/* CampusClaw 产品介绍 · 北大红浅色 */

:root {
  --pku-red: #94070a;
  --pku-red-mid: #a3282b;
  --pku-gold: #b8860b;
  --text: #1c2530;
  --text-muted: rgba(28, 37, 48, 0.72);
  --bg: #f5f6f8;
  --bg-white: #ffffff;
  --border: #e6e8ec;
  --red-soft: rgba(148, 7, 10, 0.08);
  --red-border: rgba(148, 7, 10, 0.22);
  --shadow: 0 8px 28px rgba(148, 7, 10, 0.08);
  --auto: 1200px;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  overflow-x: hidden;
}

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

img { max-width: 100%; height: auto; vertical-align: middle; }

.auto {
  max-width: var(--auto);
  margin: 0 auto;
  padding: 0 24px;
}

/* 顶栏 */
.head {
  position: fixed;
  left: 0;
  top: 0;
  z-index: 100;
  width: 100%;
  height: 72px;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  box-shadow: 0 1px 0 rgba(148, 7, 10, 0.04);
}

.head .wrap {
  position: relative;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.head .l { display: flex; align-items: center; gap: 48px; }

.cc-brand {
  font-size: 22px;
  font-weight: 900;
  color: var(--pku-red);
  letter-spacing: 0.5px;
  white-space: nowrap;
}

.cc-brand em {
  font-style: normal;
  color: var(--pku-red-mid);
}

.hd-nav ul { list-style: none; display: flex; flex-wrap: wrap; gap: 8px 28px; }

.hd-nav a {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-muted);
  line-height: 72px;
  transition: color 0.2s;
}

.hd-nav li.cur a,
.hd-nav a:hover { color: var(--pku-red); }

.hd-login {
  display: inline-block;
  padding: 8px 20px;
  font-size: 14px;
  font-weight: 700;
  color: #fff;
  background: linear-gradient(135deg, var(--pku-red) 0%, var(--pku-red-mid) 100%);
  border-radius: 999px;
  transition: opacity 0.2s, transform 0.2s;
}

.hd-login:hover { opacity: 0.92; transform: translateY(-1px); }

.sj-menu { display: none; }

/* 首屏 */
.idx-ban {
  margin-top: 72px;
  padding: 72px 0 64px;
  text-align: center;
  background: linear-gradient(165deg, #fff 0%, #fef8f8 35%, var(--bg) 100%);
  border-bottom: 1px solid var(--border);
}

.idx-ban .title {
  font-size: clamp(32px, 5vw, 48px);
  font-weight: 900;
  letter-spacing: 1px;
  margin-bottom: 12px;
  background: linear-gradient(135deg, var(--pku-red) 0%, var(--pku-red-mid) 55%, var(--pku-gold) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.idx-ban .font {
  font-size: clamp(18px, 2.5vw, 22px);
  color: var(--pku-red-mid);
  font-weight: 600;
}

.idx-ban .line {
  height: 1px;
  max-width: 480px;
  margin: 28px auto;
  background: linear-gradient(90deg, transparent, var(--red-border), transparent);
}

.idx-ban .lead {
  max-width: 880px;
  margin: 0 auto;
  text-align: left;
  font-size: 17px;
  color: var(--text-muted);
  line-height: 1.85;
}

.idx-ban .lead strong { color: var(--pku-red); font-weight: 700; }

.cta-row {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 14px;
  margin-top: 32px;
}

.cta {
  display: inline-block;
  padding: 14px 32px;
  font-size: 16px;
  font-weight: 700;
  color: #fff;
  background: var(--pku-red);
  border-radius: 12px;
  border: 2px solid var(--pku-red);
  transition: background 0.2s, color 0.2s;
}

.cta:hover { background: var(--pku-red-mid); border-color: var(--pku-red-mid); }

.cta.outline {
  background: var(--bg-white);
  color: var(--pku-red);
}

.cta.outline:hover {
  background: var(--red-soft);
}

/* 一体化方案 */
.idx-ku {
  padding: 64px 0;
  background: var(--bg-white);
}

.idx-ku .bt {
  font-size: 28px;
  font-weight: 900;
  color: var(--pku-red);
  margin-bottom: 28px;
}

.idx-ku .list {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
}

.idx-ku .item {
  flex: 1 1 calc(33.333% - 14px);
  min-width: 260px;
  padding: 24px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 16px;
  transition: box-shadow 0.25s, border-color 0.25s, transform 0.25s;
}

.idx-ku a.item:hover {
  border-color: var(--red-border);
  box-shadow: var(--shadow);
  transform: translateY(-4px);
}

.idx-ku .top {
  display: flex;
  align-items: center;
  gap: 14px;
  font-size: 20px;
  font-weight: 800;
  color: var(--text);
  margin-bottom: 12px;
}

.idx-ku .icon {
  width: 48px;
  height: 48px;
  object-fit: contain;
  filter: hue-rotate(-20deg) saturate(1.1);
}

.idx-ku .desc {
  font-size: 15px;
  color: var(--text-muted);
  line-height: 1.7;
}

.idx-ku .item.last {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  background: linear-gradient(145deg, var(--red-soft) 0%, #fff 100%);
  border-color: var(--red-border);
  min-height: 200px;
}

.idx-ku .last .title {
  font-size: 20px;
  font-weight: 800;
  color: var(--pku-red);
  margin-bottom: 16px;
}

.idx-ku .last .more {
  display: inline-block;
  padding: 12px 28px;
  font-size: 15px;
  font-weight: 700;
  color: #fff;
  background: var(--pku-red);
  border-radius: 999px;
}

