/* ========================================
   リセット & ベーススタイル
======================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* カラーパレット */
    --primary-color: #0066cc;
    --primary-dark: #004c99;
    --secondary-color: #00ccff;
    --accent-color: #ff6b00;
    --dark-color: #1a1a2e;
    --light-color: #f8f9fa;
    --gray-color: #6c757d;
    --white-color: #ffffff;
    
    /* グラデーション */
    --gradient-primary: linear-gradient(135deg, #0066cc 0%, #00ccff 100%);
    --gradient-dark: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
    --gradient-accent: linear-gradient(135deg, #ff6b00 0%, #ff8c00 100%);
    
    /* シャドウ */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.15);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.2);
    
    /* トランジション */
    --transition-fast: 0.2s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* フォント */
    --font-primary: 'Noto Sans JP', sans-serif;
    --font-display: 'Bebas Neue', sans-serif;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-primary);
    color: var(--dark-color);
    background-color: var(--white-color);
    line-height: 1.6;
    overflow-x: hidden;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition-base);
}

/* ========================================
   コンテナ & レイアウト
======================================== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

section {
    padding: 60px 0;
    position: relative;
}

/* ========================================
   セクションヘッダー
======================================== */
.section-header {
    text-align: center;
    margin-bottom: 40px;
}

.section-label {
    display: inline-block;
    font-family: var(--font-display);
    font-size: 1rem;
    letter-spacing: 3px;
    color: var(--primary-color);
    margin-bottom: 10px;
    text-transform: uppercase;
}

.section-title {
    font-size: 3rem;
    font-weight: 900;
    margin-bottom: 20px;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section-description {
    font-size: 1.1rem;
    color: var(--gray-color);
    max-width: 600px;
    margin: 0 auto;
}

/* ========================================
   ボタン
======================================== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 12px 30px;
    border: none;
    border-radius: 50px;
    font-size: 1rem;
    font-weight: 700;
    cursor: pointer;
    transition: var(--transition-base);
    text-align: center;
}

.btn i {
    font-size: 1.2rem;
}

.btn-primary {
    background: var(--gradient-primary);
    color: var(--white-color);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: transparent;
    color: var(--white-color);
    border: 2px solid var(--white-color);
}

.btn-secondary:hover {
    background: var(--white-color);
    color: var(--primary-color);
}

.btn-accent {
    background: var(--gradient-accent);
    color: var(--white-color);
}

.btn-accent:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.btn-large {
    padding: 16px 40px;
    font-size: 1.1rem;
}

.btn-xlarge {
    padding: 20px 50px;
    font-size: 1.3rem;
}

/* ========================================
   ナビゲーション
======================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(26, 26, 46, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    padding: 15px 0;
    box-shadow: var(--shadow-md);
}

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

.nav-brand {
    display: flex;
    align-items: center;
    gap: 15px;
}

.anniversary-badge {
    font-family: var(--font-display);
    font-size: 0.9rem;
    letter-spacing: 2px;
    color: var(--accent-color);
    padding: 5px 15px;
    border: 2px solid var(--accent-color);
    border-radius: 20px;
}

.event-name {
    font-family: var(--font-display);
    font-size: 1.5rem;
    letter-spacing: 3px;
    color: var(--white-color);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 30px;
    align-items: center;
}

.nav-menu a {
    color: var(--white-color);
    font-weight: 500;
    position: relative;
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--secondary-color);
    transition: var(--transition-base);
}

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

.nav-cta {
    background: var(--gradient-primary);
    padding: 8px 20px;
    border-radius: 25px;
}

.nav-cta:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
}

.mobile-menu-toggle span {
    width: 30px;
    height: 3px;
    background: var(--white-color);
    border-radius: 2px;
    transition: var(--transition-base);
}

/* ========================================
   ヒーローセクション
======================================== */
.hero {
    min-height: 100vh;
    height: auto;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
    z-index: -2;
}

.hero-background::before {
    content: '';
    position: absolute;
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, rgba(0, 204, 255, 0.3) 0%, transparent 70%);
    top: -200px;
    right: -200px;
    animation: float 20s ease-in-out infinite;
}

