:root {
    --primary: #3b82f6;
    --primary-dark: #2563eb;
    --secondary: #f97316;
    --success: #10b981;
    --danger: #ef4444;
    --light: #f8fafc;
    --dark: #1e293b;
    --gray: #64748b;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
}

body {
    background: linear-gradient(135deg, #f5f7fa 0%, #e4eaf5 100%);
    color: var(--dark);
    line-height: 1.7;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}


.breadcrumb {
    padding: 1.2rem 0;
    font-size: 0.9rem;
}

.breadcrumb a {
    color: var(--primary);
    text-decoration: none;
}

.breadcrumb span {
    color: var(--gray);
    margin: 0 0.4rem;
}

/* 转换区域 */
.convert-section {
    padding: 3rem 0 5rem;
    text-align: center;
}

.convert-section h1 {
    font-size: 2.3rem;
    margin-bottom: 1rem;
    color: var(--dark);
}

.convert-section p {
    max-width: 750px;
    margin: 0 auto 2.5rem;
    color: var(--gray);
    font-size: 1.1rem;
}

.convert-box {
    background: #fff;
    max-width: 720px;
    margin: 0 auto;
    padding: 2.5rem;
    border-radius: 16px;
    box-shadow: var(--shadow-lg);
}

/* 上传区域 */
.upload-area {
    border: 2px dashed var(--primary);
    border-radius: 12px;
    padding: 2.5rem 1rem;
    cursor: pointer;
    transition: 0.3s;
    margin-bottom: 1.5rem;
}

.upload-area:hover {
    background: rgba(59, 130, 246, 0.05);
}

.upload-icon {
    font-size: 2.8rem;
    color: var(--primary);
    margin-bottom: 0.8rem;
}

.file-info {
    display: none;
    text-align: left;
    padding: 1rem;
    background: #f1f5f9;
    border-radius: 8px;
    margin-bottom: 1rem;
}

.file-name {
    font-weight: 600;
    color: var(--dark);
}

.file-size {
    font-size: 0.85rem;
    color: var(--gray);
}

/* 进度条 */
.progress-container {
    display: none;
    margin: 1rem 0;
}

.progress-bar {
    height: 8px;
    background: #e2e8f0;
    border-radius: 99px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    width: 0%;
    background: var(--primary);
    transition: width 0.3s;
}

.progress-text {
    font-size: 0.9rem;
    color: var(--gray);
    margin-top: 0.5rem;
}

/* 结果区域 */
.result-area {
    display: none;
    padding: 1.5rem;
    background: #f0fdf4;
    border-radius: 12px;
    margin-bottom: 1rem;
}

.result-icon {
    font-size: 2rem;
    color: var(--success);
    margin-bottom: 0.5rem;
}

.result-text {
    font-weight: 600;
    color: #166534;
    margin-bottom: 1rem;
}

/* 按钮 */
.btn {
    padding: 0.9rem 2rem;
    border-radius: 8px;
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: 0.3s;
    margin: 0.3rem;
}

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

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

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

.btn-secondary {
    background: #e2e8f0;
    color: var(--dark);
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.action-buttons {
    margin-top: 1rem;
}

.file-input {
    display: none;
}

/* 内容区 */
.info-section {
    background: #fff;
    padding: 3rem;
    border-radius: 16px;
    box-shadow: var(--shadow);
    margin-bottom: 4rem;
    text-align: left;
}

.info-section h2 {
    font-size: 1.6rem;
    margin-bottom: 1rem;
    color: var(--dark);
    border-left: 4px solid var(--primary);
    padding-left: 1rem;
}

.info-section p, .info-section li {
    color: var(--gray);
    margin-bottom: 0.8rem;
}

/* 相关工具 */
.related {
    padding: 2rem 0 5rem;
}

.related h2 {
    text-align: center;
    margin-bottom: 2rem;
    font-size: 1.8rem;
}

.tool-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.5rem;
}

.tool-card {
    background: #fff;
    padding: 2rem;
    border-radius: 12px;
    text-align: center;
    box-shadow: var(--shadow);
    transition: 0.3s;
}

.tool-card:hover {
    transform: translateY(-5px);
}

.tool-card i {
    font-size: 2.2rem;
    color: var(--primary);
    margin-bottom: 1rem;
}

.tool-card h3 {
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
}

.tool-card a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 600;
}

@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        gap: 1rem;
    }

    .convert-section h1 {
        font-size: 1.9rem;
    }

    .info-section {
        padding: 2rem 1.5rem;
    }
}