:root {
    --primary-color: #0071e3;
    --secondary-color: #6e6e73;
    --accent-color: #f56300;
    --text-color: #1d1d1f;
    --bg-color: #ffffff;
    --card-bg: #f5f5f7;
    --header-bg: rgba(255, 255, 255, 0.8);
    --footer-bg: #f5f5f7;
    --gradient-start: #a960ee;
    --gradient-end: #ff8a00;
    --gradient-start-rgb: 169, 96, 238;
    --gradient-end-rgb: 255, 138, 0;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 10px 20px rgba(0, 0, 0, 0.15);
    --transition: all 0.3s ease;
    --border-radius: 12px;
}

[data-theme="dark"] {
    --primary-color: #2997ff;
    --secondary-color: #86868b;
    --accent-color: #ff9f0a;
    --text-color: #f5f5f7;
    --bg-color: #1d1d1f;
    --card-bg: #2c2c2e;
    --header-bg: rgba(29, 29, 31, 0.8);
    --footer-bg: #2c2c2e;
    --gradient-start: #2997ff;
    --gradient-end: #ff9f0a;
    --gradient-start-rgb: 41, 151, 255;
    --gradient-end-rgb: 255, 159, 10;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
    --shadow-hover: 0 10px 20px rgba(0, 0, 0, 0.4);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.5;
    transition: var(--transition);
}

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

a:hover {
    color: var(--accent-color);
}

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

/* Header & Navigation */
header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    transition: var(--transition);
}

.main-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    background: var(--header-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    box-shadow: var(--shadow);
}

.logo {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-color);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

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

.main-nav a {
    color: var(--text-color);
    font-weight: 500;
    position: relative;
}

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

.main-nav a:hover::after,
.main-nav a.active::after {
    width: 100%;
}

.theme-toggle {
    cursor: pointer;
    font-size: 1.2rem;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    background: var(--card-bg);
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.theme-toggle:hover {
    transform: rotate(30deg);
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, var(--gradient-start) 0%, var(--gradient-end) 100%);
    color: white;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('../img/pattern.svg');
    opacity: 0.1;
    z-index: 1;
}

.hero .container {
    position: relative;
    z-index: 2;
    padding: 4rem 2rem;
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero h2 {
    font-size: 2rem;
    font-weight: 500;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.intro {
    max-width: 700px;
    margin-bottom: 2rem;
    font-size: 1.1rem;
    line-height: 1.6;
}

.cta-buttons {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
}

.btn {
    display: inline-block;
    padding: 0.8rem 1.5rem;
    border-radius: 30px;
    font-weight: 500;
    transition: var(--transition);
    cursor: pointer;
}

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

.btn.primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

.btn.secondary {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    backdrop-filter: blur(5px);
}

.btn.secondary:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-3px);
}

/* Overview Section */
.overview {
    padding: 6rem 0;
    background-color: var(--bg-color);
}

.overview h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    position: relative;
}

.overview h2::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 50px;
    height: 3px;
    background: var(--primary-color);
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.card {
    background: var(--card-bg);
    border-radius: var(--border-radius);
    padding: 2rem;
    box-shadow: var(--shadow);
    transition: var(--transition);
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-hover);
}

.card i {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 1.5rem;
}

.card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.card p {
    margin-bottom: 1.5rem;
    color: var(--secondary-color);
}

.learn-more {
    margin-top: auto;
    color: var(--primary-color);
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.learn-more:hover {
    color: var(--accent-color);
}

.learn-more::after {
    content: '→';
    transition: var(--transition);
}

.learn-more:hover::after {
    transform: translateX(5px);
}

/* Footer */
footer {
    background: var(--footer-bg);
    padding: 4rem 0 2rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h4 {
    font-size: 1.2rem;
    margin-bottom: 1.5rem;
    position: relative;
}

.footer-section h4::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 0;
    width: 30px;
    height: 2px;
    background: var(--primary-color);
}

.footer-section ul {
    list-style: none;
}

.footer-section li {
    margin-bottom: 0.8rem;
}

.footer-section a {
    color: var(--secondary-color);
    transition: var(--transition);
}

.footer-section a:hover {
    color: var(--primary-color);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(128, 128, 128, 0.2);
    color: var(--secondary-color);
    font-size: 0.9rem;
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    animation: fadeIn 0.8s ease forwards;
}

.delay-1 {
    animation-delay: 0.2s;
}

.delay-2 {
    animation-delay: 0.4s;
}

.delay-3 {
    animation-delay: 0.6s;
}

.delay-4 {
    animation-delay: 0.8s;
}

/* Page Transitions */
.page-transition {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--bg-color);
    z-index: 9999;
    transform: translateY(100%);
    transition: transform 0.5s ease;
}

.page-transition.active {
    transform: translateY(0);
}

/* 特性盒子样式 */
.feature-box {
    background: var(--card-bg);
    border-radius: var(--border-radius);
    padding: 2rem;
    text-align: center;
    transition: var(--transition);
    box-shadow: var(--shadow);
}

.feature-box:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-hover);
}

.feature-box i {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 1.5rem;
}

.feature-box h3 {
    margin-bottom: 1rem;
}

.feature-box p {
    color: var(--secondary-color);
}

/* 特性部分 */
.features {
    padding: 6rem 0;
    background: linear-gradient(135deg, rgba(var(--gradient-start-rgb), 0.05) 0%, rgba(var(--gradient-end-rgb), 0.05) 100%);
}

/* 导航栏滚动效果 */
header.scrolled .main-nav {
    padding: 0.5rem 2rem;
    box-shadow: var(--shadow);
}

header.nav-hidden {
    transform: translateY(-100%);
}

/* 动画状态 */
.animate-on-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.animate-on-scroll.animated {
    opacity: 1;
    transform: translateY(0);
}

/* 导入移动端菜单样式 */
@import url('menu.css');

/* Responsive */
@media (max-width: 768px) {
    .main-nav {
        padding: 1rem;
    }

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

    .hero h2 {
        font-size: 1.5rem;
    }

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

    .btn {
        width: 100%;
        text-align: center;
        margin-bottom: 1rem;
    }

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