body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Arial', sans-serif;
    background: radial-gradient(ellipse at 50% 25%, #f7fafc 70%, #e8ebf0 120%);
    color: #222;
    min-height: 100vh;
}

header {
    text-align: center;
    padding-top: 3.1rem;
    margin-bottom: 0.4rem;
}

.logo {
    display: flex;
    justify-content: center;
    align-items: center;
}

.circle {
    display: inline-block;
    width: 54px;
    height: 54px;
    border-radius: 50%;
    background: linear-gradient(135deg, #ffd24c 0%, #fff275 80%);
    box-shadow: 0 2px 14px rgba(240,210,70,0.17);
}

h1 {
    font-size: 2.83rem;
    font-weight: 700;
    color: #222;
    letter-spacing: 1.5px;
    margin-top: 0.9rem;
}

.os {
    font-weight: 400;
    color: #bfc9d2;
    margin-left: 0.14em;
    background: linear-gradient(90deg,#bfc9d2 15%, #f6f7fb 90%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

main {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 74vh;
}

.hero {
    background: rgba(255,255,255,0.89);
    border-radius: 18px;
    box-shadow: 0 6px 28px rgba(120,120,150,0.07);
    padding: 3.2rem 3.8rem;
    text-align: center;
    max-width: 400px;
    margin-top: -2rem;
}

.hero h2 {
    font-size: 1.46rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: #0070f3;
}

.desc {
    font-size: 1.13rem;
    color: #2a3456;
    margin-bottom: 2.25rem;
    line-height: 1.5;
}

.cta {
    display: inline-block;
    text-decoration: none;
    font-size: 1.09rem;
    font-weight: 700;
    color: #fff;
    background: linear-gradient(90deg,#0070f3 0%, #00c6ff 95%);
    padding: 0.95rem 2.6rem;
    border-radius: 14px;
    box-shadow: 0 2px 18px rgba(0,110,250,0.10);
    transition: background 0.18s, transform 0.13s, box-shadow 0.13s;
    letter-spacing: 0.5px;
}

.cta:hover, .cta:focus {
    background: linear-gradient(90deg, #0065d4 0%, #42c1fe 100%);
    transform: scale(1.035) translateY(-2px);
    box-shadow: 0 8px 24px rgba(0,110,250,0.17);
}

footer {
    text-align: center;
    padding: 1.2rem 0;
    font-size: 1.01rem;
    color: #959da5;
    margin-top: 1.7rem;
    letter-spacing: 0.4px;
    background: none;
}

@media (max-width: 650px) {
    .hero {
        padding: 1.5rem 0.5rem;
        margin-top: 0;
        max-width: 94vw;
    }
    h1 { font-size: 1.7rem; }
    .hero h2 { font-size: 1.08rem; }
    .desc { font-size: 0.98rem; }
    .cta { font-size: 1rem; padding: 0.8rem 1.7rem; }
    .circle { width: 37px; height: 37px; }
}