* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Microsoft YaHei", "PingFang SC", sans-serif;
  background: #f5f3ea;
  color: #1f2430;
}

.app {
  max-width: 980px;
  margin: 0 auto;
  padding: 16px;
}

.top-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.top-bar h1 {
  margin: 0;
  font-size: 24px;
}

.controls {
  display: flex;
  gap: 10px;
  align-items: center;
  flex-wrap: wrap;
}

button,
select {
  border: 1px solid #aab2bf;
  border-radius: 6px;
  background: #fff;
  padding: 6px 10px;
  cursor: pointer;
}

button:hover {
  background: #f0f4ff;
}

.score-panel {
  margin-top: 14px;
  display: grid;
  grid-template-columns: repeat(2, minmax(180px, 1fr));
  gap: 10px;
}

.score-item {
  background: #fff;
  border: 1px solid #d8dee8;
  border-radius: 8px;
  padding: 10px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.score-item.black strong::before {
  content: "● ";
  color: #111;
}

.score-item.white strong::before {
  content: "○ ";
  color: #555;
}

.status-panel {
  margin-top: 12px;
  background: #eef3ff;
  border: 1px solid #d4dff7;
  border-radius: 8px;
  padding: 10px 12px;
  min-height: 44px;
  display: flex;
  align-items: center;
}

#statusText {
  margin: 0;
  font-weight: 600;
}

.board-wrap {
  margin-top: 14px;
  width: 100%;
  overflow-x: auto;
}

.rules-panel {
  margin-top: 16px;
  background: #fff;
  border: 1px solid #d8dee8;
  border-radius: 8px;
  padding: 12px;
}

.rules-panel h2 {
  margin: 0;
  font-size: 19px;
}

.rules-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 10px;
  margin-bottom: 10px;
  flex-wrap: wrap;
}

.rules-lang-label {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 14px;
}

.rules-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(220px, 1fr));
  gap: 10px;
}

.rules-grid.single-column {
  grid-template-columns: 1fr;
}

.rules-card {
  background: #f9fbff;
  border: 1px solid #e2e8f5;
  border-radius: 8px;
  padding: 10px 12px;
}

.rules-card h3 {
  margin: 0 0 8px;
  font-size: 16px;
}

.rules-card ul {
  margin: 0;
  padding-left: 18px;
  line-height: 1.55;
}

.rules-card.is-hidden {
  display: none;
}

.board {
  width: 750px;
  height: 750px;
  display: grid;
  grid-template-columns: repeat(15, 1fr);
  grid-template-rows: repeat(15, 1fr);
  border: 2px solid #865d2d;
  background: #e8c88c;
  position: relative;
}

.cell {
  border: 1px solid rgba(109, 75, 34, 0.35);
  position: relative;
}

.stone {
  width: 80%;
  height: 80%;
  border-radius: 50%;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

.stone.black {
  background: radial-gradient(circle at 30% 30%, #666, #111 68%);
}

.stone.white {
  background: radial-gradient(circle at 30% 30%, #fff, #d6d6d6 70%);
  border: 1px solid #bcbcbc;
}

@media (max-width: 820px) {
  .board {
    width: 600px;
    height: 600px;
  }

  .rules-grid {
    grid-template-columns: 1fr;
  }
}