff;
}

.btn-secondary {
  background-color: transparent;
  color: var(--color-accent);
  border-color: var(--color-border-strong);
}
.btn-secondary:hover {
  background-color: var(--color-surface-alt);
  border-color: var(--color-accent);
  color: var(--color-accent-dark);
}

.btn-ghost {
  background-color: transparent;
  color: var(--color-text-muted);
  border-color: transparent;
}
.btn-ghost:hover {
  background-color: var(--color-surface-alt);
  color: var(--color-text);
}

/* 反白版本 — 用喺深色背景 */
.btn-inverse {
  background-color: #fff;
  color: var(--color-primary);
  border-color: #fff;
}
.btn-inverse:hover {
  background-color: var(--color-surface-alt);
  color: var(--color-primary);
}

.btn-outline-inverse {
  background-color: transparent;
  color: #fff;
  border-color: rgba(255, 255, 255, 0.4);
}
.btn-outline-inverse:hover {
  background-color: rgba(255, 255, 255, 0.1);
  border-color: #fff;
  color: #fff;
}

.btn-lg {
  padding: var(--space-4) var(--space-6);
  font-size: var(--fs-base);
}
.btn-sm {
  padding: var(--space-2) var(--space-3);
  font-size: var(--fs-xs);
}
.btn-block {
  display: flex;
  width: 100%;
}

.btn svg {
  width: 16px;
  height: 16px;
}

/* ----------------------------------------------------------
   7. Card — 乾淨、微妙陰影
   ---------------------------------------------------------- */
.card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: var(--space-5);
  transition: box-shadow var(--transition), border-color var(--transition);
}
.card-hover:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--color-border-strong);
}

.card-feature {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  height: 100%;
}
.card-feature-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background-color: var(--color-info-bg);
  color: var(--color-accent);
  border-radius: var(--radius);
  flex-shrink: 0;
}
.card-feature-icon svg { width: 22px; height: 22px; }

.card-title {
  font-size: var(--fs-lg);
  font-weight: var(--fw-semibold);
  color: var(--color-primary);
}
.card-body {
  color: var(--color-text-muted);
  font-size: var(--fs-sm);
  line-height: var(--lh-relaxed);
}

/* Pricing card */
.card-pricing {
  position: relative;
  display: flex;
  flex-direction: column;
  height: 100%;
}
.card-pricing-featured {
  border-color: var(--color-accent);
  border-width: 2px;
}
.card-pricing-badge {
  position: absolute;
  top: -10px;
  left: 50%;
  transform: translateX(-50%);
  background-color: var(--color-accent);
  color: #fff;
  font-size: var(--fs-xs);
  font-weight: var(--fw-semibold);
  padding: 2px var(--space-3);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  white-space: nowrap;
}

/* ----------------------------------------------------------
   8. Grid Systems
   ---------------------------------------------------------- */
.stat-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-4);
}

.feature-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-5);
}

.grid-2 { display: grid; grid-template-columns: 1fr; gap: var(--space-5); }
.grid-3 { display: grid; grid-template-columns: 1fr; gap: var(--space-5); }
.grid-4 { display: grid; grid-template-columns: repeat(2, 1fr); gap: var(--space-4); }

/* Stat item */
.stat {
  text-align: center;
  padding: var(--space-5) var(--space-3);
}
.stat-value {
  font-size: var(--fs-3xl);
  font-weight: var(--fw-bold);
  color: var(--color-primary);
  line-height: 1;
  font-family: var(--font-mono);
  letter-spacing: -0.02em;
}
.stat-value-unit {
  font-size: var(--fs-lg);
  font-weight: var(--fw-medium);
  color: var(--color-accent);
  margin-left: var(--space-1);
}
.stat-label {
  margin-top: var(--space-2);
  font-size: var(--fs-sm);
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  letter-spacing: 0.02em;
}

/* ----------------------------------------------------------
   9. Hero Section
   ---------------------------------------------------------- */
.hero {
  background-color: var(--color-primary);
  color: var(--color-text-inverse);
  padding-block: var(--space-9) var(--space-8);
  position: relative;
  overflow: hidden;
}
/* 微妙嘅網格底紋 — 科技感 */
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.03) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
}

.hero-inner {
  position: relative;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--space-4);
}

.hero-eyebrow {
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  color: var(--color-accent-light);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: var(--space-3);
}

.hero-title {
  font-size: var(--fs-3xl);
  font-weight: var(--fw-bold);
  color: #fff;
  line-height: var(--lh-tight);
  margin-bottom: var(--space-4);
  letter-spacing: -0.02em;
}

