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

:root {
  --text: #1a1a1a;
  --text-light: #666;
  --text-muted: #999;
  --border: #e0e0e0;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --card-bg: rgba(255, 255, 255, 0.88);
  --overlay: rgba(255, 255, 255, 0.92);
  --nav-bg: rgba(255, 255, 255, 0.95);
  --shadow: 0 2px 16px rgba(0, 0, 0, 0.06);
  --max-width: 1100px;
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
}

body {
  font-family: 'Inter', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  color: var(--text);
  font-size: 16px;
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
  background: #f2f2f2;
}

.bg-layer {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -2;
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  transition: opacity 0.8s ease;
  will-change: opacity;
}

.bg-layer.active {
  z-index: -1;
  opacity: 1;
}

.bg-layer.inactive {
  opacity: 0;
}

.content-wrapper {
  position: relative;
  z-index: 1;
  min-height: 100vh;
  background: var(--overlay);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
}

.fade-up-block {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.7s cubic-bezier(0.25, 0.1, 0.25, 1),
              transform 0.7s cubic-bezier(0.25, 0.1, 0.25, 1);
}

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

.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--nav-bg);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 32px;
  height: 64px;
}

.logo {
  font-size: 22px;
  font-weight: 700;
  color: var(--accent);
  text-decoration: none;
  letter-spacing: -0.3px;
  transition: transform 0.2s, color 0.2s;
}

.logo:hover {
  transform: scale(1.04);
  color: var(--accent-hover);
}

.nav-links {
  display: flex;
  gap: 36px;
  list-style: none;
  align-items: center;
}

.nav-links a {
  text-decoration: none;
  color: var(--text);
  font-size: 15px;
  font-weight: 500;
  padding: 4px 0;
  position: relative;
  transition: color 0.2s;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: width 0.25s;
}

.nav-links a:hover {
  color: var(--accent);
}

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

.hero {
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
  padding: 100px 24px 60px;
}

.hero-title {
  font-size: 44px;
  font-weight: 700;
  letter-spacing: -0.8px;
  line-height: 1.2;
  margin-bottom: 16px;
}

.hero-desc {
  font-size: 18px;
  color: var(--text-light);
  line-height: 1.7;
  margin: 0 auto 40px;
  max-width: 560px;
}

.changelog {
  max-width: 860px;
  margin: 0 auto;
  padding: 40px 24px 20px;
}

.section-title {
  font-size: 28px;
  font-weight: 700;
  letter-spacing: -0.4px;
  margin-bottom: 36px;
  display: inline-block;
  position: relative;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -6px;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--accent);
}

.log-list {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.log-card {
  position: relative;
  background: var(--card-bg);
  border: 1px solid var(--border);
  padding: 32px 32px 52px 32px;
  width: 100%;
  aspect-ratio: 317 / 211;
  transition: transform 0.3s, box-shadow 0.3s, border-color 0.3s;
}

.log-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow);
  border-color: #ccc;
}

.log-card h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 10px;
  padding-right: 50px;
}

.log-card p {
  font-size: 15px;
  color: var(--text-light);
  line-height: 1.6;
  max-width: 85%;
}

.log-card .log-time {
  position: absolute;
  right: 32px;
  bottom: 20px;
  font-size: 13px;
  color: var(--text-muted);
}

/* 日志卡片下载按钮 */
.log-card .download-icon {
  position: absolute;
  top: 16px;
  right: 16px;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 1.5px solid #ccc;
  background: rgba(255, 255, 255, 0.9);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.25s ease;
  z-index: 2;
}

.log-card .download-icon:hover {
  border-color: #2563eb;
  background: #2563eb;
  transform: scale(1.1);
}

.log-card .download-icon svg {
  width: 16px;
  height: 16px;
  fill: none;
  stroke: #666;
  stroke-width: 2;
  transition: stroke 0.2s;
}

.log-card .download-icon:hover svg {
  stroke: #fff;
}

/* 下载冷却闪烁 */
.log-card .download-icon.cooldown {
  animation: cooldownPulse 1.5s ease;
  pointer-events: none;
}

@keyframes cooldownPulse {
  0%, 100% { border-color: #ccc; }
  50% { border-color: #ef4444; box-shadow: 0 0 8px rgba(239, 68, 68, 0.4); }
}

/* 下载弹窗 */
.download-modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.55);
  z-index: 9999;
  display: none;
  align-items: center;
  justify-content: center;
}

.download-modal.active {
  display: flex;
}

.download-modal-content {
  background: #fff;
  padding: 40px 36px;
  max-width: 420px;
  width: 90%;
  text-align: center;
}

.download-icon-anim {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  margin: 0 auto 20px;
  border: 3px solid #2563eb;
  display: flex;
  align-items: center;
  justify-content: center;
  animation: iconPop 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

@keyframes iconPop {
  0% { transform: scale(0); opacity: 0; }
  100% { transform: scale(1); opacity: 1; }
}

.download-modal-content h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 10px;
}

.download-modal-content p {
  font-size: 14px;
  color: #666;
  margin-bottom: 24px;
  line-height: 1.5;
}

.modal-buttons {
  display: flex;
  gap: 12px;
  justify-content: center;
}

.modal-btn {
  padding: 10px 30px;
  font-size: 14px;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: all 0.2s;
}

.modal-btn.cancel {
  background: #f0f0f0;
  color: #555;
}

.modal-btn.cancel:hover {
  background: #e0e0e0;
}

.modal-btn.confirm {
  background: #2563eb;
  color: #fff;
}

.modal-btn.confirm:hover {
  background: #1d4ed8;
}

/* 日志卡片入场动画 */
.fade-up-card {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.5s cubic-bezier(0.25, 0.1, 0.25, 1),
              transform 0.5s cubic-bezier(0.25, 0.1, 0.25, 1);
}

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

/* 底部 */
.footer {
  text-align: center;
  padding: 40px 24px;
  margin-top: 80px;
  border-top: 1px solid var(--border);
  font-size: 14px;
  color: var(--text-muted);
}

/* 响应式 */
@media (max-width: 768px) {
  .nav-inner {
    padding: 0 20px;
    height: 56px;
  }

  .logo {
    font-size: 18px;
  }

  .nav-links {
    gap: 18px;
  }

  .nav-links a {
    font-size: 13px;
  }

  .hero {
    padding: 64px 20px 40px;
  }

  .hero-title {
    font-size: 28px;
  }

  .hero-desc {
    font-size: 15px;
    margin-bottom: 28px;
    max-width: 100%;
  }

  .changelog {
    padding: 20px 20px 10px;
  }

  .section-title {
    font-size: 22px;
    margin-bottom: 24px;
  }

  .log-list {
    gap: 16px;
  }

  .log-card {
    padding: 20px 20px 44px 20px;
  }

  .log-card h3 {
    font-size: 16px;
    padding-right: 44px;
  }

  .log-card p {
    font-size: 13px;
    max-width: 100%;
  }

  .log-card .log-time {
    right: 20px;
    bottom: 14px;
    font-size: 12px;
  }

  .log-card .download-icon {
    top: 12px;
    right: 12px;
    width: 32px;
    height: 32px;
  }

  .footer {
    margin-top: 48px;
    padding: 28px 20px;
    font-size: 12px;
  }
}

@media (max-width: 480px) {
  .nav-links {
    gap: 12px;
  }

  .nav-links a {
    font-size: 12px;
  }

  .hero-title {
    font-size: 24px;
  }

  .hero-desc {
    font-size: 14px;
  }
}