:root {
  --bg: #f6f8fc;
  --text: #0f172a;
  --muted: #64748b;
  --line: rgba(148, 163, 184, .25);
  --primary: #3b82f6;
  --primary-dark: #1d4ed8;
  --danger: #dc2626;
  --shadow: 0 18px 50px rgba(15, 23, 42, .08);
}
* { box-sizing: border-box; }
body { margin: 0; background: linear-gradient(180deg, #f4f7fb 0%, #eef3fb 100%); color: var(--text); font: 14px/1.5 -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif; }
a { color: inherit; text-decoration: none; }
h1, h2, h3, h4, p { margin: 0; }
body.modal-open { overflow: hidden; }
.center-page { min-height: 100vh; display: flex; align-items: center; justify-content: center; padding: 24px; }
.exam-bg { background: radial-gradient(circle at top right, rgba(59,130,246,.15), transparent 28%), linear-gradient(180deg, #eef4ff 0%, #f8fbff 100%); }
.card { background: rgba(255,255,255,.86); backdrop-filter: blur(12px); border: 1px solid rgba(255,255,255,.65); border-radius: 24px; padding: 24px; box-shadow: var(--shadow); margin-bottom: 20px; }
.card.glass { background: linear-gradient(135deg, rgba(255,255,255,.95), rgba(255,255,255,.78)); }
.card.gradient { background: linear-gradient(135deg, rgba(219,234,254,.72), rgba(255,255,255,.9)); }
.card.narrow { width: 100%; max-width: 420px; }
.card.medium { width: 100%; max-width: 760px; }
.portal-shell { max-width: 1120px; margin: 0 auto; padding: 24px; }
.portal-header, .page-head { display: flex; justify-content: space-between; align-items: flex-start; gap: 20px; margin-bottom: 20px; }
.page-eyebrow { color: var(--primary-dark); font-size: 12px; letter-spacing: .08em; text-transform: uppercase; font-weight: 700; margin-bottom: 8px; }
.page-desc { color: var(--muted); margin: 8px 0 0; max-width: 760px; }
.inline-row, .button-row { display: flex; gap: 12px; align-items: center; flex-wrap: wrap; }
.wrap-tight { gap: 8px; }
.grid-2 { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 20px; }
.form-grid { display: grid; grid-template-columns: repeat(2, minmax(0,1fr)); gap: 16px; }
.form-grid.single-col { grid-template-columns: 1fr; }
.form-grid .col-span-2 { grid-column: span 2; }
.stat-grid { display: grid; grid-template-columns: repeat(4,minmax(0,1fr)); gap: 16px; margin-bottom: 20px; }
.stat-card { background: linear-gradient(180deg, rgba(255,255,255,.92), rgba(255,255,255,.72)); border: 1px solid rgba(255,255,255,.8); border-radius: 20px; padding: 20px; box-shadow: var(--shadow); }
.stat-card span { display:block; font-size: 13px; color: var(--muted); margin-bottom: 10px; }
.stat-card strong { font-size: 28px; }
.small-stat { font-size: 14px !important; line-height: 1.6; }
.kv-grid { display: grid; gap: 14px; }
.kv-grid div { padding: 12px 14px; background: rgba(248,250,252,.88); border: 1px solid var(--line); border-radius: 16px; }
.kv-grid span { display: block; color: var(--muted); font-size: 12px; margin-bottom: 6px; }
.kv-grid strong { line-height: 1.7; }
.section-head { display: flex; justify-content: space-between; align-items: center; gap: 12px; margin-bottom: 16px; }
label { display: block; margin: 0 0 8px; font-weight: 600; color: #334155; }
input[type=text], input[type=password], input[type=number], input[type=datetime-local], input[type=file], select, textarea { width: 100%; border: 1px solid var(--line); border-radius: 14px; padding: 12px 14px; font-size: 14px; background: rgba(255,255,255,.96); outline: none; transition: .2s ease border-color, .2s ease box-shadow; }
input:focus, select:focus, textarea:focus { border-color: rgba(59,130,246,.65); box-shadow: 0 0 0 4px rgba(59,130,246,.12); }
textarea { resize: vertical; min-height: 100px; }
.btn { display: inline-flex; justify-content: center; align-items: center; gap: 8px; border: 1px solid transparent; border-radius: 14px; padding: 10px 16px; background: rgba(226,232,240,.85); color: var(--text); cursor: pointer; font-weight: 600; transition: transform .15s ease, box-shadow .2s ease, background .2s ease; }
