/* ==========================================================================
   Design System & Custom Properties
   ========================================================================== */
:root {
    /* Color Palette */
    --color-primary: #1b4b72;       /* Slate Blue */
    --color-secondary: #1a8f6a;     /* Green/Teal */
    --color-dark: #1e293b;          /* Charcoal Dark */
    --color-light: #f8fafc;         /* Pure Light */
    --color-white: #ffffff;
    --color-muted: #64748b;         /* Muted Slate */
    --color-accent: #f59e0b;        /* Soft Amber */

    /* Gradients */
    --gradient-hero: linear-gradient(135deg, rgba(27, 75, 114, 0.85) 0%, rgba(26, 143, 106, 0.8) 100%);
    --gradient-card: linear-gradient(180deg, #ffffff 0%, #f8fafc 100%);

    /* Typography */
    --font-heading: 'Outfit', 'Noto Sans JP', sans-serif;
    --font-body: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;

    /* Shadow Styles */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 10px 25px -5px rgba(0, 0, 0, 0.08), 0 8px 10px -6px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 20px 40px -10px rgba(0, 0, 0, 0.12);
    --shadow-hover: 0 30px 60px -15px rgba(27, 75, 114, 0.25);

    /* Transition Dynamics */
    --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);

    /* Layout Spacing */
    --header-height: 80px;
    --container-width: 1200px;
}

/* ==========================================================================
   CSS Reset & Base Rules
   ========================================================================== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

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

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

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

ul {
    list-style: none;
}

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

/* ==========================================================================
   Layout Containers
   ========================================================================== */
.container {
    width: 100%;
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 24px;
}

.section {
    padding: 96px 0;
}

.bg-light {
    background-color: var(--color-light);
}

/* ==========================================================================
   Typography Rules
   ========================================================================== */
h1, h2, h3, h4 {
    font-family: var(--font-heading);
    font-weight: 700;
    line-height: 1.25;
}

.section-title {
    font-size: 2.25rem;
    color: var(--color-primary);
    margin-bottom: 40px;
    position: relative;
    padding-bottom: 12px;
}

/* Left-aligned title with primary/secondary double underline from screenshot */
.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 80px;
    height: 4px;
    background-color: var(--color-primary);
    border-radius: 2px;
}

.section-title::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 160px;
    height: 4px;
    background-color: rgba(26, 143, 106, 0.2);
    border-radius: 2px;
}

.section-title-alt {
    font-size: 2.25rem;
    color: var(--color-primary);
    margin-bottom: 24px;
}

/* ==========================================================================
   Main Header Section
   ========================================================================== */
.main-header {
    height: auto;
    min-height: var(--header-height);
    padding: 10px 0;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(226, 232, 240, 0.8);
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    display: flex;
    align-items: center;
    transition: var(--transition-normal);
}

.header-container {
    width: 100%;
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    flex-wrap: nowrap; /* ロゴとメニュー枠が2段に割れるのを防ぐ */
    justify-content: space-between;
    align-items: center;
    gap: 32px; /* ロゴとメニューの間の最低限の余白 */
}

.logo-link {
    display: flex;
    align-items: center;
    flex-shrink: 0; /* 画面が狭まってもロゴが潰れないようにする */
}

.logo-img {
    height: 48px;
    object-fit: contain;
}

/* Desktop Menu styling */
.nav-menu {
    flex: 1; /* 右側の残りのスペースをすべてメニュー領域として使う */
}

.nav-menu ul {
    display: flex;
    flex-wrap: wrap; /* メニュー項目のみがロゴの右横スペース内で折り返される */
    justify-content: flex-end; /* 右寄せを維持 */
    gap: 12px 20px;
}

.nav-menu a {
    font-family: var(--font-heading);
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--color-muted);
    padding: 8px 4px;
    position: relative;
    white-space: nowrap; /* メニュー項目テキスト自体の不自然な改行を防ぐ */
}

.nav-menu a:hover,
.nav-menu a.active {
    color: var(--color-primary);
}

/* Slide in underline hover effect */
.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--color-primary);
    transition: var(--transition-normal);
}

