/**
 * 网格样式和动画 - 舒尔特方格
 * 设计系统：极简 + 护眼绿棋盘
 */

/* 头部样式 - 简洁现代 */
.app-header {
    text-align: center;
    margin-bottom: clamp(16px, 3vh, 32px);
}

.app-header h1 {
    font-size: clamp(20px, 4vh, 32px);
    margin-bottom: clamp(12px, 2vh, 24px);
    color: var(--text-primary);
    font-weight: 800;
    font-family: 'Inter', sans-serif;
    letter-spacing: -0.5px;
}

/* 难度选择器 - 极简按钮组 */
.difficulty-selector {
    display: flex;
    gap: 8px;
    justify-content: center;
    flex-wrap: wrap;
}

.difficulty-btn {
    padding: 10px 18px;
    border: 2px solid var(--border-color);
    background: var(--bg-secondary);
    color: var(--text-primary);
    border-radius: 10px;
    cursor: pointer;
    transition: var(--transition-fast);
    font-weight: 600;
    font-size: 14px;
    font-family: 'Inter', sans-serif;
}

.difficulty-btn:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
    transform: translateY(-1px);
}

.difficulty-btn.active {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-hover) 100%);
    border-color: var(--primary-color);
    color: white;
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.25);
}

.difficulty-btn:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

.difficulty-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none !important;
}

/* 游戏信息区 - 卡片式 */
.game-info {
    display: flex;
    justify-content: center;
    margin-bottom: clamp(12px, 2vh, 24px);
    padding: clamp(10px, 2vh, 20px);
    background: linear-gradient(135deg, var(--bg-primary) 0%, #DBEAFE 100%);
    border-radius: clamp(10px, 2vh, 16px);
    border: 1px solid var(--border-color);
}

.timer-display {
    text-align: center;
}

.time {
    display: block;
    font-size: clamp(20px, 5vh, 36px);
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-family: 'Courier New', monospace;
    letter-spacing: -1px;
}

/* 游戏提示 - 简洁信息条 */
.game-hint {
    text-align: center;
    padding: clamp(8px, 1.5vh, 14px) clamp(12px, 2vh, 20px);
    margin-bottom: clamp(12px, 2vh, 24px);
    background: var(--primary-light);
    border: 1px solid var(--border-color);
    border-radius: clamp(8px, 1.5vh, 12px);
    color: var(--text-primary);
    font-size: clamp(12px, 1.8vh, 15px);
    font-weight: 500;
    font-family: 'Inter', sans-serif;
}

.game-hint strong {
    color: var(--primary-color);
    font-weight: 700;
}

/* 游戏网格 */
.game-board {
    margin-bottom: clamp(16px, 3vh, 24px);
}

.grid-container {
    display: grid;
    gap: clamp(4px, 1.5vh, 10px);
    margin: 0 auto;
    max-width: min(85vw, 420px);
    width: 100%;
}

/* 网格项样式 - 护眼绿色 + 微交互 */
.grid-item {
    background: var(--grid-bg);
    border: 2px solid transparent;
    border-radius: clamp(8px, 2vh, 14px);
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: clamp(18px, 4vh, 36px);
    font-weight: 700;
    font-family: 'Inter', sans-serif;
    cursor: pointer;
    transition: var(--transition-fast);
    user-select: none;
    aspect-ratio: 1;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
    color: var(--text-primary);
    position: relative;
}

.grid-item:hover {
    background: linear-gradient(135deg, var(--grid-hover) 0%, #BFDBFE 100%);
    transform: translateY(-2px) scale(1.02);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.12);
}

.grid-item:active {
    transform: translateY(0) scale(0.98);
}

.grid-item.correct {
    background: linear-gradient(135deg, var(--success-color) 0%, #059669 100%);
    color: white;
    border-color: var(--success-color);
    animation: correctPop 300ms cubic-bezier(0.34, 1.56, 0.64, 1);
}

@keyframes correctPop {
    0% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.08);
    }
    100% {
        transform: scale(1);
    }
}

.grid-item.wrong {
    background: linear-gradient(135deg, var(--danger-color) 0%, #DC2626 100%);
    color: white;
    border-color: var(--danger-color);
    animation: shake 300ms cubic-bezier(0.36, 0.07, 0.19, 0.97);
}

