/* Tailwind CSS CDN */
@import url('https://cdn.jsdelivr.net/npm/tailwindcss@2.2.19/dist/tailwind.min.css');

/* ===== CSS变量定义 ===== */
:root {
  /* 主色调 */
  --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --secondary-gradient: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
  --accent-gradient: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
  
  /* 背景色 */
  --bg-primary: #f8f9ff;
  --bg-secondary: #ffffff;
  --bg-dark: #1a1a2e;
  
  /* 文字颜色 */
  --text-primary: #1a1a2e;
  --text-secondary: #4a4a6a;
  --text-light: #ffffff;
  
  /* 功能色 */
  --success: #22c55e;
  --error: #ef4444;
  --warning: #f59e0b;
  
  /* 玻璃拟态效果 */
  --glass-bg: rgba(255, 255, 255, 0.15);
  --glass-border: rgba(255, 255, 255, 0.2);
  --glass-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.15);
  
  /* 字体设置 */
  --font-family: 'PingFang SC', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  
  /* 过渡动画 */
  --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-bounce: all 0.4s cubic-bezier(0.68, -0.55, 0.265, 1.55);
}

/* ===== 全局基础样式 ===== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ===== 背景装饰效果 ===== */
.bg-decoration {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: -1;
  overflow: hidden;
}

.bg-blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.4;
  animation: float 20s infinite ease-in-out;
}

.bg-blob-1 {
  width: 600px;
  height: 600px;
  background: linear-gradient(135deg, #667eea33, #764ba233);
  top: -200px;
  right: -200px;
  animation-delay: 0s;
}

.bg-blob-2 {
  width: 500px;
  height: 500px;
  background: linear-gradient(135deg, #f093fb33, #f5576c33);
  bottom: -150px;
  left: -150px;
  animation-delay: -7s;
}

.bg-blob-3 {
  width: 400px;
  height: 400px;
  background: linear-gradient(135deg, #4facfe33, #00f2fe33);
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  animation-delay: -14s;
}

@keyframes float {
  0%, 100% { transform: translate(0, 0) scale(1); }
  25% { transform: translate(30px, -30px) scale(1.05); }
  50% { transform: translate(-20px, 20px) scale(0.95); }
  75% { transform: translate(20px, 30px) scale(1.02); }
}

/* ===== 导航栏样式 ===== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 1rem 2rem;
  transition: var(--transition-smooth);
  background: transparent;
}

.navbar.scrolled {
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.08);
  border-bottom: 1px solid var(--glass-border);
}

.navbar-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.navbar-brand {
  font-size: 1.75rem;
  font-weight: 700;
  background: var(--primary-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-decoration: none;
  letter-spacing: -0.5px;
}

.navbar-menu {
  display: flex;
  gap: 2.5rem;
  list-style: none;
}

.navbar-menu a {
  color: var(--text-secondary);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.95rem;
  position: relative;
  transition: var(--transition-smooth);
  padding: 0.5rem 0;
}

.navbar-menu a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--primary-gradient);
  transition: var(--transition-smooth);
  border-radius: 1px;
}

.navbar-menu a:hover {
  color: #667eea;
}

.navbar-menu a:hover::after {
  width: 100%;
}

/* 汉堡菜单按钮 */
.hamburger {
  display: none;
  flex-direction: column;
  cursor: pointer;
  gap: 5px;
  padding: 8px;
}

.hamburger span {
  width: 25px;
  height: 3px;
  background: var(--text-primary);
  border-radius: 3px;
  transition: var(--transition-smooth);
}

.hamburger.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 6px);
}

.hamburger.active span:nth-child(2) {
  opacity: 0;
}

.hamburger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -6px);
}

/* ===== Hero区域样式 ===== */
.hero-section {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 6rem 2rem 4rem;
  position: relative;
  overflow: hidden;
}

.hero-content {
  max-width: 900px;
  z-index: 1;
}

.hero-title {
  font-size: clamp(2.5rem, 6vw, 4.5rem);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 1.5rem;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: fadeInUp 1s ease-out;
}

