:root {
  --bg: #f4f6fb;
  --panel: #ffffff;
  --panel-soft: #f8f9fd;
  --ink: #172033;
  --muted: #68738a;
  --line: #dfe5ef;
  --accent: #5b4bdb;
  --accent-strong: #4435bf;
  --accent-soft: #eeebff;
  --danger: #b9384f;
  --shadow: 0 18px 50px rgba(31, 41, 68, .10);
  --room-floor: #f4efe4;
  --room-grid: rgba(93, 76, 51, .16);
  --fixture: #3e526f;
  --fixture-soft: #e9eef5;
  --grid-cols: 8;
  --grid-rows: 8;
  --room-ratio: 1.6;
  --rail-size: clamp(38px, 4.8vw, 62px);
}

html[data-theme="dark"] {
  color-scheme: dark;
  --bg: #0f1420;
  --panel: #171e2c;
  --panel-soft: #1c2535;
  --ink: #eef1f7;
  --muted: #aeb8ca;
  --line: #34405a;
  --accent: #8d7cff;
  --accent-strong: #a899ff;
  --accent-soft: #2c2653;
  --danger: #ff889c;
  --shadow: 0 18px 50px rgba(0, 0, 0, .28);
  --room-floor: #232a34;
  --room-grid: rgba(229, 235, 245, .12);
  --fixture: #b8c7dd;
  --fixture-soft: #273244;
}

* { box-sizing: border-box; }
html { background: var(--bg); max-width: 100%; overflow-x: hidden; }
body {
  min-height: 100vh;
  max-width: 100%;
  overflow-x: hidden;
  background:
    radial-gradient(circle at 8% 12%, rgba(91,75,219,.08), transparent 26%),
    radial-gradient(circle at 92% 4%, rgba(32,196,182,.06), transparent 24%),
    var(--bg);
  color: var(--ink);
  font-family: "Nunito", ui-sans-serif, system-ui, sans-serif;
}

.app-shell {
  width: min(1540px, calc(100% - 24px));
  max-width: 100%;
  margin: 0 auto;
  padding: 20px 0 36px;
}

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  margin-bottom: 18px;
}

.brand-lockup { display: flex; align-items: center; gap: 14px; min-width: 0; }
.tool-badge {
  flex: 0 0 auto;
  width: 54px;
  height: 54px;
  display: grid;
  place-items: center;
  border-radius: 17px;
  background: linear-gradient(145deg, #7868ef, #4d3dc2);
  box-shadow: 0 9px 22px rgba(91,75,219,.28);
  font-size: 1.7rem;
}
.eyebrow {
  margin: 0 0 2px;
  color: var(--accent);
  font-family: "Fredoka", sans-serif;
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .12em;
  text-transform: uppercase;
}
h1, h2 { font-family: "Fredoka", sans-serif; }
h1 { margin: 0; font-size: clamp(1.55rem, 3vw, 2.25rem); line-height: 1; }
h2 { margin: 0; font-size: 1.38rem; }
.top-actions { display: flex; align-items: center; justify-content: flex-end; gap: 8px; min-width: 0; }
.icon-button {
  width: 42px;
  height: 42px;
  flex: 0 0 auto;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--panel);
  color: var(--ink);
  display: grid;
  place-items: center;
  font-size: 1rem;
}
.icon-button:hover, .soft-button:hover, .fixture-button:hover { border-color: var(--accent); }