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

/* Hamburger mobile button */
.menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 24px;
    height: 18px;
    background: none;
    border: none;
    cursor: pointer;
    z-index: 1001;
}

.menu-toggle .bar {
    width: 100%;
    height: 2px;
    background-color: var(--color-primary);
    transition: var(--transition-normal);
}

/* ==========================================================================
   Hero Section
   ========================================================================== */
.hero-section {
    min-height: 80vh;
    padding-top: calc(var(--header-height) + 48px);
    padding-bottom: 64px;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    display: flex;
    align-items: center;
    position: relative;
}

.hero-container {
    width: 100%;
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 24px;
    display: grid;
    grid-template-columns: 1fr;
    gap: 48px;
}

.hero-content {
    max-width: 650px;
}

.hero-subtitle {
    font-family: var(--font-heading);
    color: var(--color-secondary);
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 8px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.hero-title {
    font-size: 3.5rem;
    color: var(--color-primary);
    margin-bottom: 24px;
    font-weight: 800;
    letter-spacing: -1px;
}

.hero-info-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.hero-info-item {
    display: flex;
    align-items: center;
    gap: 12px;
}

.hero-icon {
    width: 20px;
    height: 20px;
    color: var(--color-secondary);
    flex-shrink: 0;
}

.hero-info-text {
    font-family: var(--font-heading);
    font-size: 1.15rem;
    color: var(--color-dark);
}

.font-bold {
    font-weight: 700;
}

/* Quick Action Circles below hero section */
.quick-actions {
    display: flex;
    justify-content: flex-start;
    gap: 32px;
    margin-top: 16px;
}

.action-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    text-align: center;
    width: 140px;
    transition: var(--transition-normal);
}

.action-icon-wrapper {
    width: 80px;
    height: 80px;
    background-color: var(--color-white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-md);
    border: 1px solid rgba(226, 232, 240, 0.8);
    transition: var(--transition-normal);
}

.action-icon {
    width: 32px;
    height: 32px;
    color: var(--color-secondary);
    transition: var(--transition-normal);
}

.action-label {
    font-family: var(--font-heading);
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--color-primary);
    line-height: 1.3;
}

/* Action hover micro-animations */
.action-card:hover {
    transform: translateY(-8px);
}

.action-card:hover .action-icon-wrapper {
    background-color: var(--color-secondary);
    border-color: var(--color-secondary);
    box-shadow: 0 12px 24px rgba(26, 143, 106, 0.3);
}

.action-card:hover .action-icon {
    color: var(--color-white);
    transform: scale(1.1);
}

/* ==========================================================================
   Welcome / About Section
   ========================================================================== */
.welcome-grid {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: 64px;
    align-items: center;
}

.welcome-paragraph {
    margin-bottom: 20px;
    color: var(--color-muted);
    font-size: 1.05rem;
}

.welcome-media {
    display: flex;
    justify-content: center;
    align-items: center;
}

.globe-wrapper {
    position: relative;
    padding: 16px;
    background: radial-gradient(circle, rgba(26, 143, 106, 0.05) 0%, rgba(255, 255, 255, 0) 70%);
}

.globe-img {
    width: 100%;
    max-width: 250px;
    filter: drop-shadow(0 15px 30px rgba(0, 0, 0, 0.05));
    animation: float 6s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

/* ==========================================================================
   Important Dates Section (Green Banner)
   ========================================================================== */
.dates-section {
    background-color: var(--color-secondary);
    background-image: linear-gradient(135deg, var(--color-secondary) 0%, #157355 100%);
    padding: 72px 0;
    color: var(--color-white);
}

.dates-title {
    font-size: 2.25rem;
    text-align: center;
    margin-bottom: 48px;
    font-weight: 700;
}

.dates-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 32px;
}

.date-card {
    background-color: rgba(255, 255, 255, 0.95);
    border-radius: 16px;
    padding: 24px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    color: var(--color-dark);
    display: flex;
    flex-direction: column;
    align-items: center;
    transition: var(--transition-normal);
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.date-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.15);
}

.date-label {
    font-family: var(--font-heading);
    font-size: 0.9rem;
    font-weight: 700;
    color: var(--color-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 16px;
    text-align: center;
}

