/* ==========================================================================
   AEON Design System v2.0 — themes.css
   AI / 科技感主题 · 紫蓝配色 · 亮色/暗色双模式
   ==========================================================================
   使用方式: <link rel="stylesheet" href="/static/themes.css">
   建议放在 style.css 之后加载
   ========================================================================== */

/* ==========================================================================
   1. CSS CUSTOM PROPERTIES — 亮色模式 (默认)
   ========================================================================== */

:root {
  /* ── Primary: 紫色/蓝色系 (AI 科技感) ── */
  --color-primary-50: #f5f3ff;
  --color-primary-100: #ede9fe;
  --color-primary-200: #ddd6fe;
  --color-primary-300: #c4b5fd;
  --color-primary-400: #a78bfa;
  --color-primary-500: #8b5cf6;
  --color-primary-600: #7c3aed;
  --color-primary-700: #6d28d9;
  --color-primary-800: #5b21b6;
  --color-primary-900: #4c1d95;

  --color-primary: var(--color-primary-600);
  --color-primary-light: var(--color-primary-300);
  --color-primary-dark: var(--color-primary-700);
  --color-primary-bg: var(--color-primary-50);

  /* ── Secondary: 青色/湖蓝 ── */
  --color-secondary-50: #ecfeff;
  --color-secondary-100: #cffafe;
  --color-secondary-200: #a5f3fc;
  --color-secondary-300: #67e8f9;
  --color-secondary-400: #22d3ee;
  --color-secondary-500: #06b6d4;
  --color-secondary-600: #0891b2;
  --color-secondary-700: #0e7490;
  --color-secondary-800: #155e75;
  --color-secondary-900: #164e63;

  --color-secondary: var(--color-secondary-500);
  --color-secondary-light: var(--color-secondary-300);
  --color-secondary-dark: var(--color-secondary-600);

  /* ── Accent: 靛蓝 ── */
  --color-accent: #6366f1;
  --color-accent-light: #a5b4fc;
  --color-accent-dark: #4f46e5;
  --color-accent-bg: #eef2ff;

  /* ── Neutral / Gray ── */
  --color-neutral-50: #f8fafc;
  --color-neutral-100: #f1f5f9;
  --color-neutral-200: #e2e8f0;
  --color-neutral-300: #cbd5e1;
  --color-neutral-400: #94a3b8;
  --color-neutral-500: #64748b;
  --color-neutral-600: #475569;
  --color-neutral-700: #334155;
  --color-neutral-800: #1e293b;
  --color-neutral-900: #0f172a;

  /* ── Status Colors ── */
  --color-success: #10b981;
  --color-success-light: #34d399;
  --color-success-dark: #059669;
  --color-success-bg: #d1fae5;
  --color-success-text: #065f46;

  --color-error: #ef4444;
  --color-error-light: #f87171;
  --color-error-dark: #dc2626;
  --color-error-bg: #fee2e2;
  --color-error-text: #991b1b;

  --color-warning: #f59e0b;
  --color-warning-light: #fbbf24;
  --color-warning-dark: #d97706;
  --color-warning-bg: #fef3c7;
  --color-warning-text: #92400e;

  --color-info: #3b82f6;
  --color-info-light: #60a5fa;
  --color-info-dark: #2563eb;
  --color-info-bg: #dbeafe;
  --color-info-text: #1e40af;

  /* ── Text ── */
  --color-text: var(--color-neutral-900);
  --color-text-secondary: var(--color-neutral-600);
  --color-text-muted: var(--color-neutral-400);
  --color-text-inverse: #ffffff;

  /* ── Surfaces ── */
  --color-bg: var(--color-neutral-50);
  --color-bg-card: #ffffff;
  --color-bg-subtle: var(--color-neutral-100);
  --color-bg-elevated: #ffffff;
  --color-bg-overlay: rgba(15, 23, 42, 0.45);

  --color-border: var(--color-neutral-200);
  --color-border-light: var(--color-neutral-100);
  --color-border-focus: var(--color-primary-400);

  /* ── Shadows ── */
  --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06), 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow: 0 4px 6px rgba(0, 0, 0, 0.05), 0 2px 4px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 10px 15px rgba(0, 0, 0, 0.05), 0 4px 6px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 20px 25px rgba(0, 0, 0, 0.08), 0 10px 10px rgba(0, 0, 0, 0.04);
  --shadow-xl: 0 25px 50px rgba(0, 0, 0, 0.12);

  --shadow-primary-sm: 0 1px 3px rgba(124, 58, 237, 0.3);
  --shadow-primary: 0 4px 12px rgba(124, 58, 237, 0.35);
  --shadow-primary-lg: 0 8px 24px rgba(124, 58, 237, 0.4);

  /* ── Border Radius ── */
  --radius-xs: 6px;
  --radius-sm: 8px;
  --radius: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --radius-2xl: 24px;
  --radius-full: 9999px;

  /* ── Typography ── */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'SF Mono', 'Fira Code', 'Cascadia Code', monospace;

  --font-size-xs: 0.75rem;    /* 12px */
  --font-size-sm: 0.8125rem;  /* 13px */
  --font-size-base: 0.9375rem; /* 15px */
  --font-size-lg: 1.125rem;   /* 18px */
  --font-size-xl: 1.25rem;    /* 20px */
  --font-size-2xl: 1.5rem;    /* 24px */
  --font-size-3xl: 1.75rem;   /* 28px */
  --font-size-4xl: 2.25rem;   /* 36px */
  --font-size-5xl: 3rem;      /* 48px */

  --font-weight-regular: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  --font-weight-extrabold: 800;
  --font-weight-black: 900;

  --line-height-tight: 1.15;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.625;
  --line-height-loose: 1.75;

  --letter-spacing-tight: -0.03em;
  --letter-spacing-normal: 0;
  --letter-spacing-wide: 0.05em;
  --letter-spacing-wider: 0.08em;

  /* ── Spacing (4px 基准网格) ── */
  --spacing-0: 0;
  --spacing-1: 4px;
  --spacing-2: 8px;
  --spacing-3: 12px;
  --spacing-4: 16px;
  --spacing-5: 20px;
  --spacing-6: 24px;
  --spacing-8: 32px;
  --spacing-10: 40px;
  --spacing-12: 48px;
  --spacing-16: 64px;
  --spacing-20: 80px;
  --spacing-24: 96px;

  /* ── Layout ── */
  --layout-max-w-sm: 640px;
  --layout-max-w-md: 768px;
  --layout-max-w-lg: 960px;
  --layout-max-w-xl: 1120px;
  --layout-max-w-2xl: 1280px;

  --navbar-height: 64px;
  --sidebar-width: 260px;