.hero-subtitle {
  font-size: clamp(1.1rem, 2.5vw, 1.4rem);
  color: var(--text-secondary);
  margin-bottom: 2.5rem;
  line-height: 1.8;
  animation: fadeInUp 1s ease-out 0.2s backwards;
}

.hero-buttons {
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
  animation: fadeInUp 1s ease-out 0.4s backwards;
}

.btn {
  padding: 0.9rem 2rem;
  border-radius: 50px;
  font-weight: 600;
  text-decoration: none;
  transition: var(--transition-smooth);
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1rem;
  border: none;
  cursor: pointer;
}

.btn-primary {
  background: var(--primary-gradient);
  color: white;
  box-shadow: 0 10px 30px rgba(102, 126, 234, 0.35);
}

.btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 15px 40px rgba(102, 126, 234, 0.45);
}

.btn-outline {
  background: var(--glass-bg);
  color: var(--text-primary);
  border: 2px solid var(--glass-border);
  backdrop-filter: blur(10px);
}

.btn-outline:hover {
  background: white;
  border-color: #667eea;
  transform: translateY(-3px);
  box-shadow: 0 10px 30px rgba(102, 126, 234, 0.2);
}

.scroll-indicator {
  position: absolute;
  bottom: 3rem;
  left: 50%;
  transform: translateX(-50%);
  animation: bounce 2s infinite;
}

.scroll-indicator svg {
  width: 32px;
  height: 32px;
  stroke: #667eea;
  stroke-width: 2;
}

@keyframes bounce {
  0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) translateY(0); }
  40% { transform: translateX(-50%) translateY(-12px); }
  60% { transform: translateX(-50%) translateY(-6px); }
}

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

/* ===== 内容区域通用样式 ===== */
.section {
  padding: 6rem 2rem;
  max-width: 1200px;
  margin: 0 auto;
}

.section-header {
  text-align: center;
  margin-bottom: 4rem;
}

.section-title {
  font-size: clamp(2rem, 4vw, 2.8rem);
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 1rem;
  position: relative;
  display: inline-block;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -10px;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 4px;
  background: var(--primary-gradient);
  border-radius: 2px;
}

.section-description {
  color: var(--text-secondary);
  font-size: 1.1rem;
  margin-top: 1.5rem;
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

/* ===== 卡片网格布局 ===== */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2rem;
  margin-top: 3rem;
}

/* ===== 玻璃拟态卡片样式 ===== */
.glass-card {
  background: rgba(255, 255, 255, 0.65);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid rgba(255, 255, 255, 0.3);
  border-radius: 20px;
  padding: 2rem;
  transition: var(--transition-smooth);
  position: relative;
  overflow: hidden;
}

.glass-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--primary-gradient);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.4s ease;
}

.glass-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 20px 60px rgba(102, 126, 234, 0.15);
  border-color: rgba(102, 126, 234, 0.2);
}

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

.card-image {
  width: 100%;
  height: 200px;
  object-fit: cover;
  border-radius: 12px;
  margin-bottom: 1.5rem;
  transition: var(--transition-smooth);
}

.glass-card:hover .card-image {
  transform: scale(1.02);
}

.card-meta {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1rem;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.card-date {
  display: flex;
  align-items: center;
  gap: 0.3rem;
}

.card-tag {
  padding: 0.3rem 0.8rem;
  background: linear-gradient(135deg, rgba(102, 126, 234, 0.1), rgba(118, 75, 162, 0.1));
  color: #667eea;
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 500;
}

.card-title {
  font-size: 1.35rem;
  font-weight: 650;
  color: var(--text-primary);
  margin-bottom: 0.8rem;
  line-height: 1.4;
  transition: var(--transition-smooth);
}

.glass-card:hover .card-title {
  color: #667eea;
}

.card-excerpt {
  color: var(--text-secondary);
  line-height: 1.7;
  font-size: 0.95rem;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.card-footer {
  margin-top: 1.5rem;
  padding-top: 1.2rem;
  border-top: 1px solid rgba(0, 0, 0, 0.06);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.read-more {
  color: #667eea;
  text-decoration: none;
  font-weight: 600;
  font-size: 0.9rem;
  display: flex;
  align-items: center;
  gap: 0.3rem;
  transition: var(--transition-smooth);
}

