* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Arial', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.container {
    display: flex;
    gap: 30px;
    max-width: 1400px;
    width: 100%;
    background: white;
    border-radius: 20px;
    padding: 30px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}

/* 左侧面板 - 难度选择 */
.sidebar {
    width: 150px;
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.sidebar h3 {
    color: #333;
    font-size: 16px;
    margin-bottom: 10px;
}

.difficulty-btn {
    padding: 12px 15px;
    border: 2px solid #ddd;
    background: white;
    border-radius: 8px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.3s ease;
    color: #333;
}

.difficulty-btn:hover {
    background: #f0f0f0;
    border-color: #667eea;
}

.difficulty-btn.active {
    background: #667eea;
    color: white;
    border-color: #667eea;
}

/* 主内容区 */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

/* 顶部控制栏 */
.top-bar {
    display: flex;
    justify-content: flex-start;
    align-items: center;
    flex-wrap: wrap;
    gap: 15px;
    padding-bottom: 20px;
    border-bottom: 2px solid #eee;
}

.mode-selector {
    display: flex;
    gap: 10px;
}

.mode-btn {
    padding: 10px 20px;
    border: 2px solid #ddd;
    background: white;
    border-radius: 8px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.3s ease;
    color: #333;
}

.mode-btn:hover {
    border-color: #667eea;
}

.mode-btn.active {
    background: #667eea;
    color: white;
    border-color: #667eea;
}

.action-btn {
    padding: 10px 20px;
    background: #764ba2;
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.3s ease;
}

.action-btn:hover {
    background: #6a3d93;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(118, 75, 162, 0.3);
}

.action-btn:disabled {
    background: #ccc;
    cursor: not-allowed;
    transform: none;
}

/* 重置按钮容器 */
.reset-btn-container {
    display: flex;
    justify-content: center;
    padding-top: 20px;
}

#resetBtn {
    width: auto;
    padding: 12px 40px;
    font-size: 16px;
}

/* 卡牌网格 */
.cards-container {
    display: grid;
    gap: 15px;
    justify-content: center;
}

.card {
    width: 80px;
    height: 80px;
    border-radius: 8px;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    font-weight: bold;
    font-size: 18px;
    transition: all 0.3s ease;
    border: 3px solid #ddd;
    background: linear-gradient(135deg, #f5f5f5 0%, #e0e0e0 100%);
    user-select: none;
    position: relative;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.2);
}

.card.selected {
    transform: scale(1.05);
    border-color: #667eea;
    box-shadow: 0 0 15px rgba(102, 126, 234, 0.6);
}

/* 卡牌颜色 */
/* 卡牌颜色（11对 + 11对，共22对，采用Material Design颜色系统确保差异明显） */
.card.pair-1 { background: linear-gradient(135deg, #D32F2F 0%, #FF5252 100%); color: white; }
.card.pair-2 { background: linear-gradient(135deg, #F57C00 0%, #FF9100 100%); color: white; }
.card.pair-3 { background: linear-gradient(135deg, #F9A825 0%, #FFC107 100%); color: #333; }
.card.pair-4 { background: linear-gradient(135deg, #388E3C 0%, #66BB6A 100%); color: white; }
.card.pair-5 { background: linear-gradient(135deg, #00796B 0%, #26A69A 100%); color: white; }
.card.pair-6 { background: linear-gradient(135deg, #0277BD 0%, #29B6F6 100%); color: white; }
.card.pair-7 { background: linear-gradient(135deg, #5D4037 0%, #8D6E63 100%); color: white; }
.card.pair-8 { background: linear-gradient(135deg, #3F51B5 0%, #5C6BC0 100%); color: white; }
.card.pair-9 { background: linear-gradient(135deg, #7B1FA2 0%, #AB47BC 100%); color: white; }
.card.pair-10 { background: linear-gradient(135deg, #512DA8 0%, #7E57C2 100%); color: white; }
.card.pair-11 { background: linear-gradient(135deg, #C2185B 0%, #E91E63 100%); color: white; }
.card.pair-12 { background: linear-gradient(135deg, #455A64 0%, #78909C 100%); color: white; }

.card.ghost {
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center;
    background-image: url('res/joker.png');
    background-color: #2C3E50;
}

