/* ============================================================
   电气知识培考系统 · 全局样式（响应式：手机 + 电脑）
   版本号  ：V1.0
   修改时间：2026-10-16
   ============================================================ */
:root {
  --primary: #1a6fd6;
  --primary-dark: #1457a8;
  --bg: #f2f4f8;
  --card: #ffffff;
  --line: #e3e7ee;
  --text: #26303e;
  --muted: #7a8494;
  --ok: #22a45d;
  --err: #d94343;
  --warn: #e08a1e;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
  background: var(--bg); color: var(--text); font-size: 15px; line-height: 1.6;
}
a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--primary-dark); }

/* ---- 顶栏 ---- */
.topnav {
  background: var(--card); border-bottom: 1px solid var(--line);
  position: sticky; top: 0; z-index: 50;
}
.topnav .inner {
  max-width: 1080px; margin: 0 auto; padding: 10px 16px;
  display: flex; align-items: center; gap: 18px; flex-wrap: wrap;
}
.brand { font-size: 17px; font-weight: 700; color: var(--primary-dark); white-space: nowrap; }
.brand small { font-weight: 400; color: var(--muted); font-size: 12px; margin-left: 6px; }
.nav-links { display: flex; gap: 4px; flex-wrap: wrap; }
.nav-links a {
  padding: 6px 12px; border-radius: 6px; color: var(--text); font-size: 14px;
}
.nav-links a:hover, .nav-links a.active { background: #e8f1fc; color: var(--primary-dark); }
.topnav .user {
  margin-left: auto; display: flex; align-items: center; gap: 12px;
  font-size: 13px; color: var(--muted); white-space: nowrap;
}
.topnav .user .badge {
  background: #e8f1fc; color: var(--primary-dark); padding: 2px 10px;
  border-radius: 20px; font-size: 12px;
}

/* ---- 页面容器 ---- */
.wrap { max-width: 1080px; margin: 0 auto; padding: 22px 16px 60px; }
.page-title { font-size: 20px; font-weight: 700; margin-bottom: 16px; }

/* ---- 卡片与网格 ---- */
.card {
  background: var(--card); border: 1px solid var(--line); border-radius: 10px;
  padding: 18px; margin-bottom: 16px;
}
.grid { display: grid; gap: 16px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
@media (max-width: 860px) { .grid-4, .grid-3 { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 560px) { .grid-2, .grid-4, .grid-3 { grid-template-columns: 1fr; } }

/* ---- 表格 ---- */
.table-wrap { overflow-x: auto; }
table { width: 100%; border-collapse: collapse; background: var(--card); font-size: 14px; }
th, td { padding: 9px 10px; border-bottom: 1px solid var(--line); text-align: left; vertical-align: top; }
th { background: #f7f9fc; color: var(--muted); font-weight: 600; white-space: nowrap; }
tr:hover td { background: #fafcff; }

/* ---- 按钮 ---- */
.btn {
  display: inline-block; background: var(--primary); color: #fff; border: 0;
  border-radius: 6px; padding: 9px 18px; font-size: 14px; cursor: pointer;
  font-family: inherit;
}
.btn:hover { background: var(--primary-dark); color: #fff; }
.btn.ghost { background: #fff; color: var(--primary); border: 1px solid var(--primary); }
.btn.ghost:hover { background: #e8f1fc; }
.btn.danger { background: var(--err); }
.btn.ok { background: var(--ok); }
.btn.small { padding: 4px 10px; font-size: 13px; }
.btn:disabled { opacity: .55; cursor: not-allowed; }
.btn-block { display: block; width: 100%; text-align: center; }

/* ---- 表单 ---- */
.form-item { margin-bottom: 14px; }
.form-item label { display: block; font-size: 13px; color: var(--muted); margin-bottom: 5px; }
.form-item input[type=text], .form-item input[type=email], .form-item input[type=password],
.form-item input[type=number], .form-item input[type=datetime-local],
.form-item select, .form-item textarea {
  width: 100%; padding: 9px 11px; border: 1px solid var(--line); border-radius: 6px;
  font-size: 14px; font-family: inherit; background: #fff; color: var(--text);
}
.form-item textarea { min-height: 90px; resize: vertical; }
.form-item input:focus, .form-item select:focus, .form-item textarea:focus {
  outline: none; border-color: var(--primary); box-shadow: 0 0 0 2px #e0edfb;
}
.form-row { display: flex; gap: 14px; flex-wrap: wrap; }
.form-row .form-item { flex: 1; min-width: 200px; }
.check-line { display: inline-flex; align-items: center; gap: 6px; margin: 0 14px 8px 0; font-size: 14px; }

/* ---- 胶囊式多选（chip，与早期单文件版一致） ---- */
.chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chip {
  display: inline-flex; align-items: center; gap: 6px; padding: 7px 13px;
  border: 1px solid var(--line); border-radius: 20px; font-size: 13px;
  cursor: pointer; user-select: none; background: #fff; transition: all .15s;
}
.chip:hover { border-color: var(--primary); }
.chip.on { background: var(--primary); color: #fff; border-color: var(--primary); }
.chip input { display: none; }

