* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Hiragino Sans', 'Yu Gothic', 'Meiryo', sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f8f9fa;
}



header {
    background: linear-gradient(135deg, #2c3e50, #3498db);
    color: white;
    padding: 1rem 0;
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 2rem;
}

.logo {
    font-size: 1.8rem;
    font-weight: bold;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-menu a {
    color: white;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

.nav-menu a:hover {
    color: #f39c12;
}

main {
    margin-top: 80px;
}

.hero {
    background: linear-gradient(rgba(0,0,0,0.4), rgba(0,0,0,0.4)), url('../images/kanagawa_landscape.jpg');
    background-size: cover;
    background-position: center;
    height: 60vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: white;
}

.hero-content h2 {
    font-size: 3rem;
    margin-bottom: 1rem;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.5);
}

.hero-content p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    text-shadow: 1px 1px 2px rgba(0,0,0,0.5);
}

.hero-image {
    display: none;
}

.eras-section {
    padding: 4rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.eras-section h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: #2c3e50;
}

.era-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.era-card {
    background: white;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    cursor: pointer;
}

.era-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(0,0,0,0.15);
}

.era-card img {
    width: 100%;
    height: 200px;
    object-fit: cover;
}

.era-card h3 {
    font-size: 1.5rem;
    padding: 1rem;
    color: #2c3e50;
}

.era-card p {
    padding: 0 1rem 1.5rem;
    color: #666;
}

.about-section {
    background: white;
    padding: 4rem 2rem;
    margin: 2rem 0;
}

.about-section h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 2rem;
    color: #2c3e50;
}

.about-content {
    max-width: 800px;
    margin: 0 auto;
    font-size: 1.1rem;
    line-height: 1.8;
}

.about-content p {
    margin-bottom: 1.5rem;
}

footer {
    background: #2c3e50;
    color: white;
    text-align: center;
    padding: 2rem 0;
}

@media (max-width: 768px) {
    .nav-container {
        flex-direction: column;
        gap: 1rem;
    }
    
    .nav-menu {
        gap: 1rem;
    }
    
    .hero-content h2 {
        font-size: 2rem;
    }
    
    .hero-content p {
        font-size: 1rem;
    }
    
    .era-grid {
        grid-template-columns: 1fr;
    }
    
    .eras-section h2,
    .about-section h2 {
        font-size: 2rem;
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.era-card {
    animation: fadeInUp 0.6s ease forwards;
}

.era-card:nth-child(1) { animation-delay: 0.1s; }
.era-card:nth-child(2) { animation-delay: 0.2s; }
.era-card:nth-child(3) { animation-delay: 0.3s; }
.era-card:nth-child(4) { animation-delay: 0.4s; }
.era-card:nth-child(5) { animation-delay: 0.5s; }

.splide__slide img {
  width: 100%;
  height: auto;
}



.slider-container {
    position: relative;
    max-width: 1000px;
    width: 100%;
    overflow: hidden;
    border-radius: 20px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    background: white;
    margin: 0 auto;
}

.slider-wrapper {
    display: flex;
    transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    will-change: transform;
}

.slide {
    min-width: 100%;
    position: relative;
    overflow: hidden;
}

.slide img {
    width: 100%;
    height: 60vh;
    object-fit: cover;
    display: block;
    transition: transform 0.6s ease;
}

.slide:hover img {
    transform: scale(1.05);
}

.slide-content {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: linear-gradient(to top, rgba(0,0,0,0.8) 0%, rgba(0,0,0,0.4) 50%, transparent 100%);
    color: white;
    padding: 60px 40px 40px;
    transform: translateY(20px);
    opacity: 0;
    transition: all 0.6s ease;
}

.slide.active .slide-content {
    transform: translateY(0);
    opacity: 1;
}

.slide-title {
    font-size: 2.5rem;
    margin-bottom: 15px;
    font-weight: bold;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.5);
    transform: translateY(30px);
    transition: transform 0.8s ease 0.2s;
}

.slide.active .slide-title {
    transform: translateY(0);
}

.slide-description {
    font-size: 1.2rem;
    opacity: 0.9;
    line-height: 1.6;
    transform: translateY(30px);
    transition: transform 0.8s ease 0.4s;
}

.slide.active .slide-description {
    transform: translateY(0);
}

.nav-button {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background: rgba(255, 255, 255, 0.9);
    border: none;
    width: 60px;
    height: 60px;
    border-radius: 50%;
    cursor: pointer;
    font-size: 28px;
    font-weight: bold;
    color: #333;
    z-index: 10;
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
}

.nav-button:hover {
    background: white;
    transform: translateY(-50%) scale(1.1);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.2);
}