.date-range {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
}

.date-val {
    font-family: var(--font-heading);
    font-size: 1.35rem;
    font-weight: 600;
    color: var(--color-primary);
}

.date-val.highlighted {
    color: var(--color-secondary);
    font-weight: 700;
}

.date-arrow {
    color: var(--color-muted);
    opacity: 0.6;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 2px 0;
}

/* ==========================================================================
   Content Sections (General Formatting)
   ========================================================================== */
.content-body p {
    color: var(--color-muted);
    font-size: 1.05rem;
    margin-bottom: 24px;
    max-width: 800px;
}

/* Button UI Components */
.btn-container {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    margin-top: 32px;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 28px;
    border-radius: 8px;
    font-family: var(--font-heading);
    font-weight: 600;
    font-size: 0.95rem;
    cursor: pointer;
    transition: var(--transition-normal);
}

.btn-primary {
    background-color: var(--color-primary);
    color: var(--color-white);
    box-shadow: 0 4px 14px rgba(27, 75, 114, 0.2);
}

.btn-primary:hover {
    background-color: #12334e;
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(27, 75, 114, 0.3);
}

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

.btn-secondary:hover {
    background-color: rgba(27, 75, 114, 0.05);
    transform: translateY(-2px);
}

/* ==========================================================================
   Technical Program Cards
   ========================================================================== */
.program-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 24px;
    margin-top: 40px;
}

.program-card {
    background-color: var(--color-white);
    padding: 30px;
    border-radius: 12px;
    border: 1px solid rgba(226, 232, 240, 0.8);
    box-shadow: var(--shadow-sm);
    transition: var(--transition-normal);
}

.program-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-md);
    border-color: rgba(26, 143, 106, 0.3);
}

.program-name {
    font-size: 1.25rem;
    color: var(--color-primary);
    margin-bottom: 12px;
    font-weight: 700;
}

.program-desc {
    color: var(--color-muted);
    font-size: 0.9rem;
    line-height: 1.5;
}

/* ==========================================================================
   Committees Section (Avatars and Cards)
   ========================================================================== */
.committees-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 32px;
    margin-top: 40px;
}

.committee-card {
    background-color: var(--color-white);
    border-radius: 16px;
    padding: 32px 24px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    border: 1px solid rgba(226, 232, 240, 0.8);
    transition: var(--transition-normal);
    display: flex;
    flex-direction: column;
    align-items: center;
}

.committee-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-md);
    border-color: rgba(27, 75, 114, 0.2);
}

.committee-avatar {
    width: 90px;
    height: 90px;
    border-radius: 50%;
    background-color: #e2e8f0;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
    border: 3px solid rgba(26, 143, 106, 0.1);
    transition: var(--transition-normal);
}

.committee-card:hover .committee-avatar {
    border-color: var(--color-secondary);
    transform: scale(1.05);
}

.avatar-placeholder {
    font-family: var(--font-heading);
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--color-primary);
}

.committee-name {
    font-size: 1.15rem;
    color: var(--color-dark);
    margin-bottom: 4px;
}

.committee-role {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--color-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 8px;
}

.committee-affiliation {
    font-size: 0.85rem;
    color: var(--color-muted);
}

/* ==========================================================================
   Venue & Location Map
   ========================================================================== */
.venue-container {
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: 48px;
    margin-top: 40px;
    align-items: stretch;
}

.venue-info {
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.venue-name {
    font-size: 1.85rem;
    color: var(--color-primary);
    margin-bottom: 24px;
}

.venue-detail-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
    margin-bottom: 24px;
}

.venue-detail-item {
    display: flex;
    align-items: flex-start;
    gap: 12px;
}

.venue-icon {
    width: 20px;
    height: 20px;
    color: var(--color-secondary);
    margin-top: 3px;
    flex-shrink: 0;
}

.venue-detail-text {
    font-size: 1rem;
    color: var(--color-muted);
}

.venue-note {
    font-size: 0.95rem;
    color: var(--color-muted);
    line-height: 1.6;
    border-left: 3px solid var(--color-secondary);
    padding-left: 16px;
}

