/* ==================== 设计变量 ==================== */
:root {
  --color-bg: #1a1a1a;
  --color-text: #1d1d1f;
  --color-text-soft: #6e6e73;
  --color-surface: #ffffff;
  --color-border: #e5e5ea;
  --color-accent: #2d7d46;
  --radius-card: 24px;
  --radius-pill: 999px;
  --shadow-card: 0 12px 40px rgba(0, 0, 0, 0.08);
  --shadow-overlay: 0 8px 32px rgba(0, 0, 0, 0.06);
  --header-height: 64px;
  --content-max: 1280px;
  --gap: 24px;
  --transition: 0.25s ease;
}

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

html,
body {
  height: 100%;
}

html {
  scrollbar-gutter: stable;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

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

/* ==================== Header ==================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  height: var(--header-height);
  padding: 0 32px;
  background-color: rgba(255, 255, 255, 0.5);
  backdrop-filter: saturate(180%) blur(16px);
  -webkit-backdrop-filter: saturate(180%) blur(16px);
  border-bottom: 1px solid rgba(229, 229, 234, 0.6);
}

.site-header__left {
  justify-self: start;
  display: flex;
  align-items: center;
  gap: 12px;
}

.site-header__avatar {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  object-fit: cover;
  background-color: var(--color-border);
  flex-shrink: 0;
}

.site-header__title {
  font-size: 16px;
  font-weight: 600;
  letter-spacing: 0.2px;
}

.site-header__nav {
  justify-self: center;
  display: flex;
  align-items: center;
  gap: 8px;
}

.site-header__nav-link {
  display: inline-flex;
  align-items: center;
  padding: 8px 16px;
  border-radius: var(--radius-pill);
  font-size: 14px;
  font-weight: 500;
  color: var(--color-text-soft);
  transition: background-color var(--transition), color var(--transition);
}

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

.site-header__nav-link--active {
  color: var(--color-text);
  background-color: rgba(45, 125, 70, 0.12);
}

.site-header__right {
  justify-self: end;
  display: flex;
  align-items: center;
  min-width: 36px;
}

/* ==================== 通用按钮 ==================== */
.overlay__cta {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 10px 20px;
  border-radius: var(--radius-pill);
  background-color: var(--color-accent);
  color: #fff;
  font-size: 14px;
  font-weight: 600;
  transition: transform var(--transition), box-shadow var(--transition);
}

.overlay__cta:hover {
  transform: translateY(-1px);
  box-shadow: 0 6px 18px rgba(45, 125, 70, 0.35);
}

/* ==================== 顶栏响应式 ==================== */
@media (max-width: 768px) {
  .site-header {
    padding: 0 16px;
  }
  .site-header__title {
    display: none;
  }
  .site-header__nav-link {
    padding: 8px 10px;
    font-size: 13px;
  }
}