/* ==========================================================================
   IELTS Exam Platform — Design tokens
   ========================================================================== */
:root {
  --bg: #F3F5F8;
  --surface: #FFFFFF;
  --surface-raised: #FFFFFF;
  --ink: #16202E;
  --ink-soft: #5B6472;
  --ink-faint: #8B93A1;
  --border: #E2E6EC;
  --border-strong: #C9D0DA;
  --accent: #2455D8;
  --accent-ink: #14349C;
  --accent-soft: #E9EFFE;
  --warn: #B3441E;
  --warn-soft: #FBEAE3;
  --success: #1D7A46;
  --success-soft: #E5F4EC;

  --font-sans: 'IBM Plex Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'IBM Plex Mono', 'SFMono-Regular', Consolas, monospace;

  --radius: 8px;
  --radius-sm: 5px;
  --shadow-panel: 0 1px 2px rgba(22, 32, 46, 0.06), 0 8px 24px rgba(22, 32, 46, 0.04);
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}
h1, h2, h3, h4 { font-family: var(--font-sans); font-weight: 600; margin: 0; }
p { margin: 0 0 0.6em; }
button { font-family: inherit; cursor: pointer; }
input, select { font-family: inherit; font-size: inherit; }
a { color: var(--accent); }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.hidden { display: none !important; }

/* ==========================================================================
   Screens
   ========================================================================== */
.screen { min-height: 100vh; }

/* ---- Candidate intake screen ---- */
#candidate-screen {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 32px 16px;
}
.intake-card {
  width: 100%;
  max-width: 460px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-panel);
  padding: 36px 32px 28px;
}
.intake-eyebrow {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 8px;
}
.intake-card h1 { font-size: 22px; margin-bottom: 4px; }
.intake-sub { color: var(--ink-soft); font-size: 13.5px; margin-bottom: 24px; }
.field { margin-bottom: 16px; }
.field label {
  display: block;
  font-size: 12.5px;
  font-weight: 600;
  color: var(--ink-soft);
  margin-bottom: 6px;
}
.field input {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  background: #fff;
  color: var(--ink);
}
.field input:focus { border-color: var(--accent); }
.field-error {
  font-size: 12px;
  color: var(--warn);
  margin-top: 4px;
  display: none;
}
.field.has-error input { border-color: var(--warn); }
.field.has-error .field-error { display: block; }
.test-meta-row {
  display: flex;
  gap: 16px;
  margin: 20px 0 24px;
  padding: 14px 16px;
  background: var(--accent-soft);
  border-radius: var(--radius-sm);
  font-size: 13px;
  color: var(--accent-ink);
}
.test-meta-row div strong { display: block; font-family: var(--font-mono); font-size: 15px; }
.btn-primary {
  width: 100%;
  padding: 12px 16px;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 14.5px;
  transition: background 0.15s ease;
}
.btn-primary:hover { background: var(--accent-ink); }
.btn-primary:disabled { background: var(--ink-faint); cursor: not-allowed; }
.btn-secondary {
  padding: 10px 16px;
  background: #fff;
  color: var(--ink);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 13.5px;
}
.btn-secondary:hover { border-color: var(--ink-faint); }

/* ==========================================================================
   Exam chrome (header / timer / question navigator)
   ========================================================================== */
#exam-screen { display: flex; flex-direction: column; }

.exam-topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 10px 20px;
  background: var(--ink);
  color: #fff;
}
.exam-topbar .brand {
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 0.02em;
  display: flex;
  align-items: center;
  gap: 8px;
}
.exam-topbar .brand .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--accent); }
.candidate-chip {
  font-size: 12.5px;
  color: #C7CEDB;
}
.timer {
  font-family: var(--font-mono);
  font-size: 16px;
  font-weight: 600;
  padding: 5px 12px;
  border-radius: var(--radius-sm);
  background: rgba(255,255,255,0.08);
}
.timer.warn { background: var(--warn); color: #fff; }

.exam-audio-bar {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 20px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}
.audio-status {
  font-family: var(--font-mono);
  font-size: 12.5px;
  color: var(--ink-soft);
}
.audio-missing-note {
  font-size: 12px;
  color: var(--warn);
  background: var(--warn-soft);
  padding: 6px 10px;
  border-radius: var(--radius-sm);
}

