.header-inner {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: relative;
}

.hamburger-btn {
    background: none;
    border: none;
    outline: none;
    cursor: pointer;
    width: 30px;
    height: 24px;
    position: relative;
    z-index: 100; 
}

.hamburger-btn span {
    display: block;
    position: absolute;
    width: 100%;
    height: 2px;
    background-color: #333;
    left: 0;
    transition: transform 0.3s, opacity 0.3s;
}

.hamburger-btn span:nth-child(1) { top: 0; }
.hamburger-btn span:nth-child(2) { top: 11px; }
.hamburger-btn span:nth-child(3) { top: 22px; }

.hamburger-btn.active span:nth-child(1) {
    transform: translateY(11px) rotate(45deg);
}
.hamburger-btn.active span:nth-child(2) {
    opacity: 0;
}
.hamburger-btn.active span:nth-child(3) {
    transform: translateY(-11px) rotate(-45deg);
}

.nav-menu {
    position: fixed;
    top: 0;
    right: -100%; 
    width: 250px; 
    height: 100vh;
    background-color: rgba(240, 240, 240, 0.95);
    box-shadow: -2px 0 5px rgba(0,0,0,0.1);
    padding-top: 80px;
    transition: right 0.3s ease;
    z-index: 99;
}

.nav-menu.active {
    right: 0; 
}

.nav-menu ul {
    list-style: none;
    padding: 0 20px;
}

.nav-menu ul li {
    margin-bottom: 25px;
    border-bottom: 1px solid #ccc;
    padding-bottom: 10px;
}

.nav-menu ul li a {
    text-decoration: none;
    color: #333;
    font-size: 1.2rem;
    display: block;
    transition: color 0.2s;
}

.nav-menu ul li a:hover {
    color: #007bff; 
}



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

body {
    font-family: "Helvetica Neue", Arial, "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
    color: #223344; 
    background-color: #f0f7fa; 
    line-height: 1.6;
}


.main-header {
    background: linear-gradient(135deg, #00a4e4 0%, #0072bc 100%);
    padding: 50px 20px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    margin-bottom: 40px;
}

.main-header h1 {
    font-size: 2.8rem;
    max-width: 1200px;
    margin: 0 auto;
    font-weight: bold;
    letter-spacing: 3px;
    color: #ffffff; 
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.2); 
}

.header-inner {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: relative;
}

.hamburger-btn {
    background: none;
    border: none;
    outline: none;
    cursor: pointer;
    width: 32px;
    height: 24px;
    position: relative;
    z-index: 100;
}

.hamburger-btn span {
    display: block;
    position: absolute;
    width: 100%;
    height: 3px; 
    background-color: #ffffff; 
    left: 0;
    border-radius: 2px;
    transition: transform 0.3s, opacity 0.3s, background-color 0.3s;
}

.hamburger-btn span:nth-child(1) { top: 0; }
.hamburger-btn span:nth-child(2) { top: 10px; }
.hamburger-btn span:nth-child(3) { top: 20px; }

.hamburger-btn.active span {
    background-color: #005a9c;
}
.hamburger-btn.active span:nth-child(1) {
    transform: translateY(10px) rotate(45deg);
}
.hamburger-btn.active span:nth-child(2) {
    opacity: 0;
}
.hamburger-btn.active span:nth-child(3) {
    transform: translateY(-10px) rotate(-45deg);
}

.nav-menu {
    position: fixed;
    top: 0;
    right: -100%;
    width: 280px;
    height: 100vh;
    background-color: rgba(255, 255, 255, 0.98);
    box-shadow: -4px 0 20px rgba(0,0,0,0.15);
    padding-top: 90px;
    transition: right 0.3s ease;
    z-index: 99;
}

.nav-menu.active {
    right: 0;
}

.nav-menu ul {
    list-style: none;
    padding: 0 30px;
}

.nav-menu ul li {
    margin-bottom: 25px;
    border-bottom: 2px solid #e1f0f8;
    padding-bottom: 12px;
}

.nav-menu ul li a {
    text-decoration: none;
    color: #005a9c;
    font-size: 1.25rem;
    font-weight: bold;
    display: block;
    transition: color 0.2s;
}

.nav-menu ul li a:hover {
    color: #ffb100; 
}


.container img {
    width: 100vw;       
    height: 100vh;      
    object-fit: cover; 
    display: block;
}


.month-section {
    margin-bottom: 60px;
}

.month-section h2 {
    font-size: 2rem;
    margin-bottom: 25px;
    font-weight: bold;
    color: #005a9c;
    position: relative;
    padding-left: 15px;
}


.month-section h2::before {
    content: "";
    position: absolute;
    left: 0;
    top: 4px;
    width: 6px;
    height: 80%;
    background-color: #ffb100; 
    border-radius: 3px;
}

.event-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 40px;
}


.event-card {
    display: flex;
    align-items: flex-start;
    gap: 25px;
    background-color: #ffffff;
    padding: 20px;
    border-radius: 12px; 
    box-shadow: 0 4px 10px rgba(0, 114, 188, 0.05);
    
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.event-card.show {
    opacity: 1;
    transform: translateY(0);
}


.event-image {
    width: 200px;
    height: 200px;
    background-color: #e1f0f8; 
    flex-shrink: 0;
    border-radius: 8px;
    overflow: hidden;
    position: relative;
}

.event-image a {
    display: block;
    width: 100%;
    height: 100%;
    cursor: pointer;
}

.event-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s ease, filter 0.3s ease;
}

.event-image a:hover img {
    transform: scale(1.08);
    filter: brightness(1.1); 
}


.event-details {
    flex-grow: 1;
}

.event-details h3 {
    font-size: 1.5rem;
    margin-bottom: 12px;
    font-weight: bold;
    color: #004477;
}

.event-details p {
    font-size: 0.95rem;
    margin-bottom: 10px;
    color: #445566;
}

.event-details p strong {
    color: #0072bc; 
}

.event-details .notice strong {
    color: #ff5533;
}


@media (max-width: 768px) {
    .main-header h1 {
        font-size: 2rem;
    }

    .event-grid {
        grid-template-columns: 1fr;
        gap: 25px;
    }

    .event-card {
        flex-direction: column;
        gap: 15px;
    }

    .event-image {
        width: 100%;
        height: 220px;
    }
}