*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --color-bg: #f0f4f8;
  --color-surface: #ffffff;
  --color-border: #d1dae6;
  --color-primary: #2563eb;
  --color-primary-hover: #1d4ed8;
  --color-secondary: #64748b;
  --color-secondary-hover: #475569;
  --color-human: #7c3aed;
  --color-human-bg: #f5f3ff;
  --color-human-border: #c4b5fd;
  --color-success: #16a34a;
  --color-coin-heads: #f59e0b;
  --color-coin-tails: #6b7280;
  --color-coin-heads-text: #92400e;
  --color-coin-tails-text: #ffffff;
  --color-customer-row: #fef3c7;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--color-bg);
  color: #1e293b;
  min-height: 100vh;
  padding: 1.5rem;
}

/* ── Header ─────────────────────────────────────────────── */
header {
  text-align: center;
  margin-bottom: 1.5rem;
  position: relative;
}

.header-logo {
  position: absolute;
  top: 50%;
  right: 0;
  transform: translateY(-50%);
  height: 80px;
  width: auto;
}

header h1 {
  font-size: 2rem;
  font-weight: 700;
  color: #0f172a;
}

.subtitle {
  color: var(--color-secondary);
  margin-top: 0.25rem;
  font-size: 0.95rem;
}

/* ── Controls ────────────────────────────────────────────── */
.controls {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 10px;
  padding: 0.875rem 1.25rem;
  margin-bottom: 1.25rem;
  gap: 1rem;
  flex-wrap: wrap;
}

.controls-label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.batch-buttons {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.game-buttons {
  display: flex;
  gap: 0.5rem;
}

button {
  cursor: pointer;
  border: none;
  border-radius: 6px;
  font-size: 0.875rem;
  font-weight: 600;
  padding: 0.5rem 1rem;
  transition: background 0.15s, opacity 0.15s;
}

button:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.btn-batch {
  background: var(--color-bg);
  border: 2px solid var(--color-border);
  color: var(--color-secondary);
}

.btn-batch:hover:not(:disabled) {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.btn-batch.active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: #fff;
}

.controls-divider {
  width: 1px;
  height: 1.5rem;
  background: var(--color-border);
  align-self: center;
  margin: 0 0.25rem;
}

.btn-mode {
  background: var(--color-bg);
  border: 2px solid var(--color-border);
  color: var(--color-secondary);
}

.btn-mode:hover:not(:disabled) {
  border-color: var(--color-human);
  color: var(--color-human);
}

.btn-mode.active {
  background: var(--color-human);
  border-color: var(--color-human);
  color: #fff;
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
}

.btn-primary:hover:not(:disabled) {
  background: var(--color-primary-hover);
}

.btn-secondary {
  background: var(--color-bg);
  border: 2px solid var(--color-border);
  color: var(--color-secondary);
}

.btn-secondary:hover:not(:disabled) {
  background: #e2e8f0;
}

/* ── Board ───────────────────────────────────────────────── */
.board {
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
  overflow-x: auto;
  padding-bottom: 0.5rem;
}

.section-arrow {
  font-size: 1.5rem;
  color: var(--color-secondary);
  padding-top: 3.5rem;
  flex-shrink: 0;
}

/* ── Section ─────────────────────────────────────────────── */
.section {
  flex: 1;
  min-width: 160px;
  background: var(--color-surface);
  border: 2px solid var(--color-border);
  border-radius: 10px;
  padding: 0.875rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.section-human {
  border-color: var(--color-human-border);
  background: var(--color-human-bg);
}

.section.section-active {
  box-shadow: 0 0 0 2px var(--color-primary);
}

.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.section-title {
  font-weight: 700;
  font-size: 0.9rem;
}

.section-badge {
  font-size: 0.7rem;
  font-weight: 700;
  padding: 0.2rem 0.5rem;
  border-radius: 99px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.section-badge.auto {
  background: #e0f2fe;
  color: #0369a1;
}

.section-badge.human {
  background: #ede9fe;
  color: var(--color-human);
}

/* ── Coin Grid ───────────────────────────────────────────── */
.coin-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 4px;
  min-height: 100px;
}

