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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI",
        "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
    color: #222;
    background: #fff;
    line-height: 1.7;
}

a {
    text-decoration: none;
    color: inherit;
}

.container {
    width: min(1100px, 90%);
    margin: 0 auto;
}

.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.88);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid #eee;
    z-index: 1000;
}

.nav-inner {
    height: 70px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    font-size: 22px;
    font-weight: 700;
}

nav {
    display: flex;
    gap: 30px;
}

nav a {
    font-size: 14px;
    color: #555;
    transition: 0.2s;
}

nav a:hover {
    color: #000;
}

.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 70px;
    background: radial-gradient(circle at 50% 20%, #f1f5ff, #fff 55%);
}

.hero-content {
    text-align: center;
}

.tag {
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 3px;
    color: #667eea;
    margin-bottom: 15px;
}

.hero h1 {
    font-size: clamp(42px, 7vw, 78px);
    line-height: 1.15;
    letter-spacing: -3px;
    margin-bottom: 25px;
}

.description {
    max-width: 620px;
    margin: 0 auto 35px;
    color: #666;
    font-size: 17px;
}

.buttons {
    display: flex;
    justify-content: center;
    gap: 15px;
    flex-wrap: wrap;
}

.btn {
    display: inline-block;
    padding: 12px 26px;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 600;
    transition: 0.25s;
}

.btn.primary {
    color: white;
    background: #111;
}

.btn.primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.15);
}

.btn.secondary {
    border: 1px solid #ddd;
    background: white;
}

.btn.secondary:hover {
    background: #f7f7f7;
}

.section {
    padding: 120px 0;
}

.section-title {
    text-align: center;
    margin-bottom: 60px;
}

.section-title h2 {
    font-size: 42px;
    letter-spacing: -1.5px;
    margin-bottom: 12px;
}

.section-title > p:last-child {
    color: #777;
}

.cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 25px;
}

.card {
    padding: 35px;
    border: 1px solid #eee;
    border-radius: 14px;
    background: white;
    transition: 0.25s;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.07);
}

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

.card h3 {
    margin-bottom: 10px;
    font-size: 20px;
}

.card p {
    color: #777;
    font-size: 14px;
}

.about {
    background: #f7f7f7;
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    align-items: center;
}

.about h2 {
    font-size: 42px;
    line-height: 1.25;
    letter-spacing: -1.5px;
}

.about p {
    color: #666;
    margin-bottom: 20px;
}

.contact {
    padding: 130px 0;
    text-align: center;
}

.contact h2 {
    font-size: 48px;
    margin-bottom: 15px;
}

.contact p {
    color: #777;
    margin-bottom: 30px;
}

footer {
    border-top: 1px solid #eee;
    padding: 25px 0;
    font-size: 13px;
    color: #888;
}

.footer-inner {
    display: flex;
    justify-content: space-between;
}

@media (max-width: 700px) {
    .nav-inner {
        height: 60px;
    }

    nav {
        gap: 15px;
    }

    nav a {
        font-size: 12px;
    }

    .hero h1 {
        letter-spacing: -2px;
    }

    .description {
        font-size: 15px;
    }

    .section {
        padding: 80px 0;
    }

    .section-title h2 {
        font-size: 32px;
    }

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

    .about-content {
        grid-template-columns: 1fr;
        gap: 30px;
    }

    .about h2 {
        font-size: 34px;
    }

    .contact h2 {
        font-size: 36px;
    }

    .footer-inner {
        flex-direction: column;
        gap: 5px;
        text-align: center;
    }
}