.hero-subtitle {
  font-size: var(--fs-lg);
  color: rgba(255, 255, 255, 0.8);
  line-height: var(--lh-relaxed);
  max-width: 580px;
  margin-bottom: var(--space-6);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
}

/* ----------------------------------------------------------
   10. Table — spec-sheet 風格
   ---------------------------------------------------------- */
.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--fs-sm);
  background-color: var(--color-surface);
}
.table thead th {
  background-color: var(--color-primary);
  color: #fff;
  text-align: left;
  padding: var(--space-3) var(--space-4);
  font-weight: var(--fw-semibold);
  font-size: var(--fs-xs);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  font-family: var(--font-mono);
  white-space: nowrap;
}
.table tbody td {
  padding: var(--space-3) var(--space-4);
  border-top: 1px solid var(--color-border);
  vertical-align: top;
}
.table tbody tr:nth-child(even) {
  background-color: var(--color-surface-alt);
}
.table tbody tr:hover {
  background-color: var(--color-info-bg);
}
.table .col-highlight {
  background-color: var(--color-info-bg);
  font-weight: var(--fw-medium);
  color: var(--color-primary);
}

/* Comparison table — 我哋 vs 傳統 */
.table-compare .col-us {
  background-color: var(--color-info-bg);
}

/* ----------------------------------------------------------
   11. Form Elements
   ---------------------------------------------------------- */
.form-group {
  margin-bottom: var(--space-4);
}
.form-label {
  display: block;
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  color: var(--color-text);
  margin-bottom: var(--space-2);
}
.form-label .req { color: var(--color-danger); }

.form-control {
  display: block;
  width: 100%;
  padding: var(--space-3) var(--space-4);
  font-size: var(--fs-base);
  color: var(--color-text);
  background-color: var(--color-surface);
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}
.form-control:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px rgba(49, 130, 206, 0.15);
}
.form-control::placeholder { color: var(--color-text-light); }

textarea.form-control { min-height: 120px; resize: vertical; }
select.form-control {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%23718096' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right var(--space-4) center;
  padding-right: var(--space-7);
}

.form-help {
  font-size: var(--fs-xs);
  color: var(--color-text-muted);
  margin-top: var(--space-2);
}

.form-row {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
}

/* ----------------------------------------------------------
   12. Footer
   ---------------------------------------------------------- */
.footer {
  background-color: var(--color-primary-dark);
  color: rgba(255, 255, 255, 0.7);
  padding-block: var(--space-7) var(--space-5);
  border-top: 3px solid var(--color-accent);
}
.footer-inner {
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--space-4);
}
.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-6);
  margin-bottom: var(--space-6);
}
.footer-brand {
  font-size: var(--fs-lg);
  font-weight: var(--fw-bold);
  color: #fff;
  margin-bottom: var(--space-3);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}
.footer-desc {
  font-size: var(--fs-sm);
  line-height: var(--lh-relaxed);
  max-width: 320px;
}
.footer-col-title {
  font-size: var(--fs-xs);
  font-weight: var(--fw-semibold);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #fff;
  margin-bottom: var(--space-3);
  font-family: var(--font-mono);
}
.footer-links { display: flex; flex-direction: column; gap: var(--space-2); }
.footer-link {
  color: rgba(255, 255, 255, 0.7);
  font-size: var(--fs-sm);
  transition: color var(--transition-fast);
}
.footer-link:hover { color: #fff; }

.footer-contact {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--fs-sm);
  color: rgba(255, 255, 255, 0.7);
}
.footer-contact svg { width: 16px; height: 16px; flex-shrink: 0; opacity: 0.8; }

.footer-bottom {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  padding-top: var(--space-5);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  font-size: var(--fs-xs);
  color: rgba(255, 255, 255, 0.5);
}
.footer-bottom-links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
}

/* ----------------------------------------------------------
   13. Utility & Helpers
   ---------------------------------------------------------- */
.mt-0 { margin-top: 0; }
.mt-2 { margin-top: var(--space-2); }
.mt-3 { margin-top: var(--space-3); }
.mt-4 { margin-top: var(--space-4); }
.mt-5 { margin-top: var(--space-5); }
.mt-6 { margin-top: var(--space-6); }
.mb-0 { margin-bottom: 0; }
.mb-2 { margin-bottom: var(--space-2); }
.mb-3 { margin-bottom: var(--space-3); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-5 { margin-bottom: var(--space-5); }
.mb-6 { margin-bottom: var(--space-6); }

.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.flex-wrap { flex-wrap: wrap; }
.gap-2 { gap: var(--space-2); }
.gap-3 { gap: var(--space-3); }
.gap-4 { gap: var(--space-4); }

