/* 基本スタイル */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: #fff;
    overflow-x: hidden;
    background-color: #fff;
}

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

ul {
    list-style: none;
}

/* オーシャンコンテナ */
.ocean-wrapper {
    position: relative;
    width: 100vw;
    height: 100vh;
    overflow: hidden;
}

.ocean-container {
    position: relative;
    width: 100%;
    height: 100%;
    overflow-y: auto;
    overflow-x: hidden;
    perspective: 1000px;
}

.ocean-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to bottom, rgba(0, 30, 60, 0.2), rgba(0, 20, 40, 0.6));
    z-index: 1;
    pointer-events: none;
    transition: background 5s ease-in-out;
}

.ocean-overlay.red-tide {
    background: linear-gradient(to bottom, rgba(60, 0, 0, 0.2), rgba(40, 0, 0, 0.6));
}

#oceanCanvas {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
}

/* ヘッダー */
.site-header {
    position: relative;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 5%;
    z-index: 10;
    background-color: rgba(0, 20, 40, 0.8);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
    transition: background-color 5s ease-in-out;
}

.site-header.red-tide {
    background-color: rgba(40, 0, 0, 0.8);
}

.logo {
    display: flex;
    align-items: center;
    font-size: 1.5rem;
    font-weight: 700;
    color: #fff;
}

.logo i {
    margin-right: 0.5rem;
    color: #4fc3f7;
    font-size: 1.8rem;
    transition: color 5s ease-in-out;
}

.logo.red-tide i {
    color: #f74f4f;
}

.main-nav ul {
    display: flex;
}

.main-nav li {
    margin-left: 2rem;
}

.main-nav a {
    position: relative;
    padding: 0.5rem 0;
    font-weight: 500;
    transition: color 0.3s;
}

.main-nav a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: #4fc3f7;
    transition: width 0.3s, background-color 5s ease-in-out;
}

.main-nav.red-tide a::after {
    background-color: #f74f4f;
}

.main-nav a:hover {
    color: #4fc3f7;
    transition: color 0.3s;
}

.main-nav.red-tide a:hover {
    color: #f74f4f;
}

.main-nav a:hover::after {
    width: 100%;
}

/* メインコンテンツ */
.main-content {
    position: relative;
    z-index: 2;
    padding: 2rem 5%;
    min-height: calc(100vh - 80px - 60px); /* ヘッダーとフッターの高さを引く */
}

/* ヒーローセクション */
.hero-section {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 5rem 0;
    height: 70vh;
}

.main-title {
    font-size: 4rem;
    font-weight: 800;
    margin-bottom: 1rem;
    letter-spacing: 2px;
    text-transform: uppercase;
    background: linear-gradient(to right, #4fc3f7, #00b0ff);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    transition: background 5s ease-in-out;
}

.main-title.red-tide {
    background: linear-gradient(to right, #f74f4f, #ff0000);
    -webkit-background-clip: text;
    background-clip: text;
}

.subtitle {
    font-size: 1.5rem;
    font-weight: 300;
    margin-bottom: 3rem;
    color: #b0bec5;
}

.cta-container {
    margin-top: 2rem;
}

.start-btn {
    display: flex;
    align-items: center;
    padding: 1rem 2.5rem;
    font-size: 1.2rem;
    font-weight: 600;
    color: #fff;
    background: linear-gradient(45deg, #0288d1, #4fc3f7);
    border: none;
    border-radius: 50px;
    cursor: pointer;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
    transition: all 0.3s ease, background 5s ease-in-out;
}

.start-btn.red-tide {
    background: linear-gradient(45deg, #d10202, #f74f4f);
}

.start-btn:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.3);
}

.start-btn:active {
    transform: translateY(-2px);
}

.start-btn i {
    margin-left: 0.8rem;
    font-size: 1.3rem;
}

/* 情報セクション */
.info-section {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    margin: 3rem 0;
    padding: 2rem 0;
}

.info-card {
    flex: 1;
    min-width: 250px;
    margin: 1rem;
    padding: 2rem;
    background: rgba(0, 20, 40, 0.7);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-radius: 10px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    text-align: center;
    transition: transform 0.3s ease, background 5s ease-in-out;
}

.info-card.red-tide {
    background: rgba(40, 0, 0, 0.7);
}

.info-card:hover {
    transform: translateY(-10px);
}

.info-card i {
    font-size: 2.5rem;
    margin-bottom: 1.5rem;
    color: #4fc3f7;
    transition: color 5s ease-in-out;
}

.info-card.red-tide i {
    color: #f74f4f;
}

.info-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
}

.info-card p {
    color: #b0bec5;
    font-size: 0.95rem;
}

/* フッター */
.site-footer {
    position: relative;
    z-index: 10;
    padding: 1.5rem 5%;
    background-color: rgba(0, 10, 20, 0.9);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    transition: background-color 5s ease-in-out;
}

.site-footer.red-tide {
    background-color: rgba(20, 0, 0, 0.9);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.social-links a {
    margin-left: 1rem;
    font-size: 1.2rem;
    color: #b0bec5;
    transition: color 0.3s;
}

.social-links a:hover {
    color: #4fc3f7;
}

.social-links.red-tide a:hover {
    color: #f74f4f;
}

/* レスポンシブデザイン */
@media (max-width: 992px) {
    .main-title {
        font-size: 3.5rem;
    }
    
    .info-section {
        flex-direction: column;
    }
    
    .info-card {
        margin: 1rem 0;
    }
}

@media (max-width: 768px) {
    .site-header {
        flex-direction: column;
        padding: 1rem;
    }
    
    .logo {
        margin-bottom: 1rem;
    }
    
    .main-nav ul {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .main-nav li {
        margin: 0.5rem;
    }
    
    .main-title {
        font-size: 2.8rem;
    }
    
    .subtitle {
        font-size: 1.2rem;
    }
    
    .footer-content {
        flex-direction: column;
        text-align: center;
    }
    
    .social-links {
        margin-top: 1rem;
    }
    
    .social-links a {
        margin: 0 0.5rem;
    }
}

@media (max-width: 480px) {
    .main-title {
        font-size: 2.2rem;
    }
    
    .start-btn {
        padding: 0.8rem 1.8rem;
        font-size: 1rem;
    }
}