:root {
            --primary-color: #0C306B;
            --accent-color: #D4AF37;
            --text-color: #333;
            --text-light: #555;
            --bg-main: #ffffff;
            --bg-accent: #f8f9fa;
            --font-serif: 'Shippori Mincho', serif;
        }

        html {
            scroll-behavior: smooth;
        }
        

        body {
            margin: 0;
            font-family: 'Noto Sans JP', sans-serif;
            color: var(--text-color);
            background-color: var(--bg-main);
            -webkit-font-smoothing: antialiased;
            -moz-osx-font-smoothing: grayscale;
            overflow-x: hidden;
        }

        .container {
            max-width: 1100px;
            margin: 0 auto;
            padding: 0 20px;
        }

        .section {
            padding: 100px 0;
        }

        .section-title {
            font-size: clamp(32px, 6vw, 44px);
            font-family: var(--font-serif);
            color: var(--primary-color);
            text-align: center;
            margin: 0 auto 60px;
            position: relative;
            padding-bottom: 20px;
            letter-spacing: 0.05em;
        }

        .section-title::after {
            content: '';
            position: absolute;
            bottom: 0;
            left: 50%;
            transform: translateX(-50%);
            width: 60px;
            height: 4px;
            background-color: var(--accent-color);
            border-radius: 2px;
        }

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

        .hero {
            display: flex;
            align-items: center;
            min-height: 450px;
            padding: 80px 0;
            color: #fff;
            background: linear-gradient(rgba(0, 0, 0, 0.6), rgba(0, 0, 0, 0.6)), url('https://seieisai.jp/img/firework.png');
            background-size: cover;
            background-position: center;
        }

        .hero-content {
            display: flex;
            align-items: center;
            gap: 30px;
        }

        .hero-logo {
            width: clamp(80px, 15vw, 120px);
            height: auto;
            animation: fadeInUp 1s 0.2s ease-out backwards;
        }

        .hero-text {
            text-align: left;
        }

        .hero h1,
        .hero h2 {
            text-shadow: 0 2px 8px rgba(0, 0, 0, 0.7);
            animation: fadeInUp 1s ease-out backwards;
        }

        .hero h2 {
            font-family: 'Noto Sans JP', sans-serif;
            font-size: clamp(16px, 3vw, 22px);
            font-weight: 400;
            margin: 0 0 10px;
            opacity: 0.9;
            letter-spacing: 0.1em;
            animation-delay: 0.4s;
        }

        .hero h1 {
            font-family: var(--font-serif);
            font-size: clamp(36px, 7vw, 60px);
            margin: 0;
            font-weight: 700;
            animation-delay: 0.6s;
        }

        .stats-section {
            background: var(--bg-accent);
        }

        .stats-container {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 30px;
            text-align: center;
        }

        .stat-card {
            background-color: var(--bg-main);
            padding: 30px;
            border-radius: 12px;
            box-shadow: 0 8px 25px rgba(0, 0, 0, 0.08);
            border: 1px solid #eee;
        }

        .stat-card i {
            font-size: 36px;
            color: var(--accent-color);
            margin-bottom: 20px;
        }

        .stat-number {
            font-size: 44px;
            font-weight: 700;
            color: var(--primary-color);
            line-height: 1.1;
        }

        .stat-label {
            font-size: 15px;
            color: var(--text-light);
            margin-top: 8px;
        }

        .closing-section {
            text-align: center;
        }

        .closing-section p {
            font-size: 17px;
            line-height: 2;
            color: var(--text-light);
            max-width: 800px;
            margin: 0 auto 40px;
        }

        .closing-info {
            font-size: 16px;
            display: inline-flex;
            flex-wrap: wrap;
            justify-content: center;
            gap: 15px 25px;
            padding: 15px 30px;
            border: 1px solid #ddd;
            border-radius: 50px;
            background-color: var(--bg-accent);
            color: var(--text-light);
        }