  /* ── Z-Index ── */
  --z-navbar: 100;
  --z-sidebar: 90;
  --z-overlay: 200;
  --z-modal: 300;
  --z-toast: 400;
  --z-tooltip: 500;

  /* ── Transitions ── */
  --transition-fast: 0.15s cubic-bezier(0.4, 0, 0.2, 1);
  --transition: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-spring: 0.35s cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* ==========================================================================
   2. DARK MODE
   ========================================================================== */

@media (prefers-color-scheme: dark) {
  :root {
    /* ── Primary (暗色下微调) ── */
    --color-primary-50: #1e1b4b;
    --color-primary-100: #2e1065;
    --color-primary-200: #3b0764;
    --color-primary-300: #581c87;
    --color-primary-400: #7c3aed;
    --color-primary-500: #8b5cf6;
    --color-primary-600: #a78bfa;
    --color-primary-700: #c4b5fd;
    --color-primary-800: #ddd6fe;
    --color-primary-900: #ede9fe;

    --color-primary: var(--color-primary-500);
    --color-primary-light: var(--color-primary-400);
    --color-primary-dark: var(--color-primary-600);
    --color-primary-bg: var(--color-primary-100);

    /* ── Secondary ── */
    --color-secondary: var(--color-secondary-400);
    --color-secondary-light: var(--color-secondary-300);
    --color-secondary-dark: var(--color-secondary-500);

    /* ── Accent ── */
    --color-accent: #818cf8;
    --color-accent-light: #6366f1;
    --color-accent-dark: #a5b4fc;
    --color-accent-bg: #1e1b4b;

    /* ── Neutral ── */
    --color-neutral-50: #0f172a;
    --color-neutral-100: #1e293b;
    --color-neutral-200: #334155;
    --color-neutral-300: #475569;
    --color-neutral-400: #64748b;
    --color-neutral-500: #94a3b8;
    --color-neutral-600: #cbd5e1;
    --color-neutral-700: #e2e8f0;
    --color-neutral-800: #f1f5f9;
    --color-neutral-900: #f8fafc;

    /* ── Status ── */
    --color-success: #34d399;
    --color-success-dark: #10b981;
    --color-success-light: #6ee7b7;
    --color-success-bg: #064e3b;
    --color-success-text: #a7f3d0;

    --color-error: #f87171;
    --color-error-dark: #ef4444;
    --color-error-light: #fca5a5;
    --color-error-bg: #7f1d1d;
    --color-error-text: #fecaca;

    --color-warning: #fbbf24;
    --color-warning-dark: #f59e0b;
    --color-warning-light: #fcd34d;
    --color-warning-bg: #78350f;
    --color-warning-text: #fde68a;

    --color-info: #60a5fa;
    --color-info-dark: #3b82f6;
    --color-info-light: #93c5fd;
    --color-info-bg: #1e3a5f;
    --color-info-text: #bfdbfe;

    /* ── Text ── */
    --color-text: var(--color-neutral-900);
    --color-text-secondary: var(--color-neutral-600);
    --color-text-muted: var(--color-neutral-500);
    --color-text-inverse: #0f172a;

    /* ── Surfaces ── */
    --color-bg: var(--color-neutral-50);
    --color-bg-card: var(--color-neutral-100);
    --color-bg-subtle: var(--color-neutral-200);
    --color-bg-elevated: var(--color-neutral-100);
    --color-bg-overlay: rgba(0, 0, 0, 0.65);

    --color-border: var(--color-neutral-200);
    --color-border-light: var(--color-neutral-100);

    /* ── Shadows (暗色下加深) ── */
    --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.2);
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3), 0 1px 2px rgba(0, 0, 0, 0.2);
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.3), 0 2px 4px rgba(0, 0, 0, 0.25);
    --shadow-md: 0 10px 15px rgba(0, 0, 0, 0.35), 0 4px 6px rgba(0, 0, 0, 0.25);
    --shadow-lg: 0 20px 25px rgba(0, 0, 0, 0.4), 0 10px 10px rgba(0, 0, 0, 0.2);
    --shadow-xl: 0 25px 50px rgba(0, 0, 0, 0.5);
  }
}

/* ==========================================================================
   3. BUTTON SYSTEM
   ========================================================================== */

/* ── Base Button ── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-2);
  padding: var(--spacing-2, 10px) var(--spacing-6, 24px);
  border-radius: var(--radius-sm);
  font-family: var(--font-sans);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-semibold);
  line-height: 1.4;
  text-decoration: none;
  border: 1.5px solid transparent;
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
  position: relative;
  overflow: hidden;
  user-select: none;
  -webkit-user-select: none;
}

.btn:active {
  transform: scale(0.97);
}

.btn:disabled,
.btn.disabled {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
}

/* ── Variants ── */
.btn-primary {
  background: var(--color-primary);
  color: var(--color-text-inverse);
  border-color: var(--color-primary);
  box-shadow: var(--shadow-primary-sm);
}
.btn-primary:hover {
  background: var(--color-primary-dark);
  border-color: var(--color-primary-dark);
  box-shadow: var(--shadow-primary);
  transform: translateY(-1px);
}
.btn-primary:active {
  box-shadow: none;
  transform: translateY(0);
}

.btn-secondary {
  background: var(--color-primary-bg);
  color: var(--color-primary);
  border-color: transparent;
}
.btn-secondary:hover {
  background: var(--color-primary-100);
  color: var(--color-primary-dark);
  transform: translateY(-1px);
}

.btn-outline {
  background: transparent;
  color: var(--color-primary);
  border-color: var(--color-primary);
}
.btn-outline:hover {
  background: var(--color-primary-bg);
  transform: translateY(-1px);
}

.btn-ghost {
  background: transparent;
  color: var(--color-text-secondary);
  border-color: transparent;
  padding: var(--spacing-2, 10px) var(--spacing-4, 16px);
}
.btn-ghost:hover {
  background: var(--color-bg-subtle);
  color: var(--color-text);
}

.btn-danger {
  background: var(--color-error);
  color: var(--color-text-inverse);
  border-color: var(--color-error);
  box-shadow: 0 1px 3px rgba(239, 68, 68, 0.3);
}
.btn-danger:hover {
  background: var(--color-error-dark);
  border-color: var(--color-error-dark);
  box-shadow: 0 4px 12px rgba(239, 68, 68, 0.35);
  transform: translateY(-1px);
}

.btn-success {
  background: var(--color-success);
  color: var(--color-text-inverse);
  border-color: var(--color-success);
}
.btn-success:hover {
  background: var(--color-success-dark);
  transform: translateY(-1px);
}

.btn-warning {
  background: var(--color-warning);
  color: var(--color-text-inverse);
  border-color: var(--color-warning);
}
.btn-warning:hover {
  background: var(--color-warning-dark);
  transform: translateY(-1px);
}

