/* ============================================================
   基础层：变量 / 重置 / 布局 / 通用组件
   主色沿用参照站科技蓝 #0680EC
   ============================================================ */
:root {
  --primary: #0680ec;
  --primary-dark: #0563b8;
  --primary-light: #2494f8;
  --cyan: #04b4c9;
  --green: #12b76a;
  --orange: #f79009;
  --red: #e5484d;

  --text: #1a2233;
  --text-2: #4a5568;
  --text-3: #718096;
  --text-4: #a0aec0;

  --bg: #ffffff;
  --bg-soft: #f6f9fd;
  --bg-tint: #f1f6fb;
  --bg-blue: #f4f8ff;
  --line: #e6ecf3;
  --line-2: #eef2f7;

  --radius-s: 8px;
  --radius: 14px;
  --radius-l: 20px;
  --shadow-s: 0 2px 10px rgba(16, 42, 76, .05);
  --shadow: 0 10px 30px rgba(16, 42, 76, .08);
  --shadow-l: 0 20px 50px rgba(16, 42, 76, .12);
  --wrap: 1280px;
  --head-h: 74px;
  --ease: cubic-bezier(.22, .61, .36, 1);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", "Source Han Sans SC", system-ui, -apple-system, "Segoe UI", sans-serif;
  color: var(--text);
  background: var(--bg);
  font-size: 15px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; border: 0; }
a { color: inherit; text-decoration: none; transition: color .25s; }
a:hover { color: var(--primary); }
ul, ol { margin: 0; padding: 0; list-style: none; }
h1, h2, h3, h4, h5 { margin: 0; font-weight: 600; line-height: 1.35; }
button, input, select, textarea { font-family: inherit; font-size: inherit; outline: none; }
button { cursor: pointer; border: 0; background: none; }

.wrap { width: 100%; max-width: var(--wrap); margin: 0 auto; padding: 0 32px; }
.row { display: flex; }
.center { align-items: center; }
.between { justify-content: space-between; }
.gap-s { gap: 10px; }
.gap { gap: 20px; }
.hide { display: none !important; }
.tc { text-align: center; }

/* ---------- 通用按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  height: 46px; padding: 0 28px; border-radius: 999px;
  font-size: 15px; font-weight: 500; white-space: nowrap;
  transition: all .3s var(--ease); cursor: pointer;
}
.btn-primary {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
  color: #fff; box-shadow: 0 8px 20px rgba(6, 128, 236, .28);
}
.btn-primary:hover { color: #fff; transform: translateY(-2px); box-shadow: 0 12px 28px rgba(6, 128, 236, .38); }
.btn-ghost { border: 1px solid rgba(255, 255, 255, .55); color: #fff; background: rgba(255, 255, 255, .08); }
.btn-ghost:hover { color: #fff; background: rgba(255, 255, 255, .2); border-color: #fff; }
.btn-line { border: 1px solid var(--line); color: var(--text-2); background: #fff; }
.btn-line:hover { border-color: var(--primary); color: var(--primary); }
.btn-sm { height: 38px; padding: 0 20px; font-size: 14px; }
.btn-lg { height: 52px; padding: 0 36px; font-size: 16px; }

.link-more {
  display: inline-flex; align-items: center; gap: 6px;
  color: var(--primary); font-size: 15px; font-weight: 500;
}
.link-more i { transition: transform .3s; font-style: normal; }
.link-more:hover i { transform: translateX(4px); }

/* ---------- 章节标题 ---------- */
.sec { padding: 88px 0; }
.sec-soft { background: var(--bg-soft); }
.sec-head { margin-bottom: 44px; }
.sec-head.tc { text-align: center; }
.sec-title {
  font-size: 36px; font-weight: 600; letter-spacing: -.5px; color: var(--text);
}
.sec-sub { margin-top: 12px; color: var(--text-3); font-size: 16px; }
.sec-head-row { display: flex; align-items: flex-end; justify-content: space-between; gap: 20px; flex-wrap: wrap; }

/* ---------- 通用卡片 ---------- */
.card {
  background: #fff; border: 1px solid var(--line-2); border-radius: var(--radius);
  transition: all .35s var(--ease); overflow: hidden;
}
.card:hover { border-color: transparent; box-shadow: var(--shadow); transform: translateY(-4px); }

