*, *::before, *::after {
    box-sizing: border-box;
}

:root {
    --main-color: #0055aa;
    --accent-color: #FF6928;
    --text-color: #333;
    --bg-gray: #f9f9f9;
    --font-en: "Futura", "Century Gothic", sans-serif;
    --font-jp: "Noto Sans JP", "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
    --content-width: 1000px;
    --header-height: 80px;
}

body {
    margin: 0; padding: 0;
    color: var(--text-color);
    font-family: var(--font-jp);
    font-feature-settings: "palt";
    letter-spacing: 0.05em; 
    padding-top: var(--header-height);
    background-color: #fff;
    -webkit-text-size-adjust: 100%;
}

#header {
    width: 100%; height: var(--header-height); position: fixed; top: 0; left: 0; z-index: 999;
    background: rgba(255, 255, 255, 0.95); backdrop-filter: blur(10px);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
    display: flex; align-items: center; transition: top 0.4s;
}

.header-inner { 
    width: 92%; max-width: var(--content-width); margin: 0 auto; 
    display: flex; justify-content: space-between; align-items: center; 
}

.logo-link { display: flex; align-items: center; text-decoration: none; color: var(--text-color); }
.logo-img { height: 44px; width: auto; margin-right: 15px; }

@media screen and (max-width: 480px) {
    .logo-img { height: 36px; margin-right: 10px; }
}

.logo-text { display: flex; flex-direction: column; line-height: 1.1; }
.text-upper { font-size: 16px; font-weight: bold; font-family: var(--font-en); letter-spacing: 0.08em; }
.text-lower { font-size: 10px; color: #666; font-family: var(--font-en); margin-top: 2px; }

.main-nav ul { display: flex; list-style: none; margin: 0; padding: 0; align-items: center; }
.main-nav > ul > li { margin-left: 30px; position: relative; padding: 10px 0; }
.main-nav a { text-decoration: none; color: var(--text-color); font-weight: 500; font-size: 14px; transition: color 0.3s; display: block; letter-spacing: 0.05em; }
.main-nav a:hover { color: var(--accent-color); }

.dropdown-menu {
    display: block; position: absolute; top: 100%; left: 50%; transform: translateX(-50%);
    background: rgba(255, 255, 255, 0.98); min-width: 240px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08); border-radius: 4px; padding: 10px 0 !important;
    opacity: 0; visibility: hidden; transition: all 0.3s ease;
    flex-direction: column !important; align-items: flex-start !important;
    border: 1px solid #eee;
}

@media screen and (min-width: 769px) {
    .main-nav > ul > li:hover .dropdown-menu { opacity: 1; visibility: visible; top: 100%; }
}

.dropdown-menu li { margin: 0 !important; width: 100%; list-style: none !important; }
.dropdown-menu li a { padding: 12px 20px; font-size: 13px; font-weight: normal; color: #555; white-space: nowrap; text-align: left; display: block; }
.dropdown-menu li a:hover { background: #f7f7f7; color: var(--main-color); }
.submenu-toggle { display: none; }

.hamburger { display: none; cursor: pointer; width: 30px; height: 25px; position: relative; z-index: 1000; }
.hamburger span { display: block; width: 100%; height: 2px; background: #333; position: absolute; transition: 0.3s; border-radius: 2px; }
.hamburger span:nth-child(1) { top: 0; } .hamburger span:nth-child(2) { top: 11px; } .hamburger span:nth-child(3) { top: 22px; }

@media screen and (max-width: 768px) {
    .hamburger { display: block; }
    .main-nav {
        position: fixed; top: 0; right: -100%; width: 85%; height: 100vh;
        background: #fff; padding-top: 80px; overflow-y: auto;
        transition: 0.4s cubic-bezier(0.4, 0, 0.2, 1); box-shadow: -2px 0 10px rgba(0, 0, 0, 0.1); z-index: 998;
    }
    .main-nav.nav-active { right: 0; }
    .main-nav ul { flex-direction: column; align-items: flex-start; width: 100%; }
    .main-nav > ul > li {
        margin: 0; width: 100%; border-bottom: 1px solid #eee; padding: 0;
        display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between;
        box-sizing: border-box;
    }
    .main-nav > ul > li > a { padding: 18px 20px; flex: 1; color: #333; font-size: 16px; }
    