/* ── Light variant (for dark hero backgrounds) ── */
.btn-light {
  background: rgba(255, 255, 255, 0.15);
  color: #ffffff;
  border-color: rgba(255, 255, 255, 0.3);
  backdrop-filter: blur(4px);
}
.btn-light:hover {
  background: rgba(255, 255, 255, 0.25);
  border-color: rgba(255, 255, 255, 0.5);
}

/* ── Sizes ── */
.btn-xs {
  padding: 4px 12px;
  font-size: var(--font-size-xs);
  border-radius: var(--radius-xs);
}

.btn-sm {
  padding: 6px 16px;
  font-size: var(--font-size-xs);
  border-radius: var(--radius-xs);
}

.btn-lg {
  padding: 14px 32px;
  font-size: var(--font-size-base);
  border-radius: var(--radius);
}

.btn-xl {
  padding: 18px 40px;
  font-size: var(--font-size-lg);
  border-radius: var(--radius-lg);
}

/* ── Full width ── */
.btn-block {
  width: 100%;
  justify-content: center;
  box-sizing: border-box;
  white-space: normal;
  word-break: break-word;
  min-width: 0;
}

/* ── Icon-only button ── */
.btn-icon {
  padding: 8px;
  min-width: 36px;
  min-height: 36px;
  border-radius: var(--radius-sm);
}
.btn-icon.btn-sm {
  padding: 6px;
  min-width: 30px;
  min-height: 30px;
}
.btn-icon.btn-lg {
  padding: 12px;
  min-width: 44px;
  min-height: 44px;
}

/* ── Button Group ── */
.btn-group {
  display: inline-flex;
  gap: 0;
}
.btn-group > .btn {
  border-radius: 0;
}
.btn-group > .btn:first-child {
  border-radius: var(--radius-sm) 0 0 var(--radius-sm);
}
.btn-group > .btn:last-child {
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}
.btn-group > .btn + .btn {
  margin-left: -1px;
}

/* ── Loading state ── */
.btn.loading {
  pointer-events: none;
  position: relative;
  color: transparent !important;
}
.btn.loading::after {
  content: '';
  position: absolute;
  width: 16px;
  height: 16px;
  border: 2px solid currentColor;
  border-right-color: transparent;
  border-radius: 50%;
  animation: btn-spin 0.6s linear infinite;
}
@keyframes btn-spin {
  to { transform: rotate(360deg); }
}

/* ==========================================================================
   4. CARD COMPONENTS
   ========================================================================== */

.card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius);
  box-shadow: var(--shadow-xs);
  transition: box-shadow var(--transition), transform var(--transition);
}
.card:hover {
  box-shadow: var(--shadow);
}
.card:active {
  box-shadow: var(--shadow-xs);
}

.card-header {
  padding: var(--spacing-5) var(--spacing-6) 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.card-body {
  padding: var(--spacing-6);
}
.card-footer {
  padding: var(--spacing-4) var(--spacing-6);
  border-top: 1px solid var(--color-border-light);
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: var(--spacing-2);
}

.card-compact .card-body {
  padding: var(--spacing-4);
}
.card-compact .card-header {
  padding: var(--spacing-4) var(--spacing-4) 0;
}

.card-elevated {
  box-shadow: var(--shadow);
}
.card-elevated:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
}

.card-bordered {
  border-color: var(--color-border);
}

.card-flush {
  box-shadow: none;
  border: none;
  background: transparent;
}

/* Card variants by status */
.card-success { border-left: 4px solid var(--color-success); }
.card-error { border-left: 4px solid var(--color-error); }
.card-warning { border-left: 4px solid var(--color-warning); }
.card-info { border-left: 4px solid var(--color-info); }
.card-primary { border-left: 4px solid var(--color-primary); }

/* Stat Cards */
.stat-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius);
  padding: var(--spacing-5) var(--spacing-6);
  box-shadow: var(--shadow-xs);
  transition: box-shadow var(--transition), transform var(--transition);
}
.stat-card:hover {
  box-shadow: var(--shadow);
  transform: translateY(-2px);
}

.stat-value {
  font-size: var(--font-size-4xl);
  font-weight: var(--font-weight-extrabold);
  letter-spacing: var(--letter-spacing-tight);
  line-height: 1.1;
}

.stat-label {
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
  margin-top: var(--spacing-1);
  text-transform: uppercase;
  letter-spacing: var(--letter-spacing-wide);
  font-weight: var(--font-weight-medium);
}

.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--spacing-4);
}

/* Feature Cards */
.feature-card {
  padding: var(--spacing-10) var(--spacing-6);
  text-align: center;
}
.feature-card .icon {
  font-size: 2.5rem;
  margin-bottom: var(--spacing-4);
  display: block;
}

/* Pricing Cards */
.pricing-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  padding: var(--spacing-8);
  position: relative;
  transition: all var(--transition-slow);
  box-sizing: border-box;
  overflow: hidden;
}
.pricing-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
}
.pricing-card.featured {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 1px var(--color-primary), var(--shadow);
}
.pricing-card .popular-badge {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--color-primary);
  color: var(--color-text-inverse);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-bold);
  padding: var(--spacing-1) var(--spacing-4);
  border-radius: var(--radius-full);
  box-shadow: var(--shadow-primary-sm);
  white-space: nowrap;
}
.pricing-card .plan-name {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-bold);
}
.pricing-card .plan-price {
  font-size: var(--font-size-4xl);
  font-weight: var(--font-weight-black);
  color: var(--color-primary);
  letter-spacing: var(--letter-spacing-tight);
  margin: var(--spacing-3) 0;
}
.pricing-card .plan-price span {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-muted);
}
.pricing-card .plan-features {
  list-style: none;
  margin: var(--spacing-5) 0 var(--spacing-7);
}
.pricing-card .plan-features li {
  padding: var(--spacing-1-5, 6px) 0;
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
}

/* ==========================================================================
   5. FORM COMPONENTS
   ========================================================================== */

.form-group {
  margin-bottom: var(--spacing-5);
}

.form-label {
  display: block;
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text);
  margin-bottom: var(--spacing-1-5, 6px);
}

.form-hint {
  display: block;
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
  margin-top: var(--spacing-1);
}

.form-error {
  display: block;
  font-size: var(--font-size-xs);
  color: var(--color-error);
  margin-top: var(--spacing-1);
}