.hero-background::after {
    content: '';
    position: absolute;
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(255, 107, 0, 0.2) 0%, transparent 70%);
    bottom: -150px;
    left: -150px;
    animation: float 15s ease-in-out infinite reverse;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) rotate(0deg); }
    50% { transform: translate(50px, 50px) rotate(180deg); }
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('https://page.gensparksite.com/v1/base64_upload/388638c7f75dfd90a75304b11ec97bb4') center/cover;
    opacity: 0.15;
    z-index: -1;
}

.hero-content {
    text-align: center;
    color: var(--white-color);
    z-index: 1;
    animation: fadeInUp 1s ease;
    padding-top: 100px;
}

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

.hero-badge {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
    margin-bottom: 30px;
}

.badge-line {
    width: 60px;
    height: 2px;
    background: var(--secondary-color);
}

.badge-text {
    font-family: var(--font-display);
    font-size: 1rem;
    letter-spacing: 3px;
    color: var(--secondary-color);
}

/* ヒーロー内の主催ロゴ */
.hero-organizer-logo {
    text-align: center;
    margin: 30px auto 40px;
    max-width: 500px;
    padding: 0 20px;
}

.hero-organizer-logo img {
    width: 100%;
    height: auto;
    max-width: 500px;
    /* フィルターを削除して元の色を表示 */
}

.hero-title {
    margin-bottom: 20px;
}

.title-main {
    display: block;
    font-family: var(--font-display);
    font-size: 8rem;
    letter-spacing: 10px;
    line-height: 1;
    background: linear-gradient(135deg, #fff 0%, #00ccff 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.title-year {
    display: block;
    font-family: var(--font-display);
    font-size: 3rem;
    letter-spacing: 15px;
    color: var(--accent-color);
}

.hero-subtitle {
    font-size: 1.2rem;
    margin-bottom: 15px;
    opacity: 0.9;
}

.hero-event-name {
    font-size: 2.5rem;
    font-weight: 900;
    margin-bottom: 40px;
    color: var(--white-color);
}

.hero-info {
    display: flex;
    justify-content: center;
    gap: 40px;
    margin-bottom: 50px;
    flex-wrap: wrap;
}

.info-item {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.1rem;
}

.info-item i {
    color: var(--secondary-color);
    font-size: 1.5rem;
}

.mobile-break {
    display: none;
}

.venue-link {
    color: inherit;
    text-decoration: none;
    transition: var(--transition-base);
}

.venue-link:hover {
    color: var(--secondary-color);
    text-decoration: underline;
}

.hero-cta {
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}



/* ========================================
   大会概要セクション
======================================== */
.about-section {
    background: var(--light-color);
}

.about-content {
    max-width: 900px;
    margin: 0 auto;
}

.about-details {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.detail-card {
    display: flex;
    gap: 20px;
    background: var(--white-color);
    padding: 25px;
    border-radius: 15px;
    box-shadow: var(--shadow-sm);
    transition: var(--transition-base);
}

.detail-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
}

.detail-icon {
    flex-shrink: 0;
    width: 60px;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-primary);
    border-radius: 15px;
    color: var(--white-color);
    font-size: 1.5rem;
}

.detail-content h3 {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 8px;
    color: var(--dark-color);
}

.detail-content p {
    color: var(--gray-color);
    line-height: 1.6;
}

/* 申込状況スタイル */
.current-entry-status {
    margin-top: 15px;
    padding: 15px 20px;
    background: linear-gradient(135deg, #ff6b00 0%, #ff8c00 100%);
    border-radius: 12px;
    text-align: center;
    box-shadow: var(--shadow-md);
}

.status-urgent {
    display: block;
    color: var(--white-color);
    font-size: 1.8rem;
    font-weight: 900;
    margin-bottom: 8px;
    letter-spacing: 1px;
}

.status-urgent strong {
    font-size: 2.2rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.status-date {
    display: block;
    color: rgba(255, 255, 255, 0.9);
    font-size: 0.85rem;
    font-weight: 500;
}

/* ========================================
   ピックルボールセクション
======================================== */
.pickleball-section {
    background: var(--white-color);
}

.pickleball-content {
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: 60px;
    align-items: center;
}

.description-box {
    background: var(--light-color);
    padding: 40px;
    border-radius: 20px;
    border-left: 5px solid var(--primary-color);
}

