/* ===================================
   Apple-Style Blog - 苹果风格着陆页
   =================================== */

/* ---------- 设计系统变量 ---------- */
:root {
  /* 品牌色 */
  --color-accent: #0071e3;
  --color-accent-hover: #0077ED;
  --color-accent-light: rgba(0, 113, 227, 0.08);

  /* 渐变 */
  --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --gradient-hero: linear-gradient(135deg, #0071e3 0%, #00c6fb 50%, #667eea 100%);
  --gradient-warm: linear-gradient(135deg, #f97316 0%, #facc15 100%);
  --gradient-cool: linear-gradient(135deg, #06b6d4 0%, #3b82f6 100%);
  --gradient-rose: linear-gradient(135deg, #ec4899 0%, #f43f5e 100%);
  --gradient-green: linear-gradient(135deg, #10b981 0%, #34d399 100%);

  /* 文字色 */
  --color-text-primary: #1d1d1f;
  --color-text-secondary: #6e6e73;
  --color-text-tertiary: #86868b;
  --color-text-inverse: #f5f5f7;

  /* 背景色 */
  --color-bg-primary: #ffffff;
  --color-bg-secondary: #f5f5f7;
  --color-bg-tertiary: #fbfbfd;
  --color-bg-card: rgba(255, 255, 255, 0.8);

  /* 边框 */
  --color-border: rgba(0, 0, 0, 0.06);
  --color-border-hover: rgba(0, 0, 0, 0.12);

  /* 毛玻璃 */
  --blur-nav: 20px;
  --blur-card: 16px;

  /* 圆角 */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-xl: 24px;

  /* 阴影 */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.04), 0 1px 2px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 14px rgba(0, 0, 0, 0.06), 0 2px 6px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 10px 40px rgba(0, 0, 0, 0.08), 0 4px 16px rgba(0, 0, 0, 0.04);
  --shadow-xl: 0 20px 60px rgba(0, 0, 0, 0.1), 0 8px 24px rgba(0, 0, 0, 0.06);

  /* 过渡 */
  --ease-apple: cubic-bezier(0.25, 0.1, 0.25, 1);
  --ease-apple-decel: cubic-bezier(0.0, 0.0, 0.2, 1);
  --ease-apple-accel: cubic-bezier(0.4, 0.0, 1, 1);
  --ease-apple-spring: cubic-bezier(0.175, 0.885, 0.32, 1.275);
  --transition-fast: 0.2s var(--ease-apple);
  --transition-normal: 0.35s var(--ease-apple-decel);
  --transition-slow: 0.6s var(--ease-apple-decel);

  /* 间距 */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;
  --space-4xl: 96px;
  --space-5xl: 128px;

  /* 字体 */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Segoe UI', Roboto, sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 2rem;
  --font-size-4xl: 2.5rem;
  --font-size-5xl: 3.5rem;
  --font-size-6xl: 4.5rem;
  --font-size-hero: 5.5rem;

  /* 容器 */
  --container-max: 1120px;
  --container-padding: 24px;
}

/* ---------- 深色模式 ---------- */
@media (prefers-color-scheme: dark) {
  :root {
    --color-text-primary: #f5f5f7;
    --color-text-secondary: #a1a1a6;
    --color-text-tertiary: #6e6e73;
    --color-text-inverse: #1d1d1f;
    --color-bg-primary: #000000;
    --color-bg-secondary: #0a0a0a;
    --color-bg-tertiary: #111111;
    --color-bg-card: rgba(28, 28, 30, 0.8);
    --color-border: rgba(255, 255, 255, 0.08);
    --color-border-hover: rgba(255, 255, 255, 0.15);
    --color-accent-light: rgba(0, 113, 227, 0.15);
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 14px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 40px rgba(0, 0, 0, 0.4);
    --shadow-xl: 0 20px 60px rgba(0, 0, 0, 0.5);
  }
}