.idx-ku .last .more:hover { background: var(--pku-red-mid); }

.idx-ku .contact-teaser {
  text-align: center;
  margin-bottom: 16px;
  color: var(--text-muted);
}

/* 技术 / 服务 */
.idx-fw {
  padding: 64px 0 72px;
  background: var(--bg);
}

.idx-fw .bt {
  text-align: center;
  font-size: clamp(28px, 4vw, 36px);
  font-weight: 900;
  color: var(--pku-red);
  margin-bottom: 16px;
}

.idx-fw .intro {
  max-width: 820px;
  margin: 0 auto 32px;
  text-align: center;
  font-size: 16px;
  color: var(--text-muted);
  line-height: 1.8;
}

.tabmenu {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-bottom: 32px;
  border-bottom: 1px solid var(--border);
  padding-bottom: 0;
}

.tabmenu .lk {
  padding: 12px 24px;
  font-size: 16px;
  font-weight: 700;
  color: var(--text-muted);
  border-bottom: 3px solid transparent;
  margin-bottom: -1px;
  cursor: pointer;
}

.tabmenu .lk.cur,
.tabmenu .lk:hover {
  color: var(--pku-red);
  border-bottom-color: var(--pku-red);
}

.idx-fw .list {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  list-style: none;
}

.idx-fw .list .item {
  flex: 1 1 calc(33.333% - 14px);
  min-width: 280px;
  padding: 28px;
  background: var(--bg-white);
  border: 1px solid var(--border);
  border-radius: 16px;
  position: relative;
  transition: box-shadow 0.25s;
}

.idx-fw .list .item:hover { box-shadow: var(--shadow); }

.idx-fw .list .title {
  font-size: 20px;
  font-weight: 800;
  margin-bottom: 10px;
  padding-left: 14px;
  border-left: 4px solid var(--pku-red);
}

.idx-fw .list .txt {
  font-size: 15px;
  color: var(--text-muted);
  line-height: 1.75;
  min-height: auto;
}

.idx-fw .list1 .item {
  flex: 1 1 calc(50% - 10px);
  min-height: 160px;
}

.idx-fw .list1 .icon {
  position: absolute;
  right: 20px;
  bottom: 16px;
  width: 100px;
  height: auto;
  opacity: 0.35;
}

.idx-fw .item-wide {
  flex: 1 1 100%;
}

/* 页脚 */
.foot {
  background: #fff;
  border-top: 1px solid var(--border);
  padding: 48px 0 0;
}

.ft-t {
  text-align: center;
  padding-bottom: 40px;
  border-bottom: 1px solid var(--border);
}

.ft-t .bt {
  font-size: 24px;
  font-weight: 900;
  color: var(--pku-red);
  margin-bottom: 20px;
}

.ft-menu {
  display: flex;
  flex-wrap: wrap;
  gap: 40px;
  padding: 36px 0;
  justify-content: center;
}

.ft-menu .tit {
  font-size: 15px;
  font-weight: 800;
  color: var(--pku-red);
  margin-bottom: 10px;
}

.ft-menu .lk {
  display: block;
  font-size: 14px;
  color: var(--text-muted);
  line-height: 2;
}

.ft-menu a.lk:hover { color: var(--pku-red); }

.ft-b {
  text-align: center;
  font-size: 13px;
  color: var(--text-muted);
  padding: 20px;
  background: var(--bg);
  border-top: 1px solid var(--border);
}

/* 联系我们 */
.idx-contact {
  padding: 64px 0;
  background: var(--bg-white);
  border-top: 1px solid var(--border);
}

.idx-contact .bt {
  text-align: center;
  font-size: 28px;
  font-weight: 900;
  color: var(--pku-red);
  margin-bottom: 12px;
}

.contact-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  margin-top: 8px;
}

.contact-card {
  flex: 1 1 calc(33.333% - 14px);
  min-width: 260px;
  padding: 28px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 16px;
}

.contact-card .title {
  font-size: 20px;
  font-weight: 800;
  color: var(--pku-red);
  margin-bottom: 10px;
}

.contact-card .txt {
  font-size: 15px;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 16px;
}

.contact-line {
  font-size: 14px;
  color: var(--text-muted);
}

.contact-line strong {
  color: var(--text);
  margin-right: 8px;
}

.contact-card .more {
  display: inline-block;
  padding: 10px 22px;
  font-size: 14px;
  font-weight: 700;
  color: #fff;
  background: var(--pku-red);
  border-radius: 999px;
}

.contact-card .more:hover {
  background: var(--pku-red-mid);
}

@media (max-width: 991px) {
  .head .l { gap: 16px; }
  .hd-nav { display: none; }
  .sj-menu {
    display: block;
    position: absolute;
    right: 20px;
    top: 50%;
    transform: translateY(-50%);
    width: 40px;
    height: 40px;
    background: url("../images/menu.png") no-repeat center;
    background-size: 28px;
    cursor: pointer;
    filter: hue-rotate(-30deg);
  }
  .sj-menu.open {
    background-image: url("../images/close.png");
    background-size: 24px;
  }
  .head.nav-open .hd-nav {
    display: block;
    position: fixed;
    left: 0;
    top: 72px;
    right: 0;
    bottom: 0;
    background: #fff;
    padding: 16px 24px;
    overflow-y: auto;
  }
  .head.nav-open .hd-nav ul { flex-direction: column; gap: 0; }
  .head.nav-open .hd-nav a { line-height: 52px; display: block; border-bottom: 1px solid var(--border); }
  .hd-login { margin-right: 48px; }
  .idx-ku .item,
  .idx-fw .list .item { flex: 1 1 100%; }
}