:root {
  --bg: #f6f4ef;
  --surface: #fffef9;
  --border: #d4cfc0;
  --text: #1c1b18;
  --muted: #5c574c;
  --accent: #1e4d6b;
  --accent-soft: #e8f0f5;
  --ok: #1f6b3a;
  --bad: #8b2c2c;
  --radius: 10px;
  --font: "Source Serif 4", "Georgia", serif;
  --font-ui: system-ui, -apple-system, "Segoe UI", sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-ui);
  font-size: 1rem;
  line-height: 1.5;
  color: var(--text);
  background: var(--bg);
  background-image: radial-gradient(ellipse 80% 50% at 50% -20%, #e2e9ef, transparent);
}

h1,
h2,
h3 {
  font-family: var(--font);
  font-weight: 600;
  line-height: 1.25;
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.wrap {
  max-width: 720px;
  margin: 0 auto;
  padding: 1.5rem 1.25rem 3rem;
}

header.site {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
  margin-bottom: 2rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border);
}

.badge {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--muted);
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem 1.35rem;
  margin-bottom: 1rem;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
}

.card h2 {
  margin: 0 0 0.5rem;
  font-size: 1.2rem;
}

.card p {
  margin: 0 0 0.75rem;
  color: var(--muted);
  font-size: 0.95rem;
}

.contact-welcome {
  background: linear-gradient(165deg, var(--surface) 0%, var(--accent-soft) 55%, #f0f5f8 100%);
  border: 1px solid var(--border);
  border-left: 4px solid var(--accent);
  box-shadow: 0 2px 12px rgba(30, 77, 107, 0.08);
}

.contact-welcome h2,
.contact-welcome .contact-welcome-title {
  margin: 0 0 0.5rem;
  color: var(--accent);
  font-size: 1.25rem;
  font-family: var(--font);
  font-weight: 600;
}

.contact-welcome p strong {
  color: var(--text);
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.student-signin-area .contact-welcome {
  margin-bottom: 1.25rem;
}

.login-custom-msg {
  margin-bottom: 1rem;
  border-left: 3px solid var(--accent);
  background: var(--surface);
}

.login-custom-msg-line {
  margin: 0 0 0.35rem;
  color: var(--text);
  font-size: 0.98rem;
  line-height: 1.45;
}

.login-custom-msg-line:last-child {
  margin-bottom: 0;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.35rem;
  padding: 0.5rem 1rem;
  font: inherit;
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: 8px;
  border: 1px solid var(--accent);
  background: var(--accent);
  color: #fff;
  cursor: pointer;
}

.btn:hover {
  filter: brightness(1.06);
  text-decoration: none;
}

.btn.secondary {
  background: var(--surface);
  color: var(--accent);
}

.btn.danger {
  border-color: var(--bad);
  background: #fff5f5;
  color: var(--bad);
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

label {
  display: block;
  font-weight: 600;
  font-size: 0.9rem;
  margin-bottom: 0.35rem;
}

input[type="text"],
input[type="password"],
input[type="number"],
input[type="datetime-local"],
textarea,
select {
  width: 100%;
  padding: 0.5rem 0.65rem;
  font: inherit;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fff;
}

textarea {
  min-height: 4.5rem;
  resize: vertical;
}

.field {
  margin-bottom: 1rem;
}

.question-block {
  border: 1px dashed var(--border);
  border-radius: var(--radius);
  padding: 1rem;
  margin-bottom: 1rem;
  background: #faf9f5;
}

.question-block h3 {
  margin: 0 0 0.75rem;
  font-size: 1rem;
}

.options-editor input {
  margin-bottom: 0.35rem;
}

.mc-options {
  list-style: none;
  padding: 0;
  margin: 0.5rem 0 0;
}

.mc-options li {
  margin-bottom: 0.5rem;
}

.mc-options label.opt {
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  font-weight: 400;
  cursor: pointer;
}

.mc-options input[type="radio"] {
  margin-top: 0.35rem;
  width: auto;
}

.prompt {
  font-family: var(--font);
  font-size: 1.05rem;
  margin-bottom: 0.75rem;
}

.result-row {
  padding: 0.75rem 0;
  border-bottom: 1px solid var(--border);
}

.result-row:last-child {
  border-bottom: none;
}

.tag {
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.15rem 0.45rem;
  border-radius: 4px;
}