    .submenu-toggle {
        display: block; position: relative; width: 54px; height: 54px;
        border-left: 1px solid #eee; cursor: pointer; z-index: 10; background: transparent; flex-shrink: 0;
    }
    .submenu-toggle::before, .submenu-toggle::after {
        content: ''; position: absolute; top: 50%; left: 50%; background-color: #333; transform: translate(-50%, -50%); transition: transform 0.3s;
    }
    .submenu-toggle::before { width: 14px; height: 2px; }
    .submenu-toggle::after { width: 2px; height: 14px; }
    
    .main-nav > ul > li.open { background-color: #fafafa; }
    .main-nav > ul > li.open .submenu-toggle::after { transform: translate(-50%, -50%) rotate(90deg); opacity: 0; }
    .main-nav > ul > li.open .submenu-toggle { background: #eee; }
    
    .dropdown-menu {
        display: none !important; position: static; width: 100%; padding: 0 0 10px 0 !important;
        background: transparent; box-shadow: none; opacity: 1; visibility: visible; transform: none;
        text-align: left; border: none; border-top: 1px solid #eee;
    }
    .main-nav > ul > li.open .dropdown-menu { display: block !important; animation: slideDown 0.3s ease; }
    .dropdown-menu li { margin-bottom: 0 !important; }
    .dropdown-menu li a { padding: 12px 20px 12px 40px; font-size: 14px; color: #555; }
    
    @keyframes slideDown { from { opacity: 0; transform: translateY(-10px); } to { opacity: 1; transform: translateY(0); } }
    
    .hamburger.active span:nth-child(1) { transform: rotate(45deg); top: 11px; }
    .hamburger.active span:nth-child(2) { opacity: 0; }
    .hamburger.active span:nth-child(3) { transform: rotate(-45deg); top: 11px; }
    .btn-contact { margin: 20px; display: block; width: auto; text-align: center; background: #333; color: #fff !important; padding: 12px; border-radius: 4px; font-weight: bold; }
}

.btn-area {
    text-align: center; margin: 30px 0;
    display: flex; flex-direction: column; gap: 20px; align-items: center; width: 100%;
}
@media screen and (min-width: 768px) { .btn-area { flex-direction: row; justify-content: center; } }

.default-link-btn {
    display: inline-flex; justify-content: center; align-items: center;
    background-color: var(--main-color); color: #fff;
    padding: 16px 24px; border-radius: 50px;
    text-decoration: none; font-weight: bold; font-size: 16px;
    transition: 0.3s; box-shadow: 0 4px 10px rgba(0, 85, 170, 0.2);
    width: 100%; max-width: 320px;
    border: 2px solid var(--main-color);
}
.default-link-btn:hover {
    background-color: #fff; color: var(--main-color);
    transform: translateY(-3px); box-shadow: 0 6px 15px rgba(0, 85, 170, 0.3);
}

.container { width: 92%; max-width: var(--content-width); margin: 0 auto; }
h1 { text-align: center; font-size: clamp(1.6rem, 5vw, 2.2rem); margin: 60px 0 40px; font-weight: 700; letter-spacing: 0.1em; }

.container section h2 {
    background-color: #f0f7ff;
    padding: 20px 50px 20px 20px;
    border-radius: 0 8px 8px 0;
    border-left: 6px solid var(--main-color);
    font-size: clamp(1.1rem, 4vw, 1.4rem);
    color: var(--main-color);
    position: relative;
    cursor: pointer;
    transition: background-color 0.3s;
    margin: 40px 0 20px;
    line-height: 1.5;
}
.container section h2:hover { background-color: #e6f2ff; }