.hidden { display: none !important; }
.block { display: block; }
.inline-block { display: inline-block; }

.w-full { width: 100%; }
.max-w-prose { max-width: 65ch; }

/* Badge / Tag */
.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: 2px var(--space-2);
  font-size: var(--fs-xs);
  font-weight: var(--fw-medium);
  font-family: var(--font-mono);
  letter-spacing: 0.02em;
  background-color: var(--color-surface-alt);
  color: var(--color-text-muted);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  text-transform: uppercase;
}
.badge-accent {
  background-color: var(--color-info-bg);
  color: var(--color-accent-dark);
  border-color: transparent;
}
.badge-success {
  background-color: var(--color-success-bg);
  color: var(--color-success);
  border-color: transparent;
}
.badge-warning {
  background-color: var(--color-warning-bg);
  color: var(--color-warning);
  border-color: transparent;
}

/* Divider */
.divider {
  height: 1px;
  background-color: var(--color-border);
  border: 0;
  margin-block: var(--space-6);
}

/* Process / Steps */
.steps {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-5);
  counter-reset: step;
}
.step {
  position: relative;
  padding-left: var(--space-7);
}
.step::before {
  counter-increment: step;
  content: counter(step, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 0;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--color-primary);
  color: #fff;
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  font-weight: var(--fw-bold);
  border-radius: var(--radius);
}
.step-title {
  font-size: var(--fs-lg);
  font-weight: var(--fw-semibold);
  color: var(--color-primary);
  margin-bottom: var(--space-2);
  padding-top: var(--space-2);
}
.step-body {
  color: var(--color-text-muted);
  font-size: var(--fs-sm);
  line-height: var(--lh-relaxed);
}

/* Notice / Callout */
.notice {
  display: flex;
  gap: var(--space-3);
  padding: var(--space-4);
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
  background-color: var(--color-surface-alt);
  font-size: var(--fs-sm);
}
.notice-info {
  background-color: var(--color-info-bg);
  border-color: rgba(43, 108, 176, 0.2);
}
.notice-success {
  background-color: var(--color-success-bg);
  border-color: rgba(47, 133, 90, 0.2);
}
.notice-warning {
  background-color: var(--color-warning-bg);
  border-color: rgba(192, 86, 33, 0.2);
}
.notice svg { width: 20px; height: 20px; flex-shrink: 0; }

/* ----------------------------------------------------------
   14. Responsive Breakpoints
   ---------------------------------------------------------- */

/* >= 768px — Tablet */
@media (min-width: 768px) {
  h1 { font-size: var(--fs-4xl); }
  h2 { font-size: var(--fs-3xl); }

  .hero { padding-block: var(--space-9); }
  .hero-title { font-size: var(--fs-4xl); }
  .hero-subtitle { font-size: var(--fs-xl); }

  .section { padding-block: var(--space-9); }

  .stat-grid { grid-template-columns: repeat(4, 1fr); }
  .feature-grid { grid-template-columns: repeat(3, 1fr); }
  .grid-2 { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(3, 1fr); }
  .grid-4 { grid-template-columns: repeat(4, 1fr); }

  .form-row { grid-template-columns: repeat(2, 1fr); }

  .steps { grid-template-columns: repeat(2, 1fr); }

  .footer-grid {
    grid-template-columns: 2fr 1fr 1fr 1fr;
  }
  .footer-bottom {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }

  /* 顯示桌面 nav，隱藏 hamburger */
  .nav-toggle { display: none; }
  .nav-links { display: flex; }
}

/* >= 1024px — Desktop */
@media (min-width: 1024px) {
  .container { padding-inline: var(--space-5); }
  .hero-title { font-size: 3.5rem; }
  .steps { grid-template-columns: repeat(4, 1fr); }
  .feature-grid { gap: var(--space-6); }
}

/* ----------------------------------------------------------
   15. Accessibility & Motion
   ---------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

/* Skip link for screen readers */
.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--color-primary);
  color: #fff;
  padding: var(--space-2) var(--space-4);
  z-index: 200;
  border-radius: 0 0 var(--radius) 0;
}
.skip-link:focus {
  top: 0;
  color: #fff;
}

/* Visually hidden but accessible */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* ----------------------------------------------------------
   16. Page-specific — Hero features (首頁 hero 功能 chips)
   ---------------------------------------------------------- */
.hero-features {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  margin-bottom: var(--space-6);
}
.hero-feature {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-1) var(--space-3);
  background-color: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: var(--radius);
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  color: rgba(255, 255, 255, 0.92);
}
.hero-feature svg {
  width: 14px;
  height: 14px;
  color: var(--color-accent-light);
  flex-shrink: 0;
}

