/* Video Tools 官网样式 */

/* 重置样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* 全局样式 */
:root {
    --primary-color: #6366f1;
    --primary-dark: #4f46e5;
    --secondary-color: #8b5cf6;
    --text-dark: #1f2937;
    --text-light: #6b7280;
    --bg-light: #f9fafb;
    --border-color: #e5e7eb;
    --success-color: #10b981;
    --warning-color: #f59e0b;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans', sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: #fff;
}

/* 容器 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 导航栏 */
.navbar {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.navbar-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.navbar-brand {
    display: flex;
    align-items: center;
    text-decoration: none;
    color: var(--text-dark);
    font-size: 1.5rem;
    font-weight: 700;
}

.navbar-brand-icon {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    margin-right: 12px;
    font-size: 1.2rem;
}

.navbar-nav {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.navbar-nav a {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    transition: color 0.3s;
}

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

.navbar-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
}

/* Hero 区域 */
.hero {
    padding: 160px 0 100px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.25rem;
    opacity: 0.95;
    margin-bottom: 2.5rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 14px 32px;
    border-radius: 12px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.2);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    backdrop-filter: blur(10px);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.3);
}

.btn-large {
    padding: 18px 40px;
    font-size: 1.125rem;
}

/* 特性区域 */
.features {
    padding: 100px 0;
    background: var(--bg-light);
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.section-subtitle {
    text-align: center;
    color: var(--text-light);
    font-size: 1.125rem;
    margin-bottom: 3rem;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.feature-card {
    background: white;
    padding: 2rem;
    border-radius: 16px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    transition: all 0.3s;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
}

.feature-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.75rem;
    margin-bottom: 1.5rem;
}

.feature-card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
    color: var(--text-dark);
}

.feature-card p {
    color: var(--text-light);
    line-height: 1.6;
}

/* 下载区域 */
.downloads {
    padding: 100px 0;
}

.download-tabs {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 3rem;
    flex-wrap: wrap;
}

.download-tab {
    padding: 12px 24px;
    border: 2px solid var(--border-color);
    background: white;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s;
    font-weight: 600;
    color: var(--text-dark);
}

.download-tab:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
}

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

.download-content {
    display: none;
}

.download-content.active {
    display: block;
}

.download-card {
    background: var(--bg-light);
    border-radius: 20px;
    padding: 3rem;
    max-width: 800px;
    margin: 0 auto;
}

.download-card-header {
    text-align: center;
    margin-bottom: 2rem;
}

.download-card h3 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.download-version {
    color: var(--text-light);
    font-size: 0.875rem;
}

.download-button {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    width: 100%;
    padding: 20px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 12px;
    font-size: 1.125rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    margin-bottom: 1rem;
}

.download-button:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
}

.download-info {
    display: flex;
    justify-content: space-around;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
}

.info-item {
    text-align: center;
}

.info-label {
    display: block;
    font-size: 0.75rem;
    color: var(--text-light);
    margin-bottom: 0.25rem;
}

.info-value {
    font-weight: 600;
    color: var(--text-dark);
}

.system-requirements {
    margin-top: 2rem;
    padding: 1.5rem;
    background: white;
    border-radius: 12px;
}

.system-requirements h4 {
    font-size: 1rem;
    margin-bottom: 1rem;
}

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

.system-requirements li {
    padding: 0.5rem 0;
    color: var(--text-light);
    font-size: 0.875rem;
}

.system-requirements li:before {
    content: "✓ ";
    color: var(--success-color);
    font-weight: bold;
    margin-right: 0.5rem;
}

/* 使用指南区域 */
.guide {
    padding: 100px 0;
    background: var(--bg-light);
}

.guide-section {
    background: white;
    border-radius: 20px;
    padding: 3rem;
    margin-bottom: 2rem;
}

.guide-section h3 {
    font-size: 1.75rem;
    margin-bottom: 1.5rem;
    color: var(--text-dark);
}

.guide-steps {
    list-style: none;
    counter-reset: step-counter;
}

.guide-steps li {
    position: relative;
    padding-left: 80px;
    margin-bottom: 2rem;
}

.guide-steps li:before {
    counter-increment: step-counter;
    content: counter(step-counter);
    position: absolute;
    left: 0;
    top: 0;
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.5rem;
    font-weight: 700;
}

.guide-steps h4 {
    font-size: 1.125rem;
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.guide-steps p {
    color: var(--text-light);
    line-height: 1.6;
}

.guide-image {
    width: 100%;
    border-radius: 12px;
    margin: 1.5rem 0;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

/* 支持格式区域 */
.formats {
    padding: 100px 0;
}

.formats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
    gap: 1rem;
    margin-top: 3rem;
}

.format-tag {
    background: var(--bg-light);
    padding: 12px 16px;
    border-radius: 8px;
    text-align: center;
    font-weight: 600;
    color: var(--text-dark);
    transition: all 0.3s;
}

.format-tag:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-2px);
}

/* 页脚 */
.footer {
    background: var(--text-dark);
    color: white;
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-section h4 {
    font-size: 1.125rem;
    margin-bottom: 1.5rem;
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: 0.75rem;
}

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

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

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.875rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .navbar-nav {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 1rem;
        gap: 0;
        box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
    }

    .navbar-nav.active {
        display: flex;
    }

    .navbar-nav a {
        padding: 0.75rem 0;
        border-bottom: 1px solid var(--border-color);
    }

    .navbar-toggle {
        display: block;
    }

    .hero h1 {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }

    .section-title {
        font-size: 2rem;
    }

    .features-grid {
        grid-template-columns: 1fr;
    }

    .download-card {
        padding: 2rem 1.5rem;
    }

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

    .guide-steps li {
        padding-left: 0;
    }

    .guide-steps li:before {
        position: relative;
        margin-bottom: 1rem;
    }
}

/* 动画 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    animation: fadeInUp 0.6s ease-out;
}