.exam-body {
  flex: 1;
  display: grid;
  grid-template-columns: 1fr 240px;
  gap: 0;
  max-width: 1180px;
  width: 100%;
  margin: 0 auto;
}

.exam-main {
  padding: 24px 28px 100px;
  min-width: 0;
}

.part-tabs {
  display: flex;
  gap: 6px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}
.part-tab {
  padding: 7px 14px;
  border-radius: 999px;
  border: 1px solid var(--border-strong);
  background: #fff;
  font-size: 13px;
  font-weight: 600;
  color: var(--ink-soft);
}
.part-tab.active { background: var(--accent); border-color: var(--accent); color: #fff; }

.part-panel { display: none; }
.part-panel.active { display: block; }

.part-header { margin-bottom: 18px; }
.part-header h2 {
  font-size: 17px;
  display: flex;
  align-items: baseline;
  gap: 8px;
}
.part-header h2 .range { font-family: var(--font-mono); font-size: 13px; color: var(--accent); font-weight: 600; }
.part-instructions {
  white-space: pre-line;
  color: var(--ink-soft);
  font-size: 13.5px;
  font-style: italic;
  margin-top: 6px;
}

.block { margin-bottom: 30px; }
.block-instructions {
  white-space: pre-line;
  font-size: 13.5px;
  font-style: italic;
  color: var(--ink-soft);
  margin-bottom: 10px;
}
.block-prompt { font-weight: 600; margin-bottom: 10px; }

.q-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 22px;
  height: 22px;
  padding: 0 5px;
  border-radius: 5px;
  background: var(--accent-soft);
  color: var(--accent-ink);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  margin-right: 6px;
}

/* blanks (inline text inputs) */
.blank-input {
  font-family: var(--font-mono);
  font-size: 13.5px;
  border: none;
  border-bottom: 2px solid var(--border-strong);
  background: var(--accent-soft);
  border-radius: 4px 4px 0 0;
  padding: 3px 6px;
  width: 118px;
  color: var(--ink);
}
.blank-input:focus { border-bottom-color: var(--accent); background: #fff; box-shadow: 0 0 0 1px var(--accent-soft); }
.blank-input.answered { border-bottom-color: var(--success); }

/* table completion */
.ielts-table { width: 100%; border-collapse: collapse; font-size: 13.5px; }
.ielts-table th, .ielts-table td {
  border: 1px solid var(--border);
  padding: 8px 10px;
  vertical-align: top;
  text-align: left;
}
.ielts-table th { background: var(--bg); font-size: 12.5px; text-transform: uppercase; letter-spacing: 0.03em; color: var(--ink-soft); }
.ielts-table caption {
  caption-side: top;
  text-align: left;
  font-weight: 700;
  padding-bottom: 8px;
  font-size: 14px;
}
.cell-line { white-space: pre-line; }

/* multi select (choose two letters) */
.option-list { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 6px; }
.option-list li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: #fff;
}
.option-list li.selected { border-color: var(--accent); background: var(--accent-soft); }
.option-list input { margin-top: 3px; }
.option-letter { font-family: var(--font-mono); font-weight: 700; color: var(--accent-ink); width: 16px; flex-shrink: 0; }
.select-limit-note { font-size: 12px; color: var(--ink-faint); margin-top: 6px; }
.select-limit-note.warn { color: var(--warn); }

/* labeling / map */
.diagram-wrap { display: flex; gap: 24px; flex-wrap: wrap; align-items: flex-start; margin-bottom: 14px; }
.diagram-svg-box { border: 1px solid var(--border); border-radius: var(--radius-sm); background: #fff; padding: 12px; flex-shrink: 0; }
.labeling-items { flex: 1; min-width: 220px; display: flex; flex-direction: column; gap: 8px; }
.labeling-item { display: flex; align-items: center; gap: 10px; }
.labeling-item .label-text { flex: 1; font-size: 13.5px; }
.letter-select {
  font-family: var(--font-mono);
  font-weight: 700;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  padding: 6px 8px;
  background: var(--accent-soft);
  color: var(--ink);
  width: 66px;
}
.letter-select.answered { border-color: var(--success); }

