/* ========== Apple Style Design System ========== */

/* 字体系统 */
:root {
  --font-stack: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'SF Pro Text',
    'Helvetica Neue', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  
  /* 颜色系统 */
  --color-bg: #fbfbfd;
  --color-bg-alt: #f5f5f7;
  --color-surface: #ffffff;
  --color-text: #1d1d1f;
  --color-text-secondary: #86868b;
  --color-text-tertiary: #a1a1a6;
  --color-link: #0071e3;
  --color-link-hover: #0077ed;
  --color-border: #d2d2d7;
  --color-border-light: #e5e5ea;
  
  /* 功能色 */
  --color-blue: #0071e3;
  --color-blue-dark: #0077ed;
  --color-green: #30d158;
  --color-orange: #ff9f0a;
  --color-red: #ff453a;
  --color-purple: #bf5af2;
  
  /* 渐变 */
  --gradient-hero: linear-gradient(180deg, #000000 0%, #1c1c1e 50%, #2c2c2e 100%);
  --gradient-card: linear-gradient(180deg, #ffffff 0%, #f5f5f7 100%);
  --gradient-accent: linear-gradient(135deg, #0071e3 0%, #00c7be 100%);
  --gradient-warm: linear-gradient(135deg, #ff9f0a 0%, #ff375f 100%);
  --gradient-cool: linear-gradient(135deg, #5e5ce6 0%, #bf5af2 100%);
  
  /* 圆角 */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-xl: 24px;
  --radius-full: 9999px;
  
  /* 阴影 */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.04);
  --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 24px 60px rgba(0, 0, 0, 0.15);
  --shadow-card: 0 2px 20px rgba(0, 0, 0, 0.04), 0 0 0 1px rgba(0, 0, 0, 0.02);
  --shadow-card-hover: 0 20px 60px rgba(0, 0, 0, 0.12), 0 0 0 1px rgba(0, 0, 0, 0.04);
  
  /* 过渡 */
  --transition-fast: 0.2s cubic-bezier(0.25, 0.1, 0.25, 1);
  --transition-base: 0.3s cubic-bezier(0.25, 0.1, 0.25, 1);
  --transition-slow: 0.5s cubic-bezier(0.25, 0.1, 0.25, 1);
}

/* 重置与基础 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-stack);
  background-color: var(--color-bg);
  min-height: 100vh;
  color: var(--color-text);
  line-height: 1.5;
  letter-spacing: -0.01em;
  font-feature-settings: 'cv02', 'cv03', 'cv04', 'cv11';
}

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

a:hover {
  color: var(--color-link-hover);
}

/* ========== 导航栏 (毛玻璃效果) ========== */
.navbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(251, 251, 253, 0.72);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.08);
}

.navbar-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 22px;
  height: 56px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

/* 一级导航居中容器 */
.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 22px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 32px;
  position: relative;
}

.nav-logo {
  color: var(--color-text);
  font-size: 17px;
  font-weight: 600;
  text-decoration: none;
  letter-spacing: -0.02em;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: opacity var(--transition-fast);
  position: absolute;
  left: 22px;
}

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

.nav-menu {
  display: flex;
  gap: 8px;
  align-items: center;
}

.nav-link {
  color: var(--color-text);
  text-decoration: none;
  padding: 8px 18px;
  border-radius: var(--radius-full);
  font-size: 14px;
  font-weight: 400;
  transition: all var(--transition-fast);
  position: relative;
}

.nav-link:hover {
  color: var(--color-text);
  background: rgba(0, 0, 0, 0.05);
}

.nav-link.active {
  color: var(--color-surface);
  background: var(--color-text);
  font-weight: 500;
}

.nav-access {
  position: absolute;
  right: 22px;
  display: flex;
  align-items: center;
}

.nav-btn-free {
  color: var(--color-link);
  text-decoration: none;
  padding: 6px 14px;
  border-radius: var(--radius-full);
  font-size: 13px;
  font-weight: 500;
  transition: all var(--transition-fast);
  border: 1px solid var(--color-border);
}

.nav-btn-free:hover {
  background: rgba(0, 113, 227, 0.06);
  border-color: var(--color-link);
}

/* 二级导航 */
.nav-level2 {
  display: flex;
  gap: 4px;
  align-items: center;
}

.nav-level2 a {
  color: var(--color-text);
  text-decoration: none;
  padding: 6px 14px;
  border-radius: var(--radius-full);
  font-size: 14px;
  font-weight: 400;
  transition: all var(--transition-fast);
  position: relative;
}