/* 无图时的占位封面：按 id 生成稳定渐变 */
.cover {
  position: relative; overflow: hidden; background: var(--bg-tint);
  aspect-ratio: 16 / 10;
}
.cover img { width: 100%; height: 100%; object-fit: cover; transition: transform .6s var(--ease); }
.card:hover .cover img { transform: scale(1.06); }
.cover-ph { position: absolute; inset: 0; display: grid; place-items: center; }
.cover-ph::before {
  content: ''; position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, .16) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, .16) 1px, transparent 1px);
  background-size: 26px 26px;
  mask-image: radial-gradient(ellipse at 30% 20%, #000 10%, transparent 72%);
}
.cover-ph span {
  position: relative; color: #fff; font-size: 15px; font-weight: 600;
  letter-spacing: 2px; opacity: .95; padding: 0 20px; text-align: center;
}
.g1 { background: linear-gradient(135deg, #0680ec, #29b6f6); }
.g2 { background: linear-gradient(135deg, #04b4c9, #34d399); }
.g3 { background: linear-gradient(135deg, #1e3a8a, #0680ec); }
.g4 { background: linear-gradient(135deg, #0f766e, #04b4c9); }
.g5 { background: linear-gradient(135deg, #3730a3, #6366f1); }
.g6 { background: linear-gradient(135deg, #0369a1, #0ea5e9); }

/* ---------- 标签 ---------- */
.tag {
  display: inline-block; padding: 3px 12px; border-radius: 999px;
  background: var(--bg-blue); color: var(--primary);
  font-size: 12px; line-height: 20px;
}
.tag-line { background: #fff; border: 1px solid var(--line); color: var(--text-3); }

/* ---------- 面包屑 ---------- */
.crumb { padding: 20px 0; color: var(--text-3); font-size: 14px; }
.crumb a:hover { color: var(--primary); }
.crumb span { margin: 0 8px; color: var(--text-4); }

/* ---------- 分页 ---------- */
.pager { display: flex; justify-content: center; gap: 8px; margin-top: 48px; flex-wrap: wrap; }
.pager button {
  min-width: 40px; height: 40px; padding: 0 12px; border-radius: 10px;
  border: 1px solid var(--line); background: #fff; color: var(--text-2);
  font-size: 14px; transition: all .25s;
}
.pager button:hover:not(:disabled) { border-color: var(--primary); color: var(--primary); }
.pager button.on { background: var(--primary); border-color: var(--primary); color: #fff; }
.pager button:disabled { opacity: .45; cursor: not-allowed; }

/* ---------- 空状态 / 骨架屏 ---------- */
.empty { padding: 80px 20px; text-align: center; color: var(--text-4); }
.empty-icon { font-size: 42px; opacity: .35; margin-bottom: 10px; }

.sk { background: linear-gradient(90deg, #eef2f7 25%, #f7fafc 37%, #eef2f7 63%); background-size: 400% 100%; animation: skl 1.3s infinite; border-radius: 8px; }
@keyframes skl { 0% { background-position: 100% 50%; } 100% { background-position: 0 50%; } }

/* ---------- 进场动画 ---------- */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity .7s var(--ease), transform .7s var(--ease); }
.reveal.in { opacity: 1; transform: none; }

/* ---------- 富文本 ---------- */
.rich { font-size: 16px; line-height: 2; color: var(--text-2); }
.rich h3 { margin: 34px 0 14px; font-size: 21px; color: var(--text); position: relative; padding-left: 14px; }
.rich h3::before { content: ''; position: absolute; left: 0; top: 50%; transform: translateY(-50%); width: 4px; height: 18px; border-radius: 2px; background: var(--primary); }
.rich p { margin: 0 0 16px; }
.rich ul { margin: 0 0 18px; padding-left: 4px; }
.rich ul li { position: relative; padding-left: 22px; margin-bottom: 10px; }
.rich ul li::before { content: ''; position: absolute; left: 4px; top: 14px; width: 6px; height: 6px; border-radius: 50%; background: var(--primary); }
.rich b { color: var(--text); font-weight: 600; }
.rich img { border-radius: var(--radius); margin: 20px 0; }

/* ---------- 提示条 ---------- */
.toast {
  position: fixed; left: 50%; top: 26px; transform: translate(-50%, -20px);
  padding: 12px 24px; border-radius: 10px; background: rgba(26, 34, 51, .93);
  color: #fff; font-size: 14px; z-index: 9999; opacity: 0;
  transition: all .3s var(--ease); pointer-events: none; box-shadow: var(--shadow-l);
}
.toast.on { opacity: 1; transform: translate(-50%, 0); }
.toast.err { background: #d92d20; }
.toast.ok { background: #067647; }

@media (max-width: 1100px) {
  .wrap { padding: 0 20px; }
  .sec { padding: 60px 0; }
  .sec-title { font-size: 27px; }
}