.nav-button:active {
    transform: translateY(-50%) scale(0.95);
}

.prev {
    left: 30px;
}

.next {
    right: 30px;
}

.indicators {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 15px;
    z-index: 10;
}

.indicator {
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.4);
    cursor: pointer;
    transition: all 0.4s ease;
    border: 2px solid transparent;
}

.indicator:hover {
    background: rgba(255, 255, 255, 0.7);
    transform: scale(1.2);
}

.indicator.active {
    background: white;
    transform: scale(1.3);
    border: 2px solid rgba(255, 255, 255, 0.5);
    box-shadow: 0 0 20px rgba(255, 255, 255, 0.6);
}

.play-pause-btn {
    position: absolute;
    top: 20px;
    right: 20px;
    background: rgba(0, 0, 0, 0.6);
    border: none;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    color: white;
    font-size: 16px;
    cursor: pointer;
    z-index: 10;
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
}

.play-pause-btn:hover {
    background: rgba(0, 0, 0, 0.8);
    transform: scale(1.1);
}

.slide img {
    opacity: 0;
    animation: fadeIn 0.6s ease forwards;
}

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

@media (max-width: 768px) {
    .slider-container {
        border-radius: 15px;
    }
    
    .slide img {
        height: 50vh;
    }
    
    .slide-content {
        padding: 40px 25px 25px;
    }
    
    .slide-title {
        font-size: 1.8rem;
        margin-bottom: 10px;
    }
    
    .slide-description {
        font-size: 1rem;
    }
    
    .nav-button {
        width: 50px;
        height: 50px;
        font-size: 24px;
    }
    
    .prev {
        left: 20px;
    }
    
    .next {
        right: 20px;
    }
    
    .indicators {
        bottom: 20px;
        gap: 12px;
    }
    
    .indicator {
        width: 12px;
        height: 12px;
    }
    
    .play-pause-btn {
        width: 40px;
        height: 40px;
        font-size: 14px;
        top: 15px;
        right: 15px;
    }
}

@media (max-width: 480px) {
    .slide img {
        height: 40vh;
    }
    
    .slide-title {
        font-size: 1.5rem;
    }
    
    .slide-description {
        font-size: 0.9rem;
    }
    
    .nav-button {
        width: 45px;
        height: 45px;
        font-size: 20px;
    }
    
    .prev {
        left: 15px;
    }
    
    .next {
        right: 15px;
    }
}

@media (prefers-reduced-motion: reduce) {
    .slider-wrapper,
    .slide img,
    .slide-content,
    .slide-title,
    .slide-description,
    .nav-button,
    .indicator {
        transition: none;
    }
    
    .slide:hover img {
        transform: none;
    }
}

.nav-button:focus,
.indicator:focus,
.play-pause-btn:focus {
    outline: 2px solid #4A90E2;
    outline-offset: 2px;
}

.page-header {
    background: linear-gradient(135deg, #3498db, #2c3e50);
    height: 20vh;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    text-align: center;
    margin:0px !important;
    padding:0px;
}

.content-section {
    max-width: 1000px;
    margin: 0 auto;
    padding: 3rem 2rem;
}

.sources-card {
    background: white;
    border-radius: 10px;
    padding: 2rem;
    margin: 2rem 0;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.back-button {
    display: inline-block;
    background: #3498db;
    color: white;
    padding: 0.8rem 1.5rem;
    text-decoration: none;
    border-radius: 5px;
    margin: 0.5rem;
    transition: background 0.3s ease;
}

.back-button:hover {
    background: #2980b9;
}

.source-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    margin: 0.5rem 0;
    background: #f8f9fa;
    border-radius: 5px;
    border-left: 4px solid #3498db;
}

.source-name {
    font-weight: bold;
    color: #2c3e50;
}

.source-url {
    color: #3498db;
    text-decoration: none;
    word-break: break-all;
}

.source-url:hover {
    text-decoration: underline;
}

.era-section {
    margin: 2rem 0;
}

.era-title {
    background: #3498db;
    color: white;
    padding: 1rem;
    border-radius: 5px;
    margin-bottom: 1rem;
}

.detail-card {
    background: white;
    border-radius: 10px;
    padding: 2rem;
    margin: 2rem 0;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.image-container {
    text-align: center;
    margin: 2rem 0;
}

.image-container img {
    max-width: 100%;
    height: auto;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
}

.timeline {
    background: #f8f9fa;
    padding: 2rem;
    border-radius: 10px;
    margin: 2rem 0;
}

.timeline-item {
    border-left: 3px solid #3498db;
    padding-left: 1rem;
    margin-bottom: 1.5rem;
}

.timeline-date {
    font-weight: bold;
    color: #3498db;
    margin-bottom: 0.5rem;
}