.read-more:hover {
  gap: 0.6rem;
}

.read-more svg {
  width: 16px;
  height: 16px;
  transition: var(--transition-smooth);
}

/* 学习卡片特殊样式 */
.study-card .card-tag.frontend {
  background: linear-gradient(135deg, rgba(34, 197, 94, 0.1), rgba(16, 185, 129, 0.1));
  color: #22c55e;
}

.study-card .card-tag.backend {
  background: linear-gradient(135deg, rgba(59, 130, 246, 0.1), rgba(37, 99, 235, 0.1));
  color: #3b82f6;
}

.study-card .card-tag.tool {
  background: linear-gradient(135deg, rgba(245, 158, 11, 0.1), rgba(251, 191, 36, 0.1));
  color: #f59e0b;
}

.study-card .card-tag.resource {
  background: linear-gradient(135deg, rgba(168, 85, 247, 0.1), rgba(147, 51, 234, 0.1));
  color: #a855f7;
}

.read-time {
  display: flex;
  align-items: center;
  gap: 0.3rem;
  color: var(--text-secondary);
  font-size: 0.85rem;
}

/* ===== 页脚样式 ===== */
.footer {
  background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
  color: var(--text-light);
  padding: 3rem 2rem 1.5rem;
  margin-top: 4rem;
  position: relative;
  overflow: hidden;
}

.footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--primary-gradient);
}

.footer-content {
  max-width: 1200px;
  margin: 0 auto;
  text-align: center;
}

.footer-text {
  color: rgba(255, 255, 255, 0.7);
  font-size: 0.95rem;
  margin-bottom: 1rem;
  line-height: 1.8;
}

.footer-beian {
  margin-top: 1.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-beian a {
  color: rgba(255, 255, 255, 0.6);
  text-decoration: none;
  font-size: 0.9rem;
  transition: var(--transition-smooth);
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
}

.footer-beian a:hover {
  color: #667eea;
}

/* ===== 返回顶部按钮 ===== */
.back-to-top {
  position: fixed;
  bottom: 2.5rem;
  right: 2.5rem;
  width: 48px;
  height: 48px;
  background: var(--primary-gradient);
  color: white;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: var(--transition-smooth);
  box-shadow: 0 8px 25px rgba(102, 126, 234, 0.4);
  z-index: 999;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  transform: translateY(-5px);
  box-shadow: 0 12px 35px rgba(102, 126, 234, 0.5);
}

.back-to-top svg {
  width: 24px;
  height: 24px;
}

/* ===== 动画类 ===== */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===== 响应式设计 ===== */
@media (max-width: 1024px) {
  .card-grid {
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
  }
}

@media (max-width: 768px) {
  .navbar-menu {
    position: fixed;
    top: 70px;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(20px);
    flex-direction: column;
    align-items: center;
    padding: 2rem;
    gap: 1.5rem;
    transform: translateX(100%);
    transition: var(--transition-smooth);
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
  }

  .navbar-menu.active {
    transform: translateX(0);
  }

  .hamburger {
    display: flex;
  }

  .hero-section {
    padding: 7rem 1.5rem 3rem;
  }

  .section {
    padding: 4rem 1.5rem;
  }

  .card-grid {
    grid-template-columns: 1fr;
  }

  .glass-card {
    padding: 1.5rem;
  }

  .btn {
    padding: 0.8rem 1.6rem;
    font-size: 0.9rem;
  }
}

@media (max-width: 480px) {
  .navbar {
    padding: 1rem;
  }

  .hero-title {
    font-size: 2rem;
  }

  .section-title {
    font-size: 1.75rem;
  }

  .back-to-top {
    bottom: 1.5rem;
    right: 1.5rem;
    width: 42px;
    height: 42px;
  }
}