        #theme {
            background-color: var(--bg-main);
        }

        .theme-content {
            display: grid;
            grid-template-columns: 1fr 2fr;
            gap: 40px;
            align-items: center;
            max-width: 900px;
            margin: 0 auto;
        }

        .theme-title-box {
            text-align: center;
            padding: 30px 20px;
            border: 2px solid var(--primary-color);
            border-radius: 12px;
        }

        .theme-name {
            font-family: var(--font-serif);
            font-size: clamp(32px, 5vw, 48px);
            color: var(--primary-color);
            margin: 0;
            letter-spacing: .1em;
        }

        .theme-subtitle {
            font-size: 16px;
            color: var(--text-light);
            margin-top: 10px;
            letter-spacing: .05em;
        }

        .theme-description {
            font-size: 17px;
            line-height: 2;
            color: var(--text-light);
            text-align: left;
        }

        .swiper {
            width: 100%;
            height: 100%;
        }

        .swiper-slide {
            border-radius: 12px;
            overflow: hidden;
        }

        .swiper-slide img {
            display: block;
            width: 100%;
            height: 100%;
            object-fit: cover;
        }

        .swiper-pagination-bullet-active {
            background-color: var(--primary-color);
        }

        .swiper-button-next,
        .swiper-button-prev {
            color: var(--primary-color);
            background-color: rgba(255, 255, 255, 0.7);
            width: 44px;
            height: 44px;
            border-radius: 50%;
        }

        .swiper-button-next::after,
        .swiper-button-prev::after {
            font-size: 20px;
        }

        #winners {
            background-color: var(--bg-accent);
        }

        .winner-list {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 30px;
        }

        .winner-item {
            background-color: var(--bg-main);
            border-radius: 12px;
            box-shadow: 0 5px 20px rgba(0, 0, 0, 0.07);
            overflow: hidden;
            cursor: pointer;
            transition: transform 0.3s ease-out, box-shadow 0.3s ease-out;
        }

        .winner-item:hover {
            transform: translateY(-10px);
            box-shadow: 0 12px 30px rgba(40, 50, 70, 0.15);
        }

        .winner-item-content {
            padding: 30px;
        }

        .winner-category {
            font-size: 14px;
            color: var(--accent-color);
            font-weight: 700;
            margin-bottom: 8px;
        }

        .winner-name {
            font-size: 24px;
            font-weight: 700;
            color: var(--primary-color);
            font-family: var(--font-serif);
        }

        .all-winners-container {
            margin-top: 40px;
        }

        #hidden-winners {
            max-height: 0;
            visibility: hidden; /* overflow: hidden;から修正 */
            transition: max-height 0.8s ease-in-out, visibility 0s 0.8s;
        }

        #hidden-winners.open {
            max-height: 3000px;
            visibility: visible;
            transition-delay: 0s;
        }

        .toggle-winners-btn {
            display: block;
            margin: 40px auto 0;
            padding: 15px 40px;
            font-size: 16px;
            font-weight: 700;
            color: #fff;
            background-color: var(--primary-color);
            border: none;
            border-radius: 50px;
            cursor: pointer;
            transition: background-color 0.3s, transform 0.3s;
        }

        .toggle-winners-btn:hover {
            background-color: #1a4a8a;
            transform: translateY(-3px);
        }

        .toggle-winners-btn .fa-chevron-down,
        .toggle-winners-btn .fa-chevron-up {
            transition: transform 0.3s;
        }

        .toggle-winners-btn.open .fa-chevron-down {
            transform: rotate(180deg);
        }

        .sponsors-section {
            background-color: var(--bg-main);
        }

        .sponsors-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
            gap: 30px;
            align-items: center;
        }

        .sponsor-link {
            text-decoration: none;
        }

        .sponsor-logo {
            background-color: var(--bg-main);
            padding: 10px;
            border-radius: 12px;
            box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
            transition: transform 0.3s, box-shadow 0.3s;
            display: flex;
            justify-content: center;
            align-items: center;
            min-height: 80px;
            border: 1px solid #eee;
        }

