/* ============================================
 * 全局设计系统 — 杂七杂八工具箱
 * 包含：CSS 变量、基础 reset、排版、通用组件
 * ============================================ */

/* ---------- Google Fonts ---------- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');

/* ---------- 设计令牌 ---------- */
:root {
  /* 主色板 */
  --color-bg-primary: #0a0e1a;
  --color-bg-secondary: #111827;
  --color-bg-card: rgba(17, 24, 39, 0.6);
  --color-bg-card-hover: rgba(30, 41, 59, 0.7);
  --color-bg-input: rgba(15, 23, 42, 0.8);

  /* 强调色 — 霓虹绿 */
  --color-accent: #22d3ee;
  --color-accent-glow: rgba(34, 211, 238, 0.3);
  --color-accent-secondary: #a78bfa;
  --color-accent-tertiary: #34d399;

  /* 渐变 */
  --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --gradient-accent: linear-gradient(135deg, #22d3ee 0%, #a78bfa 100%);
  --gradient-card: linear-gradient(135deg, rgba(99, 102, 241, 0.1) 0%, rgba(168, 85, 247, 0.1) 100%);
  --gradient-bg: radial-gradient(ellipse at top left, rgba(99, 102, 241, 0.15) 0%, transparent 50%),
                 radial-gradient(ellipse at bottom right, rgba(168, 85, 247, 0.1) 0%, transparent 50%);

  /* 文字 */
  --color-text-primary: #f1f5f9;
  --color-text-secondary: #94a3b8;
  --color-text-muted: #64748b;

  /* 边框 */
  --color-border: rgba(148, 163, 184, 0.1);
  --color-border-hover: rgba(148, 163, 184, 0.25);

  /* 间距 */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;

  /* 圆角 */
  --radius-sm: 0.5rem;
  --radius-md: 0.75rem;
  --radius-lg: 1rem;
  --radius-xl: 1.25rem;
  --radius-full: 9999px;

  /* 阴影 */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 25px -3px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 20px var(--color-accent-glow);

  /* 过渡 */
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
  --transition-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);

  /* 字体 */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
}

/* ---------- 基础 Reset ---------- */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-family);
  background-color: var(--color-bg-primary);
  color: var(--color-text-primary);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
}

/* 背景装饰渐变 */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--gradient-bg);
  pointer-events: none;
  z-index: 0;
}

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

a:hover {
  color: var(--color-accent-secondary);
}

img {
  max-width: 100%;
  display: block;
}

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

input, select, textarea {
  font-family: inherit;
  outline: none;
}

/* ---------- 排版 ---------- */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.2;
  color: var(--color-text-primary);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 1.75rem; }
h3 { font-size: 1.25rem; }

/* ---------- 布局容器 ---------- */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-lg);
  position: relative;
  z-index: 1;
}

/* ---------- 通用按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-lg);
  font-size: 0.9rem;
  font-weight: 600;
  border-radius: var(--radius-md);
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.btn-primary {
  background: var(--gradient-accent);
  color: var(--color-bg-primary);
  box-shadow: var(--shadow-glow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 30px var(--color-accent-glow);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-ghost {
  background: transparent;
  color: var(--color-text-secondary);
  border: 1px solid var(--color-border);
}

.btn-ghost:hover {
  border-color: var(--color-border-hover);
  color: var(--color-text-primary);
  background: rgba(148, 163, 184, 0.05);
}

/* ---------- 通用输入框 ---------- */
.input-field {
  width: 100%;
  padding: var(--space-md) var(--space-lg);
  background: var(--color-bg-input);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text-primary);
  font-size: 1rem;
  transition: all var(--transition-normal);
}

.input-field:focus {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px var(--color-accent-glow);
}

.input-field::placeholder {
  color: var(--color-text-muted);
}

/* ---------- 通用卡片 ---------- */
.card {
  background: var(--color-bg-card);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  transition: all var(--transition-normal);
}

.card:hover {
  border-color: var(--color-border-hover);
  background: var(--color-bg-card-hover);
  box-shadow: var(--shadow-lg);
}

/* ---------- 导航栏 ---------- */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(10, 14, 26, 0.8);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--color-border);
  padding: var(--space-md) 0;
}

.navbar .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.navbar-brand {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text-primary);
  text-decoration: none;
}

.navbar-brand:hover {
  color: var(--color-text-primary);
}

.navbar-brand .brand-icon {
  font-size: 1.5rem;
}

.navbar-brand .brand-text {
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ---------- 页脚 ---------- */
.footer {
  margin-top: auto;
  padding: var(--space-xl) 0;
  border-top: 1px solid var(--color-border);
  text-align: center;
  color: var(--color-text-muted);
  font-size: 0.85rem;
  position: relative;
  z-index: 1;
}

/* ---------- 动画关键帧 ---------- */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

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

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.7; }
}

@keyframes numberRoll {
  0% {
    opacity: 0;
    transform: translateY(-10px) scale(0.8);
  }
  60% {
    transform: translateY(2px) scale(1.02);
  }
  100% {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

/* 动画工具类 */
.animate-fade-in-up {
  animation: fadeInUp 0.6s var(--transition-slow) both;
}

.animate-fade-in {
  animation: fadeIn 0.4s ease both;
}

/* 交错延迟 */
.delay-1 { animation-delay: 0.1s; }
.delay-2 { animation-delay: 0.2s; }
.delay-3 { animation-delay: 0.3s; }
.delay-4 { animation-delay: 0.4s; }
.delay-5 { animation-delay: 0.5s; }

/* ---------- 响应式 ---------- */
@media (max-width: 768px) {
  html { font-size: 14px; }

  .container {
    padding: 0 var(--space-md);
  }

  h1 { font-size: 1.75rem; }
  h2 { font-size: 1.35rem; }
}

@media (max-width: 480px) {
  html { font-size: 13px; }
}