/* 手动深色模式切换 */
html.dark {
  --color-text-primary: #f5f5f7;
  --color-text-secondary: #a1a1a6;
  --color-text-tertiary: #6e6e73;
  --color-text-inverse: #1d1d1f;
  --color-bg-primary: #000000;
  --color-bg-secondary: #0a0a0a;
  --color-bg-tertiary: #111111;
  --color-bg-card: rgba(28, 28, 30, 0.8);
  --color-border: rgba(255, 255, 255, 0.08);
  --color-border-hover: rgba(255, 255, 255, 0.15);
  --color-accent-light: rgba(0, 113, 227, 0.15);
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.2);
  --shadow-md: 0 4px 14px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 10px 40px rgba(0, 0, 0, 0.4);
  --shadow-xl: 0 20px 60px rgba(0, 0, 0, 0.5);
}

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

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

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

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

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

/* ---------- 容器 ---------- */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

/* ===================================
   导航栏 - 毛玻璃悬浮效果
   =================================== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: var(--color-bg-card);
  backdrop-filter: saturate(180%) blur(var(--blur-nav));
  -webkit-backdrop-filter: saturate(180%) blur(var(--blur-nav));
  border-bottom: 1px solid var(--color-border);
  transition: var(--transition-normal);
}

.navbar.scrolled {
  box-shadow: var(--shadow-sm);
}

.nav-container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-padding);
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-size: var(--font-size-lg);
  font-weight: 700;
  color: var(--color-text-primary);
  transition: var(--transition-fast);
}

.nav-logo:hover {
  opacity: 0.7;
}

.logo-gradient {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  background: var(--gradient-hero);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: var(--font-size-lg);
  font-weight: 800;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
}

.nav-link {
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  transition: var(--transition-fast);
  position: relative;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 1.5px;
  background: var(--color-accent);
  transition: var(--transition-normal);
}

.nav-link:hover {
  color: var(--color-text-primary);
}

.nav-link:hover::after {
  width: 100%;
}

/* 移动端汉堡菜单 */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 20px;
  height: 1.5px;
  background: var(--color-text-primary);
  transition: var(--transition-fast);
  border-radius: 1px;
}

@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }
  .nav-links {
    position: fixed;
    top: 52px;
    left: 0;
    right: 0;
    background: var(--color-bg-card);
    backdrop-filter: saturate(180%) blur(var(--blur-nav));
    -webkit-backdrop-filter: saturate(180%) blur(var(--blur-nav));
    flex-direction: column;
    padding: var(--space-lg);
    gap: var(--space-md);
    border-bottom: 1px solid var(--color-border);
    transform: translateY(-10px);
    opacity: 0;
    pointer-events: none;
    transition: var(--transition-normal);
  }
  .nav-links.active {
    transform: translateY(0);
    opacity: 1;
    pointer-events: all;
  }
}

/* ===================================
   英雄区域 - 渐变背景球 + 大标题
   =================================== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
  padding: 120px var(--container-padding) 80px;
}

/* 背景渐变球体 - 苹果风格 */
.hero-bg-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.4;
  animation: orbFloat 20s ease-in-out infinite;
  pointer-events: none;
}

.orb-1 {
  width: 500px;
  height: 500px;
  background: var(--gradient-hero);
  top: -10%;
  left: -5%;
  animation-delay: 0s;
}

.orb-2 {
  width: 400px;
  height: 400px;
  background: var(--gradient-rose);
  top: 10%;
  right: -10%;
  animation-delay: -7s;
}

.orb-3 {
  width: 350px;
  height: 350px;
  background: var(--gradient-cool);
  bottom: -5%;
  left: 30%;
  animation-delay: -14s;
}

@keyframes orbFloat {
  0%, 100% {
    transform: translate(0, 0) scale(1);
  }
  25% {
    transform: translate(30px, -40px) scale(1.05);
  }
  50% {
    transform: translate(-20px, 20px) scale(0.95);
  }
  75% {
    transform: translate(40px, 30px) scale(1.02);
  }
}

.hero-content {
  text-align: center;
  max-width: 800px;
  position: relative;
  z-index: 1;
}

.hero-eyebrow {
  font-size: var(--font-size-lg);
  font-weight: 500;
  color: var(--color-accent);
  margin-bottom: var(--space-lg);
  letter-spacing: -0.01em;
}

