/* ---------- 登录页 ---------- */
.login-body {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  padding: 24px 16px;
}

.login-wrap { width: 100%; max-width: 420px; }

.login-card {
  background: #fff;
  border-radius: 22px;
  padding: 34px 32px;
  box-shadow: 0 24px 60px rgba(38, 30, 90, 0.35);
}

.login-brand {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 24px;
}

.login-brand h1 { margin: 0; font-size: 1.3rem; color: #3e3fae; }
.login-brand .brand-mark { width: 48px; height: 48px; font-size: 1.55rem; }

.alert-error { background: #fdecee; border-color: #f5c0c7; color: #b23a46; }
.alert { margin-bottom: 16px; }

.login-form label { display: block; font-weight: 600; margin-bottom: 7px; color: #3a4a63; }
.login-form input[type="password"] {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid #e4e8f2;
  border-radius: 11px;
  background: #fbfcff;
  font-size: 1rem;
  margin-bottom: 16px;
}
.login-form input[type="password"]:focus {
  outline: none;
  border-color: #667eea;
  background: #fff;
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.15);
}
.login-hint { text-align: center; font-size: 0.85rem; margin: 14px 0 0; }
.login-card .back-link { display: block; text-align: center; margin-top: 16px; }

/* ---------- 后台总布局 ---------- */
.admin-body {
  background: #edf0f8;
  min-height: 100vh;
}

.admin-topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(102, 126, 234, 0.12);
}

.admin-topbar-inner {
  max-width: 1180px;
  margin: 0 auto;
  padding: 12px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

.admin-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--ink);
}
.admin-brand .brand-mark { width: 38px; height: 38px; font-size: 1.2rem; }
.admin-brand strong { display: block; color: #3e3fae; font-size: 1.05rem; line-height: 1.2; }
.admin-brand small { color: var(--muted); font-size: 0.72rem; }

.admin-nav { display: flex; align-items: center; gap: 6px; flex-wrap: wrap; }
.admin-nav a {
  color: var(--ink-soft);
  text-decoration: none;
  font-size: 0.92rem;
  padding: 8px 12px;
  border-radius: 8px;
  transition: background 0.2s ease, color 0.2s ease;
}
.admin-nav a:hover { background: #eef1ff; color: var(--indigo); }
.admin-nav a.logout { color: #c0392b; }
.admin-nav a.logout:hover { background: #fdecee; }

.admin-wrap {
  max-width: 1180px;
  margin: 0 auto;
  padding: 28px 20px 70px;
}

.course-head-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
  background: #fff;
  border-radius: 16px;
  border: 1px solid rgba(102, 126, 234, 0.1);
  box-shadow: 0 6px 20px rgba(44, 62, 80, 0.06);
  padding: 22px 24px;
  margin-bottom: 20px;
}

.course-head-card h1 { margin: 8px 0 4px; color: #3e3fae; font-size: 1.35rem; }
.course-head-card .mini-btn { text-decoration: none; display: inline-block; }

.panel {
  background: #fff;
  border-radius: 18px;
  border: 1px solid rgba(102, 126, 234, 0.08);
  box-shadow: 0 6px 20px rgba(44, 62, 80, 0.06);
  padding: 24px;
  margin-bottom: 26px;
}

.panel-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 16px;
}
.panel-head h2 { margin: 0; color: #3e3fae; font-size: 1.25rem; }

.enroll-tools {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.enroll-tools input[type="search"] {
  padding: 8px 12px;
  border: 1px solid #e4e8f2;
  border-radius: 10px;
  background: #fbfcff;
  color: var(--ink);
  font-size: 0.9rem;
  min-width: 230px;
}

.enroll-tools input[type="search"]:focus {
  outline: none;
  border-color: var(--indigo);
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.15);
}