.layout-grid {
  display: grid;
  grid-template-columns: minmax(255px, 315px) minmax(0, 1fr);
  gap: 18px;
  align-items: start;
  min-width: 0;
}
.panel { border: 1px solid var(--line); border-radius: 22px; background: var(--panel); box-shadow: var(--shadow); min-width: 0; }
.class-panel { padding: 20px; position: sticky; top: 14px; }
.plan-panel { padding: 20px; min-width: 0; overflow: hidden; }
.panel-heading { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-bottom: 15px; }
.count-pill, .plan-status {
  padding: 7px 10px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent-strong);
  font-size: .78rem;
  font-weight: 900;
  white-space: nowrap;
}
.field-label, .toolbar-label { display: block; margin-bottom: 6px; font-size: .78rem; font-weight: 900; color: var(--ink); }
textarea, select, input[type="text"], input[type="number"] {
  width: 100%;
  min-width: 0;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--panel-soft);
  color: var(--ink);
  outline: none;
}
textarea { resize: vertical; min-height: 190px; padding: 12px; line-height: 1.45; }
select, input[type="text"] { min-height: 40px; padding: 0 10px; }
input[type="number"] { min-height: 38px; padding: 0 8px; }
textarea:focus, select:focus, input:focus { border-color: var(--accent); box-shadow: 0 0 0 3px rgba(91,75,219,.12); }
.helper, .save-note { margin: 7px 0 0; color: var(--muted); font-size: .73rem; line-height: 1.4; }
.roster-warning { margin: 8px 0 0; color: var(--danger); font-size: .76rem; font-weight: 800; }

.saved-class-box, .saved-room-box {
  margin-top: 14px;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--panel-soft);
}
.saved-class-heading { display: flex; justify-content: space-between; gap: 10px; margin-bottom: 8px; font-size: .78rem; font-weight: 900; }
.saved-class-heading small { color: var(--muted); font-size: .67rem; font-weight: 700; }
.saved-class-row { display: grid; grid-template-columns: minmax(0,1fr) auto auto; gap: 6px; }
.saved-class-row + .saved-class-row { margin-top: 7px; }
.saved-class-row.save-row { grid-template-columns: minmax(0,1fr) auto; }

.soft-button, .fixture-button, .primary-button, .text-button {
  border-radius: 11px;
  font-weight: 900;
  transition: transform .14s ease, border-color .14s ease, background .14s ease;
}
.soft-button, .fixture-button {
  min-height: 38px;
  padding: 0 10px;
  border: 1px solid var(--line);
  background: var(--panel);
  color: var(--ink);
  font-size: .74rem;
}
.soft-button:active, .fixture-button:active, .primary-button:active { transform: translateY(1px); }
.primary-button { min-height: 40px; padding: 0 14px; border: 0; background: var(--accent); color: white; }
.danger-quiet { color: var(--danger); }
.text-button { border: 0; background: transparent; color: var(--accent); padding: 5px 7px; }
.compact-actions { display: grid; grid-template-columns: 1fr 1fr auto; gap: 7px; margin-top: 11px; }
.mobile-plan-jump { display: none; margin-top: 10px; }
.mobile-plan-jump .soft-button { width: 100%; }

.plan-heading { margin-bottom: 12px; }
.toolbars {
  display: grid;
  grid-template-columns: minmax(245px, 1.1fr) minmax(245px, .9fr) minmax(280px, 1.1fr);
  gap: 10px;
  min-width: 0;
}
.toolbar-group {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: end;
  gap: 8px;
  min-width: 0;
  padding: 10px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--panel-soft);
}
.toolbar-group .toolbar-label { grid-column: 1 / -1; margin: 0; color: var(--muted); }
.arrange-group { grid-template-columns: minmax(0,1fr) auto auto; }
.arrange-group .toolbar-label { grid-column: 1 / -1; }
.grid-size-group { grid-template-columns: minmax(78px,1fr) auto minmax(78px,1fr) auto; }
.grid-size-group .toolbar-label { grid-column: 1 / -1; }
.times-mark { align-self: center; padding-bottom: 9px; color: var(--muted); font-weight: 900; }
.colour-group { grid-template-columns: minmax(0,1fr) 42px auto; }
.colour-group .toolbar-label { grid-column: 1 / -1; }
.colour-input { width: 40px; height: 40px; padding: 3px; border: 1px solid var(--line); border-radius: 10px; background: var(--panel); }
.inline-number {
  display: grid;
  grid-template-columns: auto 54px;
  align-items: center;
  gap: 6px;
  color: var(--muted);
  font-size: .68rem;
  font-weight: 900;
  white-space: nowrap;
}
.inline-number input { width: 54px; }
.arrange-group .inline-number { grid-template-columns: auto 48px; }
.arrange-group .inline-number input { width: 48px; }