.btn:hover { transform: translateY(-1px); box-shadow: 0 10px 20px rgba(15,23,42,.08); }
.btn.primary { background: linear-gradient(135deg, var(--primary), #2563eb); color: #fff; }
.btn.danger { background: linear-gradient(135deg, #ef4444, var(--danger)); color: #fff; }
.btn.small { padding: 7px 12px; font-size: 12px; border-radius: 12px; }
.btn.full { width: 100%; margin-top: 16px; }
.icon-btn { width: 36px; height: 36px; border-radius: 999px; border: 1px solid var(--line); background: #fff; cursor: pointer; font-size: 20px; line-height: 1; }
.alert { padding: 14px 16px; border-radius: 16px; margin-bottom: 16px; border: 1px solid transparent; }
.alert.error { background: #fef2f2; color: #991b1b; border-color: #fecaca; }
.alert.success { background: #ecfdf5; color: #065f46; border-color: #a7f3d0; }
.alert.warning { background: #fff7ed; color: #9a3412; border-color: #fdba74; }
.muted { color: var(--muted); }
.badge { display: inline-flex; align-items: center; gap: 6px; font-size: 12px; padding: 6px 10px; border-radius: 999px; background: #e0edff; color: var(--primary-dark); }
.badge.soft { background: #edf2f7; color: #475569; }
.badge.info { background: #ede9fe; color: #6d28d9; }
.feature-list { margin: 0; padding-left: 18px; color: var(--text); }
.feature-list li { margin-bottom: 10px; line-height: 1.7; }
.mt-16 { margin-top: 16px; }
.table-wrap { overflow: auto; }
.table { width: 100%; border-collapse: separate; border-spacing: 0 10px; }
.modern-table th { color: var(--muted); font-weight: 700; font-size: 12px; text-transform: uppercase; letter-spacing: .05em; padding: 0 12px 8px; text-align:left; }
.modern-table td { background: rgba(255,255,255,.92); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); padding: 16px 12px; vertical-align: top; }
.modern-table td:first-child { border-left: 1px solid var(--line); border-top-left-radius: 16px; border-bottom-left-radius: 16px; }
.modern-table td:last-child { border-right: 1px solid var(--line); border-top-right-radius: 16px; border-bottom-right-radius: 16px; }
.table.compact { border-spacing: 0 8px; }
.table.compact td { padding: 12px 10px; }
.table-title { font-weight: 700; margin-bottom: 4px; }
.option-chips { display: flex; gap: 10px; flex-wrap: wrap; margin: 14px 0; }
.option-chip { background: #eff6ff; color: #1d4ed8; border-radius: 999px; padding: 8px 12px; font-size: 13px; }
.question-box { border: 1px solid var(--line); background: rgba(248,250,252,.8); border-radius: 20px; padding: 20px; margin-bottom: 16px; }
.question-card-head { display: flex; align-items: flex-start; justify-content: space-between; gap: 12px; margin-bottom: 14px; }
.question-head { color: #334155; margin-bottom: 8px; font-weight: 800; }
.question-meta-grid { display: grid; gap: 12px; margin-top: 14px; }
.drag-handle { font-size: 24px; color: #94a3b8; user-select: none; cursor: move; padding: 4px 8px; }
.sortable-item.dragging { opacity: .45; }
.admin-shell { display: grid; grid-template-columns: 280px 1fr; min-height: 100vh; }
.sidebar { background: linear-gradient(180deg, #0f172a 0%, #111c34 100%); color: #fff; padding: 26px 18px; display: flex; flex-direction: column; gap: 18px; position: sticky; top: 0; height: 100vh; }
.sidebar-brand { display: flex; align-items: center; gap: 14px; padding: 6px 8px 14px; border-bottom: 1px solid rgba(255,255,255,.08); }
.sidebar-logo { width: 44px; height: 44px; display:flex; align-items:center; justify-content:center; border-radius: 16px; background: linear-gradient(135deg, #60a5fa, #2563eb); font-weight: 800; }
.sidebar-title { font-weight: 800; margin-bottom: 4px; }
.sidebar-subtitle { font-size: 12px; color: #94a3b8; }
.sidebar-nav { display: flex; flex-direction: column; gap: 8px; }
.sidebar a { color: #cbd5e1; padding: 12px 14px; border-radius: 14px; }
.sidebar a:hover { background: rgba(255,255,255,.08); color: #fff; }