.hero-title {
  font-size: clamp(var(--font-size-4xl), 8vw, var(--font-size-hero));
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.04em;
  margin-bottom: var(--space-xl);
  color: var(--color-text-primary);
}

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

.hero-subtitle {
  font-size: clamp(var(--font-size-lg), 2.5vw, var(--font-size-xl));
  color: var(--color-text-secondary);
  line-height: 1.6;
  margin-bottom: var(--space-2xl);
  max-width: 560px;
  margin-left: auto;
  margin-right: auto;
  font-weight: 400;
}

/* CTA 按钮 */
.hero-cta {
  display: flex;
  gap: var(--space-md);
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 14px 28px;
  border-radius: 980px;
  font-size: var(--font-size-base);
  font-weight: 600;
  font-family: var(--font-family);
  cursor: pointer;
  border: none;
  transition: var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.btn::after {
  content: '';
  position: absolute;
  inset: 0;
  background: white;
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.btn:hover::after {
  opacity: 0.1;
}

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

.btn-primary:hover {
  background: var(--color-accent-hover);
  transform: scale(1.02);
}

.btn-secondary {
  background: transparent;
  color: var(--color-accent);
  border: 1.5px solid var(--color-accent);
}

.btn-secondary:hover {
  background: var(--color-accent-light);
  transform: scale(1.02);
}

/* ===================================
   通用 Section 样式
   =================================== */
.section {
  padding: var(--space-5xl) 0;
}

.section-header {
  text-align: center;
  margin-bottom: var(--space-4xl);
}

.section-eyebrow {
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-accent);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: var(--space-sm);
}

.section-title {
  font-size: clamp(var(--font-size-3xl), 5vw, var(--font-size-5xl));
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.03em;
  color: var(--color-text-primary);
}

/* ===================================
   关于区域 - 卡片网格
   =================================== */
.about-section {
  background: var(--color-bg-secondary);
}

.about-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
}

.about-card {
  background: var(--color-bg-card);
  backdrop-filter: blur(var(--blur-card));
  -webkit-backdrop-filter: blur(var(--blur-card));
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-2xl);
  transition: var(--transition-normal);
}

.about-card:hover {
  transform: translateY(-4px) scale(1.01);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-border-hover);
}

.card-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  background: var(--color-accent-light);
  color: var(--color-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-lg);
}

.about-card h3 {
  font-size: var(--font-size-xl);
  font-weight: 700;
  margin-bottom: var(--space-sm);
  letter-spacing: -0.02em;
}

.about-card p {
  font-size: var(--font-size-base);
  color: var(--color-text-secondary);
  line-height: 1.65;
}

@media (max-width: 900px) {
  .about-grid {
    grid-template-columns: 1fr;
  }
}

/* ===================================
   文章区域
   =================================== */
.posts-section {
  background: var(--color-bg-primary);
}

.posts-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: var(--space-lg);
}

.post-card {
  border-radius: var(--radius-xl);
  overflow: hidden;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  transition: var(--transition-normal);
  cursor: pointer;
}

.post-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl);
  border-color: var(--color-border-hover);
}

.post-image {
  height: 240px;
  position: relative;
  overflow: hidden;
}

.post-image-primary {
  height: 300px;
}

.post-image-gradient {
  position: absolute;
  inset: 0;
  transition: transform var(--transition-slow);
}

.post-card:hover .post-image-gradient {
  transform: scale(1.05);
}

.gradient-1 {
  background: var(--gradient-hero);
}

.gradient-2 {
  background: var(--gradient-warm);
}

.gradient-3 {
  background: var(--gradient-green);
}

.post-content {
  padding: var(--space-lg);
}

.post-tag {
  display: inline-block;
  font-size: var(--font-size-xs);
  font-weight: 600;
  color: var(--color-accent);
  background: var(--color-accent-light);
  padding: 4px 10px;
  border-radius: 980px;
  margin-bottom: var(--space-sm);
}

.post-date {
  font-size: var(--font-size-xs);
  color: var(--color-text-tertiary);
  margin-left: var(--space-sm);
}

.post-title {
  font-size: var(--font-size-xl);
  font-weight: 700;
  line-height: 1.3;
  margin: var(--space-md) 0;
  letter-spacing: -0.02em;
}

