.modern-body {
  --bg: #f3f7f5;
  --ink: #15252d;
  --muted: #5c6e74;
  --panel: #ffffff;
  --line: #d3dfdc;
  --soft: #e7efec;
  --cell: #ffffff;
  --cell-alt: #f1f6f4;
  --accent: #087f78;
  --accent-2: #d9614e;
  --accent-3: #3b659c;
  --surface: #ffffff;
  --surface-soft: #f5f9f7;
  --given: #14242c;
  --selected: #ccebe5;
  --related: #e8f0ed;
  --same-number: #dce9fb;
  --board-line: #15252d;
  --button-bg: #15252d;
  --button-ink: #ffffff;
  --texture: rgba(8, 127, 120, .035);
  --top-sheen: rgba(255, 255, 255, .86);
  --panel-bg: rgba(255, 255, 255, .96);
  --shadow: 0 12px 30px rgba(21, 37, 45, .08);
}

html[data-theme="dark"] .modern-body {
  --bg: #10191c;
  --ink: #edf5f3;
  --muted: #a3b4b4;
  --panel: #192427;
  --line: #344548;
  --soft: #223034;
  --cell: #1a2629;
  --cell-alt: #213034;
  --surface: #1d292d;
  --surface-soft: #192528;
  --given: #f2f8f6;
  --selected: #235a55;
  --related: #29383b;
  --same-number: #263f62;
  --board-line: #83a09b;
  --button-bg: #ecf5f2;
  --button-ink: #142326;
  --panel-bg: rgba(25, 36, 39, .97);
  --shadow: 0 14px 36px rgba(0, 0, 0, .25);
}

.modern-body {
  background: var(--bg);
}

.modern-app {
  width: min(1320px, 100%);
  padding-top: max(18px, env(safe-area-inset-top));
}

.modern-app .topbar {
  width: min(1166px, 100%);
  min-height: 60px;
  margin: 0 auto 24px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
}

.modern-app h1 {
  font-size: 2rem;
  font-weight: 850;
}

.modern-app .brand {
  gap: 10px;
}

.modern-app .mark {
  border-color: var(--accent);
  background: var(--panel);
  box-shadow: none;
}

.modern-app .mark span:nth-child(2) { background: var(--accent); }
.modern-app .mark span:nth-child(4) { background: var(--accent-3); }

.modern-app .brand p {
  margin-top: 4px;
  font-size: .92rem;
  font-weight: 650;
}

.modern-app .icon-button,
.modern-app .select-wrap select {
  border: 0;
  box-shadow: none;
}

.modern-app .top-actions {
  gap: 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
}

.modern-app .top-actions > * + * {
  border-left: 1px solid var(--line);
}

.modern-app .top-actions > * {
  flex: 0 0 auto;
}

.modern-app .top-actions .select-wrap select {
  background: transparent;
}

.modern-app .top-actions .icon-button:hover {
  background: var(--soft);
}

.modern-app .game-shell {
  gap: 28px;
}

.modern-app .panel {
  border-color: var(--line);
  box-shadow: none;
  border-radius: 8px;
}

.modern-app .control-panel {
  border-top: 2px solid var(--accent);
}

.modern-app .assistant-panel {
  border-top: 2px solid var(--accent);
}

.modern-app .field select,
.modern-app .stat-grid > div,
.modern-app .text-button.secondary {
  background: var(--surface);
}

.modern-app .stat-grid > div {
  min-height: 72px;
}

.modern-app .board {
  border-radius: 8px;
  border-width: 2px;
  box-shadow: 0 16px 32px rgba(21, 37, 45, .12);
}

.modern-app .cell {
  font-weight: 800;
  background: var(--cell);
}

.modern-app .cell:nth-child(6n + 1) {
  background: var(--cell);
}

.modern-app .cell.box-right {
  border-right-width: 2px;
}

.modern-app .cell.box-bottom {
  border-bottom-width: 2px;
}

.modern-app .cell.selected {
  box-shadow: inset 0 0 0 3px var(--accent);
}

.modern-app .number-button {
  border-color: var(--line);
  box-shadow: none;
}

.modern-app .number-button:hover,
.modern-app .icon-button:hover,
.modern-app .text-button:hover:not(:disabled) {
  border-color: var(--accent);
}

.modern-app .toggle-row {
  border-color: var(--line);
  background: var(--soft);
}

.modern-app .segmented.active {
  box-shadow: 0 2px 8px rgba(21, 37, 45, .12);
}

.modern-app .undo-button {
  color: var(--accent);
}

.modern-app .digit-row .bar span {
  background: var(--accent);
}

.modern-app .toast,
.modern-app .dialog {
  box-shadow: var(--shadow);
}

@media (min-width: 1201px) {
  .modern-app .game-shell {
    grid-template-columns: 260px var(--board-size) 260px;
    justify-content: center;
  }

  .modern-app .control-panel,
  .modern-app .assistant-panel {
    margin-top: 34px;
  }
}

@media (max-width: 1200px) {
  .modern-app .topbar {
    width: 100%;
  }
}

@media (max-width: 560px) {
  .modern-app .topbar {
    margin-bottom: 16px;
    padding-bottom: 12px;
  }

  .modern-app .panel {
    padding: 12px;
  }
}

@media (max-width: 320px) {
  .modern-app .topbar {
    flex-wrap: wrap;
    align-items: center;
  }

  .modern-app .top-actions {
    margin-left: auto;
  }
}