.tag.ok {
  background: #e6f4ea;
  color: var(--ok);
}

.tag.bad {
  background: #fce8e8;
  color: var(--bad);
}

.score-big {
  font-family: var(--font);
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--accent);
  margin: 0.25rem 0;
}

.muted {
  color: var(--muted);
  font-size: 0.9rem;
}

.toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-items: center;
  margin-top: 0.75rem;
}

.flash {
  padding: 0.65rem 0.85rem;
  border-radius: 8px;
  margin-bottom: 1rem;
  font-size: 0.9rem;
}

.flash.err {
  background: #fce8e8;
  color: var(--bad);
}

.flash.ok {
  background: #e6f4ea;
  color: var(--ok);
}

@media (min-width: 640px) {
  .wrap {
    padding: 2rem 1.5rem 4rem;
  }
}

/* Exam countdown — full width, sticky so it stays visible while scrolling questions */
.exam-timer-strip {
  position: sticky;
  top: 0;
  z-index: 100;
  max-width: 720px;
  margin: 0 auto;
  padding: 0.85rem 1.25rem;
  background: var(--accent-soft);
  border: 1px solid var(--accent);
  border-radius: 0 0 var(--radius) var(--radius);
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

.exam-timer-digits {
  font-family: var(--font-ui);
  font-size: 1.65rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  color: var(--accent);
  letter-spacing: 0.02em;
}

.exam-dialog {
  max-width: 420px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem 1.35rem;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.15);
}

.exam-dialog::backdrop {
  background: rgba(0, 0, 0, 0.35);
}

/* ——— Admin layout ——— */
.admin-page .admin-wrap {
  max-width: 1040px;
}

.admin-site {
  margin-bottom: 1.25rem;
}

.admin-header-links {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.admin-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  position: sticky;
  top: 0;
  z-index: 50;
  padding: 0.5rem 0 0.75rem;
  margin-bottom: 0.5rem;
  background: var(--bg);
  background-image: radial-gradient(ellipse 80% 50% at 50% -20%, #e2e9ef, transparent);
  border-bottom: 1px solid var(--border);
}

.admin-tab {
  padding: 0.45rem 0.85rem;
  font: inherit;
  font-size: 0.9rem;
  font-weight: 600;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
  color: var(--muted);
  cursor: pointer;
}

.admin-tab:hover {
  color: var(--accent);
  border-color: var(--accent);
}

.admin-tab.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.admin-panel {
  display: none;
}

.admin-panel.active {
  display: block;
}

.admin-flash {
  position: sticky;
  top: 3.1rem;
  z-index: 40;
  margin-top: 0;
}

.admin-stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(7.5rem, 1fr));
  gap: 0.65rem;
}

.admin-stat {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.75rem 0.85rem;
  text-align: center;
}

.admin-stat-val {
  display: block;
  font-family: var(--font);
  font-size: 1.65rem;
  font-weight: 700;
  color: var(--accent);
  line-height: 1.1;
}

.admin-stat-label {
  display: block;
  font-size: 0.78rem;
  color: var(--muted);
  margin-top: 0.2rem;
}

.admin-stat--warn .admin-stat-val {
  color: var(--bad);
}

.admin-hint {
  margin: 1rem 0 0;
  font-size: 0.9rem;
}

.admin-split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  align-items: start;
}

.admin-card-compact h2 {
  margin: 0 0 0.25rem;
}

.admin-card-lead {
  margin: 0 0 0.85rem !important;
  font-size: 0.88rem !important;
}

.admin-form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.65rem 0.85rem;
}

.admin-form-row--narrow {
  grid-template-columns: minmax(6rem, 8rem) 1fr;
  align-items: end;
}

.admin-form-row .field {
  margin-bottom: 0.65rem;
}

.admin-field-action {
  display: flex;
  align-items: flex-end;
  padding-bottom: 0.65rem;
}

.admin-field-action .btn {
  width: 100%;
}

.admin-list-scroll {
  margin-top: 0.75rem;
  max-height: 22rem;
  overflow-y: auto;
  border-top: 1px solid var(--border);
}

.admin-list-compact {
  margin-top: 0.5rem;
  max-height: 14rem;
  overflow-y: auto;
}

.admin-stu-toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  margin: 0.75rem 0;
}

.admin-view-toggle {
  display: inline-flex;
  border: 1px solid var(--border);
  border-radius: 999px;
  overflow: hidden;
  background: var(--surface);
}

