/* checker.css — AI Checker page styles.
   Follows theme.css design tokens and typeface stack. */

.checker-page {
  min-height: calc(100vh - 65px);
  background: var(--bg);
  padding: 48px 48px 80px;
  max-width: 1400px;
  margin: 0 auto;
}

/* Header */
.checker-header {
  margin-bottom: 32px;
}
.checker-header h1 {
  font-size: 38px;
  font-weight: 700;
  margin: 8px 0 12px;
  letter-spacing: -0.02em;
}
.subhead {
  font-size: 16px;
  color: var(--ink-2);
  max-width: 580px;
  line-height: 1.65;
}

/* Exam selector */
.exam-selector {
  display: flex;
  gap: 20px;
  margin-bottom: 32px;
}
.selector-group { display: flex; flex-direction: column; gap: 6px; }
.selector-group label {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink-3);
}
.selector-group select {
  padding: 10px 36px 10px 14px;
  font-size: 14px;
  font-family: 'DM Sans', sans-serif;
  border: 1.5px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
  color: var(--ink);
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%239CA3AF' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round' fill='none'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  min-width: 160px;
}
.selector-group select:focus {
  outline: none;
  border-color: var(--amber);
  box-shadow: 0 0 0 3px rgba(245,158,11,0.15);
}

/* Split panel */
.split-panel {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
  align-items: start;
}

.panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 28px;
}

.panel-label {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-3);
  margin-bottom: 20px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border);
}

/* Upload zone */
.upload-zone {
  border: 2px dashed var(--border);
  border-radius: 12px;
  padding: 40px 24px;
  text-align: center;
  cursor: pointer;
  transition: border-color 0.2s, background 0.2s;
}
.upload-zone:hover, .upload-zone.drag-over {
  border-color: var(--amber);
  background: var(--amber-light);
}
.upload-icon { margin-bottom: 16px; }
.upload-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--ink);
  margin-bottom: 6px;
}
.upload-sub { font-size: 13px; color: var(--ink-3); margin-bottom: 20px; }
.btn-upload {
  display: inline-block;
  padding: 10px 24px;
  background: var(--ink);
  color: #fff;
  border: none;
  border-radius: 8px;
  font-size: 14px;
  font-family: 'DM Sans', sans-serif;
  font-weight: 500;
  cursor: pointer;
  transition: background 0.2s;
}
.btn-upload:hover { background: #374151; }

/* PDF preview */
.preview-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}
.preview-filename {
  font-size: 13px;
  font-weight: 500;
  color: var(--ink-2);
}
.btn-clear {
  display: flex;
  align-items: center;
  gap: 4px;
  font-size: 12px;
  color: var(--red);
  background: none;
  border: none;
  cursor: pointer;
  font-family: 'DM Sans', sans-serif;
  padding: 4px 8px;
  border-radius: 6px;
  transition: background 0.15s;
}
.btn-clear:hover { background: #FEE2E2; }

#pdf-canvas {
  width: 100%;
  border-radius: 8px;
  display: block;
  border: 1px solid var(--border);
  margin-bottom: 12px;
}

.page-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-bottom: 20px;
}
.btn-page {
  width: 32px;
  height: 32px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--surface);
  cursor: pointer;
  font-size: 14px;
  color: var(--ink);
  transition: border-color 0.15s;
}
.btn-page:hover:not(:disabled) { border-color: var(--amber); }
.btn-page:disabled { opacity: 0.35; cursor: default; }
.page-indicator { font-size: 13px; color: var(--ink-2); }

/* Extracted text block */
.extracted-label {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  font-weight: 600;
  color: var(--green);
  margin-bottom: 8px;
}
.answer-textarea {
  width: 100%;
  min-height: 160px;
  padding: 12px 14px;
  font-family: 'DM Sans', sans-serif;
  font-size: 13px;
  line-height: 1.65;
  color: var(--ink);
  background: var(--bg);
  border: 1.5px solid var(--border);
  border-radius: 8px;
  resize: vertical;
  box-sizing: border-box;
}
.answer-textarea:focus {
  outline: none;
  border-color: var(--amber);
  box-shadow: 0 0 0 3px rgba(245,158,11,0.12);
}
.edit-note { font-size: 12px; color: var(--ink-3); margin-top: 6px; }

/* Extract error */
.extract-error {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 16px;
  background: #FEF2F2;
  border: 1px solid #FECACA;
  border-radius: 10px;
  color: var(--red);
}
.extract-error svg { flex-shrink: 0; }
.extract-error p { font-size: 14px; color: var(--ink-2); line-height: 1.5; }