.nav-level2 a:hover {
  color: var(--color-text);
  background: rgba(0, 0, 0, 0.05);
}

.nav-level2 a.active {
  color: var(--color-text);
  font-weight: 500;
  background: rgba(0, 0, 0, 0.08);
}

/* 三级导航 */
.sub-nav {
  background: rgba(255, 255, 255, 0.6);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--color-border-light);
  padding: 10px 22px;
}

.sub-nav-inner {
  max-width: 1024px;
  margin: 0 auto;
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
  align-items: center;
}

.sub-nav a {
  color: var(--color-text-secondary);
  text-decoration: none;
  padding: 5px 14px;
  border-radius: var(--radius-full);
  font-size: 13px;
  font-weight: 400;
  transition: all var(--transition-fast);
  border: 1px solid transparent;
}

.sub-nav a:hover {
  color: var(--color-text);
  background: rgba(0, 0, 0, 0.04);
}

.sub-nav a.active {
  color: var(--color-text);
  background: var(--color-text);
  color: var(--color-surface);
}

.sub-nav a.active:hover {
  background: var(--color-text);
  color: var(--color-surface);
}

/* ========== 筛选栏 ========== */
.filter-bar {
  max-width: 1024px;
  margin: 24px auto;
  padding: 16px 24px;
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.filter-inner {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  width: 100%;
}

.filter-tags {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  align-items: center;
}

.filter-bar label {
  color: var(--color-text);
  font-weight: 500;
  font-size: 14px;
  margin-right: 4px;
}

.filter-tag {
  padding: 6px 16px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: all var(--transition-base);
  font-size: 13px;
  font-weight: 400;
  user-select: none;
  background: var(--color-surface);
  color: var(--color-text);
}

.filter-tag:hover {
  border-color: var(--color-text);
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

.filter-tag.active {
  background: var(--color-text);
  color: var(--color-surface);
  border-color: var(--color-text);
}

/* ========== 主内容区 ========== */
.container {
  max-width: 1024px;
  margin: 0 auto;
  padding: 0 22px;
}

.page-header {
  padding: 48px 0 32px;
  text-align: center;
}

.page-title {
  font-size: 40px;
  font-weight: 600;
  color: var(--color-text);
  letter-spacing: -0.02em;
  margin-bottom: 8px;
  line-height: 1.1;
}

.page-subtitle {
  font-size: 19px;
  color: var(--color-text-secondary);
  font-weight: 400;
  letter-spacing: 0.01em;
}

/* 返回首页按钮 */
.back-home {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--color-link);
  font-size: 14px;
  font-weight: 500;
  text-decoration: none;
  padding: 8px 16px;
  border-radius: var(--radius-full);
  transition: all var(--transition-fast);
  margin-bottom: 16px;
}

.back-home:hover {
  background: rgba(0, 113, 227, 0.08);
  transform: translateX(-2px);
}

.back-home svg {
  width: 16px;
  height: 16px;
}

/* 页面标题区域 */
.page-header {
  padding: 40px 0 24px;
  text-align: left;
}

.page-header .page-title {
  font-size: 36px;
  font-weight: 600;
  letter-spacing: -0.02em;
  margin-bottom: 8px;
}

.page-header .page-subtitle {
  font-size: 17px;
}

/* 页脚 */
.site-footer {
  margin-top: 80px;
  padding: 40px 22px;
  background: var(--color-bg-alt);
  border-top: 1px solid var(--color-border-light);
  text-align: center;
}

.site-footer .footer-inner {
  max-width: 1024px;
  margin: 0 auto;
}

.site-footer p {
  color: var(--color-text-secondary);
  font-size: 13px;
  margin: 4px 0;
}

.site-footer .footer-links {
  display: flex;
  justify-content: center;
  gap: 20px;
  margin-bottom: 12px;
}

.site-footer .footer-links a {
  color: var(--color-text-secondary);
  font-size: 13px;
  text-decoration: none;
  transition: color var(--transition-fast);
}

.site-footer .footer-links a:hover {
  color: var(--color-link);
}

/* 欢迎区域 */
.welcome-section {
  max-width: 1024px;
  margin: 0 auto;
  padding: 48px 22px 24px;
}

.welcome-box {
  background: var(--color-surface);
  border-radius: var(--radius-xl);
  padding: 36px 40px;
  box-shadow: var(--shadow-card);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
}

