:root {
  --bg: #f6f7f4;
  --panel: #ffffff;
  --ink: #1d2320;
  --muted: #68736d;
  --line: #dfe5df;
  --green: #2f6f55;
  --green-dark: #214f3d;
  --blue: #2f5f8f;
  --red: #b54747;
  --amber: #9a6a12;
  --shadow: 0 18px 45px rgba(38, 50, 44, 0.12);
}

* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: "Segoe UI", system-ui, sans-serif;
  color: var(--ink);
  background: radial-gradient(circle at top left, #eef5ed 0, var(--bg) 28rem);
}
a { color: inherit; text-decoration: none; }
button, input, select { font: inherit; }
button { cursor: pointer; }
.app-shell { min-height: 100vh; display: flex; }
.sidebar {
  width: 230px;
  padding: 24px 18px;
  background: #18231e;
  color: white;
  display: flex;
  flex-direction: column;
  gap: 28px;
}
.brand { display: flex; align-items: center; gap: 12px; }
.brand-mark {
  width: 42px; height: 42px; display: grid; place-items: center;
  border-radius: 8px; background: #d6eadc; color: #183127; font-weight: 800;
}
.brand small { display: block; color: #b9c8c0; margin-top: 4px; }
.sidebar nav { display: grid; gap: 8px; }
.sidebar nav a, .logout {
  padding: 11px 12px;
  border-radius: 8px;
  color: #dfe8e3;
}
.sidebar nav a.active, .sidebar nav a:hover, .logout:hover { background: rgba(255,255,255,0.1); }
.sidebar-footer {
  margin-top: auto;
  display: grid;
  gap: 10px;
  color: #aebdb5;
  font-size: 12px;
}
.logout { display: block; }
.main { flex: 1; padding: 32px; max-width: 1440px; margin: 0 auto; width: 100%; }
.page-header {
  display: flex; align-items: center; justify-content: space-between;
  gap: 18px; margin-bottom: 24px;
}
.page-header h1, .auth-panel h1 { margin: 0; font-size: 32px; letter-spacing: 0; }
.eyebrow { color: var(--green); text-transform: uppercase; font-size: 12px; font-weight: 800; letter-spacing: 0; margin-bottom: 6px; }
.panel, .metric, .auth-panel {
  background: rgba(255,255,255,0.94);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}
.panel { padding: 26px; }
.panel-heading { display: flex; justify-content: space-between; gap: 16px; align-items: baseline; margin-bottom: 22px; }
.panel-heading h2 { margin: 0; font-size: 20px; }
.panel-heading small, .muted { color: var(--muted); }
.panel-actions { display: flex; gap: 10px; align-items: center; }
.section-heading {
  border-left: 4px solid var(--green);
  padding-left: 12px;
  margin-bottom: 16px;
}
.section-heading.compact { margin-top: 18px; }
.section-heading h2 {
  margin: 0;
  font-size: 18px;
}
.section-heading p {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: 13px;
}
.metric-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; margin-bottom: 18px; }
.metric { padding: 18px; }
.metric span { color: var(--muted); display: block; }
.metric strong { font-size: 30px; display: block; margin-top: 8px; }
.content-grid { display: grid; grid-template-columns: minmax(0, 1fr) minmax(330px, 0.55fr); gap: 18px; align-items: start; }
.student-page-grid { display: grid; gap: 18px; align-items: start; }
.data-panel { margin-top: 18px; }
.data-grid { display: grid; grid-template-columns: minmax(280px, 0.6fr) minmax(0, 1fr); gap: 22px; align-items: start; }
.wizard-grid { display: grid; grid-template-columns: minmax(0, 1fr) 360px; gap: 18px; align-items: start; }
.result-grid { display: grid; grid-template-columns: minmax(0, 1fr) 380px; gap: 20px; align-items: start; }
.result-stack { display: grid; gap: 20px; }
.result-board-wrap { overflow-x: visible; padding-bottom: 6px; }
.result-detail-grid { display: grid; grid-template-columns: minmax(0, 1fr) minmax(280px, 0.45fr); gap: 18px; align-items: start; }
.history-grid { display: grid; gap: 20px; align-items: start; }
.history-detail { display: grid; gap: 20px; min-width: 0; }
.help-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 18px; align-items: start; }
.version-badge {
  display: inline-flex;
  align-items: center;
  min-height: 42px;
  padding: 10px 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #eef5f0;
  color: var(--green-dark);
  font-weight: 900;
