/* 现代化欧美风格设计系统 */
:root {
  --primary-blue: #2563eb;
  --primary-indigo: #6366f1;
  --primary-purple: #8b5cf6;
  --accent-orange: #f97316;
  --accent-green: #22c55e;
  --accent-pink: #ec4899;
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
  color: var(--gray-900);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1rem;
}

/* 现代化头部 */
.header {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--gray-200);
  position: sticky;
  top: 0;
  z-index: 50;
  box-shadow: var(--shadow-sm);
}

.header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 0;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: inherit;
}

.logo-icon {
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, var(--primary-blue), var(--primary-indigo));
  border-radius: 0.75rem;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: bold;
  font-size: 1.125rem;
  box-shadow: var(--shadow-md);
}

.logo-text {
  font-size: 1.25rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--primary-blue), var(--primary-indigo));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* 导航菜单 */
.nav {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.nav-link {
  color: var(--gray-600);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.875rem;
  padding: 0.5rem 0.75rem;
  border-radius: 0.5rem;
  transition: all 0.2s ease;
}

.nav-link:hover {
  color: var(--primary-blue);
  background: var(--gray-50);
}

/* 英雄区域 */
.hero {
  padding: 5rem 0 4rem;
  text-align: center;
  position: relative;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: 
    radial-gradient(circle at 20% 80%, rgba(37, 99, 235, 0.1) 0%, transparent 50%),
    radial-gradient(circle at 80% 20%, rgba(139, 92, 246, 0.1) 0%, transparent 50%);
  z-index: -1;
}

.hero-title {
  font-size: 3rem;
  font-weight: 800;
  line-height: 1.1;
  margin-bottom: 1.5rem;
  background: linear-gradient(135deg, var(--primary-blue), var(--primary-indigo), var(--primary-purple));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: var(--gray-600);
  max-width: 600px;
  margin: 0 auto 2rem;
}

/* 工具卡片 */
.tool-card {
  background: white;
  border-radius: 1rem;
  padding: 1.5rem;
  box-shadow: var(--shadow-md);
  border: 1px solid var(--gray-200);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  text-decoration: none;
  color: inherit;
  display: block;
  position: relative;
  overflow: hidden;
}

.tool-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--primary-blue), var(--primary-indigo));
  transform: scaleX(0);
  transition: transform 0.3s ease;
}

.tool-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-xl);
  border-color: var(--primary-blue);
}

.tool-card:hover::before {
  transform: scaleX(1);
}

.tool-logo {
  width: 48px;
  height: 48px;
  border-radius: 0.75rem;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  color: white;
  font-size: 1.125rem;
  margin-bottom: 1rem;
  box-shadow: var(--shadow-md);
}

.tool-name {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--gray-900);
  margin-bottom: 0.5rem;
}

.tool-description {
  color: var(--gray-600);
  font-size: 0.875rem;
  line-height: 1.5;
}

/* 分类标题 */
.category-header {
  background: linear-gradient(135deg, var(--primary-blue), var(--primary-indigo));
  color: white;
  padding: 1.5rem;
  border-radius: 1rem 1rem 0 0;
  font-size: 1.25rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.category-header::before {
  content: '';
  width: 4px;
  height: 24px;
  background: white;
  border-radius: 2px;
}

/* 网格布局 */
.grid {
  display: grid;
  gap: 1.5rem;
}

.grid-cols-2 { grid-template-columns: repeat(2, 1fr); }
.grid-cols-3 { grid-template-columns: repeat(3, 1fr); }
.grid-cols-4 { grid-template-columns: repeat(4, 1fr); }
.grid-cols-5 { grid-template-columns: repeat(5, 1fr); }

@media (max-width: 1024px) {
  .grid-cols-5 { grid-template-columns: repeat(4, 1fr); }
}

@media (max-width: 768px) {
  .grid-cols-4, .grid-cols-5 { grid-template-columns: repeat(3, 1fr); }
  .hero-title { font-size: 2.25rem; }
  .nav { display: none; }
}

@media (max-width: 640px) {
  .grid-cols-3, .grid-cols-4, .grid-cols-5 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 480px) {
  .grid-cols-2, .grid-cols-3, .grid-cols-4, .grid-cols-5 { grid-template-columns: 1fr; }
}

/* 动画 */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.fade-in {
  animation: fadeIn 0.6s ease-out;
}

/* 移动端菜单 */
.mobile-menu-button {
  display: none;
  flex-direction: column;
  gap: 4px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
}

.mobile-menu-button span {
  width: 24px;
  height: 2px;
  background: var(--gray-600);
  transition: all 0.3s ease;
}

@media (max-width: 768px) {
  .mobile-menu-button { display: flex; }
}