/* ========================================
   Aria2 Work — Design System & Base Styles
   ======================================== */

/* 1. CSS Variables */
:root {
  /* 翡翠绿主色系 */
  --primary-50: #ecfdf5;
  --primary-100: #d1fae5;
  --primary-200: #a7f3d0;
  --primary-300: #6ee7b7;
  --primary-400: #34d399;
  --primary-500: #10b981;
  --primary-600: #059669;
  --primary-700: #047857;
  --primary-800: #065f46;
  --primary-900: #064e3b;

  /* 深夜蓝 */
  --dark-900: #0f172a;
  --dark-800: #1e293b;
  --dark-700: #334155;
  --dark-600: #475569;

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

  /* 代言人主题紫 */
  --accent-purple: #a78bfa;
  --accent-purple-light: #c4b5fd;
  --accent-purple-dark: #7c3aed;

  /* 功能色 */
  --success: #22c55e;
  --warning: #f59e0b;
  --error: #ef4444;
  --info: #3b82f6;

  /* 间距 */
  --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;

  /* 圆角 */
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-2xl: 24px;
  --radius-full: 9999px;

  /* 阴影 */
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.06), 0 2px 4px -2px rgba(0,0,0,0.04);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.08), 0 4px 6px -4px rgba(0,0,0,0.04);
  --shadow-xl: 0 20px 25px -5px rgba(0,0,0,0.08), 0 8px 10px -6px rgba(0,0,0,0.04);
  --shadow-glow: 0 4px 24px rgba(16,185,129,0.25);
  --shadow-purple: 0 4px 24px rgba(167,139,250,0.25);

  /* 字体 */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'SF Mono', Consolas, monospace;

  /* 过渡 */
  --transition-fast: 0.15s ease;
  --transition-base: 0.2s ease;
  --transition-slow: 0.3s ease;
}

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--gray-800);
  background: white;
}

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

a {
  color: inherit;
  text-decoration: none;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

ul, ol {
  list-style: none;
}

/* 3. Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.2;
  color: var(--gray-900);
  letter-spacing: -0.02em;
}

h1 { font-size: clamp(36px, 5vw, 64px); }
h2 { font-size: clamp(28px, 3.5vw, 40px); }
h3 { font-size: clamp(18px, 2vw, 24px); }

p {
  color: var(--gray-600);
  line-height: 1.7;
}

/* 4. Layout Utilities */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-5);
}

.section {
  padding: var(--space-20) 0;
}

.section--dark {
  background: var(--dark-900);
  color: white;
}

.section--dark h1,
.section--dark h2,
.section--dark h3 {
  color: white;
}

.section--dark p {
  color: var(--gray-400);
}

.section--accent {
  background: var(--primary-500);
  color: white;
}

.section--accent h2,
.section--accent p {
  color: white;
}

/* 5. Grid System */
.grid {
  display: grid;
  gap: var(--space-6);
}

.grid--2 { grid-template-columns: 1fr; }
.grid--3 { grid-template-columns: 1fr; }
.grid--4 { grid-template-columns: 1fr; }

@media (min-width: 768px) {
  .grid--2 { grid-template-columns: repeat(2, 1fr); }
  .grid--3 { grid-template-columns: repeat(2, 1fr); }
  .grid--4 { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 1024px) {
  .grid--3 { grid-template-columns: repeat(3, 1fr); }
  .grid--4 { grid-template-columns: repeat(4, 1fr); }
}

/* 6. Flex Utilities */
.flex {
  display: flex;
}

.flex-col {
  flex-direction: column;
}

.items-center {
  align-items: center;
}

.justify-between {
  justify-content: space-between;
}

.justify-center {
  justify-content: center;
}

.gap-2 { gap: var(--space-2); }
.gap-3 { gap: var(--space-3); }
.gap-4 { gap: var(--space-4); }
.gap-6 { gap: var(--space-6); }
.gap-8 { gap: var(--space-8); }

/* 7. Text Utilities */
.text-center { text-align: center; }
.text-white { color: white; }
.text-primary { color: var(--primary-500); }
.text-gray { color: var(--gray-500); }