.welcome-info h2 {
  font-size: 24px;
  font-weight: 600;
  color: var(--color-text);
  letter-spacing: -0.01em;
  margin-bottom: 6px;
}

.welcome-info p {
  color: var(--color-text-secondary);
  font-size: 15px;
}

.download-stats {
  display: flex;
  gap: 24px;
  align-items: center;
}

.stat-item {
  text-align: center;
}

.stat-value {
  font-size: 28px;
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.02em;
}

.stat-label {
  font-size: 12px;
  color: var(--color-text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* 下载区 */
.download-area {
  max-width: 1024px;
  margin: 0 auto;
  padding: 0 22px;
}

.download-section {
  text-align: center;
  padding: 40px 0 24px;
}

.download-section .section-title {
  font-size: 24px;
  font-weight: 600;
  margin-bottom: 8px;
}

/* 动画类 */
.fade-in {
  animation: fadeInUp 0.6s cubic-bezier(0.25, 0.1, 0.25, 1) both;
}

@media (max-width: 768px) {
  .welcome-box {
    flex-direction: column;
    text-align: center;
  }
  
  .page-header {
    text-align: center;
    padding: 32px 0 16px;
  }
  
  .site-footer .footer-links {
    flex-direction: column;
    gap: 12px;
  }
}

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin-bottom: 24px;
}

.section-title {
  font-size: 28px;
  font-weight: 600;
  color: var(--color-text);
  letter-spacing: -0.01em;
}

/* ========== 资料卡片（居中展示） ========== */
.card-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  max-width: 1200px;
  margin: 0 auto;
  justify-content: center;
}

/* 资料卡片 */
.resource-card {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: 20px;
  box-shadow: var(--shadow-card);
  transition: all var(--transition-base);
  display: flex;
  flex-direction: column;
  position: relative;
  overflow: hidden;
  min-height: 180px;
}

.resource-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient-accent);
  opacity: 0;
  transition: opacity var(--transition-base);
}

.resource-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-card-hover);
}

.resource-card:hover::before {
  opacity: 1;
}

.card-icon-wrap {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background: linear-gradient(135deg, #f5f5f7 0%, #e5e5ea 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 14px;
  font-size: 22px;
}

.card-body {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.card-title {
  font-size: 15px;
  font-weight: 600;
  color: var(--color-text);
  line-height: 1.4;
  letter-spacing: -0.01em;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  margin-bottom: 4px;
}

.card-meta {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}

.card-tag {
  display: inline-block;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  font-size: 11px;
  font-weight: 500;
  background: rgba(0, 0, 0, 0.04);
  color: var(--color-text-secondary);
}

.card-tag.tag-exam {
  background: rgba(255, 159, 10, 0.12);
  color: #b35c00;
}

.card-tag.tag-real {
  background: rgba(255, 69, 58, 0.12);
  color: var(--color-red);
}

.card-tag.tag-sub {
  background: rgba(0, 113, 227, 0.08);
  color: var(--color-link);
}

.card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: auto;
  padding-top: 14px;
  border-top: 1px solid var(--color-border-light);
}

.card-size {
  font-size: 12px;
  color: var(--color-text-tertiary);
}

.card-download {
  font-size: 12px;
  color: var(--color-text-tertiary);
}

/* 下载按钮 - 右下角 */
.card-download-btn {
  position: absolute;
  right: 16px;
  bottom: 16px;
  width: 36px;
  height: 36px;
  background: var(--color-link);
  color: var(--color-surface);
  border: none;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  box-shadow: 0 4px 12px rgba(0, 113, 227, 0.3);
  transition: all var(--transition-fast);
  z-index: 2;
}

.card-download-btn:hover {
  background: var(--color-link-hover);
  transform: scale(1.1);
  box-shadow: 0 6px 20px rgba(0, 113, 227, 0.45);
}

.card-download-btn:active {
  transform: scale(0.95);
}

.card-download-btn:disabled {
  background: var(--color-text-tertiary);
  cursor: not-allowed;
  box-shadow: none;
}

/* 分页容器 */
.pagination-container {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 8px;
  margin: 40px auto;
  max-width: 1200px;
}

.page-btn {
  min-width: 36px;
  height: 36px;
  padding: 0 12px;
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-text);
  border-radius: var(--radius-full);
  cursor: pointer;
  font-size: 14px;
  font-weight: 500;
  transition: all var(--transition-fast);
  font-family: var(--font-stack);
}