.post-primary .post-title {
  font-size: var(--font-size-2xl);
}

.post-excerpt {
  font-size: var(--font-size-base);
  color: var(--color-text-secondary);
  line-height: 1.6;
  margin-bottom: var(--space-md);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.post-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-accent);
  transition: var(--transition-fast);
}

.post-link:hover {
  gap: var(--space-sm);
}

.posts-sidebar {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}

.post-secondary .post-image {
  height: 160px;
}

.post-secondary .post-title {
  font-size: var(--font-size-lg);
}

@media (max-width: 900px) {
  .posts-grid {
    grid-template-columns: 1fr;
  }
  .posts-sidebar {
    flex-direction: row;
  }
  .post-secondary .post-image {
    height: 140px;
  }
  @media (max-width: 600px) {
    .posts-sidebar {
      flex-direction: column;
    }
  }
}

/* ===================================
   数据统计 - 滚动触发动画
   =================================== */
.stats-section {
  background: var(--color-bg-secondary);
  padding: var(--space-4xl) 0;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-lg);
  text-align: center;
}

.stat-number {
  display: block;
  font-size: clamp(var(--font-size-3xl), 5vw, var(--font-size-5xl));
  font-weight: 800;
  letter-spacing: -0.04em;
  background: var(--gradient-hero);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.2;
}

.stat-suffix {
  font-size: 0.6em;
  font-weight: 700;
}

.stat-label {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  margin-top: var(--space-xs);
  font-weight: 500;
}

@media (max-width: 768px) {
  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-xl);
  }
}

/* ===================================
   联系区域 - 卡片
   =================================== */
.contact-section {
  background: var(--color-bg-primary);
}

.contact-card {
  max-width: 640px;
  margin: 0 auto;
  text-align: center;
  padding: var(--space-4xl) var(--space-2xl);
  border-radius: var(--radius-xl);
  background: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
}

.contact-title {
  font-size: clamp(var(--font-size-2xl), 4vw, var(--font-size-3xl));
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.03em;
  margin: var(--space-md) 0 var(--space-sm);
}

.contact-subtitle {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-2xl);
  line-height: 1.6;
}

.contact-links {
  display: flex;
  gap: var(--space-lg);
  justify-content: center;
  flex-wrap: wrap;
}

.contact-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 12px 24px;
  border-radius: 980px;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  font-size: var(--font-size-base);
  font-weight: 500;
  color: var(--color-text-primary);
  transition: var(--transition-normal);
}

.contact-link:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: var(--color-border-hover);
  background: var(--color-accent-light);
  color: var(--color-accent);
}

/* ===================================
   页脚
   =================================== */
.footer {
  padding: var(--space-2xl) 0;
  border-top: 1px solid var(--color-border);
  background: var(--color-bg-secondary);
}

.footer-content {
  text-align: center;
}

.footer-text {
  font-size: var(--font-size-sm);
  color: var(--color-text-tertiary);
}

.footer-small {
  font-size: var(--font-size-xs);
  margin-top: var(--space-xs);
}

/* ===================================
   滚动动画 & 进入动画
   =================================== */

/* 淡入上浮 - 英雄区域 */
.fade-in-up {
  opacity: 0;
  transform: translateY(30px);
  animation: fadeInUp 0.8s var(--ease-apple-decel) forwards;
}

.fade-delay-1 {
  animation-delay: 0.15s;
}

.fade-delay-2 {
  animation-delay: 0.3s;
}

.fade-delay-3 {
  animation-delay: 0.45s;
}

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

/* 滚动触发显示 - 通用 */
.reveal {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity 0.8s var(--ease-apple-decel),
              transform 0.8s var(--ease-apple-decel);
}

.reveal.revealed {
  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;
}

/* ===================================
   自定义滚动条
   =================================== */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--color-text-tertiary);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--color-text-secondary);
}

/* ===================================
   平滑选中颜色
   =================================== */
::selection {
  background: rgba(0, 113, 227, 0.2);
}

/* ===================================
   打印样式
   =================================== */
@media print {
  .navbar,
  .hero-bg-orb {
    display: none;
  }
}