.room-tools {
  display: grid;
  grid-template-columns: minmax(210px, .65fr) minmax(0, 1.35fr);
  gap: 12px;
  align-items: center;
  margin-top: 10px;
  padding: 11px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--panel-soft);
}
.room-tool-copy { display: flex; flex-direction: column; gap: 2px; }
.room-tool-copy strong { font-family: "Fredoka", sans-serif; }
.room-tool-copy span { color: var(--muted); font-size: .72rem; line-height: 1.35; }
.room-tool-buttons { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 7px; }
.fixture-button { background: var(--panel); }

.saved-room-box { margin-top: 10px; }
.saved-room-heading { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin-bottom: 8px; }
.saved-room-heading > div { display: flex; flex-direction: column; gap: 1px; }
.saved-room-heading strong { font-family: "Fredoka", sans-serif; font-size: .86rem; }
.saved-room-heading span { color: var(--muted); font-size: .68rem; }
.saved-room-controls {
  display: grid;
  grid-template-columns: minmax(150px, 1fr) auto auto minmax(150px, 1fr) auto;
  gap: 7px;
  align-items: center;
}

.selection-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  margin-top: 10px;
  padding: 10px 12px;
  border: 1px solid var(--accent);
  border-radius: 14px;
  background: var(--accent-soft);
}
.selection-bar > div:first-child { display: flex; flex-direction: column; }
.selection-kicker { font-size: .62rem; text-transform: uppercase; letter-spacing: .1em; color: var(--muted); font-weight: 900; }
.student-colours, .fixture-selection-actions, .teacher-size-controls { display: flex; align-items: center; flex-wrap: wrap; gap: 7px; }
.colour-swatch { width: 27px; height: 27px; border-radius: 8px; border: 2px solid rgba(23,32,51,.12); background: var(--swatch); }
.fixture-selection { border-color: color-mix(in srgb, var(--fixture) 50%, var(--line)); }

.plan-instructions { display: flex; flex-wrap: wrap; gap: 10px 18px; padding: 10px 2px 8px; color: var(--muted); font-size: .72rem; font-weight: 800; }

/* The room always fits the plan panel: no horizontal scrolling. */
.room-scroll { width: 100%; min-width: 0; overflow: visible; padding: 2px 0 12px; }
.room-frame {
  width: 100%;
  min-width: 0;
  padding: 10px;
  border-radius: 18px;
  background: #7c6550;
  box-shadow: inset 0 0 0 3px rgba(255,255,255,.15);
}
.front-label {
  width: max-content;
  max-width: 70%;
  margin: 0 auto 8px;
  padding: 4px 18px;
  border-radius: 999px;
  background: #f8f9fd;
  color: #263244;
  font-family: "Bungee", sans-serif;
  font-size: .68rem;
  letter-spacing: .08em;
  box-shadow: 0 3px 0 rgba(0,0,0,.12);
}
.room-layout {
  width: 100%;
  min-width: 0;
  display: grid;
  grid-template-columns: var(--rail-size) minmax(0, 1fr) var(--rail-size);
  grid-template-rows: var(--rail-size) auto var(--rail-size);
  gap: 4px;
  align-items: stretch;
}
.top-rail { grid-column: 2; grid-row: 1; }
.bottom-rail { grid-column: 2; grid-row: 3; }
.left-rail { grid-column: 1; grid-row: 2; }
.right-rail { grid-column: 3; grid-row: 2; }
.classroom-grid { grid-column: 2; grid-row: 2; }
.perimeter-rail {
  min-width: 0;
  min-height: 0;
  display: grid;
  gap: 4px;
}
.perimeter-rail.horizontal { grid-template-columns: repeat(var(--grid-cols), minmax(0, 1fr)); }
.perimeter-rail.vertical { grid-template-rows: repeat(var(--grid-rows), minmax(0, 1fr)); }
.perimeter-cell {
  position: relative;
  min-width: 0;
  min-height: 0;
  border: 1px dashed rgba(255,255,255,.28);
  border-radius: 7px;
  background: rgba(255,255,255,.08);
  display: grid;
  place-items: stretch;
}
.perimeter-cell.drag-over { border-color: #ffffff; background: rgba(255,255,255,.19); }