.venue-map {
    border-radius: 16px;
    overflow: hidden;
    box-shadow: var(--shadow-md);
    border: 1px solid rgba(226, 232, 240, 0.8);
    min-height: 350px;
}

/* ==========================================================================
   Footer Elements
   ========================================================================== */
.main-footer {
    background-color: var(--color-dark);
    color: rgba(255, 255, 255, 0.6);
    padding: 32px 0;
    text-align: center;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.footer-container {
    display: flex;
    justify-content: center;
    align-items: center;
}

.copyright {
    font-size: 0.85rem;
}

/* ==========================================================================
   Responsive Breakpoints & Layouts
   ========================================================================== */
@media (max-width: 1024px) {
    .welcome-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .welcome-media {
        order: -1; /* Display image on top in mobile */
    }

    .venue-container {
        grid-template-columns: 1fr;
        gap: 40px;
    }
    
    .venue-map {
        min-height: 300px;
    }
}

@media (max-width: 768px) {
    /* Main Layout adjustments */
    .section {
        padding: 64px 0;
    }

    /* Navigation Mobile (Hamburger active states) */
    .menu-toggle {
        display: flex;
    }

    .nav-menu {
        position: absolute;
        top: var(--header-height);
        left: -100%;
        width: 100%;
        background-color: var(--color-white);
        box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1);
        transition: var(--transition-normal);
        border-bottom: 1px solid rgba(226, 232, 240, 0.8);
    }

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

    .nav-menu ul {
        flex-direction: column;
        padding: 24px;
        gap: 0;
    }

    .nav-menu a {
        display: block;
        padding: 16px 8px;
        font-size: 1rem;
        border-bottom: 1px solid rgba(241, 245, 249, 0.8);
    }

    .nav-menu li:last-child a {
        border-bottom: none;
    }

    /* Hamburger animation */
    .menu-toggle.active .bar:nth-child(1) {
        transform: translateY(8px) rotate(45deg);
    }

    .menu-toggle.active .bar:nth-child(2) {
        opacity: 0;
    }

    .menu-toggle.active .bar:nth-child(3) {
        transform: translateY(-8px) rotate(-45deg);
    }

    /* Hero section responsive sizes */
    .hero-section {
        min-height: auto;
        padding-top: calc(var(--header-height) + 32px);
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .quick-actions {
        flex-wrap: wrap;
        justify-content: center;
        gap: 16px 24px;
    }

    .action-card {
        width: 100px;
    }

    .action-icon-wrapper {
        width: 64px;
        height: 64px;
    }

    .action-icon {
        width: 24px;
        height: 24px;
    }

    .action-label {
        font-size: 0.75rem;
    }
}

/* ==========================================================================
   Dummy Elements & Refinements
   ========================================================================== */
.program-card-center {
    background-color: var(--color-white);
    height: 140px;
    border-radius: 12px;
    border: 1px solid rgba(226, 232, 240, 0.8);
    box-shadow: var(--shadow-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 20px;
    transition: var(--transition-normal);
}

.program-card-center:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-md);
    border-color: rgba(26, 143, 106, 0.3);
}

.program-name-center {
    font-family: var(--font-heading);
    font-size: 1.15rem;
    color: var(--color-muted);
    font-weight: 500;
}

.committee-card-circle {
    width: 140px;
    height: 140px;
    border-radius: 50%;
    background-color: #e2e8f0;
    border: 3px solid rgba(26, 143, 106, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto;
    transition: var(--transition-normal);
}

.committee-card-circle:hover {
    border-color: var(--color-secondary);
    background-color: #cbd5e1;
    transform: scale(1.05);
}

.committee-circle-text {
    font-family: var(--font-heading);
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--color-primary);
    text-align: center;
    padding: 0 10px;
}

.venue-container-simple {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    background-color: var(--color-white);
    padding: 30px;
    border-radius: 16px;
    box-shadow: var(--shadow-sm);
    border: 1px solid rgba(226, 232, 240, 0.8);
    max-width: 600px;
    margin: 40px auto 0 auto;
}