.table-scroll {
  overflow-x: auto;
  border: 1px solid #e9edf6;
  border-radius: 12px;
}
table { width: 100%; border-collapse: collapse; font-size: 0.88rem; min-width: 860px; }
th, td { padding: 11px 12px; text-align: left; border-bottom: 1px solid var(--line); vertical-align: middle; }
th { background: #f6f8fd; color: #4a5a75; font-weight: 600; white-space: nowrap; }
tbody tr:hover { background: #fafbff; }
.cell-intro { max-width: 240px; white-space: normal; color: var(--ink-soft); line-height: 1.5; }
.cell-intro small { color: var(--muted); }
.cell-actions { white-space: nowrap; }
.empty-cell { text-align: center; color: var(--muted); padding: 28px; }

.tag { display: inline-block; padding: 3px 10px; border-radius: 50px; font-size: 0.78rem; white-space: nowrap; }
.tag-待审核 { background: #fff3d6; color: #9a6a00; }
.tag-已通过 { background: #e6f7ee; color: #1e7d4f; }
.tag-已拒绝 { background: #fdecee; color: #b23a46; }
.tag-招募中 { background: #eef1ff; color: #4a55b0; }
.tag-已下架 { background: #eceef3; color: #8a94a6; }
.tag-已开课 { background: #e6f0ff; color: #2f6dc0; }
.tag-已结束 { background: #eceef3; color: #6b7688; }
.tag-草稿 { background: #f2f3f7; color: #8a94a6; }

.mini-btn {
  border: none;
  border-radius: 8px;
  padding: 6px 12px;
  font-size: 0.82rem;
  font-weight: 600;
  cursor: pointer;
  text-decoration: none;
  display: inline-block;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}
.mini-btn:hover { transform: translateY(-1px); }
.mini-btn.ok { background: #e6f7ee; color: #1e7d4f; }
.mini-btn.no { background: #fdecee; color: #b23a46; }
.mini-btn.ghost { background: #f2f3f7; color: #6b7688; }
.mini-btn:disabled { opacity: 0.5; cursor: default; }

/* ---------- 后台表单 ---------- */
.admin-form .form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.admin-form .form-row-inner { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.admin-form .form-field { margin-bottom: 14px; }
.admin-form label { display: block; font-weight: 600; margin-bottom: 6px; color: #3a4a63; font-size: 0.9rem; }
.admin-form input[type="text"],
.admin-form input[type="email"],
.admin-form input[type="password"],
.admin-form input[type="number"],
.admin-form input[type="date"],
.admin-form input[type="time"],
.admin-form input[type="datetime-local"],
.admin-form select,
.admin-form textarea {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid #e4e8f2;
  border-radius: 10px;
  background: #fbfcff;
  color: var(--ink);
  font-family: inherit;
  font-size: 0.93rem;
}
.admin-form input[type="number"] { padding-right: 8px; }
.admin-form input:focus, .admin-form select:focus, .admin-form textarea:focus {
  outline: none;
  border-color: var(--indigo);
  background: #fff;
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.15);
}
.admin-form textarea { resize: vertical; }
.admin-form .form-actions { display: flex; align-items: center; gap: 14px; margin-top: 4px; }
.admin-form .submit-btn { width: auto; min-width: 180px; padding: 12px 24px; }
.form-msg { font-weight: 600; font-size: 0.9rem; }
.form-msg.ok { color: #1e7d4f; }
.form-msg.error { color: #b23a46; }

/* 长期课 / 短期课 分段选择 */
.seg { display: inline-flex; border: 1px solid #dde2f0; border-radius: 12px; overflow: hidden; background: #f6f8fd; }
.seg-opt { display: inline-flex; align-items: center; gap: 6px; padding: 9px 18px; cursor: pointer; font-weight: 600; color: var(--ink-soft); font-size: 0.92rem; margin: 0; }
.seg-opt input { accent-color: var(--indigo); width: 16px; height: 16px; }
.seg-opt:has(input:checked) { background: var(--grad); color: #fff; }

#longPanel, #shortPanel { transition: opacity 0.2s ease; }
.time-picker {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr);
  align-items: center;
  gap: 8px;
}
.time-picker-with-date {
  grid-template-columns: minmax(132px, 1.45fr) minmax(76px, 0.8fr) auto minmax(76px, 0.8fr);
}
.time-picker select, .time-picker input { margin: 0; }
.time-picker span { color: var(--ink-soft); font-weight: 700; }