.sidebar-user-card { margin-top: auto; padding: 16px; border: 1px solid rgba(255,255,255,.08); border-radius: 18px; background: rgba(255,255,255,.03); }
.content { padding: 28px; }
.exam-page { max-width: 1080px; margin: 0 auto; padding: 16px; }
.exam-topbar, .exam-bottombar { position: sticky; z-index: 3; background: #fff; box-shadow: 0 8px 30px rgba(15,23,42,.06); border-radius: 16px; padding: 14px 18px; display: flex; justify-content: space-between; align-items: center; gap: 16px; }
.exam-topbar { top: 8px; margin-bottom: 16px; }
.exam-bottombar { bottom: 8px; margin-top: 16px; }
.question-card { background: #fff; border-radius: 16px; padding: 20px; box-shadow: 0 8px 30px rgba(15,23,42,.06); margin-bottom: 16px; }
.question-title { font-weight: 700; margin-bottom: 10px; }
.question-stem { margin-bottom: 12px; line-height: 1.7; }
.option-row { display: flex; align-items: flex-start; gap: 10px; padding: 8px 0; }
.answer-textarea { min-height: 120px; }
.question-image { max-height: 240px; border-radius: 10px; margin: 10px 0; }
.inline-form { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 10px; }
.checkbox-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px 14px; margin-top: 12px; }
.checkbox-grid label { margin: 0; display: flex; gap: 8px; align-items: center; font-weight: 500; }
.options-editor.is-disabled { opacity: .65; }
.options-list { display: grid; gap: 10px; }
.option-editor-row { display: grid; grid-template-columns: 50px 1fr 70px; gap: 10px; align-items: center; }
.option-key-badge { display: inline-flex; align-items: center; justify-content: center; width: 42px; height: 42px; border-radius: 14px; background: #eff6ff; color: #1d4ed8; font-weight: 800; }
body.modal-open { overflow: hidden; }
.modal { position: fixed; inset: 0; display: none; z-index: 90; overflow-y: auto; padding: 24px 12px; box-sizing: border-box; }
.modal.is-open { display: flex; align-items: center; justify-content: center; }
.modal-backdrop { position: fixed; inset: 0; background: rgba(15,23,42,.5); backdrop-filter: blur(6px); }
.modal-dialog { position: relative; z-index: 1; width: min(720px, calc(100vw - 24px)); margin: auto; background: #fff; border-radius: 24px; box-shadow: 0 30px 80px rgba(15,23,42,.18); overflow: hidden; max-height: calc(100vh - 48px); display: flex; flex-direction: column; }
.modal-dialog-lg { width: min(920px, calc(100vw - 24px)); }
.modal-dialog-xl { width: min(1100px, calc(100vw - 24px)); }
.modal-head, .modal-foot { padding: 18px 22px; display: flex; justify-content: space-between; align-items: center; gap: 12px; border-bottom: 1px solid var(--line); }
.modal-foot { border-top: 1px solid var(--line); border-bottom: none; }
.inline-foot { justify-content: flex-end; }
.modal-body { padding: 22px; overflow: auto; }
.sortable-list { display: grid; gap: 14px; }
.tips { margin-top: 16px; color: var(--muted); }
@media (max-width: 1100px) { .admin-shell { grid-template-columns: 1fr; } .sidebar { position: static; height: auto; } }
@media (max-width: 900px) { .stat-grid, .grid-2, .form-grid, .checkbox-grid { grid-template-columns: 1fr; } .form-grid .col-span-2 { grid-column: span 1; } }
@media (max-width: 768px) { .exam-topbar, .exam-bottombar, .portal-header, .page-head { flex-direction: column; align-items: stretch; } .content, .portal-shell, .exam-page { padding: 14px; } .card { padding: 18px; border-radius: 20px; } .table { min-width: 760px; } .option-editor-row { grid-template-columns: 42px 1fr 60px; } }


/* 2026-03-20 confirm page refresh */
.confirm-shell {
  min-height: 100vh;
  padding: 32px 16px 48px;
  background:
    radial-gradient(circle at top right, rgba(59,130,246,.14), transparent 28%),
    linear-gradient(180deg, #eef4ff 0%, #f8fbff 100%);
}
.confirm-wrap {
  max-width: 980px;
  margin: 0 auto;
}
.confirm-hero {
  margin-bottom: 18px;
  padding: 24px 26px;
  border-radius: 24px;
