/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    background: rgba(255, 255, 255, 0.95);
    border-radius: 20px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
    overflow: hidden;
}

/* 头部样式 */
header {
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    color: white;
    padding: 40px;
    text-align: center;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    font-weight: 700;
}

header p {
    font-size: 1.1rem;
    opacity: 0.9;
}

/* 上传区域 */
.upload-section {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
    padding: 40px;
}

.upload-card {
    background: white;
    border-radius: 15px;
    padding: 25px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.upload-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.15);
}

.upload-card h3 {
    color: #333;
    margin-bottom: 20px;
    font-size: 1.3rem;
    text-align: center;
}

.upload-area {
    border: 3px dashed #ddd;
    border-radius: 10px;
    padding: 40px 20px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    background: #fafafa;
}

.upload-area:hover {
    border-color: #4facfe;
    background: #f0f8ff;
}

.upload-area.dragover {
    border-color: #00f2fe;
    background: #e6f7ff;
    transform: scale(1.02);
}

.upload-placeholder {
    color: #666;
}

.upload-icon {
    font-size: 3rem;
    margin-bottom: 15px;
}

.upload-placeholder p {
    font-size: 1.1rem;
    margin-bottom: 5px;
}

.upload-placeholder small {
    color: #999;
}

.preview {
    margin-top: 20px;
    text-align: center;
}

.preview img {
    max-width: 100%;
    max-height: 200px;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

/* 控制面板 */
.controls-section {
    padding: 40px;
    background: #f8f9fa;
    border-top: 1px solid #eee;
}

.control-group {
    display: flex;
    align-items: center;
    margin-bottom: 25px;
    gap: 15px;
}

.control-group label {
    font-weight: 600;
    color: #333;
    min-width: 120px;
}

.control-group input[type="range"] {
    flex: 1;
    height: 8px;
    border-radius: 5px;
    background: #ddd;
    outline: none;
    -webkit-appearance: none;
}

.control-group input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: #4facfe;
    cursor: pointer;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.2);
}

.control-group select {
    flex: 1;
    padding: 10px 15px;
    border: 2px solid #ddd;
    border-radius: 8px;
    font-size: 1rem;
    background: white;
    outline: none;
    transition: border-color 0.3s ease;
}

.control-group select:focus {
    border-color: #4facfe;
}

.control-group span {
    font-weight: 600;
    color: #4facfe;
    min-width: 60px;
    text-align: right;
}

.button-group {
    display: flex;
    gap: 15px;
    justify-content: center;
    margin-top: 30px;
}

/* 按钮样式 */
.primary-btn {
    background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    color: white;
    border: none;
    padding: 15px 30px;
    font-size: 1.1rem;
    font-weight: 600;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 5px 15px rgba(79, 172, 254, 0.3);
}

.primary-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(79, 172, 254, 0.4);
}

.secondary-btn {
    background: white;
    color: #666;
    border: 2px solid #ddd;
    padding: 15px 30px;
    font-size: 1.1rem;
    font-weight: 600;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.secondary-btn:hover {
    border-color: #4facfe;
    color: #4facfe;
    transform: translateY(-2px);
}

/* 结果区域 */
.result-section {
    padding: 40px;
    background: white;
    text-align: center;
}

.result-section h3 {
    color: #333;
    margin-bottom: 30px;
    font-size: 1.5rem;
}

.result-preview {
    margin-bottom: 30px;
}

.result-preview canvas {
    max-width: 100%;
    max-height: 500px;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.result-actions {
    display: flex;
    gap: 15px;
    justify-content: center;
    margin-bottom: 30px;
}

.tips {
    background: #f8f9fa;
    border-radius: 15px;
    padding: 25px;
    text-align: left;
    max-width: 600px;
    margin: 0 auto;
}

.tips h4 {
    color: #333;
    margin-bottom: 15px;
    font-size: 1.2rem;
}

.tips ul {
    list-style: none;
    padding: 0;
}

.tips li {
    padding: 8px 0;
    color: #666;
    position: relative;
    padding-left: 25px;
}

.tips li:before {
    content: "✓";
    position: absolute;
    left: 0;
    color: #4facfe;
    font-weight: bold;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .upload-section {
        grid-template-columns: 1fr;
        gap: 20px;
        padding: 20px;
    }
    
    .container {
        margin: 10px;
        border-radius: 15px;
    }
    
    header {
        padding: 30px 20px;
    }
    
    header h1 {
        font-size: 2rem;
    }
    
    .controls-section {
        padding: 20px;
    }
    
    .control-group {
        flex-direction: column;
        align-items: stretch;
        gap: 10px;
    }
    
    .control-group label {
        min-width: auto;
    }
    
    .button-group {
        flex-direction: column;
    }
    
    .result-actions {
        flex-direction: column;
    }
}

/* 动画效果 */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.controls-section,
.result-section {
    animation: fadeIn 0.5s ease;
}

/* 加载动画 */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 1s ease-in-out infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}