/* ---- 提示 ---- */
.flash { max-width: 1080px; margin: 12px auto 0; padding: 0 16px; }
.flash .msg { padding: 10px 14px; border-radius: 6px; margin-bottom: 8px; font-size: 14px; }
.flash .ok { background: #e7f7ee; color: #177a45; border: 1px solid #bfe8d0; }
.flash .error { background: #fdeeee; color: #a52a2a; border: 1px solid #f3c4c4; }

/* ---- 徽章 / 状态 ---- */
.tag { display: inline-block; padding: 2px 10px; border-radius: 20px; font-size: 12px; }
.tag.ok { background: #e7f7ee; color: #177a45; }
.tag.err { background: #fdeeee; color: #a52a2a; }
.tag.warn { background: #fdf3e4; color: #a8660c; }
.tag.info { background: #e8f1fc; color: #1457a8; }
.tag.gray { background: #eef1f5; color: #6b7585; }

/* ---- 统计卡片 ---- */
.stat-num { font-size: 30px; font-weight: 700; color: var(--primary-dark); }
.stat-label { font-size: 13px; color: var(--muted); }

/* ---- 题目 ---- */
.q-card { background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: 16px 18px; margin-bottom: 14px; }
.q-head { display: flex; align-items: center; gap: 10px; margin-bottom: 10px; flex-wrap: wrap; }
.q-stem { font-size: 15px; font-weight: 600; margin-bottom: 12px; }
.q-opt { display: block; padding: 9px 12px; border: 1px solid var(--line); border-radius: 8px; margin-bottom: 8px; cursor: pointer; font-size: 14px; }
.q-opt:hover { border-color: var(--primary); background: #f5f9fe; }
.q-opt.correct { border-color: var(--ok); background: #e7f7ee; color: #177a45; }
.q-opt.wrong { border-color: var(--err); background: #fdeeee; color: #a52a2a; }
.q-exp { margin-top: 10px; padding: 10px 12px; background: #f7f9fc; border-left: 3px solid var(--primary); font-size: 13px; color: #3c4655; border-radius: 0 6px 6px 0; display: none; }
.q-exp.show { display: block; }
.q-num { background: #e8f1fc; color: var(--primary-dark); border-radius: 6px; padding: 2px 9px; font-size: 13px; font-weight: 600; }

/* ---- 考试页 ---- */
.exam-bar {
  position: sticky; top: 0; z-index: 40; background: var(--primary-dark); color: #fff;
  padding: 10px 16px; display: flex; align-items: center; gap: 16px; flex-wrap: wrap;
}
.exam-bar .timer { font-size: 22px; font-weight: 700; font-variant-numeric: tabular-nums; }
.exam-bar .progress { font-size: 13px; opacity: .9; margin-left: auto; }
.answer-sheet { display: flex; flex-wrap: wrap; gap: 8px; margin: 12px 0; }
.answer-sheet .cell {
  width: 38px; height: 38px; line-height: 36px; text-align: center; border-radius: 6px;
  border: 1px solid var(--line); background: #fff; cursor: pointer; font-size: 13px;
}
.answer-sheet .cell.done { background: #e7f7ee; border-color: var(--ok); color: #177a45; }
.answer-sheet .cell.current { border: 2px solid var(--primary); }
.modal-mask {
  position: fixed; inset: 0; background: rgba(20, 30, 50, .55); z-index: 100;
  display: none; align-items: center; justify-content: center; padding: 20px;
}
.modal-mask.show { display: flex; }
.modal { background: #fff; border-radius: 12px; padding: 24px; max-width: 420px; width: 100%; }

/* ---- 登录页 ---- */
.login-body { min-height: 100vh; display: flex; align-items: center; justify-content: center; background: linear-gradient(135deg, #1457a8 0%, #1a6fd6 60%, #3b8ce8 100%); padding: 20px; }
.login-card { background: #fff; border-radius: 14px; width: 100%; max-width: 400px; padding: 30px 28px; box-shadow: 0 18px 50px rgba(0,0,0,.18); }
.login-card h1 { font-size: 20px; text-align: center; color: var(--primary-dark); margin-bottom: 4px; }
.login-card .sub { text-align: center; color: var(--muted); font-size: 13px; margin-bottom: 18px; }
.tabs { display: flex; border-bottom: 1px solid var(--line); margin-bottom: 20px; }
.tabs button {
  flex: 1; background: none; border: 0; padding: 10px; font-size: 15px; color: var(--muted);
  cursor: pointer; border-bottom: 2px solid transparent; font-family: inherit;
}
.tabs button.active { color: var(--primary-dark); border-bottom-color: var(--primary); font-weight: 600; }

/* ---- 后台 ---- */
.admin-nav { background: #1b2a3d; color: #fff; }
.admin-nav .inner { max-width: 1080px; margin: 0 auto; padding: 10px 16px; display: flex; gap: 6px; flex-wrap: wrap; align-items: center; }
.admin-nav a { color: #c7d4e4; padding: 6px 12px; border-radius: 6px; font-size: 14px; }
.admin-nav a:hover, .admin-nav a.active { background: rgba(255,255,255,.12); color: #fff; }
.admin-nav .spacer { flex: 1; }
.muted { color: var(--muted); font-size: 13px; }
.empty { text-align: center; color: var(--muted); padding: 40px 0; }

@media (max-width: 560px) {
  .topnav .user { width: 100%; justify-content: space-between; }
  .stat-num { font-size: 24px; }
  .exam-bar .timer { font-size: 18px; }
}