  background: linear-gradient(135deg, rgba(255,255,255,.92), rgba(255,255,255,.78));
  border: 1px solid rgba(255,255,255,.72);
  box-shadow: var(--shadow);
}
.confirm-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  border-radius: 999px;
  background: #e0edff;
  color: var(--primary-dark);
  font-size: 12px;
  font-weight: 700;
  margin-bottom: 12px;
}
.confirm-title {
  font-size: clamp(28px, 4vw, 42px);
  line-height: 1.15;
  margin-bottom: 10px;
}
.confirm-subtitle {
  color: var(--muted);
  line-height: 1.8;
  max-width: 760px;
}
.confirm-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(300px, .8fr);
  gap: 18px;
  align-items: start;
}
.confirm-panel {
  background: rgba(255,255,255,.9);
  border: 1px solid rgba(255,255,255,.72);
  border-radius: 24px;
  box-shadow: var(--shadow);
  padding: 24px;
}
.confirm-kv {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}
.confirm-kv .kv-item {
  padding: 14px 16px;
  border-radius: 18px;
  background: rgba(248,250,252,.95);
  border: 1px solid var(--line);
}
.confirm-kv .kv-item.full {
  grid-column: 1 / -1;
}
.confirm-kv .label {
  display: block;
  margin-bottom: 6px;
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .02em;
}
.confirm-kv .value {
  display: block;
  font-size: 16px;
  line-height: 1.7;
  color: var(--text);
  word-break: break-word;
}
.confirm-score {
  font-size: 28px;
  font-weight: 800;
  color: var(--primary-dark);
}
.status-tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border-radius: 999px;
  font-size: 13px;
  font-weight: 700;
}
.status-tag.success { background: #ecfdf5; color: #047857; }
.status-tag.warning { background: #fff7ed; color: #c2410c; }
.promise-card {
  margin-top: 18px;
  padding: 18px;
  border-radius: 20px;
  background: linear-gradient(180deg, #fff 0%, #f8fbff 100%);
  border: 1px solid var(--line);
}
.promise-title {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 18px;
  margin-bottom: 12px;
}
.promise-body {
  color: #334155;
  line-height: 1.9;
  white-space: pre-line;
}
.promise-check {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  margin-top: 16px;
  padding: 14px 16px;
  border-radius: 16px;
  background: #eff6ff;
  border: 1px solid rgba(59,130,246,.18);
}
.promise-check input[type=checkbox] {
  margin-top: 2px;
  width: 18px;
  height: 18px;
  flex: 0 0 auto;
}
.promise-check span {
  font-weight: 700;
  line-height: 1.7;
}
.confirm-side-list {
  display: grid;
  gap: 12px;
  margin-top: 14px;
}
.confirm-side-item {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  padding: 14px 16px;
  border-radius: 18px;
  background: rgba(248,250,252,.9);
  border: 1px solid var(--line);
}
.confirm-side-item strong {
  display: block;
  margin-bottom: 4px;
}
.confirm-actions {
  display: grid;
  gap: 12px;
  margin-top: 22px;
}
.confirm-actions .btn {
  min-height: 48px;
  font-size: 16px;
  border-radius: 16px;
}
.btn.ghost {
  background: #fff;
  border-color: var(--line);
}
@media (max-width: 900px) {
  .confirm-grid, .confirm-kv { grid-template-columns: 1fr; }
  .confirm-kv .kv-item.full { grid-column: auto; }
}
@media (max-width: 768px) {
  .confirm-shell { padding: 18px 12px 28px; }
  .confirm-hero, .confirm-panel { padding: 18px; border-radius: 20px; }
  .confirm-title { font-size: 26px; }
  .confirm-subtitle, .confirm-kv .value, .promise-body { font-size: 15px; }
}

/* 2026-03-20 student exam page refinement */
.exam-page.exam-page-student {
  max-width: 1180px;
  padding: 18px 16px 32px;
}
.exam-form-shell {
  display: grid;
  gap: 18px;
}
.exam-summary-card {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(320px, .8fr);
  gap: 20px;
  align-items: start;
  margin-bottom: 18px;
}
.exam-summary-main {
  min-width: 0;
}
.exam-summary-main h1 {
  font-size: clamp(30px, 4vw, 48px);
  line-height: 1.2;
}
.exam-metrics {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}