.page-btn:hover:not(:disabled) {
  border-color: var(--color-link);
  color: var(--color-link);
}

.page-btn.active {
  background: var(--color-text);
  color: var(--color-surface);
  border-color: var(--color-text);
}

.page-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

/* 下载限制提示 */
.download-info {
  text-align: center;
  color: var(--color-text-secondary);
  margin: 16px 0;
  font-size: 13px;
}

.download-info .warning {
  color: var(--color-red);
  font-weight: 500;
}

/* ========== 空状态 ========== */
.empty-state {
  text-align: center;
  padding: 80px 20px;
  color: var(--color-text-tertiary);
}

.empty-state .icon {
  font-size: 48px;
  margin-bottom: 16px;
  opacity: 0.6;
}

.empty-state h3 {
  font-size: 20px;
  font-weight: 500;
  color: var(--color-text);
  margin-bottom: 8px;
}

.empty-state p {
  font-size: 15px;
  color: var(--color-text-secondary);
}

/* ========== 首页 Hero 区域 ========== */
.hero-section {
  background: var(--color-bg);
  padding: 80px 22px 40px;
  text-align: center;
}

.hero-title {
  font-size: 56px;
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.03em;
  margin-bottom: 12px;
  line-height: 1.05;
}

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

.hero-subtitle {
  font-size: 24px;
  color: var(--color-text-secondary);
  font-weight: 400;
  letter-spacing: 0.01em;
  margin-bottom: 8px;
}

.hero-tagline {
  font-size: 17px;
  color: var(--color-text-tertiary);
  margin-bottom: 48px;
}

/* 入口卡片 */
.entry-section {
  padding: 40px 22px 80px;
  max-width: 1024px;
  margin: 0 auto;
}

.entry-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(380px, 1fr));
  gap: 24px;
}

.entry-card {
  position: relative;
  background: var(--color-surface);
  border-radius: var(--radius-xl);
  padding: 56px 48px;
  text-align: center;
  box-shadow: var(--shadow-card);
  transition: all var(--transition-slow);
  cursor: pointer;
  text-decoration: none;
  color: inherit;
  overflow: hidden;
}

.entry-card::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--gradient-accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition-slow);
}

.entry-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-card-hover);
}

.entry-card:hover::after {
  transform: scaleX(1);
}

.entry-card.free::after {
  background: linear-gradient(90deg, var(--color-green), var(--color-blue));
}

.entry-card.internal::after {
  background: linear-gradient(90deg, var(--color-orange), var(--color-red));
}

.entry-icon {
  width: 96px;
  height: 96px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 28px;
  font-size: 44px;
  color: white;
}

.entry-card.free .entry-icon {
  background: linear-gradient(135deg, #30d158, #00c7be);
  box-shadow: 0 8px 32px rgba(48, 209, 88, 0.3);
}

.entry-card.internal .entry-icon {
  background: linear-gradient(135deg, #ff9f0a, #ff375f);
  box-shadow: 0 8px 32px rgba(255, 159, 10, 0.3);
}

.entry-title {
  font-size: 28px;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 12px;
  letter-spacing: -0.01em;
}

.entry-desc {
  font-size: 15px;
  color: var(--color-text-secondary);
  line-height: 1.6;
  margin-bottom: 24px;
}

.entry-tag {
  display: inline-block;
  padding: 6px 18px;
  border-radius: var(--radius-full);
  font-size: 13px;
  font-weight: 500;
}

.entry-card.free .entry-tag {
  background: rgba(48, 209, 88, 0.12);
  color: #0a8f3c;
}

.entry-card.internal .entry-tag {
  background: rgba(255, 159, 10, 0.12);
  color: #b35c00;
}

/* ========== 邀请码页面 ========== */
.invite-container {
  max-width: 480px;
  margin: 80px auto;
  background: var(--color-surface);
  border-radius: var(--radius-xl);
  padding: 56px 48px;
  box-shadow: var(--shadow-lg);
  text-align: center;
}

.invite-icon {
  width: 80px;
  height: 80px;
  background: linear-gradient(135deg, var(--color-orange), var(--color-red));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 28px;
  font-size: 38px;
  color: white;
  box-shadow: 0 12px 40px rgba(255, 159, 10, 0.25);
}

.invite-title {
  font-size: 28px;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--color-text);
  letter-spacing: -0.01em;
}