/* ── Text Inputs ── */
.input {
  width: 100%;
  padding: 11px 16px;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: var(--font-size-sm);
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg-card);
  transition: all var(--transition);
  outline: none;
  line-height: 1.5;
}
.input:hover {
  border-color: var(--color-neutral-300);
}
.input:focus {
  border-color: var(--color-border-focus);
  box-shadow: 0 0 0 3px rgba(139, 92, 246, 0.15);
}
.input::placeholder {
  color: var(--color-text-muted);
}
.input:disabled {
  background: var(--color-bg-subtle);
  color: var(--color-text-muted);
  cursor: not-allowed;
}
.input.input-error {
  border-color: var(--color-error);
}
.input.input-error:focus {
  box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.15);
}

.input-sm {
  padding: 7px 12px;
  font-size: var(--font-size-xs);
}
.input-lg {
  padding: 14px 20px;
  font-size: var(--font-size-base);
}

/* ── Select ── */
select.input {
  appearance: none;
  -webkit-appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg width='12' height='8' viewBox='0 0 12 8' fill='none' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M1 1.5L6 6.5L11 1.5' stroke='%2364748b' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 36px;
  cursor: pointer;
}
select.input:hover {
  border-color: var(--color-neutral-300);
}
select.input option {
  background: var(--color-bg-card);
  color: var(--color-text);
}

/* ── Textarea ── */
textarea.input {
  resize: vertical;
  min-height: 80px;
  line-height: 1.6;
}

/* ── Checkbox ── */
.checkbox-group {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-2);
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  font-size: var(--font-size-sm);
  color: var(--color-text);
  cursor: pointer;
  line-height: 1.5;
}

.checkbox-label input[type="checkbox"] {
  appearance: none;
  -webkit-appearance: none;
  width: 18px;
  height: 18px;
  border: 1.5px solid var(--color-border);
  border-radius: 4px;
  background: var(--color-bg-card);
  cursor: pointer;
  flex-shrink: 0;
  position: relative;
  transition: all var(--transition-fast);
}

.checkbox-label input[type="checkbox"]:hover {
  border-color: var(--color-primary-light);
}

.checkbox-label input[type="checkbox"]:checked {
  background: var(--color-primary);
  border-color: var(--color-primary);
}

.checkbox-label input[type="checkbox"]:checked::after {
  content: '';
  position: absolute;
  top: 2px;
  left: 5px;
  width: 5px;
  height: 9px;
  border: solid var(--color-text-inverse);
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}

.checkbox-label input[type="checkbox"]:focus-visible {
  box-shadow: 0 0 0 3px rgba(139, 92, 246, 0.15);
}

/* ── Radio ── */
.radio-label {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  font-size: var(--font-size-sm);
  color: var(--color-text);
  cursor: pointer;
  line-height: 1.5;
}

.radio-label input[type="radio"] {
  appearance: none;
  -webkit-appearance: none;
  width: 18px;
  height: 18px;
  border: 1.5px solid var(--color-border);
  border-radius: 50%;
  background: var(--color-bg-card);
  cursor: pointer;
  flex-shrink: 0;
  position: relative;
  transition: all var(--transition-fast);
}

.radio-label input[type="radio"]:hover {
  border-color: var(--color-primary-light);
}

.radio-label input[type="radio"]:checked {
  border-color: var(--color-primary);
  border-width: 5px;
  background: var(--color-primary);
}

.radio-label input[type="radio"]:focus-visible {
  box-shadow: 0 0 0 3px rgba(139, 92, 246, 0.15);
}

/* ── Toggle / Switch ── */
.toggle {
  position: relative;
  display: inline-flex;
  align-items: center;
  cursor: pointer;
  gap: var(--spacing-2);
}
.toggle input {
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
}
.toggle-track {
  width: 40px;
  height: 22px;
  background: var(--color-neutral-300);
  border-radius: var(--radius-full);
  transition: background var(--transition);
  position: relative;
  flex-shrink: 0;
}
.toggle-track::after {
  content: '';
  position: absolute;
  top: 3px;
  left: 3px;
  width: 16px;
  height: 16px;
  background: white;
  border-radius: 50%;
  transition: transform var(--transition);
  box-shadow: 0 1px 3px rgba(0,0,0,0.2);
}
.toggle input:checked + .toggle-track {
  background: var(--color-primary);
}
.toggle input:checked + .toggle-track::after {
  transform: translateX(18px);
}
.toggle input:focus-visible + .toggle-track {
  box-shadow: 0 0 0 3px rgba(139, 92, 246, 0.15);
}

/* ==========================================================================
   6. BADGE / TAG
   ========================================================================== */

.badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 2px 10px;
  border-radius: var(--radius-full);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  white-space: nowrap;
  line-height: 1.5;
}

.badge-primary {
  background: var(--color-primary-bg);
  color: var(--color-primary-dark);
}
.badge-secondary {
  background: var(--color-secondary-50);
  color: var(--color-secondary-dark);
}
.badge-success {
  background: var(--color-success-bg);
  color: var(--color-success-text);
}
.badge-error {
  background: var(--color-error-bg);
  color: var(--color-error-text);
}
.badge-warning {
  background: var(--color-warning-bg);
  color: var(--color-warning-text);
}
.badge-info {
  background: var(--color-info-bg);
  color: var(--color-info-text);
}
.badge-neutral {
  background: var(--color-bg-subtle);
  color: var(--color-text-secondary);
}

.badge-outline {
  background: transparent;
  border: 1px solid;
}
.badge-outline.badge-primary {
  border-color: var(--color-primary-300);
  color: var(--color-primary);
}
.badge-outline.badge-success {
  border-color: var(--color-success);
  color: var(--color-success-dark);
}
.badge-outline.badge-error {
  border-color: var(--color-error);
  color: var(--color-error-dark);
}

.badge-sm {
  padding: 1px 8px;
  font-size: 10px;
}

.badge-lg {
  padding: 4px 14px;
  font-size: var(--font-size-sm);
}

/* Dot badge (notification indicator) */
.badge-dot {
  width: 8px;
  height: 8px;
  padding: 0;
  border-radius: 50%;
  display: inline-block;
}

/* ==========================================================================
   7. TAG / CHIP
   ========================================================================== */

.tag {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-1);
  padding: var(--spacing-1) var(--spacing-2);
  border-radius: var(--radius-xs);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
  background: var(--color-bg-subtle);
  color: var(--color-text-secondary);
  white-space: nowrap;
}
.tag .tag-close {
  cursor: pointer;
  opacity: 0.6;
  font-size: 14px;
  line-height: 1;
  transition: opacity var(--transition-fast);
}
.tag .tag-close:hover {
  opacity: 1;
}

/* ==========================================================================
   8. TABLES
   ========================================================================== */

