:root {
  color-scheme: light;
  --bg: #f4f6f8;
  --surface: #ffffff;
  --surface-strong: #eef2f4;
  --ink: #182024;
  --muted: #64727a;
  --line: #cbd5db;
  --accent: #176c72;
  --accent-strong: #0f5157;
  --danger: #b33a3a;
  --warning: #b26b13;
  --seat: #f8fbfc;
  --aisle: #ece7dc;
  --free: #dfe7ec;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--ink);
}

button,
input,
select {
  font: inherit;
}

button {
  border: 0;
  cursor: pointer;
}

button:disabled,
input:disabled,
select:disabled {
  cursor: not-allowed;
  opacity: 0.55;
}

.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 18px clamp(16px, 4vw, 36px);
  background: #ffffff;
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 10;
}

.app-header h1 {
  margin: 2px 0 0;
  font-size: clamp(1.35rem, 2.2vw, 2rem);
  line-height: 1.1;
  font-weight: 750;
}

.eyebrow {
  margin: 0;
  color: var(--muted);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0;
  font-weight: 700;
}

.header-actions,
.control-group {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}

.app-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(300px, 360px);
  gap: 18px;
  padding: 18px clamp(12px, 3vw, 32px) 28px;
}

.workspace,
.side-panel {
  min-width: 0;
}

.toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 12px;
}

.primary-button,
.ghost-button,
.danger-button,
.icon-button,
.segment {
  min-height: 38px;
  border-radius: 8px;
  padding: 0 13px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  white-space: nowrap;
  border: 1px solid transparent;
}

.primary-button {
  color: #ffffff;
  background: var(--accent);
}

.primary-button:hover {
  background: var(--accent-strong);
}

.ghost-button,
.icon-button {
  background: #ffffff;
  border-color: var(--line);
  color: var(--ink);
}

.ghost-button:hover,
.icon-button:hover {
  background: var(--surface-strong);
}

.danger-button {
  width: 100%;
  color: #ffffff;
  background: var(--danger);
}

.form-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

.form-actions .ghost-button,
.form-actions .danger-button {
  width: 100%;
  min-height: 40px;
}

.segmented {
  display: inline-flex;
  gap: 4px;
  padding: 4px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #ffffff;
}

.segment {
  min-height: 32px;
  background: transparent;
  color: var(--muted);
  padding: 0 10px;
}

.segment.active {
  color: #ffffff;
  background: var(--accent);
}

.status-pill {
  min-height: 36px;
  display: inline-flex;
  align-items: center;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #ffffff;
  color: var(--muted);
  padding: 0 12px;
  font-size: 0.92rem;
}

.grid-frame {
  overflow: auto;
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: clamp(10px, 2vw, 16px);
}

.seat-grid {
  display: grid;
  gap: 8px;
  min-width: min-content;
}

.grid-cell {
  width: 100%;
  min-width: 68px;
  min-height: 58px;
  aspect-ratio: 1.08 / 0.82;
  border-radius: 8px;
  border: 1px solid var(--line);
  background: var(--free);
  color: var(--ink);
  padding: 6px;
  display: grid;
  grid-template-rows: auto 1fr auto;
  align-items: stretch;
  position: relative;
  text-align: left;
  overflow: hidden;
}

.grid-cell:hover {
  border-color: var(--accent);
}

.grid-cell[draggable="true"] {
  cursor: grab;
}

.grid-cell.dragging {
  opacity: 0.56;
}

.grid-cell.drop-target {
  outline: 3px solid rgba(23, 108, 114, 0.38);
  border-color: var(--accent);
}

.grid-cell.quality-satisfied {
  border-color: #2b8a4b;
  box-shadow: inset 0 0 0 2px rgba(43, 138, 75, 0.25);
}

.grid-cell.quality-warning {
  border-color: #c28a13;
  box-shadow: inset 0 0 0 2px rgba(194, 138, 19, 0.28);
}

.grid-cell.quality-violated {
  border-color: #c73535;
  box-shadow: inset 0 0 0 2px rgba(199, 53, 53, 0.3);
}

.grid-cell.selected {
  outline: 3px solid rgba(23, 108, 114, 0.28);
}

.grid-cell.seat {
  background: var(--seat);
}

.grid-cell.aisle {
  background: var(--aisle);
  color: #7a6344;
  align-items: center;
  text-align: center;
}

.grid-cell.empty {
  background: var(--free);
  border-style: dashed;
}

.cell-colors {
  display: flex;
  gap: 4px;
  min-height: 8px;
}

.color-dot {
  width: 20px;
  height: 7px;
  border-radius: 999px;
  border: 1px solid rgba(0, 0, 0, 0.18);
  background: transparent;
}

.color-dot.far {
  background: var(--far-color);
}

.color-dot.near {
  background: var(--near-color);
}

.cell-name {
  align-self: center;
  font-weight: 750;
  line-height: 1.15;
  word-break: break-word;
  overflow-wrap: anywhere;
}

.cell-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 4px;
  color: var(--muted);
  font-size: 0.76rem;
  min-height: 18px;
}

