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

body {
    font-family: Arial, "Microsoft YaHei", sans-serif;
    line-height: 1.7;
    color: #222;
    background: #f5f7fb;
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 8%;
    background: #ffffff;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.06);
    position: sticky;
    top: 0;
    z-index: 10;
}

.navbar h1 {
    color: #2563eb;
}

.navbar nav {
    display: flex;
    gap: 20px;
}

.navbar a,
a {
    color: #2563eb;
    text-decoration: none;
}

.navbar a:hover,
a:hover {
    text-decoration: underline;
}

.hero {
    text-align: center;
    padding: 90px 20px;
    background: linear-gradient(135deg, #dbeafe, #eff6ff);
}

.avatar {
    width: 140px;
    height: 140px;
    object-fit: cover;
    border-radius: 50%;
    border: 5px solid white;
    margin-bottom: 20px;
}

.hero h2 {
    font-size: 38px;
    margin-bottom: 12px;
}

.button {
    display: inline-block;
    margin-top: 25px;
    padding: 10px 22px;
    color: white;
    background: #2563eb;
    border-radius: 8px;
}

.button:hover {
    background: #1d4ed8;
    text-decoration: none;
}

.section {
    max-width: 1000px;
    margin: 0 auto;
    padding: 70px 20px;
}

.section h2 {
    margin-bottom: 20px;
    font-size: 30px;
}

.cards {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 15px;
}

.card,
.project {
    padding: 25px;
    background: white;
    border-radius: 12px;
    box-shadow: 0 3px 15px rgba(0, 0, 0, 0.06);
}

footer {
    padding: 25px;
    text-align: center;
    color: #666;
    background: white;
}

@media (max-width: 700px) {
    .navbar {
        flex-direction: column;
        gap: 12px;
    }

    .navbar nav {
        gap: 10px;
        flex-wrap: wrap;
        justify-content: center;
    }

    .hero h2 {
        font-size: 30px;
    }

    .cards {
        grid-template-columns: repeat(2, 1fr);
    }
}