}
.solver-status {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  align-items: center;
  margin: -10px 0 18px;
  color: var(--muted);
  font-size: 13px;
}
.solver-pill {
  display: inline-flex;
  align-items: center;
  min-height: 30px;
  padding: 5px 10px;
  border-radius: 999px;
  border: 1px solid var(--line);
  font-weight: 900;
}
.solver-pill.ok {
  border-color: #b6d9c7;
  background: #eaf6ef;
  color: var(--green-dark);
}
.solver-pill.fallback {
  border-color: #f2cf9a;
  background: #fff7e8;
  color: #8a5a08;
}
.sticky { position: sticky; top: 24px; }
.auth-screen { min-height: 100vh; display: grid; place-items: center; width: 100%; }
.auth-panel { width: min(440px, calc(100vw - 32px)); padding: 32px; }
.auth-panel p { color: var(--muted); }
.stack-form, .form-grid { display: grid; gap: 18px; }
.form-grid { grid-template-columns: repeat(4, minmax(120px, 1fr)) auto; align-items: end; }
.student-add-form { grid-template-columns: 180px minmax(220px, 1fr) 180px 160px auto; }
.student-bulk-form { grid-template-columns: minmax(120px, 1fr) minmax(140px, 1fr) auto; }
.admin-create-form { grid-template-columns: minmax(180px, 1fr) minmax(180px, 1fr) auto; }
.option-details {
  margin-top: 22px;
  border-top: 1px solid var(--line);
  padding-top: 18px;
}
.option-details summary {
  cursor: pointer;
  color: var(--green);
  font-weight: 800;
  width: fit-content;
}
.option-details form { margin-top: 14px; }
label { display: grid; gap: 8px; color: var(--muted); font-size: 13px; font-weight: 700; }
input, select {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px 11px;
  min-width: 0;
  background: white;
  color: var(--ink);
}
textarea {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px 11px;
  min-width: 0;
  background: white;
  color: var(--ink);
  resize: vertical;
}
.primary, .secondary, .ghost, button.mode {
  border: 0;
  border-radius: 8px;
  padding: 11px 16px;
  font-weight: 800;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
}
.primary { background: var(--green); color: white; }
.primary:hover { background: var(--green-dark); }
.secondary { background: #e7eee9; color: #1e3a2f; }
.ghost { background: transparent; border: 1px solid var(--line); color: var(--ink); }
.choice-button {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 11px 18px;
  min-height: 42px;
  background: #f8faf8;
  color: var(--ink);
  font-weight: 800;
}
.choice-button.selected {
  background: var(--green);
  border-color: var(--green);
  color: white;
}
.segmented-choice { align-items: center; }
.small { padding: 7px 9px; min-height: auto; }
.text-link { display: inline-block; margin-top: 18px; color: var(--green); font-weight: 700; }
.flash-stack { display: grid; gap: 10px; margin-bottom: 18px; }
.flash { padding: 12px 14px; border-radius: 8px; background: #e9f3ec; color: var(--green-dark); border: 1px solid #c9dfd0; }
.flash.error { background: #fff0f0; color: var(--red); border-color: #efc6c6; }
.table-wrap { overflow-x: visible; margin-bottom: 16px; }
table { width: 100%; border-collapse: collapse; }
th, td { padding: 10px; border-bottom: 1px solid var(--line); text-align: left; vertical-align: middle; }
th { color: var(--muted); font-size: 12px; }
.student-list-panel table { table-layout: fixed; }
.student-list-panel input, .student-list-panel select { width: 100%; }
.col-no { width: 64px; }
.col-gender { width: 130px; }
.col-group { width: 110px; }
.col-action { width: 86px; }
.hidden { display: none !important; }
.check-list { display: grid; gap: 10px; }
.check { padding: 12px; border-radius: 8px; border: 1px solid var(--line); display: grid; gap: 4px; }
.check strong { font-size: 14px; }
.check span { color: var(--muted); line-height: 1.55; white-space: normal; }
.check.ok { background: #edf7f0; border-color: #c7e2d0; }
.check.warn { background: #fff8e8; border-color: #efd28c; }
.check.danger { background: #fff1f1; border-color: #edc8c8; }
.manual-list {
  margin: 0;
  padding-left: 22px;
  display: grid;
  gap: 10px;
