body {
    margin: 0;
    font-family: 'Segoe UI', 'Microsoft Yahei', Arial, sans-serif;
    background: #f6fafe;
    color: #222;
}

header {
    background: #1b82e3;
    color: #fff;
    padding: 0.6rem 0;
}

header .logo {
    text-align: center;
    padding: 10px 0 4px 0;
}
nav {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 12px;
    padding-bottom: 8px;
}
nav a {
    color: #fff;
    padding: 6px 12px;
    text-decoration: none;
    font-size: 16px;
    border-radius: 3px;
    transition: background 0.15s;
}
nav a:hover {
    background: rgba(255,255,255,0.13);
}

main {
    max-width: 980px;
    margin: 1.5rem auto 2.8rem;
    padding: 20px 20px 30px 20px;
    background: #fff;
    border-radius: 12px;
    box-shadow: 0 3px 24px #b1dcff2c;
}
h1, h2 {
    color: #1886d9;
    font-weight: 600;
    margin-bottom: 10px;
}
h2 {
    margin-top: 30px;
}

.hero {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 30px;
    margin-bottom: 36px;
}
.hero-left {
    flex: 1 1 340px;
}
.hero-right {
    flex: 1 1 260px; text-align:center;
}
.hero .app-screenshot {
    width: 220px;
    border-radius: 20px;
    box-shadow: 0 3px 18px #91b0db61;
    margin: 0 16px;
}

.features-preview ul {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px,1fr));
    gap: 8px;
}
.features-preview li {
    list-style: square;
    padding: 8px 12px;
    margin: 0 10px 6px 0;
    background: #f0f5fc;
    border-radius: 4px;
}

.gallery-row {
    display: flex;
    flex-wrap: wrap;
    gap: 18px;
    justify-content: flex-start;
    margin: 8px 0 30px 0;
}
.gallery-row img {
    width: 140px;
    border-radius: 9px;
    box-shadow: 0 2px 12px #c1d8ef25;
    background:#fbfbfd;
    object-fit: cover;
}

.btn-link {
    text-decoration: none;
    color: #1886d9;
    font-weight: 500;
}
.reviews blockquote {
    background: #f8fafd;
    border-left: 4px solid #1886d9;
    padding: 9px 18px;
    margin: 14px 0;
    font-size: 1rem;
    color: #2d3c54;
    border-radius: 0 7px 7px 0;
}

/* footer */
footer {
    text-align: center;
    color: #888;
    font-size: 15px;
    padding: 20px 0 13px 0;
    margin-top: 30px;
    background: #e8f2fc;
    border-top: 1px solid #ddeeff;
}

/* --- ↓↓↓ Responsive Layout ↓↓↓ --- */
@media (max-width: 780px) {
    main {
        padding: 8px 2vw 25px 2vw;
        margin: 1vw;
    }
    .hero {
        flex-direction: column;
        align-items: stretch;
        gap: 0;
    }
    .gallery-row {
        justify-content: center;
    }
}
@media (max-width:480px) {
    nav {
        font-size: 15px;
        flex-direction: column;
        gap: 6px;
    }
    .hero .app-screenshot {
        width: 98vw;
        max-width: 260px;
    }
    .gallery-row img {
        width: 90vw;
        max-width: 160px;
    }
    .hero-left, .hero-right {
        width: 100%;
    }
    main {
        padding: 5px 0 16px 0;
    }
    h1 {
        font-size: 1.3rem;
    }
    h2 {
        font-size: 1.08rem;
    }
}