.cell-tags {
  display: inline-flex;
  gap: 3px;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.quality-icons {
  position: absolute;
  top: 5px;
  right: 5px;
  display: inline-flex;
  gap: 3px;
}

.quality-icons span {
  min-width: 18px;
  height: 18px;
  display: inline-grid;
  place-items: center;
  border-radius: 999px;
  border: 1px solid rgba(0, 0, 0, 0.2);
  background: #ffffff;
  color: #9b2424;
  font-size: 0.78rem;
  font-weight: 850;
  line-height: 1;
}

.mini-tag {
  border: 1px solid var(--line);
  border-radius: 5px;
  padding: 0 4px;
  background: #ffffff;
  color: #445058;
  line-height: 1.35;
}

.side-panel {
  display: grid;
  gap: 14px;
  align-content: start;
}

.panel-section {
  background: #ffffff;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 14px;
}

.section-heading {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 10px;
  margin-bottom: 12px;
}

.section-heading h2 {
  margin: 0;
  font-size: 1.05rem;
}

.section-heading span {
  color: var(--muted);
  font-size: 0.86rem;
}

.student-form {
  display: grid;
  gap: 12px;
}

.student-form[hidden],
.empty-selection[hidden] {
  display: none;
}

label {
  display: grid;
  gap: 6px;
  color: #344148;
  font-size: 0.88rem;
  font-weight: 650;
}

input[type="text"],
input[type="password"],
input[type="number"],
select {
  width: 100%;
  min-height: 38px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #ffffff;
  color: var(--ink);
  padding: 0 10px;
}

input[type="checkbox"] {
  width: 17px;
  height: 17px;
  accent-color: var(--accent);
}

.form-grid {
  display: grid;
  gap: 10px;
}

.form-grid.two {
  grid-template-columns: 1fr 1fr;
}

.toggle-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 14px;
}

.toggle-row.stacked {
  display: grid;
}

.toggle-row label,
.color-control {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 650;
}

.color-grid {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 8px;
  align-items: center;
}

.color-control {
  min-height: 40px;
  justify-content: space-between;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 0 8px 0 10px;
}

.color-control span {
  min-width: 0;
}

input[type="color"] {
  width: 34px;
  height: 28px;
  border: 0;
  background: transparent;
  padding: 0;
}

.advanced-settings {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #ffffff;
  overflow: hidden;
}

.advanced-settings summary {
  min-height: 40px;
  display: flex;
  align-items: center;
  padding: 0 10px;
  color: #344148;
  font-weight: 750;
  cursor: pointer;
  user-select: none;
}

.advanced-settings[open] summary {
  border-bottom: 1px solid var(--line);
  background: var(--surface-strong);
}

.advanced-settings-body {
  display: grid;
  gap: 12px;
  padding: 12px;
}

.advanced-hint {
  color: var(--muted);
  font-size: 0.86rem;
  line-height: 1.4;
}

.weight-control {
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 6px 10px;
}

.weight-control span {
  min-width: 0;
}

.weight-control input[type="range"] {
  grid-column: 1 / -1;
  width: 100%;
  accent-color: var(--accent);
}

.weight-control output {
  color: var(--muted);
  font-variant-numeric: tabular-nums;
  font-weight: 750;
}

.empty-selection,
.metrics,
.message-area,
.autosave-status {
  color: var(--muted);
  font-size: 0.92rem;
  line-height: 1.45;
}

.autosave-status {
  padding: 8px 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface-strong);
}

.metrics {
  display: grid;
  gap: 6px;
  margin-top: 12px;
  padding-top: 12px;
  border-top: 1px solid var(--line);
}

.quality-summary {
  display: grid;
  gap: 8px;
  padding: 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #ffffff;
}

.quality-headline {
  font-size: 1rem;
  font-weight: 800;
  color: var(--ink);
}

.quality-group {
  display: grid;
  gap: 2px;
}

.quality-group strong {
  font-size: 0.82rem;
}

.quality-group.satisfied strong {
  color: #237344;
}

.quality-group.partial strong {
  color: #a3650f;
}

.quality-group.violated strong {
  color: var(--danger);
}

.metric-row {
  display: flex;
  justify-content: space-between;
  gap: 10px;
}

.metric-row strong {
  color: var(--ink);
}

.message-area {
  min-height: 26px;
  margin-top: 10px;
}

.message-area.error {
  color: var(--danger);
}

.message-area.success {
  color: #1d6a45;
}

@media (max-width: 980px) {
  .app-shell {
    grid-template-columns: 1fr;
  }

  .side-panel {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 700px) {
  .app-header {
    position: static;
    align-items: stretch;
    flex-direction: column;
  }

  .header-actions,
  .control-group,
  .toolbar {
    align-items: stretch;
  }

  .header-actions > *,
  .control-group > * {
    flex: 1 1 132px;
  }

  .segmented,
  .side-panel {
    width: 100%;
  }

  .segment {
    flex: 1;
  }

  .side-panel {
    grid-template-columns: 1fr;
  }

  .form-grid.two {
    grid-template-columns: 1fr;
  }

  .form-actions {
    grid-template-columns: 1fr;
  }
}