  line-height: 1.7;
  color: var(--ink);
}
.manual-block {
  display: grid;
  gap: 10px;
  color: var(--muted);
  line-height: 1.7;
}
.manual-block p { margin: 0; }
.action-list { display: grid; gap: 10px; }
.action-list a { padding: 13px; border: 1px solid var(--line); border-radius: 8px; background: #fafcfb; font-weight: 800; }
.history-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 10px;
}
.history-item {
  display: grid;
  gap: 5px;
  padding: 13px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fbfcfb;
}
.history-item strong { font-size: 14px; }
.history-item span, .history-item small { color: var(--muted); line-height: 1.4; }
.history-item.selected {
  border-color: var(--green);
  background: #edf7f0;
  box-shadow: inset 4px 0 0 var(--green);
}
.inline-reset-form {
  display: grid;
  grid-template-columns: minmax(180px, 1fr) auto;
  gap: 8px;
  align-items: center;
}
.status-ok {
  color: var(--green-dark);
  font-weight: 800;
}
.status-danger {
  color: var(--red);
  font-weight: 900;
}
.layout-toolbar, .mode-bar, .footer-actions, .choice-row {
  display: flex; flex-wrap: wrap; gap: 14px; align-items: end; margin-bottom: 22px;
}
.form-grid > button { align-self: end; margin-top: 20px; }
.footer-actions {
  margin-top: 24px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
}
.panel-heading + .footer-actions { margin-top: 0; }
.mode-bar { align-items: center; }
button.mode { background: #eef2ef; color: var(--ink); }
button.mode.active, .active-choice { outline: 2px solid var(--green); background: #e0efe6; }
.inline-control { display: flex; align-items: center; gap: 8px; }
.board-frame { margin-top: 24px; overflow-x: visible; }
.board-header-with-sides {
  display: grid;
  grid-template-columns: 32px minmax(0, 1fr) 32px;
  gap: 8px;
}
.board-with-sides {
  display: grid;
  grid-template-columns: 32px minmax(0, 1fr) 32px;
  gap: 8px;
  align-items: stretch;
}
.side-label {
  writing-mode: vertical-rl;
  text-orientation: upright;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 150px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #eef5f0;
  color: var(--green-dark);
  font-weight: 900;
  letter-spacing: 0;
}
.board-label {
  text-align: center;
  background: #27322d;
  color: white;
  border-radius: 8px;
  padding: 9px;
  margin-bottom: 16px;
  font-weight: 800;
}
.seat-board { display: grid; gap: 12px; min-width: 0; }
.car-block { border: 1px solid var(--line); border-radius: 8px; padding: 10px; background: #fbfcfb; min-width: 0; }
.car-block h3 { margin: 0 0 10px; font-size: 16px; text-align: center; color: var(--green-dark); }
.car-heading {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  margin-bottom: 10px;
}
.car-heading h3 { margin: 0; }
.car-row-tools { display: flex; gap: 4px; }
.car-row-tools button {
  border: 1px solid var(--line);
  background: white;
  border-radius: 6px;
  min-height: 26px;
  padding: 3px 7px;
  font-size: 12px;
}
.seat-row {
  display: grid;
  grid-template-columns: repeat(var(--seat-slots, 4), minmax(38px, 56px)) 42px;
  gap: 6px;
  align-items: center;
  justify-content: center;
  min-height: 58px;
  margin-bottom: 8px;
}
.seat-card {
  width: 100%; height: 48px; border-radius: 8px; border: 1px solid #cbd6d0;
  background: white; color: var(--ink); display: grid; place-items: center; gap: 0; padding: 5px;
}
.seat-card strong, .seat-card span, .seat-card em { max-width: 100%; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.seat-card span { color: var(--muted); font-size: 12px; }
.seat-card em { color: var(--muted); font-size: 12px; font-style: normal; }
.seat-card.disabled { opacity: 0.35; background: repeating-linear-gradient(45deg, #f0f0f0, #f0f0f0 6px, #fff 6px, #fff 12px); }
.gender-male { border-color: #9dc0df; background: #f2f8ff; }
.gender-female { border-color: #e5a8bb; background: #fff5f8; }
.row-tools { display: grid; gap: 3px; grid-template-columns: 1fr; }
.row-tools button { width: 40px; min-height: 23px; border: 1px solid var(--line); background: white; border-radius: 6px; font-size: 11px; }