.classroom-grid {
  position: relative;
  width: 100%;
  min-width: 0;
  min-height: 330px;
  aspect-ratio: var(--room-ratio);
  display: grid;
  grid-template-columns: repeat(var(--grid-cols), minmax(0, 1fr));
  grid-template-rows: repeat(var(--grid-rows), minmax(0, 1fr));
  gap: 4px;
  padding: 5px;
  border-radius: 10px;
  background: var(--room-floor);
  overflow: hidden;
}
.grid-cell {
  position: relative;
  min-width: 0;
  min-height: 0;
  border: 1px dashed rgba(93,76,51,.20);
  border-radius: 7px;
  transition: background .12s ease, border-color .12s ease;
}
.grid-cell.drag-over { border-color: var(--accent); background: rgba(91,75,219,.13); }
.grid-cell:focus-visible, .perimeter-cell:focus-visible { outline: 3px solid var(--accent); outline-offset: -2px; }

.room-item {
  position: relative;
  z-index: 3;
  width: 100%;
  height: 100%;
  min-width: 0;
  min-height: 0;
  border: 0;
  border-radius: 8px;
  padding: 4px 5px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 4px;
  text-align: center;
  overflow: hidden;
  font-family: "Fredoka", sans-serif;
  font-weight: 700;
  line-height: 1.05;
  box-shadow: 0 2px 6px rgba(29,36,54,.13);
  user-select: none;
  touch-action: manipulation;
  cursor: grab;
}
.room-item:active { cursor: grabbing; }
.room-item.selected { outline: 3px solid var(--accent); outline-offset: -1px; z-index: 5; }
.student-card {
  color: var(--student-ink, #243046);
  background: var(--student-colour, #dff1ff);
  font-size: clamp(.52rem, .76vw, .78rem);
  text-overflow: ellipsis;
}
.student-card span { min-width: 0; max-width: 100%; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.student-card::after {
  content: "";
  position: absolute;
  top: 3px;
  right: 3px;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: rgba(0,0,0,.2);
  opacity: 0;
  transition: opacity .12s ease;
}
.student-card:hover::after, .student-card.selected::after { opacity: 1; }
.fixture-card {
  background: var(--fixture-soft);
  color: var(--fixture);
  border: 1px solid color-mix(in srgb, var(--fixture) 28%, transparent);
  font-size: clamp(.5rem, .66vw, .68rem);
}
.teacher-card { z-index: 4; box-shadow: 0 4px 10px rgba(29,36,54,.18); }
.fixture-icon { flex: 0 0 auto; font-size: .95rem; }
.fixture-label { min-width: 0; overflow: hidden; text-overflow: ellipsis; }
.fixture-remove {
  position: absolute;
  top: 2px;
  right: 3px;
  width: 17px;
  height: 17px;
  display: grid;
  place-items: center;
  border: 0;
  border-radius: 50%;
  background: rgba(0,0,0,.12);
  color: inherit;
  opacity: 0;
  font-size: .68rem;
}
.fixture-card:hover .fixture-remove, .fixture-card.selected .fixture-remove { opacity: 1; }
.perimeter-rail.vertical .fixture-label { display: none; }
.perimeter-rail .fixture-card { padding: 2px; }
.perimeter-rail .fixture-icon { font-size: clamp(.72rem, 1.1vw, 1rem); }

.plan-footer-actions { display: flex; align-items: center; gap: 8px; margin-top: 2px; }
.autosave-note { margin-left: auto; color: var(--muted); font-size: .7rem; font-weight: 700; }
.toast {
  position: fixed;
  left: 50%;
  bottom: 22px;
  transform: translate(-50%, 18px);
  z-index: 30;
  max-width: min(90vw, 620px);
  padding: 10px 14px;
  border-radius: 999px;
  background: #172033;
  color: white;
  text-align: center;
  font-size: .78rem;
  font-weight: 800;
  opacity: 0;
  pointer-events: none;
  transition: opacity .18s ease, transform .18s ease;
  box-shadow: 0 10px 30px rgba(0,0,0,.22);
}
.toast.show { opacity: 1; transform: translate(-50%, 0); }

