/* 自定义样式 */
.nav-item.active {
    background-color: #dbeafe;
    color: #2563eb;
    font-weight: 600;
}

.nav-item.active i {
    color: #2563eb;
}

/* 图片标记工具样式 */
.canvas-container {
    position: relative;
    border: 2px solid #e5e7eb;
    border-radius: 8px;
    background: #f9fafb;
}

.toolbar {
    background: white;
    border-bottom: 1px solid #e5e7eb;
    padding: 12px;
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.tool-btn {
    padding: 8px 16px;
    border: 1px solid #d1d5db;
    border-radius: 6px;
    background: white;
    cursor: pointer;
    transition: all 0.2s;
}

.tool-btn:hover {
    background: #f3f4f6;
    border-color: #9ca3af;
}

.tool-btn.active {
    background: #2563eb;
    color: white;
    border-color: #2563eb;
}

/* 合约样式 */
.contract-section {
    border: 1px solid #e5e7eb;
    border-radius: 8px;
    padding: 20px;
    margin-bottom: 20px;
    background: white;
}

.signature-area {
    border: 2px dashed #d1d5db;
    border-radius: 8px;
    padding: 40px;
    text-align: center;
    background: #f9fafb;
    min-height: 150px;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* 响应式优化 */
@media (max-width: 640px) {
    .contract-section {
        padding: 12px;
    }
    
    .signature-area {
        padding: 20px;
        min-height: 120px;
    }
}

/* 加载动画 */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid #f3f3f3;
    border-top: 3px solid #2563eb;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* 卡片悬停效果 */
.card-hover {
    transition: transform 0.2s, box-shadow 0.2s;
}

.card-hover:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
}