.step-indicator { display: flex; gap: 6px; align-items: baseline; color: var(--green); font-weight: 900; }
#wizardStep h2 { font-size: 26px; margin: 12px 0 18px; }
.student-pills { display: flex; flex-wrap: wrap; gap: 8px; margin: 14px 0; }
.fixed-seat-editor {
  display: grid;
  grid-template-columns: minmax(180px, 0.7fr) minmax(220px, 1fr) auto;
  gap: 14px;
  align-items: end;
  margin: 14px 0 18px;
}
.fixed-seat-board-wrap {
  overflow-x: visible;
  margin: 14px 0;
  padding-bottom: 4px;
}
.fixed-seat-board {
  gap: 12px;
  min-width: 0;
}
.fixed-board-with-sides {
  grid-template-columns: 30px minmax(0, 1fr) 30px;
}
.fixed-board-with-sides .side-label {
  min-height: 120px;
  font-size: 12px;
}
.fixed-seat-board .car-block { padding: 10px; }
.fixed-seat-board .seat-row {
  grid-template-columns: repeat(var(--seat-slots, 4), minmax(36px, 52px));
  gap: 6px;
  min-height: 46px;
}
.fixed-seat-board .seat-card {
  width: 100%;
  height: 42px;
  padding: 4px;
}
.fixed-seat-board .seat-card strong { font-size: 12px; }
.fixed-seat-board .seat-card span { font-size: 10px; }
.fixed-select-seat.selected-seat {
  outline: 3px solid var(--green);
  border-color: var(--green);
  background: #edf7f0;
}
.selected-fixed-seat {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 10px 12px;
  background: #fbfcfb;
  display: grid;
  gap: 4px;
}
.selected-fixed-seat span { color: var(--muted); }
.pill {
  border: 1px solid var(--line);
  background: white;
  border-radius: 999px;
  padding: 9px 12px;
  color: var(--ink);
}
.pill.selected { background: var(--green); color: white; border-color: var(--green); }
.summary-list { display: grid; gap: 8px; }
.summary-item {
  display: grid; gap: 4px; padding: 11px; border: 1px solid var(--line);
  border-radius: 8px; background: #fbfcfb;
}
.summary-item span { color: var(--muted); }
.summary-item button { justify-self: start; }
.priority-control {
  max-width: 180px;
  margin-bottom: 10px;
}
.priority-badge {
  display: inline-flex;
  align-items: center;
  margin-left: 8px;
  padding: 2px 7px;
  border-radius: 999px;
  background: #e7eee9;
  color: var(--green-dark);
  font-size: 11px;
  font-weight: 800;
  vertical-align: middle;
}
.blocking { max-width: 760px; }
.result-seat.selected-seat { outline: 3px solid var(--blue); }
.result-unused-seat {
  cursor: default;
}
.result-board .result-unused-seat,
.history-board .result-unused-seat {
  border-style: dashed;
  border-color: #c2cbc5;
  background: repeating-linear-gradient(45deg, #f0f2f0, #f0f2f0 7px, #ffffff 7px, #ffffff 14px);
  color: #6f7a73;
  opacity: 0.72;
}
.result-board .result-unused-seat strong,
.history-board .result-unused-seat strong {
  font-size: 12px;
}
.result-board {
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  min-width: 0;
}
.result-board .car-block { min-width: 0; }
.result-board .seat-row { grid-template-columns: repeat(var(--seat-slots, 4), minmax(54px, 72px)); gap: 8px; min-height: 72px; }
.result-board .seat-card {
  width: 100%;
  height: 66px;
  align-content: center;
  gap: 2px;
}
.result-board .seat-card strong { font-size: 14px; }
.result-board .seat-card span { font-size: 11px; color: var(--muted); }
.history-board .seat-card { pointer-events: none; }
h3 { margin: 18px 0 10px; }
@media (max-width: 900px) {
  .app-shell { display: block; }
  .sidebar { width: 100%; flex-direction: row; align-items: center; overflow-x: auto; }
  .sidebar nav { display: flex; }
  .sidebar-footer { margin-top: 0; margin-left: auto; grid-auto-flow: column; align-items: center; }
  .main { padding: 20px; }
  .content-grid, .data-grid, .wizard-grid, .result-grid, .result-detail-grid, .metric-grid, .history-grid, .help-grid { grid-template-columns: 1fr; }
  .form-grid { grid-template-columns: 1fr; }
  .fixed-seat-editor { grid-template-columns: 1fr; }
  .form-grid > button { width: 100%; margin-top: 6px; }
  .footer-actions > * { flex: 1 1 180px; }
  .page-header { align-items: stretch; flex-direction: column; }
}