:root {
  --bg: #0f172a;
  --panel: #1e293b;
  --card: #ffffff;
  --primary: #2563eb;
  --primary-d: #1d4ed8;
  --text: #e2e8f0;
  --muted: #94a3b8;
  --given: #1e293b;
  --solved: #16a34a;
  --border: #334155;
  --line: #cbd5e1;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Microsoft YaHei", sans-serif;
  background: linear-gradient(160deg, #0f172a, #1e293b);
  color: var(--text);
  min-height: 100vh;
}

.container {
  max-width: 640px;
  margin: 0 auto;
  padding: 28px 18px 48px;
}

.hero h1 {
  font-size: 28px;
  margin: 0 0 6px;
}

.subtitle {
  color: var(--muted);
  margin: 0 0 18px;
  line-height: 1.6;
}

.subtitle b {
  color: #93c5fd;
}

/* 模式切换 */
.tabs {
  display: flex;
  gap: 8px;
  margin-bottom: 16px;
}

.tab {
  flex: 1;
  text-align: center;
  padding: 12px;
  border-radius: 10px;
  background: var(--panel);
  color: var(--muted);
  cursor: pointer;
  border: 1px solid var(--border);
  font-weight: 600;
  transition: all 0.15s;
}

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

/* 面板 */
.panel {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
  margin-bottom: 16px;
}

.field {
  margin-bottom: 14px;
}

.field label {
  display: block;
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 6px;
}

select,
input[type="file"] {
  width: 100%;
  padding: 10px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: #0b1220;
  color: var(--text);
  font-size: 14px;
}

.hint {
  color: var(--muted);
  font-size: 13px;
  margin: 0 0 4px;
}

/* 剪贴板粘贴区 */
.paste-zone {
  width: 100%;
  box-sizing: border-box;
  padding: 16px 12px;
  border: 1.5px dashed var(--border);
  border-radius: 10px;
  text-align: center;
  color: var(--muted);
  font-size: 13px;
  cursor: pointer;
  background: rgba(255, 255, 255, 0.02);
  transition: border-color 0.15s, color 0.15s, background 0.15s;
  outline: none;
}

.paste-zone:hover,
.paste-zone:focus {
  border-color: #3b82f6;
  color: var(--text);
  background: rgba(59, 130, 246, 0.08);
}

.paste-zone kbd {
  display: inline-block;
  padding: 1px 6px;
  border-radius: 4px;
  border: 1px solid var(--border);
  background: #0b1220;
  font-size: 12px;
  font-family: inherit;
}

/* 裁剪区 */
.crop-section {
  margin-top: 6px;
}

.crop-canvas-wrap {
  display: flex;
  justify-content: center;
  margin: 10px 0;
}

#cropCanvas {
  max-width: 100%;
  border-radius: 8px;
  border: 1px solid var(--border);
  cursor: crosshair;
  touch-action: none;
  background: #0b1220;
}

.crop-actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

/* 预览 */
.preview {
  margin: 12px 0;
  text-align: center;
}

.preview img {
  max-width: 100%;
  max-height: 260px;
  border-radius: 8px;
  border: 1px solid var(--border);
}

/* 按钮 */
.btn {
  padding: 11px 20px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--panel);
  color: var(--text);
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s;
}

.btn:hover {
  border-color: var(--primary);
}

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

.btn.primary:hover {
  background: var(--primary-d);
}

.btn.ghost {
  background: transparent;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* 状态条 */
.status-bar {
  background: #0b1220;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px 14px;
  margin-bottom: 14px;
  font-size: 14px;
  color: #93c5fd;
}

.status-bar.working {
  color: #fbbf24;
}

/* 网格 */
.board-wrap {
  display: flex;
  justify-content: center;
  margin-bottom: 18px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(9, 1fr);
  width: min(100%, 450px);
  aspect-ratio: 1 / 1;
  background: var(--line);
  gap: 1px;
  border: 3px solid var(--given);
  border-radius: 6px;
  overflow: hidden;
}

.cell {
  width: 100%;
  height: 100%;
  border: none;
  text-align: center;
  font-size: clamp(16px, 5vw, 26px);
  font-weight: 700;
  background: #fff;
  color: var(--given);
  outline: none;
  padding: 0;
}

.cell:focus {
  background: #dbeafe;
}

/* 粗边框划分 3x3 宫 */
.cell.bl {
  border-left: 2px solid var(--given);
}
.cell.bt {
  border-top: 2px solid var(--given);
}
.cell.br {
  border-right: 2px solid var(--given);
}
.cell.bb {
  border-bottom: 2px solid var(--given);
}

.cell.given {
  background: #e2e8f0;
  color: var(--given);
}

.cell.solved {
  background: #dcfce7;
  color: var(--solved);
}

/* 操作区 */
.actions {
  display: flex;
  gap: 10px;
  justify-content: center;
  margin-bottom: 16px;
}

/* 结果 */
.result {
  min-height: 20px;
  padding: 12px 14px;
  border-radius: 10px;
  font-size: 14px;
  line-height: 1.6;
}

.result.success {
  background: rgba(22, 163, 74, 0.15);
  border: 1px solid rgba(22, 163, 74, 0.4);
  color: #bbf7d0;
}

.result.error {
  background: rgba(220, 38, 38, 0.15);
  border: 1px solid rgba(220, 38, 38, 0.4);
  color: #fecaca;
}

.result.warn {
  background: rgba(234, 179, 8, 0.15);
  border: 1px solid rgba(234, 179, 8, 0.4);
  color: #fde68a;
}

.foot {
  margin-top: 24px;
  color: var(--muted);
  font-size: 12px;
  line-height: 1.6;
  text-align: center;
}