        .sponsor-logo:hover {
            transform: translateY(-8px);
            box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
        }

        .sponsor-logo img {
            height: auto;
            width: auto;
            max-width: 100%;
            object-fit: contain;
            opacity: 1;
        }

        .final-section {
            text-align: center;
            border-radius: 12px;
            padding: 60px 40px;
        }

        .final-section h2 {
            font-family: var(--font-serif);
            font-size: 32px;
            margin-bottom: 20px;
        }

        .final-section p {
            font-size: 17px;
            line-height: 2;
            max-width: 600px;
            margin: 0 auto 30px;
        }

        #greeting-card {
            background: var(--primary-color);
            color: #fff;
        }

        #next-year-card {
            background: var(--accent-color);
            color: var(--primary-color);
        }

        footer {
            background-color: #2d3748;
            color: #fff;
            text-align: center;
            padding: 40px 20px;
            font-size: 14px;
            margin-top: 100px;
        }

        .footer-links a {
            color: #fff;
            margin: 0 10px;
            text-decoration: none;
        }

        .modal {
            display: none;
            position: fixed;
            z-index: 1000;
            left: 0;
            top: 0;
            width: 100%;
            height: 100%;
            overflow: auto;
            background-color: rgba(0, 0, 0, 0.8);
            justify-content: center;
            align-items: center;
            animation: fadeIn 0.3s;
        }

        .modal-content {
            background-color: #fff;
            margin: auto;
            padding: 40px;
            border-radius: 8px;
            max-width: 600px;
            width: 90%;
            position: relative;
            box-shadow: 0 5px 20px rgba(0, 0, 0, 0.2);
            animation: slideIn 0.4s;
        }

        .modal-close {
            position: absolute;
            top: 10px;
            right: 10px;
            color: #333;
            font-size: 20px;
            cursor: pointer;
            width: 40px;
            height: 40px;
            background-color: rgba(255, 255, 255, 0.8);
            border-radius: 50%;
            display: flex;
            justify-content: center;
            align-items: center;
            line-height: 1;
            transition: background-color 0.2s, transform 0.2s;
        }

        .modal-close:hover {
            background-color: rgba(255, 255, 255, 1);
            transform: scale(1.1);
        }

        .modal img {
            width: 100%;
            border-radius: 8px;
            margin-bottom: 20px;
        }

        .modal h3 {
            font-size: 26px;
            margin: 0 0 15px;
            color: var(--primary-color);
            font-family: var(--font-serif);
        }

        .modal p {
            margin-top: 0 !important;
            margin-bottom: 4px !important;
            font-size: 16px;
            line-height: 1.8;
            color: var(--text-light);
        }

        @keyframes fadeIn {
            from {
                opacity: 0;
            }
            to {
                opacity: 1;
            }
        }

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

        .reveal {
            opacity: 0;
            transform: translateY(50px);
            transition: opacity 0.8s cubic-bezier(0.5, 0, 0, 1), transform 0.8s cubic-bezier(0.5, 0, 0, 1);
        }

        .reveal.visible {
            opacity: 1;
            transform: translateY(0);
        }

        @media (max-width: 768px) {
            .section {
                padding: 60px 0;
            }
            .section-title {
                font-size: 28px;
                margin-bottom: 40px;
            }
            .hero-content {
                flex-direction: column;
                text-align: center;
                gap: 20px;
            }
            .hero-text {
                text-align: center;
            }
            .closing-section p {
                font-size: 16px;
                margin-top: -20px;
            }
            .theme-content {
                grid-template-columns: 1fr;
                gap: 30px;
            }
            .theme-description {
                text-align: center;
            }
            .swiper {
                height: 300px;
            }
            .winner-item-content {
                padding: 25px;
            }
            .final-section {
                padding: 40px 20px;
            }
            .final-section h2 {
                font-size: 26px;
            }
            .final-section p {
                font-size: 16px;
            }
        }