/* ============================================
   燃坤AI 统一设计系统 V2 - 基于Logo科技蓝色调
   主色：#0066b3 科技蓝
   深色：#003d7a 深蓝
   浅色：#3b9ee0 天蓝
   点缀：#e53e3e 红色（Logo菱形）
   ============================================ */

:root {
  /* 品牌色 - 科技蓝 */
  --color-primary-50: #e6f2fa;
  --color-primary-100: #b3d7f0;
  --color-primary-200: #80bce6;
  --color-primary-300: #4da1dc;
  --color-primary-400: #268bd4;
  --color-primary-500: #0066b3;
  --color-primary-600: #005099;
  --color-primary-700: #003d7a;
  --color-primary-800: #002a5c;
  --color-primary-900: #001a3d;

  /* 点缀色 - 红色 */
  --color-accent-50: #fef2f2;
  --color-accent-100: #fee2e2;
  --color-accent-500: #e53e3e;
  --color-accent-600: #dc2626;

  /* 辅助色 */
  --color-success-50: #ecfdf5;
  --color-success-500: #10b981;
  --color-success-600: #059669;
  --color-warning-50: #fffbeb;
  --color-warning-500: #f59e0b;
  --color-warning-600: #d97706;
  --color-error-50: #fef2f2;
  --color-error-500: #ef4444;
  --color-error-600: #dc2626;
  --color-info-50: #eff6ff;
  --color-info-500: #3b82f6;

  /* 中性色 */
  --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;

  /* 语义化颜色 */
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-tertiary: #f1f5f9;
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --border-default: #e2e8f0;
  --border-light: #f1f5f9;

  /* 渐变 */
  --gradient-primary: linear-gradient(135deg, #0050b4 0%, #1478b4 100%);
  --gradient-hero: linear-gradient(180deg, #e6f2fa 0%, #ffffff 100%);
  --gradient-card: linear-gradient(135deg, #f0f7fc 0%, #e6f2fa 100%);

  /* 圆角 */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  /* 阴影 */
  --shadow-sm: 0 1px 2px rgba(0, 61, 122, 0.05);
  --shadow-md: 0 4px 12px rgba(0, 61, 122, 0.08);
  --shadow-lg: 0 8px 24px rgba(0, 61, 122, 0.12);
  --shadow-xl: 0 16px 48px rgba(0, 61, 122, 0.16);

  /* 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;

  /* 导航高度 */
  --nav-height: 64px;

  /* 过渡 */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
}

/* 基础重置 */
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  color: var(--text-primary);
  background: var(--bg-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }

/* 容器 */
.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

/* 工具类 */
.flex { display: flex; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.flex-wrap { flex-wrap: wrap; }
.gap-2 { gap: 8px; }
.gap-3 { gap: 12px; }
.gap-4 { gap: 16px; }
.gap-6 { gap: 24px; }
.mt-4 { margin-top: 16px; }
.mt-6 { margin-top: 24px; }
.mt-8 { margin-top: 32px; }
.mb-2 { margin-bottom: 8px; }
.mb-3 { margin-bottom: 12px; }
.mb-4 { margin-bottom: 16px; }
.mb-6 { margin-bottom: 24px; }
.mb-8 { margin-bottom: 32px; }
.text-center { text-align: center; }
.w-full { width: 100%; }

/* ========== 导航栏 ========== */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-default);
  height: var(--nav-height);
}
.navbar-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.navbar-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 800;
  color: var(--color-primary-600);
}
.navbar-logo img { height: 36px; width: auto; }
.navbar-menu { display: flex; gap: 4px; }
.navbar-link {
  padding: 8px 16px;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-secondary);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}
.navbar-link:hover { color: var(--color-primary-600); background: var(--color-primary-50); }
.navbar-link.active { color: var(--color-primary-600); background: var(--color-primary-50); font-weight: 600; }
.navbar-actions { display: flex; align-items: center; gap: 12px; }
.navbar-user {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-secondary);
  padding: 6px 12px;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}
.navbar-user:hover { background: var(--bg-tertiary); color: var(--text-primary); }

/* ========== 按钮 ========== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 20px;
  font-size: 14px;
  font-weight: 600;
  border-radius: var(--radius-md);
  border: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  white-space: nowrap;
}
.btn-primary { background: var(--gradient-primary); color: #fff; box-shadow: 0 2px 8px rgba(0, 80, 180, 0.25); }
.btn-primary:hover { transform: translateY(-1px); box-shadow: 0 4px 16px rgba(0, 80, 180, 0.35); }
.btn-secondary { background: var(--bg-tertiary); color: var(--text-primary); }
.btn-secondary:hover { background: var(--gray-200); }
.btn-outline { background: transparent; color: var(--color-primary-600); border: 1.5px solid var(--color-primary-300); }
.btn-outline:hover { background: var(--color-primary-50); border-color: var(--color-primary-500); }
.btn-ghost { background: transparent; color: var(--text-secondary); }
.btn-ghost:hover { background: var(--bg-tertiary); color: var(--text-primary); }
.btn-sm { padding: 6px 14px; font-size: 13px; }
.btn-lg { padding: 14px 28px; font-size: 16px; }

/* ========== 卡片 ========== */
.card {
  background: var(--bg-primary);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: all var(--transition-normal);
}
.card:hover { box-shadow: var(--shadow-md); }
.card-header { padding: 20px 24px; border-bottom: 1px solid var(--border-default); }
.card-body { padding: 24px; }

