/* Nền tảng dùng chung: màu sân, chữ, nút, ô nhập. */
:root {
  --ground: #edf2ef;
  --surface: #ffffff;
  --surface-2: #f5f8f6;
  --ink: #10231b;
  --ink-2: #3e5549;
  --ink-3: #5e7268;
  --rule: #d5e0da;
  --rule-strong: #b7c7bf;

  --surround: #1f5a45;
  --surround-deep: #174535;
  --court: #2461a8;
  --court-deep: #1b4d88;
  --kitchen: #2d70bd;
  --line: #f4f8fb;

  --ball: #e2f23c;
  --ball-deep: #c9db1f;
  --ball-ink: #13261c;

  --ok: #1d7a4f;
  --ok-soft: #e3f3ea;
  --warn: #8a5a00;
  --warn-soft: #fbf1d9;
  --danger: #b3261e;
  --danger-soft: #fbe9e7;
  --focus: #1b4d88;

  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 1px 2px rgb(16 35 27 / 0.06), 0 8px 24px -8px rgb(16 35 27 / 0.16);
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);

  --font: "Be Vietnam Pro", system-ui, -apple-system, "Segoe UI", sans-serif;
  color-scheme: light;
}

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

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--ground);
  color: var(--ink);
  font-family: var(--font);
  font-size: 1rem;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

::selection { background: var(--ball); color: var(--ball-ink); }

h1, h2, h3 { line-height: 1.2; text-wrap: balance; margin: 0; }

a { color: var(--court-deep); text-underline-offset: 3px; }

:focus-visible { outline: 2.5px solid var(--focus); outline-offset: 2px; }

.visually-hidden {
  position: absolute; width: 1px; height: 1px; overflow: hidden;
  clip-path: inset(50%); white-space: nowrap;
}

[hidden] { display: none !important; }

svg { width: 1.25em; height: 1.25em; flex: none; }

/* ─── Ô nhập ─── */
label { display: block; font-weight: 600; font-size: 0.9375rem; margin-bottom: 6px; }
label .optional { font-weight: 400; color: var(--ink-3); }

input, select {
  width: 100%;
  font: inherit;
  color: var(--ink);
  background: var(--surface);
  border: 1.5px solid var(--rule-strong);
  border-radius: var(--radius-sm);
  padding: 11px 14px;
  min-height: 48px;
  caret-color: var(--court);
  transition: border-color 150ms, box-shadow 150ms;
}
input::placeholder { color: #71857b; }
input:hover, select:hover { border-color: var(--ink-3); }
input:focus-visible, select:focus-visible {
  outline: none;
  border-color: var(--court);
  box-shadow: 0 0 0 3px rgb(36 97 168 / 0.22);
}
input[aria-invalid="true"] { border-color: var(--danger); }
input:disabled { background: var(--surface-2); color: var(--ink-3); }

.field { margin-bottom: 18px; }
.field-hint { margin: 6px 0 0; font-size: 0.8125rem; color: var(--ink-3); }
.field-error, .form-error { margin: 6px 0 0; font-size: 0.875rem; font-weight: 500; color: var(--danger); }
.form-error { padding: 10px 12px; background: var(--danger-soft); border-radius: var(--radius-sm); margin-bottom: 14px; }

/* ─── Nút ─── */
.button {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  min-height: 48px;
  padding: 0 20px;
  font: inherit; font-weight: 700;
  border: 0; border-radius: 999px;
  cursor: pointer;
  transition: transform 150ms var(--ease-out), background-color 150ms, box-shadow 150ms, opacity 150ms;
}
.button:active:not(:disabled) { transform: translateY(1px) scale(0.99); }
.button:disabled { cursor: not-allowed; opacity: 0.55; }

.button-ball {
  width: 100%;
  background: var(--ball);
  color: var(--ball-ink);
  font-size: 1.0625rem;
  box-shadow: inset 0 -3px 0 var(--ball-deep), 0 6px 16px -6px rgb(120 140 0 / 0.55);
}
.button-ball:hover:not(:disabled) { background: #eaf85a; }
.button-ball.is-busy .button-label::after {
  content: ""; display: inline-block; width: 0.9em; height: 0.9em; margin-left: 10px; vertical-align: -0.1em;
  border: 2px solid currentColor; border-right-color: transparent; border-radius: 50%;
  animation: spin 700ms linear infinite;
}

.button-quiet { background: var(--surface-2); color: var(--ink); border: 1.5px solid var(--rule-strong); }
.button-quiet:hover:not(:disabled) { border-color: var(--ink-3); background: #fff; }

.button-danger { background: var(--danger); color: #fff; }
.button-danger:hover:not(:disabled) { background: #9a1f18; }

.link-button {
  font: inherit; font-weight: 600; color: inherit; background: none; border: 0; padding: 4px 2px;
  text-decoration: underline; text-underline-offset: 3px; cursor: pointer;
}

@keyframes spin { to { transform: rotate(360deg); } }

.demo-strip {
  display: flex; flex-wrap: wrap; gap: 4px 14px; justify-content: center; align-items: center;
  padding: 8px 16px;
  background: var(--warn-soft); color: var(--warn);
  font-size: 0.875rem; font-weight: 500; text-align: center;
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 1ms !important; animation-iteration-count: 1 !important; transition-duration: 1ms !important; }
}