.invite-desc {
  color: var(--color-text-secondary);
  font-size: 15px;
  margin-bottom: 36px;
  line-height: 1.5;
}

.invite-input {
  width: 100%;
  padding: 16px 20px;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: 16px;
  font-family: var(--font-stack);
  transition: all var(--transition-base);
  margin-bottom: 20px;
  background: var(--color-bg-alt);
  color: var(--color-text);
}

.invite-input:focus {
  outline: none;
  border-color: var(--color-blue);
  background: var(--color-surface);
  box-shadow: 0 0 0 4px rgba(0, 113, 227, 0.12);
}

.invite-btn {
  width: 100%;
  padding: 16px;
  background: var(--color-link);
  color: var(--color-surface);
  border: none;
  border-radius: var(--radius-full);
  font-size: 16px;
  font-weight: 500;
  cursor: pointer;
  font-family: var(--font-stack);
  transition: all var(--transition-base);
  letter-spacing: 0.01em;
}

.invite-btn:hover {
  background: var(--color-link-hover);
  transform: scale(1.02);
  box-shadow: 0 8px 32px rgba(0, 113, 227, 0.3);
}

.invite-btn:active {
  transform: scale(0.98);
}

.invite-message {
  margin-top: 20px;
  padding: 14px 18px;
  border-radius: var(--radius-md);
  font-size: 14px;
  display: none;
  text-align: left;
}

.invite-message.error {
  background: rgba(255, 69, 58, 0.1);
  color: var(--color-red);
  display: block;
}

.invite-message.success {
  background: rgba(48, 209, 88, 0.12);
  color: #0a8f3c;
  display: block;
}

/* ========== 管理员入口 ========== */
.admin-entry {
  position: fixed;
  bottom: 24px;
  right: 24px;
  width: 44px;
  height: 44px;
  background: rgba(0, 0, 0, 0.05);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  color: var(--color-text-tertiary);
  font-size: 18px;
  transition: all var(--transition-base);
  border: 1px solid var(--color-border-light);
  z-index: 999;
}

.admin-entry:hover {
  background: rgba(0, 0, 0, 0.08);
  color: var(--color-text);
  transform: scale(1.05);
}

/* ========== 管理后台 ========== */
.admin-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 40px 22px;
}

.admin-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 40px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--color-border-light);
}

.admin-title {
  font-size: 32px;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.admin-logout {
  padding: 8px 20px;
  background: transparent;
  color: var(--color-link);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  cursor: pointer;
  font-family: var(--font-stack);
  font-size: 14px;
  transition: all var(--transition-fast);
}

.admin-logout:hover {
  background: rgba(0, 113, 227, 0.06);
  border-color: var(--color-link);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 20px;
  margin-bottom: 48px;
}

.stat-card {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: 28px;
  box-shadow: var(--shadow-card);
  text-align: center;
  transition: all var(--transition-base);
}

.stat-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-card-hover);
}

.stat-value {
  font-size: 40px;
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.02em;
  margin-bottom: 8px;
}

.stat-label {
  font-size: 13px;
  color: var(--color-text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.admin-tabs {
  display: flex;
  gap: 8px;
  margin-bottom: 32px;
  border-bottom: 1px solid var(--color-border-light);
}

.admin-tab {
  padding: 12px 24px;
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  cursor: pointer;
  font-size: 15px;
  font-weight: 500;
  color: var(--color-text-secondary);
  font-family: var(--font-stack);
  transition: all var(--transition-fast);
  margin-bottom: -1px;
}

.admin-tab:hover {
  color: var(--color-text);
}

.admin-tab.active {
  color: var(--color-text);
  border-bottom-color: var(--color-link);
}

.admin-panel {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  padding: 32px;
  box-shadow: var(--shadow-card);
  display: none;
}

.admin-panel.active {
  display: block;
}

.admin-actions {
  display: flex;
  gap: 12px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

.btn-primary {
  padding: 10px 24px;
  background: var(--color-link);
  color: var(--color-surface);
  border: none;
  border-radius: var(--radius-full);
  cursor: pointer;
  font-size: 14px;
  font-weight: 500;
  font-family: var(--font-stack);
  transition: all var(--transition-fast);
}

.btn-primary:hover {
  background: var(--color-link-hover);
  transform: translateY(-1px);
  box-shadow: 0 4px 16px rgba(0, 113, 227, 0.25);
}

