/* ─── Base ─────────────────────────────────────────────── */

body {
  background-color: #f5f6fa;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  color: #333;
}

/* ─── App Wrapper ───────────────────────────────────────── */

.app-wrapper {
  max-width: 1600px;
  margin: 0 auto;
  padding: 16px 20px;
}

/* ─── Header ────────────────────────────────────────────── */

.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 18px;
}

.app-title {
  margin: 0;
  font-size: 24px;
  font-weight: 700;
  color: #2c3e50;
  letter-spacing: -0.3px;
}

.app-subtitle {
  font-weight: 300;
  color: #7f8c8d;
  font-size: 20px;
}

/* ─── Stats badge ───────────────────────────────────────── */

.stats-badge {
  background: #fff;
  border: 1px solid #d5dce8;
  border-radius: 6px;
  padding: 8px 16px;
  font-size: 14px;
  display: flex;
  align-items: center;
  gap: 6px;
  box-shadow: 0 1px 3px rgba(0,0,0,0.06);
}

.stats-label {
  color: #7f8c8d;
  font-weight: 500;
}

.stats-value {
  font-weight: 700;
  color: #2c3e50;
  font-size: 15px;
}

.stats-sep {
  color: #ccc;
}

/* ─── Notification bar ──────────────────────────────────── */

.notification-bar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 9999;
  padding: 12px 20px;
  font-size: 14px;
  font-weight: 500;
  text-align: center;
  border-radius: 0;
  border: none;
  margin: 0;
  box-shadow: 0 2px 8px rgba(0,0,0,0.15);
  cursor: pointer;
}

/* ─── Cards ─────────────────────────────────────────────── */

.card {
  background: #fff;
  border: 1px solid #dde3ed;
  border-radius: 8px;
  box-shadow: 0 1px 4px rgba(0,0,0,0.06);
  margin-bottom: 16px;
  overflow: hidden;
}

.card-heading {
  background: #f7f9fc;
  border-bottom: 1px solid #dde3ed;
  padding: 10px 14px;
  font-size: 13px;
  font-weight: 600;
  color: #4a5568;
  letter-spacing: 0.2px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.card-hint {
  font-weight: 400;
  color: #a0aec0;
  font-size: 11px;
  margin-left: 6px;
}

.card-body {
  padding: 14px;
}

.full-height-card {
  height: calc(100% - 16px);
}

.table-card-body {
  padding: 0;
  overflow-x: auto;
}

/* ─── Slider section ────────────────────────────────────── */

.section-card .card-body .slider {
  margin-bottom: 30px;
  margin-top: 8px;
  width: 98%;
  float: none;
}

/* ─── Range controls ────────────────────────────────────── */

.range-controls {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  padding-top: 4px;
  clear: both;
}

.control-group {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 6px;
}

.control-label-sm {
  font-size: 12px;
  color: #7f8c8d;
  margin: 0;
  white-space: nowrap;
}

.control-input {
  width: 130px !important;
}

.control-input-narrow {
  width: 90px !important;
}

/* ─── Main content row ──────────────────────────────────── */

.main-content {
  margin-top: 0;
  margin-left: -8px;
  margin-right: -8px;
}

.main-content > [class*="col-"] {
  padding-left: 8px;
  padding-right: 8px;
}

/* ─── Textareas ─────────────────────────────────────────── */

.grade-textarea {
  width: 100%;
  resize: vertical;
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  font-size: 12px;
  line-height: 1.55;
  border: 1px solid #d5dce8;
  border-radius: 4px;
  padding: 8px 10px;
  background: #fafbfc;
  color: #2d3748;
  transition: border-color 0.15s;
  box-sizing: border-box;
}

.grade-textarea:focus {
  outline: none;
  border-color: #4a90d9;
  background: #fff;
  box-shadow: 0 0 0 2px rgba(74,144,217,0.15);
}

.result-textarea {
  background: #f7f9fc;
  color: #4a5568;
  cursor: default;
}

.result-textarea:disabled {
  opacity: 1;
}

.textarea-hint {
  font-size: 11px;
  color: #a0aec0;
  margin-top: 5px;
}

/* ─── Sample button ─────────────────────────────────────── */

.sample-btn {
  flex-shrink: 0;
}

/* ─── Grade distribution table ──────────────────────────── */

.grade-table {
  margin-bottom: 0;
  font-size: 12px;
}

.grade-table thead th {
  background: #f7f9fc;
  border-bottom: 2px solid #dde3ed;
  font-size: 11px;
  font-weight: 600;
  color: #718096;
  text-transform: uppercase;
  letter-spacing: 0.4px;
  padding: 8px 10px;
}

.grade-table tbody td {
  padding: 7px 10px;
  border-top: 1px solid #edf2f7;
  vertical-align: middle;
}

.grade-table tbody tr:first-child td {
  border-top: none;
}

/* ─── Chart ─────────────────────────────────────────────── */

.chartContainer {
  height: 260px;
  width: 100%;
}

/* ─── Footer ────────────────────────────────────────────── */

.app-footer {
  margin-top: 8px;
  padding: 14px 0;
  border-top: 1px solid #dde3ed;
  font-size: 12px;
  color: #a0aec0;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 6px;
}

.footer-link {
  color: #718096;
  text-decoration: none;
  cursor: pointer;
}

.footer-link:hover {
  color: #4a5568;
  text-decoration: underline;
}

.footer-sep {
  color: #d5dce8;
}

/* ─── Utility ───────────────────────────────────────────── */

.clickable {
  cursor: pointer;
}