.grid-item.completed {
    background: var(--border-color);
    color: var(--text-muted);
    border-color: var(--border-color);
    cursor: default;
    pointer-events: none;
    opacity: 0.6;
}

/* 动画定义 */
@keyframes shake {
    0%, 100% {
        transform: translateX(0);
    }
    20%, 60% {
        transform: translateX(-6px);
    }
    40%, 80% {
        transform: translateX(6px);
    }
}

/* 控制按钮 */
.controls {
    display: flex;
    gap: clamp(8px, 1.5vh, 12px);
    justify-content: center;
    margin-bottom: clamp(12px, 2vh, 24px);
}

/* 统计面板 - 现代卡片 */
.stats-panel {
    margin-top: clamp(16px, 3vh, 24px);
    padding: clamp(12px, 2vh, 20px);
    background: linear-gradient(135deg, var(--bg-primary) 0%, #DBEAFE 100%);
    border-radius: clamp(10px, 2vh, 16px);
    border: 1px solid var(--border-color);
}

.stats-panel h2 {
    font-size: 16px;
    margin-bottom: 16px;
    color: var(--text-primary);
    font-weight: 700;
    font-family: 'Inter', sans-serif;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.stats-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 16px;
}

.best-time {
    flex: 1;
}

.best-time .value {
    font-size: 24px;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-family: 'Courier New', monospace;
}

/* 参考标准面板 */
.reference-panel {
    margin-top: clamp(16px, 3vh, 24px);
    padding: clamp(12px, 2vh, 20px);
    background: var(--bg-elevated);
    border-radius: clamp(10px, 2vh, 16px);
    border: 1px solid var(--border-color);
    box-shadow: var(--box-shadow-sm);
}

.reference-panel h2 {
    font-size: 16px;
    margin-bottom: 16px;
    color: var(--text-primary);
    text-align: center;
    font-weight: 700;
    font-family: 'Inter', sans-serif;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* 参考标准表格 - 简洁设计 */
.reference-table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    font-size: 13px;
    border-radius: 12px;
    overflow: hidden;
    font-family: 'Inter', sans-serif;
}

.reference-table thead {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-hover) 100%);
    color: white;
}

.reference-table th {
    padding: 12px 8px;
    text-align: center;
    font-weight: 600;
    font-size: 12px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.reference-table tbody tr {
    border-bottom: 1px solid var(--border-subtle);
    transition: var(--transition-fast);
}

.reference-table tbody tr:last-child {
    border-bottom: none;
}

.reference-table tbody tr:hover {
    background: var(--primary-light);
}

.reference-table tbody tr.active-row {
    background: var(--primary-light);
    font-weight: 600;
    box-shadow: inset 3px 0 0 var(--primary-color);
}

.reference-table td {
    padding: 12px 8px;
    text-align: center;
    font-family: 'Courier New', monospace;
    font-weight: 500;
}

.reference-table td:first-child {
    font-weight: 600;
    color: var(--text-primary);
    font-family: inherit;
}

.reference-table td:nth-child(2) {
    color: var(--text-secondary);
    font-family: inherit;
}

/* 历史记录标签 */
.history-tabs {
    display: flex;
    gap: 8px;
    margin-bottom: 16px;
    flex-wrap: wrap;
}

.history-tabs .tab {
    padding: 8px 16px;
    border: 1px solid var(--primary-color);
    background: var(--bg-secondary);
    color: var(--primary-color);
    border-radius: 20px;
    cursor: pointer;
    transition: var(--transition);
    font-size: 14px;
}

.history-tabs .tab.active {
    background: var(--primary-color);
    color: white;
}

/* 历史记录列表 */
.history-list {
    max-height: 300px;
    overflow-y: auto;
    margin-bottom: 16px;
}

.history-item {
    display: flex;
    justify-content: space-between;
    padding: 12px;
    border-bottom: 1px solid var(--border-color);
    animation: fadeIn 0.3s ease;
}

.history-item:last-child {
    border-bottom: none;
}

.history-item .rank {
    font-weight: 700;
    color: var(--primary-color);
    min-width: 40px;
}

.history-item .time {
    font-family: 'Courier New', monospace;
    color: var(--text-primary);
    font-weight: 600;
}

.history-item .date {
    color: var(--text-secondary);
    font-size: 14px;
}