@media (max-width: 860px) {
  .admin-topbar-inner { flex-direction: column; align-items: flex-start; }
  .admin-form .form-row { grid-template-columns: 1fr; }
}

@media (max-width: 520px) {
  .panel { padding: 16px; }
  .admin-form .form-row-inner { grid-template-columns: 1fr; }
  .time-picker-with-date { grid-template-columns: minmax(112px, 1.25fr) minmax(68px, 0.75fr) auto minmax(68px, 0.75fr); gap: 5px; }
}

/* ---------- 系统设置 ---------- */
.settings-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
  align-items: start;
}

.settings-card {
  background: #fbfcff;
  border: 1px solid #e9edf6;
  border-radius: 14px;
  padding: 20px;
}

.settings-card h3 {
  margin: 0 0 6px;
  color: #3e3fae;
  font-size: 1.05rem;
}

.settings-card > .muted {
  margin: 0 0 16px;
  line-height: 1.6;
}

.settings-card .admin-form .form-row,
.settings-card .admin-form .form-row-inner {
  grid-template-columns: 1fr 1fr;
}

.check-line {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--ink-soft);
  font-size: 0.9rem;
  margin: 4px 0 14px;
  cursor: pointer;
}

.check-line input { width: 16px; height: 16px; accent-color: var(--indigo); }

.submit-btn.secondary {
  background: #fff;
  color: #4a55b0;
  border: 1px solid #cdd6f5;
}

.submit-btn.secondary:hover {
  background: #eef1ff;
}

.smtp-test {
  margin-top: 18px;
  padding-top: 18px;
  border-top: 1px dashed #dde2f0;
}

@media (max-width: 860px) {
  .settings-grid { grid-template-columns: 1fr; }
}

/* ============================================================
   后台 · 左侧索引 + 右侧内容 布局
   ============================================================ */
.admin-shell {
  display: flex;
  min-height: 100vh;
}

.admin-sidebar {
  position: sticky;
  top: 0;
  flex: 0 0 238px;
  width: 238px;
  height: 100vh;
  display: flex;
  flex-direction: column;
  background: #fff;
  border-right: 1px solid #e6eaf5;
  padding: 18px 14px;
  box-sizing: border-box;
  overflow-y: auto;
}

.admin-sidebar .admin-brand {
  padding: 2px 8px 16px;
  border-bottom: 1px dashed #e9edf6;
  margin-bottom: 8px;
}

.side-caption {
  margin: 14px 8px 6px;
  font-size: 0.72rem;
  font-weight: 700;
  color: #9aa3b8;
  letter-spacing: 0.08em;
}

.side-nav {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.side-nav a {
  display: block;
  padding: 10px 12px;
  border-radius: 10px;
  color: #44506b;
  text-decoration: none;
  font-weight: 600;
  font-size: 0.93rem;
  transition: background 0.2s ease, color 0.2s ease;
}

.side-nav a:hover { background: #eef1ff; color: #4a55b0; }
.side-nav a.active {
  background: linear-gradient(135deg, #667eea, #764ba2);
  color: #fff;
  box-shadow: 0 6px 14px rgba(102, 126, 234, 0.25);
}

.side-links a {
  font-weight: 500;
  color: #6b7688;
  font-size: 0.9rem;
}

.side-foot {
  margin-top: auto;
  padding-top: 14px;
  border-top: 1px solid #e9edf6;
}

.side-foot .logout {
  display: block;
  text-align: center;
  padding: 10px;
  border-radius: 10px;
  color: #c0392b;
  font-weight: 600;
  text-decoration: none;
}

.side-foot .logout:hover { background: #fdecee; }

.admin-main {
  flex: 1;
  min-width: 0;
  background: #f3f5fb;
}

.admin-bar {
  position: sticky;
  top: 0;
  z-index: 40;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(102, 126, 234, 0.12);
  padding: 14px 26px;
}

.admin-bar strong { color: #3e3fae; font-size: 1.05rem; }
.admin-bar .muted { font-size: 0.82rem; }

