* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: #111;
    color: #fff;
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

header {
    height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    position: relative;
}

.logo {
    font-size: 6rem;
    font-weight: 900;
    letter-spacing: 2px;
    position: relative;
    margin-bottom: 2rem;
    text-transform: none; /* 大文字変換を無効に */
}

.logo span {
    color: #FFC107;
    position: relative;
    display: inline-block;
    animation: logoPulse 3s infinite;
    text-transform: lowercase; /* span内の文字を小文字に */
}

.logo span:nth-child(2) { /* 2番目のspan（Hの部分）のみ特定 */
    text-transform: uppercase; /* Hのみ大文字に */
    color: #FFFFFF; /* Hのみ白色に */
}



.logo::after {
    content: '';
    position: absolute;
    width: 100%;
    height: 4px;
    background-color: #FFC107;
    bottom: -10px;
    left: 0;
    transform: scaleX(0);
    transform-origin: left;
    animation: lineGrow 1.5s forwards;
}



.slogan {
    font-size: 1.5rem;
    text-align: center;
    margin-bottom: 2rem;
    opacity: 0;
    animation: fadeIn 2s forwards 1s;
}

.keywords {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 2rem;
    margin-top: 3rem;
}

.keyword {
    font-size: 1.8rem;
    font-weight: 700;
    padding: 1rem 2rem;
    background-color: rgba(255, 255, 255, 0.05);
    border-radius: 5px;
    position: relative;
    overflow: hidden;
    opacity: 0;
    transform: translateY(20px);
}

.keywords .keyword:nth-child(1) {
    animation: slideUp 0.5s forwards 1.2s;
}

.keywords .keyword:nth-child(2) {
    animation: slideUp 0.5s forwards 1.4s;
}

.keyword::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(255, 193, 7, 0.2);
    transform: translateX(-100%);
    transition: transform 0.5s ease;
}

.keyword:hover::before {
    transform: translateX(0);
}

.keyword span {
    color: #FFC107;
    position: relative;
    z-index: 1;
}

.particles {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
}

.particle {
    position: absolute;
    background-color: rgba(255, 255, 255, 0.5);
    border-radius: 50%;
    pointer-events: none;
}

.cta-button {
    margin-top: 4rem;
    padding: 1rem 2.5rem;
    background-color: #FFC107;
    color: #111;
    font-weight: 700;
    border: none;
    border-radius: 50px;
    cursor: pointer;
    font-size: 1.2rem;
    letter-spacing: 1px;
    text-transform: uppercase;
    position: relative;
    overflow: hidden;
    transition: all 0.3s ease;
    opacity: 0;
    animation: fadeIn 1s forwards 2s;
}

.cta-button:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(255, 193, 7, 0.3);
}

.cta-button::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: 0.5s;
}

.cta-button:hover::before {
    left: 100%;
}

@keyframes slideUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    to {
        opacity: 1;
    }
}

@keyframes lineGrow {
    to {
        transform: scaleX(1);
    }
}

@keyframes logoPulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
}

@keyframes moveAround {
    0%, 100% {
        transform: translate(0, 0);
    }
    25% {
        transform: translate(30px, -30px);
    }
    50% {
        transform: translate(-30px, -30px);
    }
    75% {
        transform: translate(-30px, 30px);
    }
}

@media (max-width: 768px) {
    .logo {
        font-size: 3.5rem;
    }
    .slogan {
        font-size: 1.2rem;
    }
    .keywords {
        flex-direction: column;
        gap: 1rem;
    }
    .keyword {
        font-size: 1.5rem;
    }
}