/* flowchart */
.flow-box {
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
  margin-bottom: 14px;
  background: var(--bg);
}
.flow-box .flow-box-title { font-weight: 700; font-size: 12.5px; text-transform: uppercase; letter-spacing: 0.03em; color: var(--ink-soft); margin-bottom: 8px; }
.flow-option { font-size: 13.5px; margin-bottom: 4px; }
.flow-title { font-weight: 600; margin-bottom: 12px; }
.flow-steps { display: flex; flex-direction: column; align-items: center; }
.flow-step {
  width: 100%;
  max-width: 420px;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: #fff;
}
.flow-step .flow-label { flex: 1; font-size: 13.5px; }
.flow-arrow { font-family: var(--font-mono); color: var(--ink-faint); padding: 4px 0; }

/* notes completion */
.notes-heading { font-weight: 700; margin-bottom: 12px; }
.notes-section { margin-bottom: 14px; }
.notes-subheading { font-weight: 600; font-size: 13.5px; margin-bottom: 6px; color: var(--accent-ink); }
.notes-intro { font-size: 13.5px; margin-bottom: 6px; }
.notes-bullets { list-style: none; margin: 0; padding: 0; }
.notes-bullets li { position: relative; padding-left: 16px; font-size: 13.5px; margin-bottom: 7px; }
.notes-bullets li::before { content: "•"; position: absolute; left: 0; color: var(--ink-faint); }

/* ==========================================================================
   Question navigator (sidebar)
   ========================================================================== */
.nav-sidebar {
  border-left: 1px solid var(--border);
  background: var(--surface);
  padding: 20px 16px;
  position: sticky;
  top: 89px;
  align-self: start;
  height: calc(100vh - 89px);
  overflow-y: auto;
}
.nav-sidebar h3 { font-size: 12.5px; text-transform: uppercase; letter-spacing: 0.04em; color: var(--ink-soft); margin-bottom: 4px; }
.nav-progress { font-family: var(--font-mono); font-size: 20px; font-weight: 700; margin-bottom: 12px; }
.nav-progress span { font-size: 13px; color: var(--ink-faint); font-weight: 500; }
.nav-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 6px; margin-bottom: 18px; }
.nav-cell {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  height: 30px;
  border-radius: 5px;
  border: 1px solid var(--border-strong);
  background: #fff;
  color: var(--ink-soft);
}
.nav-cell.answered { background: var(--success-soft); border-color: var(--success); color: var(--success); }
.nav-cell.current { outline: 2px solid var(--accent); outline-offset: 1px; }
.nav-submit-note { font-size: 12px; color: var(--ink-faint); margin-bottom: 12px; line-height: 1.5; }

/* ==========================================================================
   Submit bar / review / confirmation
   ========================================================================== */
.exam-footer {
  position: sticky;
  bottom: 0;
  z-index: 15;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 20px;
  background: var(--surface);
  border-top: 1px solid var(--border);
  grid-column: 1 / -1;
}
.footer-status { font-size: 12.5px; color: var(--ink-soft); }
.footer-actions { display: flex; gap: 10px; }

#submit-screen {
  display: flex; align-items: center; justify-content: center; padding: 32px 16px;
}
.result-card {
  max-width: 480px; width: 100%;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-panel);
  padding: 36px 32px;
  text-align: center;
}
.result-icon {
  width: 46px; height: 46px; border-radius: 50%;
  background: var(--success-soft); color: var(--success);
  display: flex; align-items: center; justify-content: center;
  margin: 0 auto 16px; font-size: 22px; font-weight: 700;
}
.result-icon.error { background: var(--warn-soft); color: var(--warn); }
.result-card h2 { margin-bottom: 8px; }
.result-card p { color: var(--ink-soft); font-size: 13.5px; }
.result-meta {
  margin-top: 18px; padding: 12px 14px; background: var(--bg); border-radius: var(--radius-sm);
  font-family: var(--font-mono); font-size: 12.5px; color: var(--ink-soft); text-align: left;
}

/* ==========================================================================
   Responsive
   ========================================================================== */
@media (max-width: 860px) {
  .exam-body { grid-template-columns: 1fr; }
  .nav-sidebar {
    position: static; height: auto; border-left: none; border-top: 1px solid var(--border);
  }
  .nav-grid { grid-template-columns: repeat(8, 1fr); }
  .exam-main { padding: 18px 16px 90px; }
}
@media (max-width: 520px) {
  .diagram-wrap { flex-direction: column; }
  .nav-grid { grid-template-columns: repeat(6, 1fr); }
  .exam-topbar { flex-wrap: wrap; }
  .blank-input { width: 100px; }
}