/* 左侧导航：默认只显示当前选中面板（仅作用于后台主面板布局）。 */
.admin-shell .panel { display: none; }
.admin-shell .panel.active { display: block; }

@media (max-width: 980px) {
  .admin-shell { flex-direction: column; }
  .admin-sidebar {
    position: static;
    width: 100%;
    height: auto;
    flex: none;
    border-right: none;
    border-bottom: 1px solid #e6eaf5;
    padding: 10px 12px;
  }
  .admin-sidebar .admin-brand,
  .side-caption { display: none; }
  .side-nav { flex-direction: row; flex-wrap: wrap; gap: 4px; }
  .side-nav a { padding: 8px 12px; font-size: 0.88rem; }
  .side-links { display: none; }
  .side-foot {
    margin-top: 6px;
    padding-top: 0;
    border-top: none;
  }
  .side-foot .logout {
    display: inline-block;
    padding: 8px 14px;
  }
  .admin-bar { padding: 12px 16px; }
}

/* ---------- 添加学员（后台补录）弹窗 ---------- */
.modal-mask {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(30, 34, 70, 0.45);
  padding: 18px;
}

.modal-mask[hidden] {
  display: none;
}

.modal-card {
  width: 100%;
  max-width: 640px;
  max-height: calc(100vh - 40px);
  overflow-y: auto;
  background: #fff;
  border-radius: 18px;
  box-shadow: 0 28px 70px rgba(30, 34, 70, 0.32);
  padding: 26px 28px 28px;
}

.modal-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 14px;
  border-bottom: 1px solid var(--line);
  padding-bottom: 14px;
  margin-bottom: 14px;
}

.modal-head h3 {
  margin: 0 0 4px;
  color: #3e3fae;
  font-size: 1.2rem;
}

.modal-head .muted {
  font-size: 0.86rem;
  word-break: break-all;
}

.modal-close {
  border: none;
  background: #f2f3f7;
  color: #6b7688;
  width: 34px;
  height: 34px;
  flex-shrink: 0;
  border-radius: 50%;
  font-size: 1.2rem;
  line-height: 1;
  cursor: pointer;
}

.modal-close:hover {
  background: #fdecee;
  color: #b23a46;
}

.modal-note {
  margin: 0 0 16px;
  padding: 10px 14px;
  border-radius: 10px;
  background: #eef7ff;
  border: 1px solid #d4e8fb;
  color: #2f6dc0;
  font-size: 0.88rem;
  line-height: 1.7;
}

.backup-json {
  max-width: 420px;
  max-height: 180px;
  overflow: auto;
  margin: 8px 0 0;
  padding: 8px;
  white-space: pre-wrap;
  word-break: break-word;
  font-size: 12px;
  background: #f7f8fc;
  border: 1px solid #e3e7f3;
  border-radius: 6px;
}

.cover-thumb {
  width: 76px;
  height: 48px;
  object-fit: cover;
  border-radius: 8px;
  border: 1px solid #e4e8f2;
  vertical-align: middle;
}

.cell-qr {
  text-align: center;
}

.qr-thumb {
  width: 86px;
  height: 86px;
  display: block;
  margin: 0 auto 6px;
  padding: 3px;
  background: #fff;
  border: 1px solid #e4e8f2;
  border-radius: 8px;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.qr-thumb:hover {
  border-color: #667eea;
  box-shadow: 0 4px 12px rgba(102, 126, 234, 0.25);
}

.qr-code-text {
  display: block;
  font-family: Consolas, "Courier New", monospace;
  font-size: 0.72rem;
  color: #8a94a6;
  letter-spacing: 0.02em;
  user-select: all;
}

.form-msg a {
  color: #4a55b0;
  font-weight: 700;
  text-decoration: underline;
}

.cover-preview {
  margin: 4px 0 16px;
}

.cover-preview img {
  display: block;
  max-width: 100%;
  max-height: 260px;
  border-radius: 12px;
  border: 1px solid #e4e8f2;
  object-fit: cover;
}

@media (max-width: 620px) {
  .modal-card {
    padding: 20px 16px;
    border-radius: 14px;
  }
}