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

body {
    font-family: 'PingFang SC', 'Microsoft YaHei', sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f0f7ff;
}

.yandex-header {
    background: linear-gradient(135deg, #2296f3 0%, #64b5f6 100%);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-inner {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo-box {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo-icon {
    font-size: 1.5rem;
}

.logo-box h1 a {
    color: #fff;
    text-decoration: none;
    font-size: 1.5rem;
}

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

.yandex-nav ul li a {
    color: #fff;
    text-decoration: none;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    transition: all 0.3s ease;
}

.yandex-nav ul li a:hover,
.yandex-nav ul li a.active {
    background: rgba(255, 255, 255, 0.2);
}

.hero-section {
    background: linear-gradient(rgba(34, 150, 243, 0.8), rgba(100, 181, 246, 0.8)),
                url('https://trae-api-cn.mchost.guru/api/ide/v1/text_to_image?prompt=search%20engine%20technology%20blue&image_size=landscape_16_9');
    background-size: cover;
    background-position: center;
    height: 400px;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: #fff;
}

.hero-content h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.hero-content p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
}

.btn {
    display: inline-block;
    background: #fff;
    color: #2296f3;
    padding: 1rem 2rem;
    text-decoration: none;
    border-radius: 30px;
    font-weight: 600;
    transition: all 0.3s ease;
}

.btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
}

.btn-small {
    padding: 0.5rem 1.5rem;
    font-size: 0.9rem;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 4rem 2rem;
}

.features-section h3,
.upcoming-section h3,
.leaderboard-section h3 {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 3rem;
    color: #333;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 2rem;
}

.feature-card {
    background: #fff;
    padding: 2rem;
    border-radius: 15px;
    text-align: center;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
    transition: transform 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-10px);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.feature-card h4 {
    margin-bottom: 0.5rem;
    color: #333;
}

.feature-card p {
    color: #666;
    font-size: 0.9rem;
}

.upcoming-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.upcoming-card {
    background: #fff;
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.08);
}

.upcoming-card .date {
    display: inline-block;
    background: #2296f3;
    color: #fff;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.8rem;
    margin-bottom: 1rem;
}

.upcoming-card h4 {
    margin-bottom: 0.5rem;
    color: #333;
}

.upcoming-card p {
    color: #666;
    margin-bottom: 1rem;
}

.leaderboard-section {
    background: #fff;
}

.leaderboard {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    max-width: 400px;
    margin: 0 auto;
}

.leader-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 1.5rem;
    background: #f8f9fa;
    border-radius: 10px;
}

.leader-item.top {
    background: linear-gradient(135deg, #fff3e0 0%, #ffe0b2 100%);
}

.leader-item .rank {
    font-size: 1.5rem;
}

.leader-item .name {
    flex: 1;
    margin-left: 1rem;
}

.leader-item .score {
    font-weight: 600;
    color: #2296f3;
}

.yandex-footer {
    background: #333;
    padding: 3rem 0;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h4 {
    color: #fff;
    margin-bottom: 1rem;
}

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

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section ul li a {
    color: #999;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section ul li a:hover {
    color: #fff;
}

.footer-section p {
    color: #999;
}

.copyright {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid #444;
    color: #999;
}

@media (max-width: 900px) {
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .upcoming-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .header-inner {
        flex-direction: column;
        gap: 1rem;
    }
    .yandex-nav ul {
        flex-wrap: wrap;
        justify-content: center;
        gap: 1rem;
    }
    .features-grid {
        grid-template-columns: 1fr;
    }
    .upcoming-grid {
        grid-template-columns: 1fr;
    }
    .footer-content {
        grid-template-columns: 1fr;
    }
}