.admin-view-btn {
  padding: 0.4rem 0.85rem;
  font: inherit;
  font-size: 0.85rem;
  font-weight: 600;
  border: none;
  background: transparent;
  color: var(--muted);
  cursor: pointer;
}

.admin-view-btn:hover {
  color: var(--accent);
}

.admin-view-btn.active {
  background: var(--accent-soft);
  color: var(--accent);
}

.admin-stu-focus-detail {
  margin-top: 0.5rem;
  padding-top: 0.75rem;
  border-top: 1px solid var(--border);
}

.admin-stu-meta {
  margin: 0 0 0.75rem;
  font-size: 0.88rem;
  color: var(--muted);
  line-height: 1.45;
}

.admin-stu-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.admin-section-title {
  font-family: var(--font);
  font-size: 1.1rem;
  margin: 0.5rem 0 0.75rem;
}

.admin-subhead {
  font-family: var(--font);
  font-size: 1.05rem;
  margin: 0 0 0.35rem;
}

.admin-divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 1rem 0;
}

.admin-toolbar-tight {
  margin-top: 0.5rem;
}

.admin-exam-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(14rem, 1fr));
  gap: 0.65rem;
  margin-bottom: 1rem;
}

.admin-exam-card {
  margin-bottom: 0;
  padding: 0.9rem 1rem;
}

.admin-exam-card h2 {
  font-size: 1rem;
  margin: 0 0 0.25rem;
}

.admin-exam-card p {
  font-size: 0.85rem;
  margin: 0 0 0.65rem;
}

.admin-exam-card .btn {
  width: 100%;
  font-size: 0.85rem;
  padding: 0.4rem 0.65rem;
}

.admin-details {
  margin-bottom: 0.65rem;
}

.admin-details summary {
  font-family: var(--font);
  font-size: 1.05rem;
  font-weight: 600;
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.admin-details summary::-webkit-details-marker {
  display: none;
}

.admin-details summary::before {
  content: "▸";
  color: var(--accent);
  font-size: 0.85rem;
  transition: transform 0.15s ease;
}

.admin-details[open] summary::before {
  transform: rotate(90deg);
}

.admin-details-body {
  margin-top: 0.85rem;
  padding-top: 0.85rem;
  border-top: 1px solid var(--border);
}

.admin-create-bar .admin-form-row {
  grid-template-columns: 1fr 1fr auto;
  align-items: end;
}

.admin-tag-ref-card {
  margin-top: 1rem;
}

.admin-tag-ref-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(17rem, 1fr));
  gap: 0.65rem;
}

.admin-tag-ref-section {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.75rem 0.85rem;
  background: #faf9f5;
}

.admin-tag-ref-section h3 {
  margin: 0 0 0.35rem;
  font-family: var(--font);
  font-size: 0.95rem;
  color: var(--accent);
}

.admin-tag-ref-rule {
  margin: 0 0 0.5rem;
  font-size: 0.82rem;
  color: var(--muted);
  line-height: 1.4;
}

.admin-tag-ref-list {
  margin: 0;
  padding-left: 1.1rem;
  font-size: 0.82rem;
  line-height: 1.45;
  color: var(--text);
}

.admin-tag-ref-list li {
  margin-bottom: 0.2rem;
}

.admin-tag-ref-examples {
  margin: 0.5rem 0 0;
  padding: 0.45rem 0.55rem;
  font-size: 0.8rem;
  background: var(--surface);
  border-radius: 6px;
  border: 1px dashed var(--border);
  color: var(--muted);
  line-height: 1.4;
}

.admin-tag-ref-examples strong {
  color: var(--text);
  font-size: 0.78rem;
}

.admin-tag-ref-hints {
  margin: 0.35rem 0 0;
  font-size: 0.78rem;
  color: var(--muted);
}

.admin-tag-card {
  margin-top: 0.65rem;
}

.admin-tag-report {
  overflow-x: auto;
}

.admin-tag-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
}

.admin-tag-table th,
.admin-tag-table td {
  padding: 0.45rem 0.55rem;
  text-align: left;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}

.admin-tag-table th {
  font-size: 0.8rem;
  color: var(--muted);
  font-weight: 600;
}

