:root {
  --bg: #f4f8ff;
  --card: #ffffff;
  --text: #1f2a44;
  --accent: #4a7dff;
  --accent-soft: #e9f0ff;
  --board-bg: #f3d7a7;
  --line: #8b6f47;
  --win: #39b36a;
  --danger: #d95050;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Microsoft YaHei", "PingFang SC", sans-serif;
  background: radial-gradient(circle at top, #ffffff, var(--bg));
  color: var(--text);
}

.app {
  max-width: 1200px;
  margin: 0 auto;
  padding: 16px;
}

.card {
  background: var(--card);
  border-radius: 16px;
  box-shadow: 0 8px 24px rgba(37, 63, 125, 0.12);
}

.topbar {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  padding: 16px;
  margin-bottom: 16px;
}

h1 {
  margin: 0 0 6px;
  font-size: 1.8rem;
}

.subtitle {
  margin: 0;
  color: #5f6a86;
}

.controls {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: flex-end;
  gap: 8px;
  min-width: 320px;
}

button,
select {
  border: 0;
  border-radius: 10px;
  padding: 8px 12px;
  font-size: 0.95rem;
}

button,
select,
label {
  font-weight: 600;
}

select,
button.ghost {
  background: var(--accent-soft);
  color: var(--text);
}

button {
  background: var(--accent);
  color: #fff;
  cursor: pointer;
  transition: transform 0.15s ease, opacity 0.15s ease;
}

button:hover {
  transform: translateY(-1px);
}

button:disabled {
  opacity: 0.65;
  cursor: not-allowed;
}

.layout {
  display: grid;
  grid-template-columns: minmax(530px, 1fr) 320px;
  gap: 16px;
}

.board-wrap {
  padding: 16px;
}

.board {
  position: relative;
  display: grid;
  grid-template-columns: repeat(15, 34px);
  grid-template-rows: repeat(15, 34px);
  gap: 0;
  justify-content: center;
  background: var(--board-bg);
  border: 4px solid #d2af79;
  border-radius: 12px;
  padding: 10px;
}

.cell {
  width: 34px;
  height: 34px;
  border: 1px solid var(--line);
  position: relative;
  cursor: pointer;
}

.cell.black::after,
.cell.white::after {
  content: "";
  position: absolute;
  left: 50%;
  top: 50%;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  transform: translate(-50%, -50%);
}

.cell.black::after {
  background: radial-gradient(circle at 30% 30%, #5f5f5f, #121212);
}

.cell.white::after {
  background: radial-gradient(circle at 30% 30%, #fff, #d9d9d9);
  border: 1px solid #bcbcbc;
}

.cell.hint {
  outline: 3px dashed #3f80ff;
  outline-offset: -3px;
  animation: pulse 0.9s infinite;
}

@keyframes pulse {
  0%,
  100% { opacity: 1; }
  50% { opacity: 0.5; }
}

.panel {
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.status {
  line-height: 1.6;
  min-height: 96px;
  padding: 10px;
  border-radius: 10px;
  background: #f8fbff;
  border: 1px solid #e3ebff;
}

.status.win {
  color: var(--win);
  font-weight: 700;
}

.status.lose {
  color: var(--danger);
  font-weight: 700;
}

.card-inset {
  background: #f8fbff;
  border: 1px solid #e3ebff;
  border-radius: 12px;
  padding: 10px;
}

.coach ul {
  margin: 8px 0 0 0;
  padding-left: 18px;
  line-height: 1.6;
}

.star-burst {
  position: fixed;
  left: 50%;
  top: 15%;
  transform: translateX(-50%);
  font-size: 2rem;
  animation: burst 1s ease-out forwards;
  pointer-events: none;
}

@keyframes burst {
  0% { opacity: 0; transform: translate(-50%, -20px) scale(0.4); }
  30% { opacity: 1; transform: translate(-50%, 0) scale(1); }
  100% { opacity: 0; transform: translate(-50%, -60px) scale(1.3); }
}

@media (max-width: 980px) {
  .layout {
    grid-template-columns: 1fr;
  }

  .board {
    transform: scale(0.95);
    transform-origin: top center;
  }
}