.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius);
  background: var(--color-bg-card);
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--font-size-sm);
}

thead th {
  text-align: left;
  padding: 12px 20px;
  font-weight: var(--font-weight-semibold);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: var(--letter-spacing-wider);
  color: var(--color-text-muted);
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  white-space: nowrap;
}

tbody td {
  padding: 12px 20px;
  border-bottom: 1px solid var(--color-border-light);
  color: var(--color-text-secondary);
  vertical-align: middle;
}

tbody tr:last-child td {
  border-bottom: none;
}

tbody tr:hover td {
  background: var(--color-bg);
}

/* Table sizes */
.table-sm thead th,
.table-sm tbody td {
  padding: 8px 12px;
  font-size: var(--font-size-xs);
}

.table-lg thead th,
.table-lg tbody td {
  padding: 16px 24px;
}

/* Table sticky header */
.table-sticky th {
  position: sticky;
  top: 0;
  z-index: 1;
}

/* Table striped */
.table-striped tbody tr:nth-child(even) td {
  background: var(--color-bg);
}
.table-striped tbody tr:nth-child(even):hover td {
  background: var(--color-bg-subtle);
}

/* ==========================================================================
   9. NAVIGATION
   ========================================================================== */

/* ── Top Navbar ── */
.navbar {
  display: flex;
  align-items: center;
  justify-content: center;
  height: var(--navbar-height, 64px);
  padding: 0 var(--spacing-8);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(24px) saturate(180%);
  -webkit-backdrop-filter: blur(24px) saturate(180%);
  border-bottom: 1px solid var(--color-border-light);
  position: sticky;
  top: 0;
  z-index: var(--z-navbar);
}

.navbar > * {
  max-width: var(--layout-max-w-xl);
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.navbar-brand {
  font-size: var(--font-size-xl);
  font-weight: var(--font-weight-extrabold);
  color: var(--color-primary);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  letter-spacing: var(--letter-spacing-tight);
}
.navbar-brand .brand-icon {
  font-size: 1.25rem;
}
.navbar-brand .subtitle {
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-muted);
  letter-spacing: normal;
}

.navbar-links {
  display: flex;
  align-items: center;
  gap: var(--spacing-6);
}

.navbar-links a {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-secondary);
  text-decoration: none;
  transition: color var(--transition-fast);
  position: relative;
  padding: var(--spacing-1) 0;
}

.navbar-links a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-primary);
  border-radius: 1px;
  transition: width var(--transition);
}
.navbar-links a:hover {
  color: var(--color-primary);
}
.navbar-links a:hover::after {
  width: 100%;
}
.navbar-links a.active {
  color: var(--color-primary);
}
.navbar-links a.active::after {
  width: 100%;
}

/* Dark mode navbar */
@media (prefers-color-scheme: dark) {
  .navbar {
    background: rgba(15, 23, 42, 0.92);
    border-bottom-color: var(--color-border);
  }
}

/* ── Side Navigation ── */
.sidebar {
  width: var(--sidebar-width, 260px);
  background: var(--color-bg-card);
  border-right: 1px solid var(--color-border-light);
  height: 100vh;
  position: fixed;
  top: 0;
  left: 0;
  z-index: var(--z-sidebar);
  display: flex;
  flex-direction: column;
  overflow-y: auto;
}
.sidebar-header {
  padding: var(--spacing-5);
  border-bottom: 1px solid var(--color-border-light);
}
.sidebar-nav {
  padding: var(--spacing-3);
  flex: 1;
}
.sidebar-nav a {
  display: flex;
  align-items: center;
  gap: var(--spacing-3);
  padding: var(--spacing-2-5, 10px) var(--spacing-3);
  border-radius: var(--radius-sm);
  color: var(--color-text-secondary);
  text-decoration: none;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  transition: all var(--transition-fast);
  margin-bottom: 2px;
}
.sidebar-nav a:hover {
  background: var(--color-bg-subtle);
  color: var(--color-text);
}
.sidebar-nav a.active {
  background: var(--color-primary-bg);
  color: var(--color-primary);
  font-weight: var(--font-weight-semibold);
}
.sidebar-nav .nav-label {
  font-size: 10px;
  font-weight: var(--font-weight-semibold);
  text-transform: uppercase;
  letter-spacing: var(--letter-spacing-wider);
  color: var(--color-text-muted);
  padding: var(--spacing-3) var(--spacing-3) var(--spacing-1);
}

/* ── Breadcrumbs ── */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: var(--spacing-1);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  padding: var(--spacing-3) 0;
}
.breadcrumb a {
  color: var(--color-text-secondary);
  text-decoration: none;
  transition: color var(--transition-fast);
}
.breadcrumb a:hover {
  color: var(--color-primary);
}
.breadcrumb .separator {
  color: var(--color-text-muted);
  margin: 0 var(--spacing-1);
}
.breadcrumb .current {
  color: var(--color-text);
  font-weight: var(--font-weight-medium);
}

/* ── Tabs ── */
.tabs {
  display: flex;
  gap: 0;
  border-bottom: 1px solid var(--color-border);
  overflow-x: auto;
}
.tab-item {
  padding: var(--spacing-3) var(--spacing-5);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-secondary);
  text-decoration: none;
  border-bottom: 2px solid transparent;
  transition: all var(--transition-fast);
  white-space: nowrap;
  cursor: pointer;
}
.tab-item:hover {
  color: var(--color-text);
  border-bottom-color: var(--color-neutral-300);
}
.tab-item.active {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
  font-weight: var(--font-weight-semibold);
}

/* ==========================================================================
   10. MODAL / DIALOG
   ========================================================================== */

.modal-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: var(--color-bg-overlay);
  z-index: var(--z-modal);
  align-items: center;
  justify-content: center;
  padding: var(--spacing-6);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
}

.modal-overlay.open {
  display: flex;
}

.modal {
  background: var(--color-bg-card);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
  width: 100%;
  max-width: 500px;
  max-height: 85vh;
  display: flex;
  flex-direction: column;
  animation: modal-in var(--transition-slow);
}

@keyframes modal-in {
  from {
    opacity: 0;
    transform: scale(0.95) translateY(10px);
  }
  to {
    opacity: 1;
    transform: scale(1) translateY(0);
  }
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-5) var(--spacing-6);
  border-bottom: 1px solid var(--color-border-light);
}
.modal-header h2 {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-bold);
  letter-spacing: var(--letter-spacing-tight);
}
.modal-close {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: var(--radius-xs);
  cursor: pointer;
  background: transparent;
  border: none;
  color: var(--color-text-muted);
  font-size: 20px;
  transition: all var(--transition-fast);
}
.modal-close:hover {
  background: var(--color-bg-subtle);
  color: var(--color-text);
}

.modal-body {
  padding: var(--spacing-6);
  overflow-y: auto;
  flex: 1;
}

.modal-footer {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: var(--spacing-3);
  padding: var(--spacing-4) var(--spacing-6);
  border-top: 1px solid var(--color-border-light);
}