/* ----------------------------------------------------------
   17. Testimonials (客戶見證)
   ---------------------------------------------------------- */
.testimonial {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  height: 100%;
}
.testimonial-quote {
  width: 28px;
  height: 28px;
  color: var(--color-accent);
  opacity: 0.55;
  flex-shrink: 0;
}
.testimonial-text {
  font-size: var(--fs-base);
  line-height: var(--lh-relaxed);
  color: var(--color-text);
  flex: 1;
  margin: 0;
}
.testimonial-author {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding-top: var(--space-3);
  border-top: 1px solid var(--color-border);
}
.testimonial-name {
  font-size: var(--fs-sm);
  font-weight: var(--fw-semibold);
  color: var(--color-primary);
}
.testimonial-role {
  font-size: var(--fs-xs);
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  letter-spacing: 0.02em;
}

/* ----------------------------------------------------------
   18. Pricing (定價卡)
   ---------------------------------------------------------- */
.pricing-grid {
  align-items: stretch;
}
.pricing-head {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: var(--space-1);
  padding-bottom: var(--space-4);
  border-bottom: 1px solid var(--color-border);
  margin-bottom: var(--space-4);
}
.pricing-plan-name {
  font-size: var(--fs-lg);
  font-weight: var(--fw-semibold);
  color: var(--color-primary);
}
.pricing-price {
  display: flex;
  align-items: baseline;
  gap: var(--space-1);
  margin-top: var(--space-1);
}
.pricing-price-currency {
  font-size: var(--fs-base);
  font-weight: var(--fw-medium);
  color: var(--color-text-muted);
  font-family: var(--font-mono);
}
.pricing-price-amount {
  font-size: var(--fs-3xl);
  font-weight: var(--fw-bold);
  color: var(--color-primary);
  font-family: var(--font-mono);
  letter-spacing: -0.02em;
  line-height: 1;
}
.pricing-price-note {
  font-size: var(--fs-xs);
  color: var(--color-text-light);
  font-family: var(--font-mono);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-top: var(--space-1);
}
.pricing-desc {
  font-size: var(--fs-sm);
  color: var(--color-text-muted);
  line-height: var(--lh-relaxed);
  margin-bottom: var(--space-4);
}
.pricing-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  margin-bottom: var(--space-5);
  flex: 1;
}
.pricing-list li {
  display: flex;
  align-items: flex-start;
  gap: var(--space-2);
  font-size: var(--fs-sm);
  color: var(--color-text);
  line-height: var(--lh-normal);
}
.pricing-list svg {
  width: 16px;
  height: 16px;
  color: var(--color-success);
  flex-shrink: 0;
  margin-top: 3px;
}
.pricing-cta {
  margin-top: auto;
}

/* Featured plan badge spacing */
.card-pricing-featured .pricing-head {
  border-bottom-color: var(--color-accent);
}

/* ----------------------------------------------------------
   19. Guarantee notices
   ---------------------------------------------------------- */
.guarantee-notice {
  align-items: flex-start;
  height: 100%;
}
.guarantee-notice strong {
  display: block;
  font-size: var(--fs-base);
  font-weight: var(--fw-semibold);
  color: var(--color-primary);
  margin-bottom: var(--space-1);
}
.guarantee-notice p {
  font-size: var(--fs-sm);
  color: var(--color-text-muted);
  line-height: var(--lh-relaxed);
  margin: 0;
}

/* ----------------------------------------------------------
   20. FAQ accordion (定價頁底部)
   ---------------------------------------------------------- */
.faq-item {
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background-color: var(--color-surface);
  margin-bottom: var(--space-2);
  overflow: hidden;
}
.faq-item summary {
  padding: var(--space-4);
  font-size: var(--fs-base);
  font-weight: var(--fw-semibold);
  color: var(--color-primary);
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  transition: background var(--transition-fast);
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: '+';
  font-family: var(--font-mono);
  font-size: var(--fs-lg);
  color: var(--color-accent);
  font-weight: var(--fw-bold);
  transition: transform var(--transition);
}
.faq-item[open] summary::after { content: '−'; }
.faq-item summary:hover { background-color: var(--color-surface-alt); }
.faq-item p {
  padding: 0 var(--space-4) var(--space-4);
  font-size: var(--fs-sm);
  color: var(--color-text-muted);
  line-height: var(--lh-relaxed);
  margin: 0;
}

/* Print */
@media print {
  .nav, .footer, .btn, .nav-toggle, .nav-mobile { display: none !important; }
  body { background: #fff; color: #000; }
}