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

body {
    font-family: 'Hiragino Kaku Gothic ProN', 'Hiragino Sans', 'Yu Gothic Medium', 'Meiryo', 'Helvetica Neue', sans-serif;
    background: white;
    min-height: 100vh;
    padding-top: 90px;
}

/* ===== 画像セクション ===== */
.hero-image-section {
    position: relative;
    height: 400px;
    background: url('../images/research/research_brain.jpg') center/cover no-repeat;
    overflow: hidden;
}

.hero-image-section::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 100px;
    background: linear-gradient(to bottom, transparent, white);
    pointer-events: none;
}

/* ===== テキストセクション ===== */
.hero-text-section {
    padding: 3rem 2rem 4rem;
    background: white;
    text-align: center;
}

.hero-content {
    max-width: 1000px;
    margin: 0 auto;
}

.hero-title {
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: bold;
    margin-bottom: 1.5rem;
    color: #1e3c72;
}

.hero-subtitle {
    font-size: clamp(1rem, 2.5vw, 1.3rem);
    margin-bottom: 2rem;
    color: #4a5568;
}

.hero-description {
    font-size: clamp(0.95rem, 2vw, 1.1rem);
    line-height: 1.8;
    max-width: 800px;
    margin: 0 auto;
    color: #4a5568;
}

/* ===== 共通コンテナ ===== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.section {
    padding: 4rem 0;
}

.section-title {
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    color: #1e3c72;
    margin-bottom: 1rem;
    font-weight: 600;
    text-align: center;
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.section-title.visible {
    opacity: 1;
    transform: translateY(0);
}

.section-description {
    font-size: clamp(0.95rem, 2vw, 1.05rem);
    color: #555;
    line-height: 1.8;
    margin-bottom: 3rem;
    text-align: center;
    max-width: 800px;
    margin: 0 auto 3rem;
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease 0.1s, transform 0.6s ease 0.1s;
}

.section-description.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ミッションセクション - 番号なしシンプル版 */
.mission-pillars {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 50px;
    max-width: 1200px;
    margin: 40px auto 0;
}

.mission-pillar {
    text-align: left;
    padding: 30px;
    background: white;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease, box-shadow 0.3s ease, transform 0.3s ease;
}

.mission-pillar.visible {
    opacity: 1;
    transform: translateY(0);
}

.mission-pillar:nth-child(1) { transition-delay: 0.1s; }
.mission-pillar:nth-child(2) { transition-delay: 0.2s; }
.mission-pillar:nth-child(3) { transition-delay: 0.3s; }

.mission-pillar:hover {
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    transform: translateY(-5px);
}

.pillar-title {
    font-size: 1.3rem;
    color: #1e3c72;
    margin-bottom: 1rem;
    font-weight: 600;
    line-height: 1.4;
}

.pillar-description {
    color: #555;
    line-height: 1.8;
}

/* ===== アプローチセクション - 番号なしグリッド版 ===== */
.approach-section {
    background: #f8f9fa;
}

.approach-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.approach-item {
    padding: 30px;
    background: white;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease, box-shadow 0.3s ease, transform 0.3s ease;
}

.approach-item.visible {
    opacity: 1;
    transform: translateY(0);
}

.approach-item:nth-child(1) { transition-delay: 0.1s; }
.approach-item:nth-child(2) { transition-delay: 0.2s; }
.approach-item:nth-child(3) { transition-delay: 0.3s; }
.approach-item:nth-child(4) { transition-delay: 0.4s; }
.approach-item:nth-child(5) { transition-delay: 0.5s; }

.approach-item:hover {
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    transform: translateY(-5px);
}

.approach-item-title {
    font-size: clamp(1rem, 2.5vw, 1.3rem);
    font-weight: 600;
    color: #1e3c72;
    margin-bottom: 15px;
}

.approach-item-description {
    font-size: clamp(0.9rem, 2vw, 1rem);
    color: #555;
    line-height: 1.8;
}

/* ===== レスポンシブ調整 ===== */
@media (max-width: 768px) {
    .hero-image-section {
        height: 250px;
    }

    .hero-text-section {
        padding: 2rem 1rem 3rem;
    }

    .section {
        padding: 3rem 0;
    }

    .container {
        padding: 0 1rem;
    }

    .mission-item,
    .approach-item {
        padding: 1.5rem;
    }
}
/* ミッションセクション - タイポグラフィスタイル */
.mission-pillars {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 50px;
    max-width: 1200px;
    margin: 40px auto 0;
}

.mission-pillar {
    text-align: left;
    position: relative;
    padding: 30px;
    border-bottom: 2px solid #e0e0e0;
    transition: border-color 0.3s ease;
}

.mission-pillar:hover {
    border-color: #1e3c72;
}

.pillar-number {
    font-size: 5rem;
    font-weight: 700;
    color: #f0f0f0;
    line-height: 1;
    margin-bottom: 10px;
}

