:root {
  color-scheme: light;
  /* 颜色 Token（苹果式） */
  --color-primary: #0a2540;        /* 深蓝：强调 */
  --color-gold: #b9975b;           /* 金色：极克制 */
  --color-accent: #0a2540;
  --color-accent-secondary: #b9975b;
  --color-background: #f5f5f7;     /* Apple 经典浅灰 */
  --color-surface: #ffffff;
  --color-card: #ffffff;
  --color-text: #1d1d1f;
  --color-muted-text: #6e6e73;
  --color-border: #d2d2d7;
  --color-on-image: #ffffff;       /* 背景图上的文字 */
  --color-on-image-muted: rgba(255, 255, 255, 0.75);
  --color-focus: #0a2540;
  /* 字体 Token */
  --font-body: -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC", "Helvetica Neue", sans-serif;
  --font-display: -apple-system, BlinkMacSystemFont, "SF Pro Display", "PingFang SC", sans-serif;
  /* 圆角 / 间距 / 宽度 */
  --radius-sm: 12px;
  --radius-md: 18px;
  --radius-lg: 28px;
  --space-unit: 0.5rem;
  --content-width: 62rem;
  /* 层级 */
  --shadow-card: 0 4px 24px rgba(0, 0, 0, 0.06);
  --shadow-card-hover: 0 12px 40px rgba(0, 0, 0, 0.1);
}

* {
  box-sizing: border-box;
}

html {
  background: var(--color-background);
  color: var(--color-text);
  font-family: var(--font-body);
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100dvh;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--color-primary); }

button,
input,
select,
textarea {
  font: inherit;
}

:focus-visible {
  outline: 3px solid var(--color-focus);
  outline-offset: 3px;
}

.skip-link {
  left: 1rem;
  position: fixed;
  top: 1rem;
  transform: translateY(-200%);
  z-index: 100;
  background: var(--color-surface);
  padding: 0.5rem 1rem;
  border-radius: var(--radius-sm);
}

.skip-link:focus {
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}

/* ================= 共享壳层 ================= */

/* 毛玻璃粘性导航 */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(245, 245, 247, 0.78);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.06);
}
.nav-inner {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 1.5rem;
  min-height: 3.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}
.nav-logo {
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-text);
  text-decoration: none;
  letter-spacing: -0.01em;
  white-space: nowrap;
}
.nav-links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1.375rem;
  list-style: none;
  margin: 0;
  padding: 0;
}
.nav-links a {
  font-size: 0.8125rem;
  color: var(--color-muted-text);
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.2s ease;
}
.nav-links a:hover { color: var(--color-text); }
.nav-links a[aria-current="page"] {
  color: var(--color-text);
  font-weight: 600;
}
@media (max-width: 46rem) {
  .nav-inner {
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 0.625rem 1rem;
    gap: 0.375rem;
  }
  .nav-links { justify-content: center; gap: 1rem; }
}

/* 页面容器与版块 */
.page {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}
main .page > section {
  padding: calc(var(--space-unit) * 9) 0;
}

.page-head {
  padding: calc(var(--space-unit) * 10) 0 calc(var(--space-unit) * 3);
}
.page-head h1 {
  margin: 0;
  font-size: clamp(2.25rem, 5vw, 3.25rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.12;
}
.section-eyebrow {
  margin: 0 0 calc(var(--space-unit) * 2);
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-accent-secondary);
}
.section-title {
  margin: 0;
  font-size: clamp(1.625rem, 3.2vw, 2.25rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
}
.section-desc {
  margin: calc(var(--space-unit) * 2) 0 calc(var(--space-unit) * 5);
  max-width: 40rem;
  font-size: 1.0625rem;
  line-height: 1.75;
  color: var(--color-muted-text);
}
.section-header-row {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 1.5rem;
  flex-wrap: wrap;
}
.section-header-row .section-desc { margin-bottom: calc(var(--space-unit) * 5); }
.section-more {
  margin-bottom: calc(var(--space-unit) * 5);
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--color-primary);
  text-decoration: none;
  white-space: nowrap;
}
.section-more:hover { text-decoration: underline; }

/* 按钮 */
.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  border-radius: 980px;
  border: 1px solid var(--color-border);
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-text);
  text-decoration: none;
  background: var(--color-surface);
  cursor: pointer;
  transition: background 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
}
.btn:hover { border-color: var(--color-primary); transform: translateY(-1px); }
.btn-solid {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: #fff;
}
.btn-solid:hover { background: #123a5f; border-color: #123a5f; }

/* 筛选胶囊 */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  margin: calc(var(--space-unit) * 3) 0;
}
.filter-label {
  font-size: 0.8125rem;
  color: var(--color-muted-text);
  margin-right: 0.25rem;
}
.chip {
  padding: 0.375rem 0.9375rem;
  border-radius: 980px;
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  font-size: 0.875rem;
  color: var(--color-text);
  cursor: pointer;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}
.chip:hover { border-color: var(--color-primary); }
.chip.is-active,
.chip[aria-pressed="true"] {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: #fff;
}

/* 页脚 */
.site-footer {
  margin-top: calc(var(--space-unit) * 8);
  padding: calc(var(--space-unit) * 6) 0;
  border-top: 1px solid var(--color-border);
  text-align: center;
}
.footer-note {
  margin: 0.25rem 0;
  font-size: 0.8125rem;
  color: var(--color-muted-text);
  line-height: 1.7;
}
.footer-note a { color: var(--color-muted-text); text-decoration: none; }
.footer-note a:hover { color: var(--color-primary); text-decoration: underline; }