.card.ghost .card-label {
    display: none;
}

.card.star {
    background-size: contain;
    background-repeat: no-repeat;
    background-position: center;
    background-image: url('res/star.png');
    background-color: #FFD93D;
}

.card.star .card-label {
    display: none;
}

.card-label {
    text-align: center;
    line-height: 1.2;
}

/* 状态信息 */
.status {
    text-align: center;
    color: #666;
    font-size: 14px;
    padding: 10px;
    background: #f9f9f9;
    border-radius: 8px;
    border-left: 4px solid #667eea;
}

.status.warning {
    background: #fff3cd;
    border-left-color: #ffc107;
}

.status.success {
    background: #d4edda;
    border-left-color: #28a745;
}

/* 响应式布局 */
@media (max-width: 1200px) {
    .container {
        flex-direction: column;
    }

    .sidebar {
        width: 100%;
        flex-direction: row;
        justify-content: center;
    }
}

@media (max-width: 992px) {
    .container {
        padding: 20px;
        gap: 20px;
    }

    .sidebar {
        gap: 10px;
    }

    .sidebar h3 {
        font-size: 14px;
    }

    .difficulty-btn {
        padding: 10px 12px;
        font-size: 13px;
    }

    .card {
        width: 80px;
        height: 80px;
        font-size: 16px;
    }

    .cards-container {
        gap: 6px;
    }
}

@media (max-width: 768px) {
    body {
        padding: 10px;
    }

    .container {
        padding: 15px;
        gap: 15px;
        border-radius: 12px;
    }

    .sidebar {
        flex-wrap: wrap;
        justify-content: center;
        gap: 8px;
    }

    .sidebar h3 {
        width: 100%;
        text-align: center;
        font-size: 14px;
        margin-bottom: 5px;
    }

    .difficulty-btn {
        padding: 8px 10px;
        font-size: 12px;
        flex: 0 1 calc(25% - 6px);
    }

    .main-content {
        gap: 15px;
    }

    .top-bar {
        flex-direction: column;
        align-items: stretch;
        gap: 10px;
        padding-bottom: 15px;
    }

    .mode-selector {
        justify-content: center;
        gap: 8px;
    }

    .mode-btn {
        flex: 1;
        padding: 8px 10px;
        font-size: 12px;
    }

    .action-btn {
        padding: 8px 15px;
        font-size: 12px;
    }
    .reset-btn-container {
        padding-top: 15px;
    }

    #resetBtn {
        width: 100%;
        padding: 14px 20px;
        font-size: 16px;
    }
    .card {
        width: 64px;
        height: 64px;
        font-size: 13px;
        border: 2px solid #ddd;
    }

    .cards-container {
        gap: 4px;
    }

    .status {
        font-size: 12px;
        padding: 8px;
    }
}

@media (max-width: 480px) {
    body {
        padding: 5px;
    }

    .container {
        padding: 10px;
        gap: 10px;
        border-radius: 10px;
    }

    .sidebar {
        gap: 6px;
    }

    .sidebar h3 {
        font-size: 13px;
        margin-bottom: 3px;
    }

    .difficulty-btn {
        padding: 6px 8px;
        font-size: 11px;
        flex: 0 1 calc(25% - 5px);
    }

    .main-content {
        gap: 12px;
    }

    .top-bar {
        gap: 8px;
        padding-bottom: 10px;
        border-bottom: 1px solid #eee;
    }

    .mode-selector {
        gap: 6px;
    }

    .mode-btn {
        padding: 6px 8px;
        font-size: 11px;
    }

    .action-btn {
        padding: 6px 12px;
        font-size: 11px;
    }

    .reset-btn-container {
        padding-top: 12px;
    }

    #resetBtn {
        width: 100%;
        padding: 12px 16px;
        font-size: 14px;
    }

    .card {
        width: 52px;
        height: 52px;
        font-size: 12px;
        border: 2px solid #ddd;
    }

    .cards-container {
        gap: 3px;
    }

    .card-label {
        line-height: 1;
    }

    .status {
        font-size: 11px;
        padding: 6px;
        border-left: 3px solid #667eea;
    }

    .status.warning {
        border-left-color: #ffc107;
    }

    .status.success {
        border-left-color: #28a745;
    }
}