:root {
    --primary-color: #3b82f6;
    --secondary-color: #1d4ed8;
    --text-color: #1f2937;
    --light-bg: #f8fafc;
    --hover-color: #2563eb;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    opacity: 0;
    animation: fadeIn 0.5s ease forwards;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 导航栏样式 */
header {
    background: white;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 100;
}

nav {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-links {
    display: flex;
    list-style: none;
    align-items: center;
    gap: 2rem;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-color);
    position: relative;
    padding-bottom: 0.25rem;
}

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

.nav-links a:hover::after {
    width: 100%;
}

/* 主要内容样式 */
.hero {
    padding: 8rem 2rem 4rem;
    text-align: center;
    background: var(--light-bg);
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.subtitle {
    font-size: 1.5rem;
    color: #4b5563;
    margin-bottom: 2rem;
}

/* 按钮样式 */
.cta-button, .primary-button, .login-button {
    background: var(--primary-color);
    color: white;
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 0.375rem;
    cursor: pointer;
    font-weight: 500;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.cta-button:hover, .primary-button:hover, .login-button:hover {
    background: var(--secondary-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.2);
}

.cta-button:active, .primary-button:active, .login-button:active {
    transform: translateY(0);
}

.secondary-button {
    background: white;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
    padding: 0.75rem 1.5rem;
    border-radius: 0.375rem;
    cursor: pointer;
    font-weight: 500;
    margin-left: 1rem;
    transition: all 0.3s ease;
}

.secondary-button:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.2);
}

/* 特性卡片样式 */
.features {
    max-width: 1200px;
    margin: 4rem auto;
    padding: 2rem;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.feature-card {
    text-align: center;
    padding: 2rem;
    border-radius: 1rem;
    background: white;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    transition: all 0.3s ease;
    border: 1px solid rgba(0,0,0,0.05);
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 12px 24px rgba(0,0,0,0.1);
}

.feature-card i {
    font-size: 48px;
    color: var(--primary-color);
    margin-bottom: 1.5rem;
    transition: all 0.3s ease;
}

.feature-card:hover i {
    transform: scale(1.1);
    color: var(--secondary-color);
}

/* 页脚样式 */
footer {
    background: var(--light-bg);
    padding: 2rem;
    margin-top: 4rem;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    text-align: center;
}

.footer-links {
    margin-bottom: 1rem;
}

.footer-links a {
    color: var(--text-color);
    text-decoration: none;
    margin: 0 1rem;
}

.copyright {
    color: #6b7280;
    font-size: 0.875rem;
}

/* 添加使用流程部分的样式 */
.how-it-works {
    max-width: 1200px;
    margin: 4rem auto;
    padding: 2rem;
    text-align: center;
}

.how-it-works h2 {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: var(--text-color);
}

.steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.step {
    padding: 2rem;
    background: white;
    border-radius: 1rem;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    transition: all 0.3s ease;
    border: 1px solid rgba(0,0,0,0.05);
}

.step:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 16px rgba(0,0,0,0.1);
}

.step-number {
    display: inline-block;
    width: 40px;
    height: 40px;
    line-height: 40px;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    margin-bottom: 1rem;
    font-weight: bold;
    transition: all 0.3s ease;
}

.step:hover .step-number {
    transform: scale(1.1);
    box-shadow: 0 4px 8px rgba(59, 130, 246, 0.3);
}

.step h3 {
    margin-bottom: 1rem;
    color: var(--text-color);
}

/* 添加汉堡菜单按钮样式 */
.menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 30px;
    height: 21px;
    cursor: pointer;
    z-index: 200;
}

.menu-toggle span {
    display: block;
    height: 3px;
    width: 100%;
    background-color: var(--text-color);
    transition: all 0.3s ease;
}

/* 移动端适配 */
@media screen and (max-width: 768px) {
    .menu-toggle {
        display: flex;
    }

    .nav-links {
        position: fixed;
        top: 0;
        right: -100%;
        height: 100vh;
        width: 70%;
        max-width: 300px;
        background: white;
        flex-direction: column;
        padding: 80px 2rem 2rem;
        transition: all 0.3s ease;
        box-shadow: -2px 0 10px rgba(0, 0, 0, 0.1);
        z-index: 150;
    }

    .nav-links.active {
        right: 0;
    }

    .nav-links li {
        margin: 1.5rem 0;
    }

    /* 汉堡菜单动画 */
    .menu-toggle.active span:nth-child(1) {
        transform: translateY(9px) rotate(45deg);
    }

    .menu-toggle.active span:nth-child(2) {
        opacity: 0;
    }

    .menu-toggle.active span:nth-child(3) {
        transform: translateY(-9px) rotate(-45deg);
    }

    /* 遮罩层 */
    .overlay {
        display: none;
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background: rgba(0, 0, 0, 0.5);
        z-index: 100;
    }

    .overlay.active {
        display: block;
    }

    /* 调整其他元素的响应式布局 */
    .hero h1 {
        font-size: 2rem;
    }

    .subtitle {
        font-size: 1.2rem;
    }

    .cta-group {
        display: flex;
        flex-direction: column;
        gap: 1rem;
    }

    .secondary-button {
        margin-left: 0;
    }

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

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