:root {
    --primary-color: #7e57c2;
    --primary-gradient: linear-gradient(135deg, #5e35b1, #7e57c2);
    --secondary-color: #ff9800;
    --accent-color: #7c4dff;
    --text-dark: #333;
    --text-light: #777;
    --bg-light: #f8f9fa;
    --card-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
    --hover-shadow: 0 15px 35px rgba(0, 0, 0, 0.15);
}

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

body {
    font-family: 'Inter', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    color: var(--text-dark);
    line-height: 1.6;
    background-color: #f5f7fa;
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 40px 0;
}

/* 头部样式 */
header {
    background-color: white;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
    position: sticky;
    top: 0;
    z-index: 100;
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 0;
}

.logo {
    display: flex;
    align-items: center;
}

.logo h1 {
    font-size: 28px;
    margin: 0;
    color: var(--primary-color);
    letter-spacing: -0.5px;
    font-weight: 700;
}

.logo span {
    color: var(--secondary-color);
}

.logo p {
    margin: 0 0 0 10px;
    font-size: 14px;
    color: var(--text-light);
    letter-spacing: 0.5px;
}

nav {
    display: flex;
}

nav ul {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
}

nav li {
    margin-left: 30px;
}

nav a {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    font-size: 16px;
    position: relative;
    transition: all 0.3s ease;
}

nav a:hover {
    color: var(--primary-color);
}

nav a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--primary-color);
    transition: width 0.3s ease;
}

nav a:hover::after {
    width: 100%;
}

/* 移动端菜单按钮 */
.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 24px;
    color: var(--text-dark);
    cursor: pointer;
}

/* 应用包装器 */
.app-wrapper {
    background-color: white;
    border-radius: 16px;
    box-shadow: var(--card-shadow);
    overflow: hidden;
}

.app-header {
    background: var(--primary-gradient);
    color: white;
    padding: 40px;
    text-align: center;
}

.app-header h1 {
    font-size: 32px;
    margin-bottom: 10px;
    font-weight: 700;
}

.app-subtitle {
    font-size: 18px;
    opacity: 0.9;
}

/* 转换器内容区域 */
.converter-content {
    padding: 30px;
}

/* 选项卡样式 */
.converter-tabs {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 30px;
    border-bottom: 1px solid #eee;
    padding-bottom: 15px;
}

.tab-btn {
    background: none;
    border: none;
    padding: 12px 20px;
    font-size: 16px;
    font-weight: 500;
    color: var(--text-light);
    cursor: pointer;
    border-radius: 8px;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 8px;
}

.tab-btn i {
    font-size: 18px;
}

.tab-btn:hover {
    background-color: rgba(126, 87, 194, 0.1);
    color: var(--primary-color);
}

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

/* 转换面板 */
.converter-panel {
    display: none;
}

.converter-panel.active {
    display: block;
}

.converter-card {
    border: 1px solid #eee;
    border-radius: 12px;
    overflow: hidden;
    margin-bottom: 30px;
}

.card-header {
    background-color: #f8f9fa;
    padding: 20px;
    display: flex;
    align-items: center;
    gap: 15px;
}

.card-header i {
    font-size: 24px;
    color: var(--primary-color);
    background-color: rgba(126, 87, 194, 0.1);
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 10px;
}

.card-title {
    font-size: 20px;
    margin-bottom: 5px;
}

.section-subtitle {
    color: var(--text-light);
    font-size: 14px;
}

.card-body {
    padding: 30px;
}

/* 输入组样式 */
.input-group {
    margin-bottom: 25px;
}

.input-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
}

.converter-input,
.converter-select,
.converter-textarea {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid #ddd;
    border-radius: 8px;
    font-size: 16px;
    transition: all 0.3s ease;
}

.converter-input:focus,
.converter-select:focus,
.converter-textarea:focus {
    border-color: var(--primary-color);
    outline: none;
    box-shadow: 0 0 0 3px rgba(126, 87, 194, 0.2);
}

.converter-textarea {
    min-height: 120px;
    resize: vertical;
}

.converter-color {
    width: 50px;
    height: 40px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
}

.converter-range {
    width: 100%;
    height: 8px;
    border-radius: 5px;
    background-color: #ddd;
    outline: none;
    -webkit-appearance: none;
}

.converter-range::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
}

/* 选项组样式 */
.options-group {
    background-color: #f8f9fa;
    padding: 20px;
    border-radius: 10px;
    margin-bottom: 25px;
}

.options-group h3 {
    font-size: 18px;
    margin-bottom: 15px;
    color: var(--text-dark);
}

.option-desc {
    color: var(--text-light);
    font-size: 14px;
    margin-bottom: 15px;
}

.option-row {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
}

.option-item {
    flex: 1;
    min-width: 200px;
}

/* 复选框组样式 */
.checkbox-group {
    display: flex;
    flex-direction: column;
    gap: 12px;
    width: 100%;
}

.checkbox-item {
    display: flex;
    align-items: center;
    gap: 8px;
}

.checkbox-item input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
    accent-color: var(--primary-color);
}

.checkbox-item label {
    cursor: pointer;
    font-size: 15px;
}

/* ICO预览样式 */
.ico-preview-grid {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 20px;
}

.preview-sizes {
    display: flex;
    flex-direction: column;
}

.ico-sizes-preview {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    background-color: #fff;
    border: 1px solid #eee;
    padding: 20px;
    border-radius: 10px;
    height: 100%;
    align-items: center;
}

