/* === SHARED DESIGN SYSTEM === */
/* 品牌套件 brand-kit.html 是颜色/字体/间距的唯一真相源 */

/* === CSS VARIABLES — aligned to brand-kit 8-color palette === */
:root {
  --white:      #FFFFFF;
  --ink:        #18181B;
  --sage:       #3D6B4A;
  --grey-1:     #3F3F46;
  --grey-2:     #F4F4F5;
  --grey-3:     #E4E4E7;
  --grey-4:     #71717A;
  --grey-5:     #A1A1AA;
  --border:     #D4D4D8;
  --border-light: #E8E8EC;
  --sage-soft:  rgba(61,107,74,0.1);
  --sage-mid:   rgba(61,107,74,0.18);
  --loop-red:     #B91C1C;   /* 调度主色: 边框/连线/粒子 */
  --loop-red-bg:  #FEF2F2;   /* 调度卡片底色 */
  --loop-red-trk: #FECACA;   /* 调度连线轨道 */
  --loop-blue:    #1D4ED8;   /* 验证主色: 边框/连线/粒子 */
  --loop-blue-bg: #EFF6FF;   /* 验证卡片底色 */
  --loop-blue-trk:#BFDBFE;   /* 验证连线轨道 */
  --amber:       #D97706;   /* 稳定回路 暖橙色 */
  --sans:       "Helvetica Neue","Helvetica","PingFang SC","Microsoft YaHei UI","Arial",system-ui,sans-serif;
  --sans-zh:    "PingFang SC","Hiragino Sans GB","Noto Sans SC","Source Han Sans SC","Microsoft YaHei UI",sans-serif;
  --serif:      "Noto Serif SC","Source Han Serif SC","Songti SC","SimSun",serif;
  --mono:       "SF Mono","Consolas","Cascadia Code","IBM Plex Mono",ui-monospace,monospace;
  --wmax:       2100px;
  --pad:        48px;
}

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

body {
  background: var(--white);
  font-family: var(--sans), var(--sans-zh);
  font-weight: 400;
  color: var(--grey-1);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* === NAV === */
#nav {
  position: sticky; top: 0; z-index: 100;
  background: #fff;
  border-bottom: 1px solid var(--border);
  padding: 0 var(--pad);
  height: 56px;
  display: flex; align-items: center; justify-content: space-between;
}
#nav .logo {
  font-family: var(--mono);
  font-size: 13px; font-weight: 600;
  letter-spacing: 0.06em;
}
#nav .logo a { color: var(--ink); text-decoration: none; }
#nav .nav-links {
  display: flex; gap: 28px;
  font-size: 14px; font-weight: 450;
}
#nav .nav-links a {
  color: var(--grey-1); text-decoration: none;
  transition: color 0.15s;
}
#nav .nav-links a:hover { color: var(--ink); }
#nav .nav-links a.active {
  color: var(--sage);
  font-weight: 500;
  position: relative;
}
#nav .nav-links a.active::after {
  content: "";
  position: absolute;
  bottom: -4px; left: 0; right: 0;
  height: 2px;
  background: var(--sage);
  border-radius: 1px;
}

/* === HAMBURGER === */
#hamburger {
  display: none;
  background: none; border: none; cursor: pointer;
  width: 36px; height: 36px;
  padding: 8px 6px;
  flex-direction: column; justify-content: center; gap: 4px;
}
#hamburger span {
  display: block; width: 100%; height: 2px;
  background: var(--ink); border-radius: 1px;
  transition: transform 0.25s, opacity 0.25s;
}
#hamburger.open span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
#hamburger.open span:nth-child(2) { opacity: 0; }
#hamburger.open span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

/* === RESPONSIVE NAV === */
@media (max-width: 640px) {
  :root { --pad: 24px; }
  #nav { height: 48px; }
  #hamburger { display: flex; }
  #nav .nav-links {
    display: none;
    position: absolute; top: 48px; left: 0; right: 0;
    background: #fff;
    border-bottom: 1px solid var(--border);
    padding: 16px var(--pad);
    flex-direction: column; gap: 12px;
  }
  #nav .nav-links.open { display: flex; }
}