/* ── Coin ────────────────────────────────────────────────── */
.coin {
  aspect-ratio: 1;
  border-radius: 50%;
  background: var(--color-coin-heads);
  color: var(--color-coin-heads-text);
  font-size: 0.65rem;
  font-weight: 800;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: default;
  user-select: none;
  transition: transform 0.3s ease;
  transform-style: preserve-3d;
  position: relative;
}

.coin.clickable {
  cursor: pointer;
  box-shadow: 0 2px 4px rgba(0,0,0,0.15);
}

.coin.clickable:hover {
  transform: scale(1.1);
  box-shadow: 0 4px 8px rgba(0,0,0,0.2);
}

.coin.flipped {
  background: var(--color-coin-tails);
  color: var(--color-coin-tails-text);
}

.coin.flipping {
  animation: flip 0.3s ease;
}

@keyframes flip {
  0%   { transform: rotateY(0deg) scale(1); }
  50%  { transform: rotateY(90deg) scale(0.8); }
  100% { transform: rotateY(0deg) scale(1); }
}

.coin.clickable.flipped:hover {
  transform: scale(1.1);
}

/* ── Section Footer ──────────────────────────────────────── */
.section-footer {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.flip-count {
  font-size: 0.78rem;
  color: var(--color-secondary);
  text-align: center;
}

.btn-move {
  width: 100%;
  background: var(--color-success);
  color: #fff;
  font-size: 0.78rem;
  padding: 0.4rem 0.5rem;
  border-radius: 6px;
}

.btn-move:hover:not(:disabled) {
  background: #15803d;
}

.btn-move:disabled {
  background: #d1fae5;
  color: #6ee7b7;
  cursor: not-allowed;
  opacity: 1;
}

.btn-hidden {
  visibility: hidden;
}

/* ── Modal ───────────────────────────────────────────────── */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
}

.modal-overlay.hidden {
  display: none;
}

.modal {
  background: var(--color-surface);
  border-radius: 12px;
  width: 560px;
  max-width: 90vw;
  max-height: 85vh;
  overflow-y: auto;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.25);
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem 1.5rem;
  border-bottom: 1px solid var(--color-border);
}

.modal-header h2 {
  font-size: 1.25rem;
  font-weight: 700;
  color: #0f172a;
}

.modal-close {
  background: none;
  border: none;
  font-size: 1.5rem;
  line-height: 1;
  color: var(--color-secondary);
  cursor: pointer;
  padding: 0.25rem 0.5rem;
  border-radius: 4px;
}

.modal-close:hover {
  background: var(--color-bg);
  color: #0f172a;
}

.modal-body {
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.modal-body h3 {
  font-size: 0.9rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-primary);
  margin-bottom: 0.25rem;
}

.modal-body p,
.modal-body ul {
  font-size: 0.95rem;
  color: #334155;
  line-height: 1.6;
}

.modal-body ul {
  padding-left: 1.25rem;
}

/* ── Customer Timer ──────────────────────────────────────── */
.customer-timer {
  text-align: center;
  padding: 0.6rem 1rem;
  background: #eff6ff;
  border: 1px solid #bfdbfe;
  border-radius: 8px;
  color: #1e40af;
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 1rem;
}

.customer-timer.hidden {
  display: none;
}

/* ── Results Table ───────────────────────────────────────── */
.results-container {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 10px;
  padding: 1.25rem;
}

.results-container h2 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

.results-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
}

.results-table th,
.results-table td {
  padding: 0.6rem 1rem;
  text-align: center;
  border-bottom: 1px solid var(--color-border);
}

.results-table th {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--color-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.results-table .row-label {
  text-align: left;
  font-weight: 600;
  color: #374151;
}

.results-table tbody tr:last-child td {
  border-bottom: none;
}

.first-value-row {
  background: #f0fdf4;
  font-weight: 600;
}

.first-value-row .row-label {
  color: #166534;
}

.customer-row {
  background: var(--color-customer-row);
  font-weight: 700;
}

.customer-row .row-label {
  color: #92400e;
}

.results-note {
  font-size: 0.75rem;
  color: var(--color-secondary);
  margin-top: 0.75rem;
  text-align: center;
}

/* ── Round complete message ──────────────────────────────── */
.round-complete-banner {
  text-align: center;
  padding: 0.75rem;
  background: #dcfce7;
  border: 1px solid #86efac;
  border-radius: 8px;
  color: #166534;
  font-weight: 600;
  font-size: 0.9rem;
  margin-bottom: 1rem;
}