:root {
    /* 默认颜色变量，将被 JavaScript 动态覆盖 */
    --primary: #2C3E50;
    --primary-light: #4A6582;
    --secondary: #E74C3C;
    --tertiary: #3498DB;
    --accent: #1ABC9C;
    --dark: #1A1A1A;
    --gray: #7F8C8D;
    --light: #F8F9FA;
    --card-bg: rgba(255, 255, 255, 0.95);
    --body-bg: #f9f9f9;
    --header-bg: rgba(255, 255, 255, 0.95);
    --header-border: rgba(0, 0, 0, 0.08);
    --mobile-menu-bg: white;
    --mobile-menu-shadow: -10px 0 30px rgba(0, 0, 0, 0.1);
    --card-shadow: 0 8px 25px rgba(0, 0, 0, 0.06);
    --card-border: rgba(0, 0, 0, 0.08);
    --screenshot-bg: #f0f2f5;
    --sidebar-bg: white;
    --sidebar-shadow: 0 10px 30px rgba(0, 0, 0, 0.06);
    --transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.1);
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--body-bg);
    color: var(--dark);
    line-height: 1.7;
    overflow-x: hidden;
}

h1, h2, h3, h4 {
    font-family: 'Space Grotesk', sans-serif;
    font-weight: 600;
    line-height: 1.3;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 24px;
}

header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    padding: 24px 0;
    transition: var(--transition);
    background-color: var(--header-bg);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--header-border);
}

header.scrolled {
    padding: 16px 0;
    box-shadow: 0 5px 25px rgba(0, 0, 0, 0.05);
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 36px;
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 16px;
}

.logo {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--dark);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo-dot {
    width: 10px;
    height: 10px;
    background-color: var(--accent);
    border-radius: 50%;
    display: inline-block;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 36px;
}

.nav-links a {
    text-decoration: none;
    color: var(--dark);
    font-weight: 500;
    font-size: 1rem;
    position: relative;
    transition: var(--transition);
}

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

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

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

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--dark);
    cursor: pointer;
}

.mobile-menu {
    position: fixed;
    top: 0;
    right: -100%;
    width: 300px;
    height: 100vh;
    background-color: var(--mobile-menu-bg);
    z-index: 2000;
    padding: 40px;
    box-shadow: var(--mobile-menu-shadow);
    transition: var(--transition);
    display: flex;
    flex-direction: column;
}

.mobile-menu.active {
    right: 0;
}

.mobile-menu-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 40px;
}

.mobile-menu-links {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.mobile-menu-links a {
    text-decoration: none;
    color: var(--dark);
    font-size: 1.2rem;
    font-weight: 500;
    transition: var(--transition);
}

.mobile-menu-links a:hover {
    color: var(--primary);
}

.menu-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 1999;
    display: none;
}

.menu-overlay.active {
    display: block;
}

footer {
    background-color: var(--primary);
    color: white;
    padding: 80px 0 40px;
    margin-top: 80px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 50px;
    margin-bottom: 60px;
}

.footer-section h3 {
    font-size: 1.3rem;
    margin-bottom: 25px;
    color: white;
}

.footer-section p {
    color: rgba(255, 255, 255, 0.8);
    margin-bottom: 25px;
    line-height: 1.8;
}

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

.social-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 45px;
    height: 45px;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: 10px;
    color: white;
    text-decoration: none;
    transition: var(--transition);
}

.social-link:hover {
    background-color: var(--accent);
    transform: translateY(-5px);
}

.copyright {
    text-align: center;
    padding-top: 40px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.95rem;
}

.theme-toggle {
    background: none;
    border: none;
    font-size: 1.2rem;
    color: var(--dark);
    cursor: pointer;
    padding: 8px;
    border-radius: 50%;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    flex-shrink: 0;
}

.theme-toggle:hover {
    background-color: rgba(0, 0, 0, 0.05);
    transform: scale(1.1);
}

:root.dark-theme .theme-toggle:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .mobile-menu-btn {
        display: block;
    }
}