.metric-item {
  padding: 16px;
  border-radius: 18px;
  background: rgba(248,250,252,.9);
  border: 1px solid var(--line);
}
.metric-item span,
.exam-action-title {
  display: block;
  font-size: 12px;
  color: var(--muted);
  margin-bottom: 6px;
}
.metric-item strong {
  display: block;
  font-size: 30px;
  line-height: 1.15;
}
.metric-item-wide {
  grid-column: 1 / -1;
}
.student-question-card {
  border: 1px solid rgba(148,163,184,.18);
  border-radius: 22px;
  padding: 22px;
  box-shadow: 0 12px 32px rgba(15,23,42,.05);
  margin-bottom: 0;
}
.question-card-headline {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 16px;
  margin-bottom: 16px;
}
.question-seq {
  display: inline-flex;
  align-items: center;
  min-height: 32px;
  padding: 0 12px;
  border-radius: 999px;
  background: #e8f0ff;
  color: #1d4ed8;
  font-size: 13px;
  font-weight: 700;
  margin-bottom: 10px;
}
.student-question-card .question-title {
  margin: 0;
  font-size: 24px;
  line-height: 1.35;
}
.question-score-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 34px;
  padding: 0 14px;
  border-radius: 999px;
  background: rgba(219,234,254,.92);
  color: #1d4ed8;
  font-size: 13px;
  font-weight: 700;
}
.student-question-card .question-stem {
  margin-bottom: 0;
  font-size: 20px;
  line-height: 1.85;
  color: #0f172a;
  white-space: pre-wrap;
  word-break: break-word;
}
.options-list-modern {
  display: grid;
  gap: 8px;
  margin-top: 16px;
}
.option-card {
  display: grid;
  grid-template-columns: 28px minmax(0, 1fr);
  gap: 12px;
  align-items: center;
  padding: 10px 12px;
  border-radius: 16px;
  border: 1px solid transparent;
  background: transparent;
  cursor: pointer;
  transition: .2s ease border-color, .2s ease background, .2s ease box-shadow;
}
.option-card:hover {
  background: rgba(248,250,252,.92);
  border-color: rgba(148,163,184,.24);
}
.option-card.is-selected {
  background: rgba(239,246,255,.92);
  border-color: rgba(96,165,250,.34);
}
.option-card-control {
  display: inline-flex;
  align-items: center;
  justify-content: center;
}
.option-card input {
  margin: 0;
  width: 20px;
  height: 20px;
  accent-color: var(--primary);
}
.option-card-content {
  min-width: 0;
  display: flex;
  align-items: flex-start;
  gap: 10px;
}
.option-card-key {
  flex: 0 0 auto;
  min-width: 20px;
  font-size: 18px;
  font-weight: 700;
  color: #334155;
  line-height: 1.8;
}
.option-card-text {
  min-width: 0;
  font-size: 18px;
  line-height: 1.8;
  color: #0f172a;
  word-break: break-word;
}
.answer-textarea {
  min-height: 170px;
  font-size: 16px;
  line-height: 1.9;
  padding: 16px 18px;
  border-radius: 18px;
  margin-top: 16px;
}
.exam-action-panel {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  margin-top: 4px;
}
.exam-action-title {
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .06em;
}
.exam-action-note {
  color: var(--muted);
  line-height: 1.7;
}
.exam-action-note.is-success { color: #047857; }
.exam-action-note.is-error { color: #b91c1c; }
.exam-action-buttons {
  justify-content: flex-end;
}

@media (max-width: 980px) {
  .exam-summary-card {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .exam-page.exam-page-student {
    padding: 12px 12px 28px;
  }
  .student-question-card,
  .exam-summary-card,
  .exam-action-panel {
    border-radius: 20px;
  }
  .student-question-card {
    padding: 18px;
  }
  .question-card-headline,
  .exam-action-panel {
    flex-direction: column;
    align-items: stretch;
  }
  .student-question-card .question-title {
    font-size: 20px;
  }
  .student-question-card .question-stem,
  .option-card-text {
    font-size: 16px;
    line-height: 1.8;
  }
  .exam-action-buttons {
    width: 100%;
  }
  .exam-action-buttons .btn {
    flex: 1 1 0;
  }
}

@media (max-width: 480px) {
  .option-card {
    padding: 10px 8px;
  }
  .metric-item strong {
    font-size: 26px;
  }
}