.admin-tag-nums {
  font-variant-numeric: tabular-nums;
  font-weight: 600;
}

.admin-tag-nums.ok {
  color: var(--ok);
}

.admin-tag-nums.bad {
  color: var(--bad);
}

.admin-tag-missing-list {
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 0.85rem;
  color: var(--muted);
  line-height: 1.45;
}

.admin-tag-missing-list li {
  margin-bottom: 0.2rem;
}

.admin-tag-missing-list strong {
  color: var(--text);
}

@media (max-width: 800px) {
  .admin-split {
    grid-template-columns: 1fr;
  }

  .admin-create-bar .admin-form-row {
    grid-template-columns: 1fr;
  }

  .admin-form-row--narrow {
    grid-template-columns: 1fr;
  }

  .admin-field-action {
    padding-bottom: 0;
  }
}

@media (max-width: 480px) {
  .exam-timer-digits {
    font-size: 1.35rem;
  }
  .exam-timer-strip {
    padding: 0.6rem 0.85rem;
  }
  .admin-table {
    display: block;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
  }
}


/* ——— STEM, Geometry & Figure Styles ——— */
.stem-diagram {
  display: block;
  max-width: 100%;
  max-height: 380px;
  margin: 0.75rem auto;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #ffffff;
  padding: 0.5rem;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.05);
  cursor: zoom-in;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

.stem-diagram:hover {
  transform: scale(1.01);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.katex-display {
  overflow-x: auto;
  overflow-y: hidden;
  padding: 0.5rem 0;
}

/* Figure / Image Options (for NVR, 3D nets, geometry, circuits) */
.stem-figure-options {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 0.75rem;
  margin: 1rem 0;
  list-style: none;
  padding: 0;
}

.stem-figure-card {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  border: 2px solid var(--border);
  border-radius: 8px;
  background: #ffffff;
  padding: 0.6rem;
  cursor: pointer;
  transition: border-color 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.stem-figure-card:hover {
  border-color: var(--accent);
  background: var(--accent-soft);
}

.stem-figure-card input[type="radio"] {
  position: absolute;
  top: 0.5rem;
  left: 0.5rem;
  margin: 0;
}

.stem-figure-card.selected {
  border-color: var(--accent);
  background: #e8f3fa;
  box-shadow: 0 0 0 2px var(--accent);
}

.stem-figure-label {
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--accent);
  margin-top: 0.35rem;
}

.stem-figure-img {
  max-width: 100%;
  max-height: 120px;
  object-fit: contain;
  margin-top: 1rem;
}

/* Lightbox Modal for Diagram inspection */
.stem-modal {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 9999;
  align-items: center;
  justify-content: center;
}

.stem-modal.active {
  display: flex;
}

.stem-modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.75);
  backdrop-filter: blur(2px);
}

.stem-modal-content {
  position: relative;
  z-index: 10;
  background: #ffffff;
  padding: 1.5rem;
  border-radius: 12px;
  max-width: 90vw;
  max-height: 90vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
}

.stem-modal-content img {
  max-width: 85vw;
  max-height: 75vh;
  object-fit: contain;
}

.stem-modal-close {
  position: absolute;
  top: 0.5rem;
  right: 0.75rem;
  background: none;
  border: none;
  font-size: 2rem;
  line-height: 1;
  color: #333;
  cursor: pointer;
}

.stem-modal-caption {
  margin: 0.75rem 0 0;
  font-size: 0.9rem;
  color: var(--muted);
}

/* Stage & Subject Filter Badges */
.taxonomy-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 1rem;
}

.taxonomy-pill {
  padding: 0.3rem 0.75rem;
  font-size: 0.85rem;
  font-weight: 600;
  border: 1px solid var(--border);
  border-radius: 20px;
  background: var(--surface);
  cursor: pointer;
  transition: all 0.15s ease;
}

.taxonomy-pill:hover,
.taxonomy-pill.active {
  background: var(--accent);
  color: #ffffff;
  border-color: var(--accent);
}

.stage-badge {
  display: inline-block;
  padding: 0.15rem 0.5rem;
  border-radius: 4px;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  margin-right: 0.35rem;
}

.stage-badge.KS2 { background: #e0f2fe; color: #0369a1; }
.stage-badge.KS3 { background: #f0fdf4; color: #15803d; }
.stage-badge.KS4 { background: #f3e8ff; color: #7e22ce; }
.stage-badge.KS5 { background: #fef3c7; color: #b45309; }