.ico-preview-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
}

.ico-size-label {
    font-size: 12px;
    color: var(--text-light);
}

.ico-size-preview {
    border: 1px solid #ddd;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    background-color: rgba(0, 0, 0, 0.03);
    background-image: linear-gradient(45deg, #f0f0f0 25%, transparent 25%, transparent 75%, #f0f0f0 75%, #f0f0f0),
                     linear-gradient(45deg, #f0f0f0 25%, transparent 25%, transparent 75%, #f0f0f0 75%, #f0f0f0);
    background-size: 16px 16px;
    background-position: 0 0, 8px 8px;
}

.ico-size-preview#preview16 {
    width: 32px;
    height: 32px;
}

.ico-size-preview#preview32 {
    width: 64px;
    height: 64px;
}

.ico-size-preview#preview48 {
    width: 96px;
    height: 96px;
}

.ico-size-preview#preview64 {
    width: 128px;
    height: 128px;
}

.ico-size-preview img {
    max-width: 100%;
    max-height: 100%;
}

/* 上传区域样式 */
.upload-container {
    margin-bottom: 25px;
}

.drop-area {
    border: 2px dashed #ddd;
    border-radius: 10px;
    padding: 40px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
}

.drop-area:hover {
    border-color: var(--primary-color);
    background-color: rgba(126, 87, 194, 0.05);
}

.drop-area i {
    font-size: 40px;
    color: var(--primary-color);
    margin-bottom: 15px;
}

.drop-area p {
    color: var(--text-light);
    margin: 0;
}

/* 预览容器样式 */
.preview-container {
    margin-bottom: 25px;
}

.preview-container h3 {
    font-size: 18px;
    margin-bottom: 15px;
    color: var(--text-dark);
}

.svg-preview,
.image-preview {
    background-color: #f8f9fa;
    border: 1px solid #ddd;
    border-radius: 10px;
    min-height: 200px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    overflow: hidden;
}

.svg-preview img,
.image-preview img {
    max-width: 100%;
    max-height: 300px;
    object-fit: contain;
}

.preview-comparison {
    display: flex;
    gap: 20px;
}

.preview-item {
    flex: 1;
}

.preview-item h4 {
    font-size: 16px;
    margin-bottom: 10px;
    color: var(--text-dark);
}

/* 按钮样式 */
.action-buttons {
    display: flex;
    gap: 15px;
}

.btn {
    display: inline-block;
    background-color: var(--primary-color);
    color: white;
    padding: 12px 20px;
    border-radius: 30px;
    text-decoration: none;
    font-weight: 600;
    font-size: 16px;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 8px;
    box-shadow: 0 4px 10px rgba(126, 87, 194, 0.3);
}

.btn:hover {
    background-color: #6a46b5;
    transform: translateY(-2px);
    box-shadow: 0 6px 15px rgba(126, 87, 194, 0.4);
}

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

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

.btn-secondary {
    background-color: var(--secondary-color);
    box-shadow: 0 4px 10px rgba(255, 152, 0, 0.3);
}

.btn-secondary:hover {
    background-color: #e68900;
    box-shadow: 0 6px 15px rgba(255, 152, 0, 0.4);
}

/* 页脚样式 */
footer {
    background-color: #2c3e50;
    color: white;
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-bottom: 40px;
}

.footer-logo h2 {
    color: white;
    font-size: 24px;
    margin-bottom: 10px;
}

.footer-logo p {
    color: rgba(255, 255, 255, 0.7);
    font-size: 14px;
}

.footer-links h3,
.footer-contact h3 {
    color: white;
    font-size: 18px;
    margin-bottom: 20px;
    position: relative;
    display: inline-block;
}

.footer-links h3:after,
.footer-contact h3:after {
    content: '';
    position: absolute;
    left: 0;
    bottom: -8px;
    width: 30px;
    height: 2px;
    background-color: var(--primary-color);
}

.footer-links ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.footer-links li {
    margin-bottom: 10px;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: all 0.3s ease;
}

.footer-links a:hover {
    color: white;
}

.footer-contact p {
    color: rgba(255, 255, 255, 0.7);
}

.social-icons {
    display: flex;
    gap: 15px;
}

.social-icons a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background-color: rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.7);
    transition: all 0.3s ease;
}

.social-icons a:hover {
    background-color: var(--primary-color);
    color: white;
}

.copyright {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.7);
}

/* 响应式设计 */
@media (max-width: 768px) {
    .container {
        width: 95%;
        padding: 20px 0;
    }
    
    .app-header {
        padding: 30px 20px;
    }
    
    .app-header h1 {
        font-size: 24px;
    }
    
    .converter-content {
        padding: 20px;
    }
    
    .converter-tabs {
        overflow-x: auto;
        padding-bottom: 10px;
    }
    
    .tab-btn {
        padding: 10px 15px;
        font-size: 14px;
    }
    
    .card-body {
        padding: 20px;
    }
    
    .option-row {
        flex-direction: column;
        gap: 15px;
    }
    
    .option-item {
        min-width: 100%;
    }
    
    .preview-comparison {
        flex-direction: column;
    }
    
    .action-buttons {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
        justify-content: center;
    }
    
    nav {
        display: none;
    }
    
    .mobile-menu-toggle {
        display: block;
    }
    
    nav.active {
        display: flex;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background-color: white;
        box-shadow: 0 5px 10px rgba(0, 0, 0, 0.1);
        padding: 20px;
        flex-direction: column;
    }
    
    nav.active ul {
        flex-direction: column;
    }
    
    nav.active li {
        margin: 10px 0;
    }
    
    .ico-preview-grid {
        grid-template-columns: 1fr;
    }
    
    .ico-sizes-preview {
        justify-content: center;
    }
}