/* Modal sizes */
.modal-sm { max-width: 400px; }
.modal-lg { max-width: 640px; }
.modal-xl { max-width: 800px; }
.modal-full { max-width: calc(100vw - 48px); max-height: calc(100vh - 48px); }

/* ==========================================================================
   11. TOAST / NOTIFICATION
   ========================================================================== */

.toast-container {
  position: fixed;
  top: var(--spacing-6);
  right: var(--spacing-6);
  z-index: var(--z-toast);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-3);
  pointer-events: none;
}

.toast {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-3);
  padding: var(--spacing-4) var(--spacing-5);
  background: var(--color-bg-card);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  min-width: 320px;
  max-width: 420px;
  pointer-events: auto;
  animation: toast-in var(--transition-slow);
  position: relative;
}

@keyframes toast-in {
  from {
    opacity: 0;
    transform: translateX(20px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.toast-icon {
  flex-shrink: 0;
  font-size: 1.25rem;
  line-height: 1;
}

.toast-content {
  flex: 1;
  min-width: 0;
}
.toast-title {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text);
  margin-bottom: 2px;
}
.toast-message {
  font-size: var(--font-size-xs);
  color: var(--color-text-secondary);
  line-height: 1.4;
}

.toast-close {
  flex-shrink: 0;
  width: 20px;
  height: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  background: transparent;
  border: none;
  color: var(--color-text-muted);
  font-size: 16px;
  border-radius: 4px;
  transition: all var(--transition-fast);
}
.toast-close:hover {
  background: var(--color-bg-subtle);
  color: var(--color-text);
}

/* Toast variants */
.toast-success {
  border-left: 4px solid var(--color-success);
}
.toast-error {
  border-left: 4px solid var(--color-error);
}
.toast-warning {
  border-left: 4px solid var(--color-warning);
}
.toast-info {
  border-left: 4px solid var(--color-info);
}

/* Toast exit animation */
.toast.removing {
  animation: toast-out var(--transition-slow) forwards;
}
@keyframes toast-out {
  to {
    opacity: 0;
    transform: translateX(20px);
  }
}

/* ── Alert / Inline Notification ── */
.alert {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-3);
  padding: var(--spacing-3) var(--spacing-4);
  border-radius: var(--radius-sm);
  font-size: var(--font-size-sm);
  line-height: 1.5;
}
.alert-icon {
  flex-shrink: 0;
  font-size: 1.125rem;
  line-height: 1.4;
}

.alert-success {
  background: var(--color-success-bg);
  color: var(--color-success-text);
}
.alert-info {
  background: var(--color-info-bg);
  color: var(--color-info-text);
}
.alert-warning {
  background: var(--color-warning-bg);
  color: var(--color-warning-text);
}
.alert-error {
  background: var(--color-error-bg);
  color: var(--color-error-text);
}

/* ==========================================================================
   12. LOADING & SPINNERS
   ========================================================================== */

/* ── Spinner ── */
.spinner {
  display: inline-block;
  width: 20px;
  height: 20px;
  border: 2.5px solid var(--color-border);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: spinner-rotate 0.6s linear infinite;
}

.spinner-sm {
  width: 14px;
  height: 14px;
  border-width: 2px;
}

.spinner-lg {
  width: 32px;
  height: 32px;
  border-width: 3px;
}

.spinner-primary { border-top-color: var(--color-primary); }
.spinner-white { border-color: rgba(255,255,255,0.3); border-top-color: #ffffff; }
.spinner-success { border-top-color: var(--color-success); }

@keyframes spinner-rotate {
  to { transform: rotate(360deg); }
}

/* ── Skeleton Loading ── */
.skeleton {
  background: linear-gradient(
    90deg,
    var(--color-bg-subtle) 25%,
    var(--color-bg-card) 50%,
    var(--color-bg-subtle) 75%
  );
  background-size: 200% 100%;
  animation: skeleton-shimmer 1.5s ease-in-out infinite;
  border-radius: var(--radius-xs);
}

.skeleton-text {
  height: 14px;
  margin-bottom: 8px;
  width: 100%;
}
.skeleton-text:last-child {
  width: 60%;
}

.skeleton-title {
  height: 20px;
  width: 40%;
  margin-bottom: 12px;
}

.skeleton-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
}

.skeleton-card {
  height: 120px;
}

@keyframes skeleton-shimmer {
  0% { background-position: 200% 0; }
  100% { background-position: -200% 0; }
}

/* ── Typing dots (chat) ── */
.typing-dots {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: var(--spacing-3) var(--spacing-5);
  background: var(--color-bg-subtle);
  border-radius: var(--radius-lg);
}
.typing-dot {
  width: 8px;
  height: 8px;
  background: var(--color-text-muted);
  border-radius: 50%;
  animation: typing-bounce 1.4s infinite ease-in-out;
}
.typing-dot:nth-child(1) { animation-delay: 0s; }
.typing-dot:nth-child(2) { animation-delay: 0.2s; }
.typing-dot:nth-child(3) { animation-delay: 0.4s; }

@keyframes typing-bounce {
  0%, 60%, 100% {
    opacity: 0.3;
    transform: scale(0.8);
  }
  30% {
    opacity: 1;
    transform: scale(1);
  }
}

/* ── Page Loader ── */
.page-loader {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-bg);
  z-index: 9999;
  transition: opacity var(--transition-slow);
}
.page-loader.loaded {
  opacity: 0;
  pointer-events: none;
}

/* ── Progress Bar ── */
.progress {
  width: 100%;
  height: 6px;
  background: var(--color-bg-subtle);
  border-radius: var(--radius-full);
  overflow: hidden;
}
.progress-bar {
  height: 100%;
  background: var(--color-primary);
  border-radius: var(--radius-full);
  transition: width var(--transition-slow);
}
.progress-bar.success { background: var(--color-success); }
.progress-bar.warning { background: var(--color-warning); }
.progress-bar.error { background: var(--color-error); }

.progress-sm { height: 3px; }
.progress-lg { height: 10px; }

/* ==========================================================================
   13. HERO / LANDING SECTION
   ========================================================================== */

.hero {
  position: relative;
  padding: 100px 24px 80px;
  text-align: center;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #6366f1 100%);
  color: var(--color-text-inverse);
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 20% 50%, rgba(255,255,255,0.1) 0%, transparent 50%),
    radial-gradient(circle at 80% 30%, rgba(255,255,255,0.06) 0%, transparent 50%),
    radial-gradient(circle at 50% 80%, var(--color-primary-light) 0%, transparent 40%);
  opacity: 0.3;
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 700px;
  margin: 0 auto;
}

.hero h1 {
  font-size: var(--font-size-5xl);
  font-weight: var(--font-weight-black);
  letter-spacing: var(--letter-spacing-tight);
  margin-bottom: var(--spacing-4);
  line-height: 1.1;
}