.font-mono { font-family: var(--font-mono); }
.font-semibold { font-weight: 600; }
.font-bold { font-weight: 700; }

.text-sm { font-size: 14px; }
.text-lg { font-size: 18px; }
.text-xl { font-size: 20px; }

/* 8. Spacing Utilities */
.mt-2 { margin-top: var(--space-2); }
.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
.mt-8 { margin-top: var(--space-8); }
.mt-12 { margin-top: var(--space-12); }

.mb-2 { margin-bottom: var(--space-2); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }
.mb-8 { margin-bottom: var(--space-8); }

/* 9. Animation Keyframes */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-8px); }
}

@keyframes pulse-glow {
  0%, 100% { box-shadow: 0 0 0 0 rgba(16,185,129,0.4); }
  50% { box-shadow: 0 0 0 12px rgba(16,185,129,0); }
}

@keyframes countUp {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes slideInLeft {
  from { opacity: 0; transform: translateX(-30px); }
  to { opacity: 1; transform: translateX(0); }
}

@keyframes slideInRight {
  from { opacity: 0; transform: translateX(30px); }
  to { opacity: 1; transform: translateX(0); }
}

@keyframes typing {
  from { width: 0; }
  to { width: 100%; }
}

/* 10. Animation Classes */
.animate-fade-in {
  opacity: 0;
  animation: fadeInUp 0.6s ease forwards;
}

.animate-float {
  animation: float 4s ease-in-out infinite;
}

.animate-pulse-glow {
  animation: pulse-glow 2s ease-in-out infinite;
}

/* Scroll-triggered visibility */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.reveal-delay-1 { transition-delay: 0.1s; }
.reveal-delay-2 { transition-delay: 0.2s; }
.reveal-delay-3 { transition-delay: 0.3s; }
.reveal-delay-4 { transition-delay: 0.4s; }

/* ========================================
   Theme Toggle — Blue Theme
   ======================================== */

/* Smooth theme transitions for all color properties */
*, *::before, *::after {
  transition: background-color 0.3s ease, border-color 0.3s ease, color 0.3s ease, box-shadow 0.3s ease, fill 0.3s ease, stroke 0.3s ease;
}

/* Blue theme overrides */
[data-theme="blue"] {
  --primary-50: #eff6ff;
  --primary-100: #dbeafe;
  --primary-200: #bfdbfe;
  --primary-300: #93c5fd;
  --primary-400: #60a5fa;
  --primary-500: #3b82f6;
  --primary-600: #2563eb;
  --primary-700: #1d4ed8;
  --primary-800: #1e40af;
  --primary-900: #1e3a8a;
  --shadow-glow: 0 4px 24px rgba(59,130,246,0.25);
}

/* Theme toggle button */
.theme-toggle {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 2px solid var(--primary-400);
  background: var(--primary-50);
  color: var(--primary-700);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0;
  flex-shrink: 0;
}

.theme-toggle:hover {
  background: var(--primary-100);
  color: var(--primary-800);
  border-color: var(--primary-500);
}

.theme-toggle__icon {
  width: 18px;
  height: 18px;
}

/* Language Toggle */
.lang-toggle {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 2px solid var(--primary-400);
  background: var(--primary-50);
  color: var(--primary-700);
  font-size: 12px;
  font-weight: 700;
  text-decoration: none;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  cursor: pointer;
  transition: background 0.2s ease, border-color 0.2s ease;
}
.lang-toggle:hover {
  background: var(--primary-100);
  border-color: var(--primary-500);
}

/* ========================================
   Theme-Aware Logo & Icon Switching
   ======================================== */
.logo-blue,
.icon-blue {
  display: none !important;
}
[data-theme="blue"] .logo-green,
[data-theme="blue"] .icon-green {
  display: none !important;
}
[data-theme="blue"] .logo-blue,
[data-theme="blue"] .icon-blue {
  display: inline !important;
}
[data-theme="blue"] .logo-blue.block-display,
[data-theme="blue"] .icon-blue.block-display {
  display: block !important;
}

/* Reduced 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;
  }
}