/* Check button */
.btn-check {
  width: 100%;
  padding: 14px;
  margin-top: 20px;
  background: var(--amber);
  color: var(--ink);
  border: none;
  border-radius: 10px;
  font-size: 15px;
  font-weight: 600;
  font-family: 'DM Sans', sans-serif;
  cursor: pointer;
  transition: background 0.2s, opacity 0.2s;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}
.btn-check:hover:not(:disabled) { background: #D97706; }
.btn-check:disabled { opacity: 0.45; cursor: not-allowed; }
.btn-check-loading { display: flex; align-items: center; gap: 8px; }

.spinner {
  animation: spin 0.8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* Right panel — AI Feedback */
.panel-right { min-height: 500px; }

/* Empty state */
.feedback-empty {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 60px 24px;
  text-align: center;
  gap: 12px;
}
.empty-icon { margin-bottom: 4px; }
.empty-title { font-size: 15px; font-weight: 600; color: var(--ink-2); }
.empty-sub { font-size: 13px; color: var(--ink-3); }

/* Loading */
.feedback-loading {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 60px 24px;
  gap: 16px;
}
.loading-inner { text-align: center; }
.loading-bar {
  width: 120px;
  height: 4px;
  background: var(--border);
  border-radius: 4px;
  overflow: hidden;
  margin-bottom: 16px;
}
.loading-bar::after {
  content: '';
  display: block;
  height: 100%;
  width: 40%;
  background: var(--amber);
  border-radius: 4px;
  animation: loading-slide 1.2s ease-in-out infinite;
}
@keyframes loading-slide {
  0% { transform: translateX(-100%); }
  100% { transform: translateX(350%); }
}
.loading-label { font-size: 15px; font-weight: 600; color: var(--ink); margin-bottom: 4px; }
.loading-sub { font-size: 13px; color: var(--ink-3); }

/* Results */
.feedback-result { display: flex; flex-direction: column; gap: 20px; }

/* Score banner */
.score-banner {
  display: flex;
  align-items: center;
  gap: 20px;
  padding: 20px;
  background: linear-gradient(135deg, #1a1a2e 0%, #2d2d4a 100%);
  border-radius: 12px;
}
.score-big {
  font-family: 'Playfair Display', serif;
  font-size: 40px;
  font-weight: 700;
  color: var(--amber);
  letter-spacing: -0.02em;
}
.score-details { display: flex; flex-direction: column; gap: 4px; }
.score-pct {
  font-size: 20px;
  font-weight: 600;
  color: #fff;
}
.score-band {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.45);
}
.result-summary {
  font-size: 15px;
  color: var(--ink-2);
  line-height: 1.6;
  font-style: italic;
}

/* Feedback grid */
.feedback-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
.feedback-col {
  padding: 16px;
  border-radius: 10px;
}
.col-success { background: #F0FDF4; border: 1px solid #BBF7D0; }
.col-warning { background: #FFFBEB; border: 1px solid #FDE68A; }
.col-header {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--ink-2);
  margin-bottom: 12px;
}
.feedback-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.feedback-list li {
  font-size: 13px;
  color: var(--ink-2);
  line-height: 1.5;
  padding-left: 14px;
  position: relative;
}
.col-success .feedback-list li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--green);
  font-weight: 700;
}
.col-warning .feedback-list li::before {
  content: '→';
  position: absolute;
  left: 0;
  color: var(--amber);
  font-weight: 700;
}

/* Detailed feedback */
.feedback-detail-box {
  padding: 16px;
  background: var(--bg);
  border-radius: 10px;
  border: 1px solid var(--border);
}
.feedback-detail-label {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-3);
  margin-bottom: 8px;
}
.feedback-detail-box p {
  font-size: 14px;
  color: var(--ink-2);
  line-height: 1.65;
}

/* Tip */
.feedback-tip {
  padding: 14px 16px;
  background: var(--amber-light);
  border: 1px solid #FDE68A;
  border-radius: 10px;
}
.tip-label {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--amber);
  margin-bottom: 6px;
}
.feedback-tip p {
  font-size: 14px;
  color: var(--ink);
  line-height: 1.55;
  font-weight: 500;
}

/* Actions */
.result-actions { padding-top: 4px; }
.btn-check-another {
  width: 100%;
  padding: 11px;
  background: transparent;
  color: var(--ink-2);
  border: 1.5px solid var(--border);
  border-radius: 8px;
  font-size: 14px;
  font-family: 'DM Sans', sans-serif;
  font-weight: 500;
  cursor: pointer;
  transition: border-color 0.2s, background 0.2s;
}
.btn-check-another:hover {
  border-color: var(--amber);
  background: var(--amber-light);
}

/* Responsive */
@media (max-width: 900px) {
  .checker-page { padding: 32px 24px 60px; }
  .split-panel { grid-template-columns: 1fr; }
  .feedback-grid { grid-template-columns: 1fr; }
  .exam-selector { flex-wrap: wrap; }
}