.pillar-title {
    font-size: 1.3rem;
    color: #1e3c72;
    margin-bottom: 1rem;
    font-weight: 600;
    margin-top: -50px;
    position: relative;
    z-index: 1;
    line-height: 1.4;
}

.pillar-description {
    color: #555;
    line-height: 1.8;
}

/* レスポンシブ対応 */
@media (max-width: 768px) {
    .mission-pillars {
        grid-template-columns: 1fr;
    }
    
    .pillar-number {
        font-size: 3.5rem;
    }
    
    .pillar-title {
        margin-top: -40px;
        font-size: 1.2rem;
    }
}
/* 研究キーワードセクション */
.keywords-section {
    padding: 60px 20px;
    background: white;
}

.keywords-title {
    text-align: center;
    font-size: 1.5rem;
    color: #1e3c72;
    margin-bottom: 30px;
    font-weight: 600;
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.keywords-title.visible {
    opacity: 1;
    transform: translateY(0);
}

.keywords-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    justify-content: center;
    max-width: 1000px;
    margin: 0 auto;
}

.keyword-tag {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 12px 24px;
    border-radius: 30px;
    font-size: 0.95rem;
    font-weight: 500;
    box-shadow: 0 2px 10px rgba(102, 126, 234, 0.3);
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.5s ease, transform 0.5s ease, box-shadow 0.3s ease;
    cursor: pointer;
}

.keyword-tag.visible {
    opacity: 1;
    transform: translateY(0);
}

.keyword-tag:nth-child(1) { transition-delay: 0.05s; }
.keyword-tag:nth-child(2) { transition-delay: 0.1s; }
.keyword-tag:nth-child(3) { transition-delay: 0.15s; }
.keyword-tag:nth-child(4) { transition-delay: 0.2s; }
.keyword-tag:nth-child(5) { transition-delay: 0.25s; }
.keyword-tag:nth-child(6) { transition-delay: 0.3s; }
.keyword-tag:nth-child(7) { transition-delay: 0.35s; }
.keyword-tag:nth-child(8) { transition-delay: 0.4s; }
.keyword-tag:nth-child(9) { transition-delay: 0.45s; }

.keyword-tag::before {
    content: '# ';
    opacity: 0.8;
}

.keyword-tag:hover {
    transform: translateY(-3px);
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.5);
}

/* レスポンシブ対応 */
@media (max-width: 768px) {
    .keywords-section {
        padding: 40px 15px;
    }
    
    .keywords-title {
        font-size: 1.3rem;
    }
    
    .keyword-tag {
        font-size: 0.85rem;
        padding: 10px 18px;
    }
}
/* レスポンシブ対応 */
@media (max-width: 768px) {
    .mission-pillars {
        grid-template-columns: 1fr;
    }
    
    .approach-list {
        grid-template-columns: 1fr;
    }
}
/* 研究テーマモーダル */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(5px);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    animation: fadeIn 0.3s ease;
}

.modal-overlay.active {
    display: flex;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.modal-content {
    background: white;
    border-radius: 15px;
    max-width: 600px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
    box-shadow: 0 10px 40px rgba(0,0,0,0.3);
    animation: slideUp 0.3s ease;
}

@keyframes slideUp {
    from { 
        opacity: 0;
        transform: translateY(50px);
    }
    to { 
        opacity: 1;
        transform: translateY(0);
    }
}

.modal-header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 25px 30px;
    border-radius: 15px 15px 0 0;
    position: relative;
}

.modal-title {
    font-size: 1.5rem;
    font-weight: 600;
    padding-right: 40px;
}

.modal-close {
    position: absolute;
    top: 20px;
    right: 20px;
    width: 35px;
    height: 35px;
    background: rgba(255,255,255,0.2);
    border: none;
    border-radius: 50%;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
}

.modal-close:hover {
    background: rgba(255,255,255,0.3);
    transform: rotate(90deg);
}

.modal-body {
    padding: 30px;
}

.modal-description {
    color: #555;
    line-height: 1.8;
    font-size: 1rem;
}

/* モーダル レスポンシブ対応 */
@media (max-width: 768px) {
    .modal-content {
        width: 95%;
        max-height: 90vh;
    }
    
    .modal-header {
        padding: 20px;
    }
    
    .modal-title {
        font-size: 1.3rem;
    }
    
    .modal-body {
        padding: 20px;
    }
}

/* ===== フッター ===== */
.footer {
    background: #1e3c72;
    color: white;
    text-align: center;
    padding: 40px 20px;
}

.footer-content {
    max-width: 800px;
    margin: 0 auto;
}

.copyright {
    font-size: 0.85em;
    opacity: 0.8;
    line-height: 1.6;
}