.lead-text {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 20px;
    line-height: 1.4;
}

.description-box p {
    color: var(--gray-color);
    margin-bottom: 30px;
    line-height: 1.8;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.feature-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 15px;
    background: var(--white-color);
    border-radius: 10px;
    font-weight: 600;
    color: var(--dark-color);
    transition: var(--transition-base);
}

.feature-item:hover {
    transform: translateX(5px);
    box-shadow: var(--shadow-sm);
}

.feature-item i {
    color: var(--accent-color);
    font-size: 1.5rem;
}

.pickleball-image {
    border-radius: 20px;
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.pickleball-image img {
    width: 100%;
    height: auto;
    transition: var(--transition-slow);
}

.pickleball-image:hover img {
    transform: scale(1.05);
}

/* ========================================
   協賛企業募集セクション
======================================== */
.sponsors-section {
    background: var(--light-color);
}

.sponsors-content {
    display: grid;
    gap: 60px;
}

.benefits-title {
    font-size: 2rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 40px;
    color: var(--dark-color);
}

.benefits-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
}

.benefit-card {
    background: var(--white-color);
    padding: 25px 20px;
    border-radius: 15px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: var(--transition-base);
}

.benefit-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-md);
}

.benefit-icon {
    width: 60px;
    height: 60px;
    margin: 0 auto 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-primary);
    border-radius: 50%;
    color: var(--white-color);
    font-size: 1.5rem;
}

.benefit-card h4 {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 15px;
    color: var(--dark-color);
}

.benefit-card p {
    color: var(--gray-color);
    line-height: 1.6;
    font-size: 0.95rem;
}

.sponsors-cta {
    text-align: center;
}

.cta-box {
    max-width: 700px;
    margin: 0 auto;
    background: var(--white-color);
    padding: 35px;
    border-radius: 20px;
    box-shadow: var(--shadow-md);
}

.cta-box h3 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 20px;
    color: var(--dark-color);
}

.cta-box p {
    color: var(--gray-color);
    margin-bottom: 30px;
    line-height: 1.8;
}

/* 協賛企業一覧 */
.current-sponsors-list {
    margin-top: 50px;
    padding: 30px;
    background: var(--light-color);
    border-radius: 20px;
    text-align: center;
}

.sponsors-list-title {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--dark-color);
    margin-bottom: 40px;
    position: relative;
    display: inline-block;
}

.sponsors-list-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60%;
    height: 3px;
    background: var(--gradient-primary);
}

.sponsors-logos-section {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 60px;
    flex-wrap: wrap;
    margin-bottom: 30px;
}

.sponsor-logo-item {
    display: block;
    background: var(--white-color);
    padding: 25px 40px;
    border-radius: 15px;
    box-shadow: var(--shadow-md);
    transition: var(--transition-base);
    text-decoration: none;
    cursor: pointer;
}

.sponsor-logo-item:hover {
    transform: translateY(-8px) scale(1.05);
    box-shadow: var(--shadow-lg);
}

.sponsor-logo-item img {
    height: 60px;
    width: auto;
    display: block;
}

.sponsors-thanks {
    color: var(--gray-color);
    font-size: 1rem;
    font-style: italic;
}

/* ========================================
   参加申込セクション
======================================== */
.entry-section {
    position: relative;
    background: var(--dark-color);
    color: var(--white-color);
}

.entry-section .section-label,
.entry-section .section-title {
    color: var(--white-color);
    background: none;
    -webkit-text-fill-color: var(--white-color);
}

.entry-section .section-description {
    color: rgba(255, 255, 255, 0.8);
}

.entry-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('https://images.unsplash.com/photo-1587280501635-68a0e82cd5ff?w=1920') center/cover;
    opacity: 0.1;
}

.entry-content {
    position: relative;
    z-index: 1;
}

.entry-highlights {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin-bottom: 40px;
}

.highlight-card {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    padding: 30px 20px;
    border-radius: 15px;
    text-align: center;
    border: 2px solid rgba(255, 255, 255, 0.2);
    transition: var(--transition-base);
}

.highlight-card:hover {
    background: rgba(255, 255, 255, 0.15);
    transform: translateY(-5px);
}