@media (max-width: 1220px) {
  .toolbars { grid-template-columns: 1fr 1fr; }
  .colour-group { grid-column: 1 / -1; }
  .room-tools { grid-template-columns: 1fr; }
  .room-tool-buttons { justify-content: flex-start; }
  .saved-room-controls { grid-template-columns: minmax(150px,1fr) auto auto; }
  .saved-room-controls #roomNameInput { grid-column: 1 / 3; }
}

@media (max-width: 900px) {
  .layout-grid { grid-template-columns: 255px minmax(0, 1fr); gap: 12px; }
  .toolbars { grid-template-columns: 1fr; }
  .colour-group { grid-column: auto; }
  :root { --rail-size: clamp(34px, 5.5vw, 50px); }
  .classroom-grid { min-height: 300px; }
}

@media (max-width: 760px) {
  .app-shell { width: min(100% - 12px, 1540px); padding-top: 12px; }
  .topbar { align-items: flex-start; gap: 10px; }
  .top-actions { flex-wrap: wrap; }
  .brand-lockup { gap: 10px; }
  .tool-badge { width: 46px; height: 46px; border-radius: 14px; }
  .layout-grid { grid-template-columns: 1fr; }
  .class-panel { position: static; }
  .mobile-plan-jump { display: block; }
  .plan-panel { padding: 12px; }
  .selection-bar { align-items: flex-start; flex-direction: column; }
  .plan-instructions { font-size: .66rem; }
  .room-frame { padding: 7px; }
  :root { --rail-size: clamp(30px, 9vw, 44px); }
  .classroom-grid { min-height: 285px; gap: 3px; padding: 4px; }
  .room-layout, .perimeter-rail { gap: 3px; }
  .autosave-note { display: none; }
  .saved-room-controls { grid-template-columns: 1fr 1fr; }
  .saved-room-controls select, .saved-room-controls #roomNameInput { grid-column: 1 / -1; }
  .saved-room-controls #roomNameInput { grid-column: 1 / -1; }
}

@media (max-width: 520px) {
  h1 { font-size: 1.3rem; }
  .header-nav-link { max-width: 112px; text-align: center; }
  .saved-class-row { grid-template-columns: 1fr 1fr; }
  .saved-class-row select { grid-column: 1 / -1; }
  .saved-class-row.save-row { grid-template-columns: 1fr; }
  .compact-actions { grid-template-columns: 1fr 1fr; }
  .compact-actions .danger-quiet { grid-column: 1 / -1; }
  .arrange-group { grid-template-columns: 1fr auto; }
  .arrange-group .inline-number { grid-column: 1 / -1; justify-self: start; }
  .grid-size-group { grid-template-columns: 1fr auto 1fr; }
  .grid-size-group .soft-button { grid-column: 1 / -1; }
  .room-tool-buttons { display: grid; grid-template-columns: 1fr 1fr; }
  .room-tool-buttons .danger-quiet { grid-column: 1 / -1; }
  .plan-footer-actions { flex-wrap: wrap; }
  .front-label { font-size: .57rem; padding: 4px 12px; }
  :root { --rail-size: 32px; }
  .classroom-grid { min-height: 260px; }
  .student-card { padding: 2px; font-size: .5rem; }
  .fixture-card { font-size: .48rem; }
  .fixture-label { display: none; }
}

@media print {
  @page { size: landscape; margin: 7mm; }
  body { background: white !important; overflow: visible !important; }
  .topbar, .class-panel, .toolbars, .room-tools, .saved-room-box, .selection-bar, .plan-instructions, .plan-footer-actions, .toast { display: none !important; }
  .app-shell { width: 100%; padding: 0; }
  .layout-grid { display: block; }
  .plan-panel { box-shadow: none; border: 0; padding: 0; overflow: visible; }
  .panel-heading { margin-bottom: 3mm; }
  .room-scroll { overflow: visible; }
  .room-frame { width: 100%; min-width: 0; break-inside: avoid; }
  .classroom-grid { min-height: 0; height: 155mm; aspect-ratio: auto; }
  .fixture-remove { display: none !important; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition: none !important; }
}