:root {
  color-scheme: light dark;
  --bg: #f4f6f5;
  --surface: #ffffff;
  --surface-alt: #eef3f0;
  --text: #1c2622;
  --muted: #5c6b64;
  --border: #d5ddd8;
  --accent: #14694a;
  --accent-text: #ffffff;
  --danger: #b3261e;
  --danger-bg: #fbeceb;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #141916;
    --surface: #1d2420;
    --surface-alt: #262f2a;
    --text: #e8eeeb;
    --muted: #a0aea7;
    --border: #3a4640;
    --accent: #5cc79c;
    --accent-text: #0c1a14;
    --danger: #f2a29c;
    --danger-bg: #3a2120;
  }
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }

body {
  margin: 0;
  padding: 24px 16px 48px;
  background: var(--bg);
  color: var(--text);
  font-family: "Leelawadee UI", "Noto Sans Thai", Tahoma, sans-serif;
  font-size: 16px;
  line-height: 1.5;
}

.page-header {
  max-width: 1240px;
  margin: 0 auto 20px;
}

h1 { margin: 0 0 4px; font-size: 1.6rem; line-height: 1.3; }
.page-header p { margin: 0; color: var(--muted); }

.panels {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 460px), 1fr));
  gap: 20px;
  max-width: 1240px;
  margin: 0 auto;
  align-items: start;
}

.panel {
  min-width: 0;
  padding: 20px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
}

h2 { margin: 0 0 16px; font-size: 1.3rem; color: var(--accent); }

.step + .step {
  margin-top: 20px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
}

h3 {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 12px;
  font-size: 1rem;
}

.step-no {
  flex: none;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--accent);
  color: var(--accent-text);
  font-size: .85rem;
  line-height: 24px;
  text-align: center;
}

input {
  width: 100%;
  min-height: 40px;
  padding: 6px 10px;
  background: var(--surface);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  font: inherit;
}

input[aria-invalid="true"] {
  border-color: var(--danger);
  background: var(--danger-bg);
}

input:focus-visible, button:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}

.row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 112px 40px;
  gap: 8px;
  align-items: center;
  margin-bottom: 8px;
}

.panel[data-mode="roundrobin"] .row {
  grid-template-columns: minmax(0, 1fr) 96px 96px 40px;
}

.row-head {
  align-items: end;
  margin-bottom: 4px;
  color: var(--muted);
  font-size: .85rem;
}

.empty { margin: 0 0 8px; color: var(--muted); }

button { font: inherit; cursor: pointer; }

.btn-add {
  min-height: 40px;
  padding: 6px 14px;
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent);
  border-radius: 6px;
}

.btn-add:hover { background: var(--surface-alt); }

.btn-remove {
  width: 40px;
  height: 40px;
  padding: 0;
  background: transparent;
  color: var(--muted);
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 1.1rem;
}

.btn-remove:hover {
  color: var(--danger);
  border-color: var(--danger);
  background: var(--danger-bg);
}

.fields {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

label { display: block; color: var(--muted); font-size: .9rem; }
label input { margin-top: 4px; font-size: 1rem; }

.errors {
  margin: 0;
  padding: 10px 12px 10px 30px;
  background: var(--danger-bg);
  color: var(--danger);
  border-radius: 6px;
}

.stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
  margin-bottom: 12px;
}

.stat {
  padding: 10px 12px;
  background: var(--surface-alt);
  border-radius: 6px;
}

.stat-wide { grid-column: 1 / -1; }
.stat-label { color: var(--muted); font-size: .85rem; }
.stat-value { font-size: 1.35rem; font-weight: 700; line-height: 1.35; }
.stat-wide .stat-value { font-size: 1.1rem; }
.stat-sub { color: var(--muted); font-size: .85rem; }

table {
  width: 100%;
  border-collapse: collapse;
  font-size: .95rem;
}

th, td {
  padding: 6px 8px;
  border-bottom: 1px solid var(--border);
  text-align: right;
  font-variant-numeric: tabular-nums;
}

th:first-child, td:first-child {
  text-align: left;
  overflow-wrap: anywhere;
}

.cell-sub { color: var(--muted); font-size: .8rem; }
thead th { color: var(--muted); font-weight: 400; font-size: .85rem; }
tfoot th { border-bottom: 0; font-weight: 700; }

.notes {
  margin: 12px 0 0;
  padding-left: 18px;
  color: var(--muted);
  font-size: .85rem;
}

@media (max-width: 420px) {
  .panel { padding: 16px; }
  .row { grid-template-columns: minmax(0, 1fr) 84px 40px; }
  .panel[data-mode="roundrobin"] .row {
    grid-template-columns: minmax(0, 1fr) 68px 68px 40px;
    gap: 6px;
  }
}