.hero {
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center;

    background: radial-gradient(circle at center,
        rgba(79,163,255,0.25),
        rgba(10,15,25,1)
    );
}

.hero-inner {
    animation: fadeIn 1.5s ease-out;
}

.hero-logo img {
    width: min(60vw, 260px);
    filter: drop-shadow(0 0 20px #4fa3ff);
    animation: logoGlow 4s infinite ease-in-out;
}

.hero-title {
    font-size: 2rem;
    margin-top: 20px;
    color: #ffffff;
    text-shadow: 0 0 10px #4fa3ff;
}

.hero-subtitle {
    margin-top: 10px;
    color: #a8d8ff;
    letter-spacing: 0.1em;
}

.hero-share {
    margin-top: 30px;
}

.share-btn {
    background: rgba(79,163,255,0.2);
    border: 1px solid #4fa3ff;
    padding: 10px 20px;
    margin: 0 10px;
    color: #a8d8ff;
    cursor: pointer;
    border-radius: 6px;
    transition: 0.3s;
}

.share-btn:hover {
    background: rgba(79,163,255,0.4);
}

/* アニメーション */
@keyframes logoGlow {
    0% { filter: drop-shadow(0 0 10px #4fa3ff); }
    50% { filter: drop-shadow(0 0 30px #4fa3ff); }
    100% { filter: drop-shadow(0 0 10px #4fa3ff); }
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}