.btn-danger {
  padding: 10px 24px;
  background: transparent;
  color: var(--color-red);
  border: 1px solid var(--color-red);
  border-radius: var(--radius-full);
  cursor: pointer;
  font-size: 14px;
  font-weight: 500;
  font-family: var(--font-stack);
  transition: all var(--transition-fast);
}

.btn-danger:hover {
  background: var(--color-red);
  color: var(--color-surface);
}

/* 表格样式 */
.data-table {
  width: 100%;
  border-collapse: collapse;
}

.data-table th {
  text-align: left;
  padding: 16px;
  font-size: 12px;
  font-weight: 600;
  color: var(--color-text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  border-bottom: 1px solid var(--color-border-light);
}

.data-table td {
  padding: 16px;
  font-size: 14px;
  color: var(--color-text);
  border-bottom: 1px solid var(--color-border-light);
}

.data-table tr:last-child td {
  border-bottom: none;
}

.data-table tr:hover {
  background: var(--color-bg);
}

/* 表单元素 */
.form-group {
  margin-bottom: 20px;
}

.form-label {
  display: block;
  font-size: 14px;
  font-weight: 500;
  color: var(--color-text);
  margin-bottom: 8px;
}

.form-input,
.form-select,
.form-textarea {
  width: 100%;
  padding: 12px 16px;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-md);
  font-size: 15px;
  font-family: var(--font-stack);
  transition: all var(--transition-base);
  background: var(--color-bg-alt);
  color: var(--color-text);
}

.form-input:focus,
.form-select:focus,
.form-textarea:focus {
  outline: none;
  border-color: var(--color-blue);
  background: var(--color-surface);
  box-shadow: 0 0 0 4px rgba(0, 113, 227, 0.12);
}

/* 登录页面 */
.login-container {
  max-width: 400px;
  margin: 100px auto;
  background: var(--color-surface);
  border-radius: var(--radius-xl);
  padding: 56px 48px;
  box-shadow: var(--shadow-lg);
}

.login-title {
  font-size: 24px;
  font-weight: 600;
  text-align: center;
  margin-bottom: 32px;
  letter-spacing: -0.01em;
}

/* ========== 响应式设计 ========== */
@media (max-width: 1024px) {
  .hero-title {
    font-size: 44px;
  }
  
  .page-title {
    font-size: 32px;
  }
  
  .container,
  .filter-bar,
  .page-header {
    max-width: 100%;
  }
  
  .card-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 768px) {
  .navbar-inner {
    padding: 0 16px;
  }
  
  .nav-level2 {
    gap: 0;
  }
  
  .nav-level2 a {
    padding: 6px 10px;
    font-size: 13px;
  }
  
  .hero-section {
    padding: 56px 20px 24px;
  }
  
  .hero-title {
    font-size: 36px;
  }
  
  .hero-subtitle {
    font-size: 20px;
  }
  
  .hero-tagline {
    font-size: 15px;
  }
  
  .entry-section {
    padding: 24px 16px 56px;
  }
  
  .entry-grid {
    grid-template-columns: 1fr;
  }
  
  .entry-card {
    padding: 40px 32px;
  }
  
  .page-title {
    font-size: 28px;
  }
  
  .page-header {
    padding: 32px 0 20px;
  }
  
  .card-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
  }
  
  .filter-bar {
    margin: 16px;
    padding: 12px 16px;
  }
  
  .invite-container {
    margin: 40px 20px;
    padding: 40px 28px;
  }
  
  .login-container {
    margin: 40px 20px;
    padding: 40px 28px;
  }
  
  .admin-container {
    padding: 24px 16px;
  }
  
  .admin-header {
    flex-direction: column;
    gap: 16px;
    align-items: flex-start;
  }
  
  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .admin-panel {
    padding: 20px;
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 32px;
  }
  
  .stats-grid {
    grid-template-columns: 1fr;
  }
  
  .stat-value {
    font-size: 32px;
  }
}

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

.animate-in {
  animation: fadeInUp 0.6s cubic-bezier(0.25, 0.1, 0.25, 1) both;
}

.animate-in-delay-1 { animation-delay: 0.1s; }
.animate-in-delay-2 { animation-delay: 0.2s; }
.animate-in-delay-3 { animation-delay: 0.3s; }

/* ========== 滚动条美化 ========== */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

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

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

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

/* 选中文本颜色 */
::selection {
  background: rgba(0, 113, 227, 0.2);
  color: var(--color-text);
}