.highlight-number {
    font-family: var(--font-display);
    font-size: 3.5rem;
    color: var(--secondary-color);
    margin-bottom: 10px;
}

.highlight-label {
    font-size: 1.1rem;
    color: var(--white-color);
    opacity: 0.9;
}

/* 残り人数カード（特別スタイル） */
.highlight-remaining {
    background: linear-gradient(135deg, #ff6b00 0%, #ff8c00 100%);
    border: 3px solid rgba(255, 255, 255, 0.5);
    box-shadow: 0 8px 32px rgba(255, 107, 0, 0.4);
}

.highlight-remaining:hover {
    background: linear-gradient(135deg, #ff8c00 0%, #ffa500 100%);
    transform: translateY(-8px) scale(1.05);
}

.remaining-number {
    color: var(--white-color);
    font-size: 4.5rem;
    text-shadow: 2px 2px 8px rgba(0, 0, 0, 0.3);
}

.highlight-date {
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.9);
    margin-top: 10px;
    font-weight: 500;
}

.entry-action {
    text-align: center;
}

.action-box {
    max-width: 700px;
    margin: 0 auto;
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    padding: 35px;
    border-radius: 20px;
    border: 2px solid rgba(255, 255, 255, 0.2);
}

.action-box h3 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 20px;
}

.action-box p {
    margin-bottom: 30px;
    line-height: 1.8;
    opacity: 0.9;
}

.entry-note {
    font-size: 0.9rem;
    margin-top: 20px;
    opacity: 0.7;
}

/* ========================================
   お問い合わせセクション
======================================== */
.contact-section {
    background: var(--white-color);
}

.contact-content {
    max-width: 900px;
    margin: 0 auto;
}

.contact-info h3 {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 30px;
    color: var(--dark-color);
}

.contact-details {
    display: flex;
    flex-direction: column;
    gap: 20px;
    margin-bottom: 30px;
}

.contact-item {
    display: flex;
    gap: 20px;
    align-items: flex-start;
}

.contact-item i {
    flex-shrink: 0;
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-primary);
    border-radius: 12px;
    color: var(--white-color);
    font-size: 1.3rem;
}

.contact-item strong {
    display: block;
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 5px;
    color: var(--dark-color);
}

.contact-item p {
    color: var(--gray-color);
    line-height: 1.6;
}

.contact-item a {
    color: var(--primary-color);
    font-weight: 600;
}

.contact-item a:hover {
    text-decoration: underline;
}

.social-links {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
}

.social-link {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 20px;
    background: var(--light-color);
    border-radius: 30px;
    font-weight: 600;
    transition: var(--transition-base);
}

.social-link:hover {
    background: var(--primary-color);
    color: var(--white-color);
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

.social-link i {
    font-size: 1.3rem;
}



/* ========================================
   フッター
======================================== */
.footer {
    background: var(--gradient-dark);
    color: var(--white-color);
    padding: 60px 0 30px;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 40px;
    padding-bottom: 40px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-brand h3 {
    font-family: var(--font-display);
    font-size: 2rem;
    letter-spacing: 3px;
    margin-bottom: 10px;
}

.footer-brand p {
    opacity: 0.7;
    font-size: 0.9rem;
}

.footer-links {
    display: flex;
    gap: 30px;
}

.footer-links a {
    opacity: 0.8;
    transition: var(--transition-base);
}

.footer-links a:hover {
    opacity: 1;
    color: var(--secondary-color);
}

.footer-bottom {
    text-align: center;
    opacity: 0.6;
    font-size: 0.9rem;
}

/* ========================================
   トップに戻るボタン
======================================== */
.scroll-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--gradient-primary);
    color: var(--white-color);
    border: none;
    border-radius: 50%;
    font-size: 1.2rem;
    cursor: pointer;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transition: var(--transition-base);
    z-index: 999;
}

.scroll-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.scroll-to-top:hover {
    transform: translateY(-5px);
}

/* ========================================
   レスポンシブデザイン
======================================== */

/* タブレット（768px以下） */
@media (max-width: 768px) {
    .section-title {
        font-size: 2.5rem;
    }
    