.hero p {
  font-size: var(--font-size-lg);
  opacity: 0.9;
  margin-bottom: var(--spacing-10);
  line-height: var(--line-height-relaxed);
  max-width: 500px;
  margin-left: auto;
  margin-right: auto;
}

.hero-actions {
  display: flex;
  gap: var(--spacing-3);
  justify-content: center;
  flex-wrap: wrap;
}

/* ── Section ── */
.section {
  padding: var(--spacing-16) 0;
}
.section-sm {
  padding: var(--spacing-8) 0;
}
.section-lg {
  padding: var(--spacing-24) 0;
}

/* ==========================================================================
   14. LAYOUT
   ========================================================================== */

.page-wrapper {
  max-width: var(--layout-max-w-xl);
  margin: 0 auto;
  padding: var(--spacing-10) var(--spacing-8);
  width: 100%;
}

.page-wrapper-sm { max-width: var(--layout-max-w-sm); }
.page-wrapper-md { max-width: var(--layout-max-w-md); }
.page-wrapper-lg { max-width: var(--layout-max-w-lg); }

/* ── Container (通用居中容器) ── */
.container {
  max-width: var(--layout-max-w-xl);
  margin: 0 auto;
  padding: 0 var(--spacing-8);
  width: 100%;
}

/* ── Flex Grid ── */
.flex-grid {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-4);
}
.flex-grid > * {
  flex: 1 1 280px;
}

/* ── Grid Layouts ── */
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: var(--spacing-6); }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--spacing-6); }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--spacing-6); }

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-6);
}

.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-5);
}

/* ── Auth Pages ── */
.auth-page {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  padding: var(--spacing-6);
}

.auth-card {
  background: var(--color-bg-card);
  border-radius: var(--radius-xl);
  padding: var(--spacing-12);
  width: 100%;
  max-width: 420px;
  box-shadow: var(--shadow-xl);
}

.auth-logo {
  text-align: center;
  margin-bottom: var(--spacing-9, 36px);
}
.auth-logo .brand-icon {
  font-size: 3rem;
  margin-bottom: var(--spacing-3);
  display: block;
}
.auth-logo h1 {
  font-size: var(--font-size-2xl);
  font-weight: var(--font-weight-extrabold);
  color: var(--color-primary);
}
.auth-logo p {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  margin-top: var(--spacing-1);
  margin-bottom: 0;
}

.auth-footer {
  text-align: center;
  margin-top: var(--spacing-7, 28px);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
}
.auth-footer a {
  color: var(--color-primary);
  text-decoration: none;
  font-weight: var(--font-weight-semibold);
}
.auth-footer a:hover {
  text-decoration: underline;
}

/* ── Divider ── */
.divider {
  display: flex;
  align-items: center;
  gap: var(--spacing-3);
  color: var(--color-text-muted);
  font-size: var(--font-size-xs);
  margin: var(--spacing-5) 0;
}
.divider::before,
.divider::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--color-border);
}

/* ── Footer ── */
.footer {
  text-align: center;
  padding: var(--spacing-8) var(--spacing-6);
  border-top: 1px solid var(--color-border-light);
  margin-top: var(--spacing-12);
}
.footer p {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-2);
}
.footer-links {
  display: flex;
  gap: var(--spacing-4);
  justify-content: center;
  flex-wrap: wrap;
}
.footer-links a {
  color: var(--color-text-muted);
  text-decoration: none;
  font-size: var(--font-size-sm);
  transition: color var(--transition-fast);
}
.footer-links a:hover {
  color: var(--color-primary);
}

/* ── Text Gradient ── */
.text-gradient {
  background: linear-gradient(135deg, var(--color-secondary-400), var(--color-primary-400), var(--color-accent-light));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ==========================================================================
   15. TOOLTIP
   ========================================================================== */

[data-tooltip] {
  position: relative;
  cursor: help;
}

[data-tooltip]::after {
  content: attr(data-tooltip);
  position: absolute;
  bottom: calc(100% + 8px);
  left: 50%;
  transform: translateX(-50%) scale(0.9);
  padding: var(--spacing-1-5, 6px) var(--spacing-2-5, 10px);
  background: var(--color-neutral-800);
  color: #fff;
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
  border-radius: var(--radius-xs);
  white-space: nowrap;
  opacity: 0;
  pointer-events: none;
  transition: all var(--transition-fast);
  z-index: var(--z-tooltip);
  box-shadow: var(--shadow);
}

[data-tooltip]:hover::after {
  opacity: 1;
  transform: translateX(-50%) scale(1);
}

/* ==========================================================================
   16. AVATAR
   ========================================================================== */

.avatar {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--color-primary-bg);
  color: var(--color-primary);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-bold);
  overflow: hidden;
  flex-shrink: 0;
}
.avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.avatar-sm { width: 28px; height: 28px; font-size: var(--font-size-xs); }
.avatar-lg { width: 48px; height: 48px; font-size: var(--font-size-lg); }
.avatar-xl { width: 64px; height: 64px; font-size: var(--font-size-2xl); }

.avatar-group {
  display: flex;
}
.avatar-group .avatar {
  border: 2px solid var(--color-bg-card);
  margin-left: -8px;
}
.avatar-group .avatar:first-child {
  margin-left: 0;
}

/* ==========================================================================
   17. EMPTY STATE
   ========================================================================== */

.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-16) var(--spacing-6);
  text-align: center;
}
.empty-state .empty-icon {
  font-size: 3rem;
  margin-bottom: var(--spacing-4);
  opacity: 0.6;
}
.empty-state h3 {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-bold);
  margin-bottom: var(--spacing-1);
}
.empty-state p {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  max-width: 300px;
  margin-bottom: var(--spacing-5);
}

/* ==========================================================================
   18. DROPDOWN MENU
   ========================================================================== */

.dropdown {
  position: relative;
  display: inline-block;
}
.dropdown-menu {
  display: none;
  position: absolute;
  top: calc(100% + 4px);
  right: 0;
  min-width: 180px;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  z-index: var(--z-tooltip);
  padding: var(--spacing-1);
}
.dropdown.open .dropdown-menu {
  display: block;
  animation: dropdown-in var(--transition-fast);
}
@keyframes dropdown-in {
  from {
    opacity: 0;
    transform: translateY(-4px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.dropdown-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  padding: var(--spacing-2) var(--spacing-3);
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  text-decoration: none;
  border-radius: var(--radius-xs);
  cursor: pointer;
  transition: all var(--transition-fast);
  border: none;
  background: none;
  width: 100%;
  text-align: left;
  font-family: var(--font-sans);
}
.dropdown-item:hover {
  background: var(--color-bg-subtle);
  color: var(--color-text);
}
.dropdown-item.danger {
  color: var(--color-error);
}
.dropdown-item.danger:hover {
  background: var(--color-error-bg);
}

