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

:root {
  --bg: #f4f6fb;
  --card: #ffffff;
  --primary: #4a6cf7;
  --primary-dark: #3451d6;
  --free: #2bb673;
  --taken: #c9cedd;
  --mine: #f6b54a;
  --danger: #e25c5c;
  --warn: #e8a13a;
  --text: #2b3144;
  --muted: #8a90a2;
  --border: #e3e7f0;
}

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
}

.page { max-width: 1100px; margin: 0 auto; padding: 18px; }
.hidden { display: none !important; }

/* ---------- 登录页 ---------- */
#loginPage {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
}
.login-card {
  background: var(--card);
  width: 360px;
  max-width: 92vw;
  padding: 32px 28px;
  border-radius: 16px;
  box-shadow: 0 12px 40px rgba(60, 80, 160, 0.12);
}
.login-card h1 {
  font-size: 24px;
  text-align: center;
  color: var(--primary-dark);
  margin-bottom: 6px;
}
.login-card .sub {
  text-align: center;
  color: var(--muted);
  font-size: 13px;
  margin-bottom: 22px;
}
.login-card label {
  display: block;
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 14px;
}
.login-card input {
  display: block;
  width: 100%;
  margin-top: 6px;
  padding: 11px 12px;
  font-size: 15px;
  border: 1px solid var(--border);
  border-radius: 9px;
  outline: none;
  transition: border-color .15s;
}
.login-card input:focus { border-color: var(--primary); }
.login-card button {
  width: 100%;
  padding: 12px;
  font-size: 15px;
  color: #fff;
  background: var(--primary);
  border: none;
  border-radius: 9px;
  cursor: pointer;
  transition: background .15s;
}
.login-card button:hover { background: var(--primary-dark); }
.login-card button:disabled { background: #9aa6d6; cursor: not-allowed; }

/* ---------- 顶栏 ---------- */
.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: var(--card);
  padding: 12px 16px;
  border-radius: 12px;
  box-shadow: 0 2px 10px rgba(60, 80, 160, 0.06);
}
.topbar .title { font-size: 18px; font-weight: 600; color: var(--primary-dark); }
.topbar .who { font-size: 14px; color: var(--muted); display: flex; align-items: center; gap: 10px; }

.link-btn {
  background: none; border: none; color: var(--primary); cursor: pointer;
  font-size: 13px; padding: 4px 6px; border-radius: 6px;
}
.link-btn:hover { background: rgba(74,108,247,.08); }

/* ---------- 状态条 ---------- */
.status-bar {
  display: flex; gap: 18px; align-items: center;
  margin: 14px 2px; font-size: 13px; color: var(--muted);
}
.status-bar .hint { margin-left: auto; }

/* ---------- 讲台 ---------- */
.podium {
  margin: 6px 0 18px;
  text-align: center;
  letter-spacing: 8px;
  font-size: 16px;
  color: var(--primary-dark);
  background: linear-gradient(180deg, #eef2ff, #dde4ff);
  border: 2px solid #c3cefb;
  border-radius: 10px;
  padding: 14px;
  font-weight: 600;
}

/* ---------- 座位图 ---------- */
.seat-map {
  display: flex;
  justify-content: center;
  gap: 26px;          /* 过道 */
  background: var(--card);
  padding: 22px 14px;
  border-radius: 14px;
  box-shadow: 0 4px 16px rgba(60, 80, 160, 0.06);
  overflow-x: auto;
}
.group {
  display: flex;
  flex-direction: column;
  align-items: center;
}
.group-label {
  font-size: 12px; color: var(--muted); margin-bottom: 8px; font-weight: 600;
}
.group-grid {
  display: grid;
  gap: 8px;
}
/* 行号在最左？这里直接网格即可，列数由内联 style 控制 */

.seat {
  width: 92px;
  min-height: 54px;
  padding: 6px;
  border-radius: 9px;
  font-size: 13px;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  cursor: default;
  border: 2px solid transparent;
  transition: transform .08s, box-shadow .15s;
  user-select: none;
  line-height: 1.25;
}
.seat .seat-id { font-size: 10px; color: var(--muted); }
.seat.free {
  background: #e9f8f0;
  border-color: var(--free);
  color: var(--free);
  cursor: pointer;
}
.seat.free:hover { transform: translateY(-2px); box-shadow: 0 4px 10px rgba(43,182,115,.25); }
.seat.taken {
  background: var(--taken);
  color: #5b6178;
}
.seat.mine {
  background: #fff3dd;
  border-color: var(--mine);
  color: #b9791a;
  box-shadow: 0 0 0 2px rgba(246,181,74,.25);
}
.seat .name { font-weight: 600; }

/* ---------- 我的座位面板 ---------- */
.my-panel {
  margin-top: 18px;
  background: var(--card);
  padding: 16px;
  border-radius: 12px;
  box-shadow: 0 2px 10px rgba(60,80,160,.06);
  display: flex; flex-wrap: wrap; align-items: center; gap: 14px;
}
.my-panel .actions { margin-left: auto; display: flex; gap: 8px; align-items: center; }
.btn-warn, .btn-danger {
  padding: 8px 14px; border: none; border-radius: 8px; cursor: pointer;
  font-size: 13px; color: #fff;
}
.btn-warn { background: var(--warn); }
.btn-warn:hover { background: #d68f2c; }
.btn-danger { background: var(--danger); }
.btn-danger:hover { background: #d24b4b; }

.foot { text-align: center; color: var(--muted); font-size: 12px; margin: 18px 0; }

.msg { font-size: 13px; color: var(--danger); min-height: 18px; }
.msg.ok { color: var(--free); }

/* ---------- 弹层 ---------- */
.modal {
  position: fixed; inset: 0; background: rgba(20,28,50,.45);
  display: flex; align-items: center; justify-content: center; z-index: 50;
}
.modal-card {
  background: #fff; width: 340px; max-width: 92vw; padding: 22px;
  border-radius: 14px; box-shadow: 0 16px 50px rgba(0,0,0,.25);
}
.modal-card h3 { margin-bottom: 8px; color: var(--primary-dark); }
.modal-card p { font-size: 13px; color: var(--muted); margin-bottom: 12px; }
.modal-card input {
  width: 100%; padding: 10px; border: 1px solid var(--border);
  border-radius: 8px; font-size: 14px; outline: none; margin-bottom: 8px;
}
.modal-card input:focus { border-color: var(--primary); }
.modal-actions { display: flex; justify-content: flex-end; gap: 8px; margin-top: 6px; }

/* ---------- Toast ---------- */
.toast {
  position: fixed; left: 50%; bottom: 36px; transform: translateX(-50%);
  background: #2b3144; color: #fff; padding: 10px 18px; border-radius: 24px;
  font-size: 14px; box-shadow: 0 8px 24px rgba(0,0,0,.2); z-index: 80;
  opacity: .96;
}
.toast.err { background: var(--danger); }
.toast.ok { background: var(--free); }

/* ---------- 手机适配 ---------- */
@media (max-width: 640px) {
  .seat { width: 64px; min-height: 46px; font-size: 11px; }
  .seat .seat-id { font-size: 9px; }
  .seat-map { gap: 14px; padding: 14px 8px; }
  .topbar .title { font-size: 15px; }
  .status-bar { flex-wrap: wrap; gap: 8px; }
  .status-bar .hint { margin-left: 0; width: 100%; }
  .my-panel .actions { margin-left: 0; width: 100%; }
}