/* 基础主题变量（浅色为主），颜色来自应用配色 */
:root {
  --c-text: #191919;             /* primaryBlack(light) */
  --c-text-2: #8c8c8c;           /* secondaryGray(light) */
  --c-bg: #f8f9fa;               /* statisticsBackground(light) */
  --c-surface: #ffffff;          /* surfaceWhite(light) */
  --c-divider: #e0e0e0;          /* dividerColor(light) */
  --c-accent: #cbfd5f;           /* accentGreen */
  --c-link: #2196f3;             /* linkBlue(light) */
  --c-btn-bg: #191919;           /* buttonPrimaryBackground(light) */
  --c-btn-fg: #ffffff;           /* buttonPrimaryForeground(light) */
  --c-success: #4caf50;          /* successGreen */
  --c-warning: #ffa000;          /* warningOrange */
  --c-error: #f44336;            /* errorRed */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --shadow-1: 0 1px 2px rgba(0,0,0,0.04), 0 4px 12px rgba(0,0,0,0.06);
  --shadow-2: 0 1px 3px rgba(0,0,0,0.06), 0 8px 24px rgba(0,0,0,0.08);
}

@media (prefers-color-scheme: dark) {
  :root {
    --c-text: #e8e8e8;          /* primaryBlack(dark) */
    --c-text-2: #9e9e9e;        /* secondaryGray(dark) */
    --c-bg: #121212;            /* backgroundGray(dark) */
    --c-surface: #1e1e1e;       /* surfaceWhite(dark) */
    --c-divider: #3d3d3d;       /* dividerColor(dark) */
    --c-link: #64b5f6;          /* linkBlue(dark) */
    --c-btn-bg: #cbfd5f;        /* buttonPrimaryBackground(dark) */
    --c-btn-fg: #191919;        /* buttonPrimaryForeground(dark) */
  }
}

/* 基础排版与布局 */
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--c-text);
  background: var(--c-bg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, "Noto Sans", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif, "Apple Color Emoji", "Segoe UI Emoji";
  line-height: 1.6;
}

.container {
  width: 100%;
  max-width: 1040px;
  margin: 0 auto;
  padding: 0 20px;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: auto;
  width: 1px;
  height: 1px;
  overflow: hidden;
}
.skip-link:focus {
  position: fixed;
  left: 16px;
  top: 16px;
  width: auto;
  height: auto;
  padding: 8px 12px;
  background: var(--c-surface);
  color: var(--c-text);
  border: 1px solid var(--c-divider);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-1);
  z-index: 1000;
}

/* 头部 */
.site-header {
  position: sticky;
  top: 0;
  background: color-mix(in srgb, var(--c-bg) 70%, #fff 30%);
  backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--c-divider);
  z-index: 10;
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
}
.brand {
  font-weight: 700;
  color: var(--c-text);
  text-decoration: none;
}
.site-nav a {
  color: var(--c-text);
  text-decoration: none;
  margin-left: 16px;
  padding: 6px 8px;
  border-radius: 6px;
}
.site-nav a:hover,
.site-nav a:focus {
  background: var(--c-surface);
  outline: none;
}

/* 区块 */
.section { padding: 72px 0; }
.section-alt { background: var(--c-surface); }
.section h2 { font-size: 28px; margin: 0 0 16px; }
.section p.note { color: var(--c-text-2); margin-top: 8px; }
.section p.small { font-size: 14px; }

/* 首屏 */
.hero { padding: 88px 0 72px; }
.hero-inner { display: grid; grid-template-columns: 1fr; gap: 24px; }
.hero-text h1 { font-size: 44px; margin: 0 0 8px; }
.subtitle { font-size: 20px; color: var(--c-text-2); margin: 0 0 12px; }
.value-points { display: flex; flex-wrap: wrap; gap: 8px; color: var(--c-text-2); margin: 0 0 16px; }
.value-points span { background: var(--c-surface); border: 1px solid var(--c-divider); padding: 4px 8px; border-radius: 999px; }
.cta-row { display: flex; flex-wrap: wrap; gap: 12px; margin: 16px 0; }
.note { color: var(--c-text-2); }

/* 特性列表 */
.feature-list { list-style: none; padding: 0; margin: 0; display: grid; gap: 12px; }
.feature-list li { background: transparent; border-left: 3px solid var(--c-divider); padding: 8px 12px; }
.feature-list strong { color: var(--c-text); }

/* 截图占位 */
.shot-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
.shot-card { background: var(--c-surface); border: 1px solid var(--c-divider); border-radius: var(--radius-md); height: 220px; display: grid; place-items: center; color: var(--c-text-2); box-shadow: var(--shadow-1); }

/* 下载区 */
.download-grid { display: grid; grid-template-columns: 1fr; gap: 16px; }
.download-card { background: var(--c-surface); border: 1px solid var(--c-divider); border-radius: var(--radius-md); padding: 16px; box-shadow: var(--shadow-1); }
.checksum { color: var(--c-text-2); font-size: 14px; margin-top: 8px; word-break: break-all; }

/* 按钮 */
.btn {
  appearance: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 16px;
  border-radius: 10px;
  border: 1px solid transparent;
  text-decoration: none;
  cursor: pointer;
  font-weight: 600;
  transition: transform .06s ease, background .2s ease, border-color .2s ease, color .2s ease;
}
.btn:focus-visible { outline: 2px solid color-mix(in srgb, var(--c-accent) 60%, #000 40%); outline-offset: 2px; }
.btn-primary { background: var(--c-btn-bg); color: var(--c-btn-fg); }
.btn-primary:hover { transform: translateY(-1px); }
.btn-secondary { background: transparent; color: var(--c-text); border-color: var(--c-divider); }
.btn-secondary:hover { border-color: color-mix(in srgb, var(--c-text) 20%, var(--c-divider) 80%); transform: translateY(-1px); }

/* 页脚 */
.site-footer { border-top: 1px solid var(--c-divider); padding: 20px 0; background: color-mix(in srgb, var(--c-bg) 70%, #fff 30%); }
.footer-inner { display: flex; align-items: center; justify-content: space-between; color: var(--c-text-2); }
.meta-links a { color: var(--c-text-2); text-decoration: none; margin-left: 12px; }
.meta-links a:hover { color: var(--c-link); }

/* 无脚本提示 */
.noscript { background: var(--c-warning); color: #000; padding: 8px 12px; text-align: center; }

/* 响应式 */
@media (min-width: 720px) {
  .hero-inner { grid-template-columns: 1.2fr 0.8fr; }
  .shot-grid { grid-template-columns: repeat(4, 1fr); }
  .download-grid { grid-template-columns: 1fr 1fr; }
}

/* 降低动效 */
@media (prefers-reduced-motion: reduce) {
  .btn { transition: none; }
}