.dropdown-divider {
  height: 1px;
  background: var(--color-border-light);
  margin: var(--spacing-1) 0;
}

/* ==========================================================================
   19. UTILITY CLASSES
   ========================================================================== */

/* ── Text ── */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }
.text-muted { color: var(--color-text-muted); }
.text-secondary { color: var(--color-text-secondary); }
.text-sm { font-size: var(--font-size-sm); }
.text-xs { font-size: var(--font-size-xs); }
.text-lg { font-size: var(--font-size-lg); }
.text-nowrap { white-space: nowrap; }
.text-truncate {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.font-mono { font-family: var(--font-mono); }
.font-bold { font-weight: var(--font-weight-bold); }
.font-medium { font-weight: var(--font-weight-medium); }
.lead {
  font-size: var(--font-size-lg);
  line-height: var(--line-height-relaxed);
}

/* ── Display ── */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.flex-wrap { flex-wrap: wrap; }
.flex-1 { flex: 1; }
.items-center { align-items: center; }
.items-start { align-items: flex-start; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.justify-end { justify-content: flex-end; }
.gap-1 { gap: var(--spacing-1); }
.gap-2 { gap: var(--spacing-2); }
.gap-3 { gap: var(--spacing-3); }
.gap-4 { gap: var(--spacing-4); }
.gap-6 { gap: var(--spacing-6); }

/* ── Spacing helpers ── */
.mt-1 { margin-top: var(--spacing-1); }
.mt-2 { margin-top: var(--spacing-2); }
.mt-3 { margin-top: var(--spacing-3); }
.mt-4 { margin-top: var(--spacing-4); }
.mt-6 { margin-top: var(--spacing-6); }
.mt-8 { margin-top: var(--spacing-8); }
.mb-1 { margin-bottom: var(--spacing-1); }
.mb-2 { margin-bottom: var(--spacing-2); }
.mb-3 { margin-bottom: var(--spacing-3); }
.mb-4 { margin-bottom: var(--spacing-4); }
.mb-6 { margin-bottom: var(--spacing-6); }
.mb-8 { margin-bottom: var(--spacing-8); }
.ml-auto { margin-left: auto; }
.mr-auto { margin-right: auto; }
.mx-auto { margin-left: auto; margin-right: auto; }

.p-1 { padding: var(--spacing-1); }
.p-2 { padding: var(--spacing-2); }
.p-3 { padding: var(--spacing-3); }
.p-4 { padding: var(--spacing-4); }
.p-6 { padding: var(--spacing-6); }
.px-2 { padding-left: var(--spacing-2); padding-right: var(--spacing-2); }
.px-3 { padding-left: var(--spacing-3); padding-right: var(--spacing-3); }
.px-4 { padding-left: var(--spacing-4); padding-right: var(--spacing-4); }
.px-6 { padding-left: var(--spacing-6); padding-right: var(--spacing-6); }
.py-1 { padding-top: var(--spacing-1); padding-bottom: var(--spacing-1); }
.py-2 { padding-top: var(--spacing-2); padding-bottom: var(--spacing-2); }
.py-3 { padding-top: var(--spacing-3); padding-bottom: var(--spacing-3); }

/* ── Borders ── */
.rounded { border-radius: var(--radius); }
.rounded-sm { border-radius: var(--radius-sm); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-xl { border-radius: var(--radius-xl); }
.rounded-full { border-radius: var(--radius-full); }

/* ── Shadows ── */
.shadow-sm { box-shadow: var(--shadow-sm); }
.shadow { box-shadow: var(--shadow); }
.shadow-md { box-shadow: var(--shadow-md); }
.shadow-lg { box-shadow: var(--shadow-lg); }

/* ── Backgrounds ── */
.bg-card { background: var(--color-bg-card); }
.bg-subtle { background: var(--color-bg-subtle); }
.bg-primary { background: var(--color-primary); }
.bg-primary-light { background: var(--color-primary-bg); }
.bg-success-light { background: var(--color-success-bg); }
.bg-error-light { background: var(--color-error-bg); }
.bg-warning-light { background: var(--color-warning-bg); }
.bg-info-light { background: var(--color-info-bg); }

/* ── Visibility ── */
.hidden { display: none !important; }
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  border: 0;
}

/* ── Animations ── */
.fade-in {
  animation: fade-in var(--transition-slow) ease-out;
}
@keyframes fade-in {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.slide-up {
  animation: slide-up var(--transition-slow) ease-out;
}
@keyframes slide-up {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.scale-in {
  animation: scale-in var(--transition) ease-out;
}
@keyframes scale-in {
  from { opacity: 0; transform: scale(0.95); }
  to { opacity: 1; transform: scale(1); }
}

/* ==========================================================================
   20. RESPONSIVE BREAKPOINTS
   ========================================================================== */

/* ── Tablets & small screens (≤768px) ── */
@media (max-width: 768px) {
  :root {
    --navbar-height: 56px;
  }

  .page-wrapper {
    padding: var(--spacing-6) var(--spacing-4);
  }
  .hide-mobile { display: none !important; }

  .navbar {
    padding: 0 var(--spacing-4);
  }
  .navbar-links {
    gap: var(--spacing-3);
  }
  .navbar-links a {
    font-size: var(--font-size-xs);
  }
  .navbar-brand {
    font-size: var(--font-size-lg);
  }

  h1 { font-size: var(--font-size-3xl) !important; }
  h2 { font-size: var(--font-size-xl) !important; }

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

  .hero {
    padding: 60px 20px 48px;
  }
  .hero h1 {
    font-size: var(--font-size-4xl);
  }
  .hero p {
    font-size: var(--font-size-base);
  }

  .auth-card {
    padding: var(--spacing-8);
  }

  .modal {
    max-width: calc(100vw - 32px);
    margin: 0 auto;
  }
  .toast {
    min-width: auto;
    max-width: calc(100vw - 32px);
  }
}

/* ── Desktop (≥769px) ── */
@media (min-width: 769px) {
  .hide-desktop { display: none !important; }
}

/* ── Large screens (≥1200px) ── */
@media (min-width: 1200px) {
  .page-wrapper {
    padding: var(--spacing-12) var(--spacing-8);
  }
}

/* ── Print ── */
@media print {
  .navbar,
  .sidebar,
  .toast-container,
  .modal-overlay {
    display: none !important;
  }
  body {
    background: white !important;
    color: black !important;
  }
  .card {
    box-shadow: none !important;
    border: 1px solid #ddd !important;
  }
}

/* ==========================================================================
   END OF AEON DESIGN SYSTEM v2.0
   ========================================================================== */