.container section h2::after {
    content: '▼';
    position: absolute; right: 20px; top: 50%; transform: translateY(-50%);
    font-size: 0.8rem; color: var(--main-color); transition: transform 0.3s;
}
.container section h2.is-open::after { transform: translateY(-50%) rotate(180deg); }

.container section p {
    padding: 0 20px 0 35px;
    margin-bottom: 30px;
    position: relative;
    font-size: 16px;
    line-height: 1.8;
    color: #444;
}

.container section p::before {
    content: "A.";
    position: absolute; left: 10px; top: 0;
    font-weight: bold; color: var(--accent-color);
}

@media screen and (max-width: 600px) {
    .container section h2 { padding: 15px 40px 15px 15px; font-size: 1.1rem; }
    .container section p { padding-left: 25px; padding-right: 10px; font-size: 15px; }
    .container section p::before { left: 0; }
}

.container section p strong {
    color: var(--main-color);
    background: linear-gradient(transparent 70%, #aaccff 70%);
}

#contact { background: #333; color: #fff; padding: 60px 0 20px; margin-top: 100px; scroll-margin-top: 100px; }
.footer-inner { max-width: var(--content-width); margin: 0 auto; text-align: center; padding: 0 20px; }

.footer-sponsors { margin-bottom: 50px; }
.footer-sponsors h3 { color: #fff; font-size: clamp(1.1rem, 3vw, 1.3rem); margin-bottom: 20px; }
.sponsor-list { 
    list-style: none; padding: 0; display: flex; flex-wrap: wrap; justify-content: center; gap: 15px; margin-bottom: 50px; 
}
.sponsor-list li { 
    background: #444; padding: 10px 20px; border-radius: 4px; font-size: 13px; letter-spacing: 0.05em; color: #fff; 
}
.sponsor-list a { color: #ffffff; text-decoration: none; display: block; }
.sponsor-list a:hover { opacity: 0.8; }

.footer-sitemap {
    display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    justify-content: center; gap: 40px 20px; text-align: left;
    margin-bottom: 60px; padding: 0 10px; align-items: start; 
}
.footer-col h4 {
    color: #fff; font-size: 15px; margin-bottom: 20px; padding-bottom: 8px;
    border-bottom: 2px solid var(--main-color); display: inline-block; 
    min-width: 40px; letter-spacing: 0.05em;
}
.footer-col h4 a { color: #fff; text-decoration: none; font-weight: bold; display: block; }
.footer-col h4 a:hover { opacity: 0.8; }
.footer-col ul { list-style: none; padding: 0; margin: 0; }
.footer-col li { margin-bottom: 10px; }
.footer-col li a {
    color: #bbb; text-decoration: none; font-size: 13px; transition: all 0.3s ease;
    display: block; line-height: 1.6; position: relative; padding-left: 0;
}
.footer-col li a:hover { color: #fff; padding-left: 5px; }

@media screen and (max-width: 768px) {
    .footer-sitemap { grid-template-columns: repeat(2, 1fr); gap: 40px 15px; }
    .footer-col h4 { width: 100%; border-bottom: 1px solid #555; }
}
@media screen and (max-width: 480px) {
    .footer-sitemap { grid-template-columns: 1fr; gap: 30px; text-align: center; }
    .footer-col h4 { margin-bottom: 15px; }
    .footer-col ul { display: flex; flex-direction: column; align-items: center; }
}

.footer-line { border: none; border-top: 1px solid #555; margin: 40px 0; }
.footer-info h3 { color: #fff; margin-bottom: 15px; }
.footer-info h3 span { font-size: 0.9em; }
.footer-info p { text-align: center !important; color: #ccc !important; font-size: 14px; line-height: 1.8; }
.footer-info a { color: #88ccff; text-decoration: none; font-weight: bold; }
.copyright { margin-top: 40px; font-size: 12px; color: #777; font-family: var(--font-en); }