    .section-header {
        margin-bottom: 30px;
    }
    
    section {
        padding: 40px 0;
    }
    
    /* ナビゲーション */
    .nav-menu {
        display: flex;
        position: fixed;
        top: 70px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 70px);
        background: rgba(26, 26, 46, 0.98);
        flex-direction: column;
        justify-content: flex-start;
        padding: 40px 0;
        transition: var(--transition-base);
        z-index: 999;
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .mobile-menu-toggle {
        display: flex;
    }
    
    /* ヒーロー */
    .hero-content {
        padding-top: 90px;
    }
    
    .title-main {
        font-size: 4rem;
    }
    
    .title-year {
        font-size: 2rem;
    }
    
    .hero-event-name {
        font-size: 1.8rem;
    }
    
    .hero-info {
        flex-direction: column;
        gap: 20px;
    }
    
    .mobile-break {
        display: block;
    }
    
    .hero-cta {
        flex-direction: column;
    }
    
    .hero-organizer-logo {
        max-width: 380px;
        margin: 20px auto 30px;
    }
    
    .sponsors-logos-section {
        gap: 30px;
    }
    
    .sponsor-logo-item {
        padding: 20px 30px;
    }
    
    .sponsor-logo-item img {
        height: 45px;
    }
    
    .current-entry-status {
        padding: 12px 15px;
    }
    
    .status-urgent {
        font-size: 1.5rem;
    }
    
    .status-urgent strong {
        font-size: 1.8rem;
    }
    
    /* SNSリンクを縦並びに */
    .social-links {
        flex-direction: column;
        width: 100%;
    }
    
    .social-link {
        width: 100%;
        justify-content: center;
    }
    
    /* ピックルボール */
    .pickleball-content {
        grid-template-columns: 1fr;
    }
    
    /* 協賛企業 */
    .benefits-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 15px;
    }
    
    .benefit-card {
        padding: 20px 15px;
    }
    
    /* 参加申込 */
    .entry-highlights {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    

    
    /* フッター */
    .footer-content {
        flex-direction: column;
        gap: 30px;
        text-align: center;
    }
    
    .footer-links {
        flex-direction: column;
        gap: 15px;
    }
}

/* スマートフォン（480px以下） */
@media (max-width: 480px) {
    section {
        padding: 30px 0;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .section-header {
        margin-bottom: 25px;
    }
    
    .hero-content {
        padding-top: 85px;
    }
    
    .title-main {
        font-size: 3rem;
        letter-spacing: 5px;
    }
    
    .title-year {
        font-size: 1.5rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .hero-event-name {
        font-size: 1.5rem;
    }
    
    .info-item {
        font-size: 0.95rem;
    }
    
    .btn-large {
        padding: 14px 30px;
        font-size: 1rem;
    }
    
    .btn-xlarge {
        padding: 16px 35px;
        font-size: 1.1rem;
    }
    
    .benefits-grid {
        grid-template-columns: 1fr;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .cta-box,
    .action-box {
        padding: 25px 20px;
    }
    
    .entry-highlights {
        gap: 15px;
        margin-bottom: 30px;
    }
    
    .highlight-card {
        padding: 25px 15px;
    }
    
    .hero-organizer-logo {
        max-width: 320px;
        margin: 18px auto 25px;
    }
    
    .sponsors-logos-section {
        flex-direction: column;
        gap: 20px;
    }
    
    .sponsor-logo-item {
        padding: 15px 25px;
    }
    
    .sponsor-logo-item img {
        height: 35px;
    }
    
    .current-sponsors-list {
        padding: 25px 15px;
        margin-top: 35px;
    }
    
    .sponsors-list-title {
        font-size: 1.4rem;
        margin-bottom: 25px;
    }
    
    .sponsors-logos-section {
        margin-bottom: 20px;
    }
    
    .current-entry-status {
        padding: 10px 12px;
    }
    
    .status-urgent {
        font-size: 1.3rem;
    }
    
    .status-urgent strong {
        font-size: 1.6rem;
    }
    
    .status-date {
        font-size: 0.75rem;
    }
    
    .remaining-number {
        font-size: 3.5rem;
    }
    
    .highlight-date {
        font-size: 0.8rem;
    }
    
    .social-links {
        flex-direction: column;
    }
    
    .social-link {
        width: 100%;
        justify-content: center;
    }
    
    .event-name {
        font-size: 1.2rem;
    }
}