/* ========== 表单 ========== */
.form-group { margin-bottom: 20px; }
.form-label { display: block; font-size: 14px; font-weight: 600; color: var(--text-primary); margin-bottom: 8px; }
.form-input {
  width: 100%;
  padding: 10px 14px;
  font-size: 14px;
  border: 1.5px solid var(--border-default);
  border-radius: var(--radius-md);
  outline: none;
  transition: all var(--transition-fast);
  background: var(--bg-primary);
  color: var(--text-primary);
}
.form-input:focus { border-color: var(--color-primary-400); box-shadow: 0 0 0 3px rgba(0, 102, 179, 0.1); }
.form-input::placeholder { color: var(--text-muted); }
.form-select {
  width: 100%;
  padding: 10px 14px;
  font-size: 14px;
  border: 1.5px solid var(--border-default);
  border-radius: var(--radius-md);
  outline: none;
  background: var(--bg-primary);
  color: var(--text-primary);
  cursor: pointer;
}
.form-textarea {
  width: 100%;
  padding: 10px 14px;
  font-size: 14px;
  border: 1.5px solid var(--border-default);
  border-radius: var(--radius-md);
  outline: none;
  resize: vertical;
  min-height: 100px;
  font-family: inherit;
}

/* ========== 标签/徽章 ========== */
.tag {
  display: inline-flex;
  align-items: center;
  padding: 6px 14px;
  font-size: 13px;
  font-weight: 500;
  border-radius: var(--radius-full);
  background: var(--bg-tertiary);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
  border: none;
}
.tag:hover { background: var(--gray-200); }
.tag.active { background: var(--color-primary-50); color: var(--color-primary-600); font-weight: 600; }
.badge {
  display: inline-flex;
  align-items: center;
  padding: 3px 10px;
  font-size: 12px;
  font-weight: 600;
  border-radius: var(--radius-full);
}
.badge-primary { background: var(--color-primary-50); color: var(--color-primary-600); }
.badge-success { background: var(--color-success-50); color: var(--color-success-600); }
.badge-warning { background: var(--color-warning-50); color: var(--color-warning-600); }
.badge-error { background: var(--color-error-50); color: var(--color-error-600); }
.badge-info { background: var(--color-info-50); color: var(--color-info-500); }

/* ========== Hero区域 ========== */
.hero {
  background: var(--gradient-hero);
  padding: 80px 0 60px;
  text-align: center;
}
.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 18px;
  background: var(--color-primary-50);
  color: var(--color-primary-600);
  border-radius: var(--radius-full);
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 24px;
}
.hero-title {
  font-size: 48px;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 20px;
  color: var(--text-primary);
}
.gradient-text {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-subtitle {
  font-size: 18px;
  color: var(--text-secondary);
  max-width: 700px;
  margin: 0 auto 32px;
  line-height: 1.7;
}
.hero-actions { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }

/* ========== 区块 ========== */
.section { padding: 80px 0; }
.section-header { text-align: center; margin-bottom: 48px; }
.section-title { font-size: 32px; font-weight: 800; margin-bottom: 12px; }
.section-subtitle { font-size: 16px; color: var(--text-secondary); max-width: 600px; margin: 0 auto; }
.bg-secondary { background: var(--bg-secondary); }

/* ========== 特性卡片 ========== */
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.feature-card {
  background: var(--bg-primary);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-lg);
  padding: 32px;
  transition: all var(--transition-normal);
}
.feature-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); border-color: var(--color-primary-200); }
.feature-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-md);
  background: var(--color-primary-50);
  color: var(--color-primary-600);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  margin-bottom: 16px;
}
.feature-card h3 { font-size: 18px; font-weight: 700; margin-bottom: 8px; }
.feature-card p { font-size: 14px; color: var(--text-secondary); line-height: 1.7; }

/* ========== 模型展示 ========== */
.model-showcase {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
}
.model-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 20px;
  background: var(--bg-primary);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  font-size: 14px;
  font-weight: 500;
  color: var(--text-secondary);
  transition: all var(--transition-fast);
}
.model-item:hover { border-color: var(--color-primary-300); color: var(--color-primary-600); transform: translateY(-2px); box-shadow: var(--shadow-sm); }
.model-icon { font-size: 18px; }

/* ========== 页脚 ========== */
.footer {
  background: var(--gray-900);
  color: var(--gray-400);
  padding: 60px 0 24px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}
.footer-brand h3 { color: #fff; font-size: 20px; font-weight: 800; margin-bottom: 12px; }
.footer-brand p { font-size: 14px; line-height: 1.7; }
.footer-col h4 { color: #fff; font-size: 14px; font-weight: 700; margin-bottom: 16px; }
.footer-col ul { list-style: none; }
.footer-col li { margin-bottom: 10px; }
.footer-col a { font-size: 13px; color: var(--gray-400); transition: color var(--transition-fast); }
.footer-col a:hover { color: #fff; }
.footer-bottom {
  border-top: 1px solid var(--gray-800);
  padding-top: 24px;
  display: flex;
  justify-content: space-between;
  font-size: 13px;
  flex-wrap: wrap;
  gap: 12px;
}

/* 响应式 */
@media (max-width: 1024px) {
  .grid-3 { grid-template-columns: repeat(2, 1fr); }
  .grid-4 { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .hero-title { font-size: 36px; }
}
@media (max-width: 768px) {
  .navbar-menu { display: none; }
  .grid-3 { grid-template-columns: 1fr; }
  .grid-4 { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .hero-title { font-size: 28px; }
  .hero-subtitle { font-size: 16px; }
  .section { padding: 48px 0; }
}