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

:root {
    --primary-color: #2563eb;
    --primary-dark: #1e40af;
    --secondary-color: #7c3aed;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --bg-light: #f9fafb;
    --bg-white: #ffffff;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans JP', 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    color: var(--text-primary);
    line-height: 1.7;
    background-color: var(--bg-white);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* ヘッダー */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
    transition: all 0.3s ease;
}

.nav {
    padding: 1rem 0;
}

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

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    letter-spacing: -0.02em;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-links a {
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s ease;
    position: relative;
}

.nav-links a:hover {
    color: var(--primary-color);
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--primary-color);
    transition: width 0.3s ease;
}

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

/* ヒーローセクション */
.hero {
    position: relative;
    height: 100vh;
    min-height: 600px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg width="100" height="100" xmlns="http://www.w3.org/2000/svg"><defs><pattern id="grid" width="100" height="100" patternUnits="userSpaceOnUse"><path d="M 100 0 L 0 0 0 100" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="1"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)"/></svg>');
    opacity: 0.3;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.2);
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    color: white;
    padding: 2rem;
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 700;
    margin-bottom: 1rem;
    letter-spacing: -0.02em;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

.hero-subtitle {
    font-size: clamp(1.25rem, 2.5vw, 1.75rem);
    font-weight: 300;
    margin-bottom: 2rem;
    opacity: 0.95;
}

.hero-badge {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.hero-badge span {
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    padding: 0.5rem 1.5rem;
    border-radius: 50px;
    font-size: 0.9rem;
    font-weight: 500;
    border: 1px solid rgba(255, 255, 255, 0.3);
}

/* セクション */
.section {
    padding: 5rem 0;
}

.section-title {
    font-size: clamp(2rem, 4vw, 2.5rem);
    font-weight: 700;
    text-align: center;
    margin-bottom: 3rem;
    color: var(--text-primary);
    letter-spacing: -0.02em;
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -1rem;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    border-radius: 2px;
}

/* 部会紹介 */
.about-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 3rem;
    align-items: start;
}

.about-text .lead {
    font-size: 1.25rem;
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
    line-height: 1.8;
}

.about-text p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    line-height: 1.8;
}

.about-info {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.info-card {
    background: var(--bg-light);
    padding: 1.5rem;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.info-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-color);
}

.info-card h3 {
    font-size: 1rem;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.info-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
}

/* 目標セクション */
.goals-section {
    background: var(--bg-light);
}

.goals-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.goal-card {
    background: var(--bg-white);
    padding: 2.5rem;
    border-radius: 16px;
    text-align: center;
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
    border: 1px solid var(--border-color);
}

.goal-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

.goal-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.goal-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    line-height: 1.6;
}

/* 活動内容 */
.activities-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.activity-card {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.activity-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-color);
}

.activity-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.activity-card p {
    color: var(--text-secondary);
    line-height: 1.7;
}

/* 年間予定 */
.schedule-section {
    background: var(--bg-light);
}

.schedule-timeline {
    max-width: 800px;
    margin: 0 auto;
    position: relative;
    padding-left: 2rem;
}

.schedule-timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 2px;
    background: linear-gradient(180deg, var(--primary-color), var(--secondary-color));
}

.timeline-item {
    position: relative;
    padding-bottom: 3rem;
    padding-left: 3rem;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -1.5rem;
    top: 0.5rem;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--primary-color);
    border: 3px solid var(--bg-light);
    box-shadow: 0 0 0 2px var(--primary-color);
}

.timeline-month {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.timeline-content h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.timeline-content p {
    color: var(--text-secondary);
    line-height: 1.7;
}

/* 実績 */
.achievement-card {
    max-width: 800px;
    margin: 0 auto;
    background: var(--bg-white);
    padding: 2.5rem;
    border-radius: 16px;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
    text-align: center;
}

.achievement-card h3 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.achievement-type {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    font-size: 1rem;
}

.achievement-link {
    display: inline-block;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    padding: 0.75rem 2rem;
    border: 2px solid var(--primary-color);
    border-radius: 8px;
    transition: all 0.3s ease;
}

.achievement-link:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

/* お問い合わせ */
.contact-section {
    background: var(--bg-light);
}

.contact-content {
    max-width: 800px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 3rem;
}

.contact-info h3,
.social-links h3 {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.email {
    font-size: 1.1rem;
}

.email a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s ease;
}

.email a:hover {
    color: var(--primary-dark);
    text-decoration: underline;
}

.social-icons {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.social-link {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--text-primary);
    text-decoration: none;
    padding: 0.75rem 1rem;
    background: var(--bg-white);
    border-radius: 8px;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

.social-link:hover {
    transform: translateX(4px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.social-link svg {
    flex-shrink: 0;
}

.social-link span {
    font-weight: 500;
}

/* フッター */
.footer {
    background: var(--text-primary);
    color: white;
    padding: 2rem 0;
    text-align: center;
}

.footer p {
    margin-bottom: 0.5rem;
    color: rgba(255, 255, 255, 0.8);
}

.footer-link a {
    color: rgba(255, 255, 255, 0.9);
    text-decoration: none;
    transition: color 0.2s ease;
}

.footer-link a:hover {
    color: white;
    text-decoration: underline;
}

/* レスポンシブデザイン */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }

    .hero {
        min-height: 500px;
    }

    .about-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .goals-grid {
        grid-template-columns: 1fr;
    }

    .activities-grid {
        grid-template-columns: 1fr;
    }

    .contact-content {
        grid-template-columns: 1fr;
    }

    .container {
        padding: 0 1.5rem;
    }

    .section {
        padding: 3rem 0;
    }
}

@media (max-width: 480px) {
    .hero-badge {
        flex-direction: column;
        align-items: center;
    }

    .hero-badge span {
        width: 100%;
        text-align: center;
    }

    .schedule-timeline {
        padding-left: 1.5rem;
    }

    .timeline-item {
        padding-left: 2rem;
    }
}