@charset "UTF-8";

:root {
    --primary-color: #00518F;
    --primary-light: #1A6BA8;
    --primary-dark: #003A66;
    --accent-color: #FFC72C;
    --light-bg: #f8f9fa;
    --dark-text: #333;
    --light-text: #fff;
    --gray-text: #6c757d;
    --border-color: #e9ecef;
    --card-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

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

body {
    font-family: 'Noto Sans JP', sans-serif;
    color: var(--dark-text);
    line-height: 1.7;
    background-color: var(--light-bg);
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    background-color: white;
    box-shadow: 0 0 30px rgba(0, 0, 0, 0.05);
    overflow: hidden;
}

/* ヘッダーセクション */
.hero {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    padding: 7rem 2rem 5rem;
    color: var(--light-text);
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: url('data:image/svg+xml;charset=utf8,%3Csvg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1440 320"%3E%3Cpath fill="%23ffffff" fill-opacity="0.05" d="M0,224L48,229.3C96,235,192,245,288,250.7C384,256,480,256,576,229.3C672,203,768,149,864,138.7C960,128,1056,160,1152,186.7C1248,213,1344,235,1392,245.3L1440,256L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z"%3E%3C/path%3E%3C/svg%3E');
    background-size: cover;
    background-position: center;
    opacity: 0.3;
}

.hero h1 {
    font-size: 2.8rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    letter-spacing: 0.05em;
    position: relative;
}

.hero h2 {
    font-size: 1.4rem;
    font-weight: 400;
    margin-bottom: 0.5rem;
    opacity: 0.9;
    position: relative;
}

.hero-accent {
    width: 70px;
    height: 4px;
    background-color: var(--accent-color);
    margin: 2rem auto;
    position: relative;
}

.representative-info{
    flex: 1;
}

.representative-img img{
    width: 200px;
    height: 200px;
}

/* ナビゲーション */
nav {
    background-color: white;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 0.8rem 0;
    transition: all 0.3s ease;
}

nav.scrolled {
    padding: 0.5rem 0;
}

nav ul {
    display: flex;
    justify-content: center;
    list-style-type: none;
    flex-wrap: wrap;
}

nav ul li {
    margin: 0;
}

nav ul li a {
    color: var(--primary-color);
    text-decoration: none;
    font-size: 0.95rem;
    font-weight: 500;
    padding: 0.7rem 1.2rem;
    display: block;
    transition: all 0.3s;
    border-radius: 4px;
    position: relative;
}

nav ul li a:hover {
    color: var(--primary-light);
    background-color: rgba(0, 81, 143, 0.05);
}

nav ul li a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background-color: var(--primary-color);
    transition: all 0.3s;
    transform: translateX(-50%);
}

nav ul li a:hover::after {
    width: 70%;
}

/* セクション共通スタイル */
section {
    padding: 5rem 2rem;
    position: relative;
}

section:nth-child(even) {
    background-color: var(--light-bg);
}

.section-heading {
    position: relative;
    margin-bottom: 3rem;
    padding-bottom: 1rem;
    text-align: center;
}

.section-heading h3 {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.section-heading::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 3px;
    background-color: var(--primary-color);
}

.section-content {
    max-width: 900px;
    margin: 0 auto;
}

/* 研究室代表セクション */
.representative-card {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 3rem;
    padding: 2rem;
    background-color: white;
    border-radius: 10px;
    box-shadow: var(--card-shadow);
}

.representative-img {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    overflow: hidden;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    background-color: #e9ecef;
    display: flex;
    align-items: center;
    justify-content: center;
}

.representative-img i {
    font-size: 80px;
    color: var(--primary-color);
    opacity: 0.5;
}

.representative-info h4 {
    font-size: 1.6rem;
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

.representative-info p {
    font-size: 1.1rem;
    color: var(--gray-text);
    margin-bottom: 1rem;
}

/* 代表挨拶セクション */
.greeting-content {
    padding: 2rem;
    background-color: white;
    border-radius: 10px;
    box-shadow: var(--card-shadow);
}

.greeting-content p {
    margin-bottom: 1.5rem;
    text-align: justify;
    line-height: 1.8;
}

/* 研究理念セクション */
.philosophy-card {
    padding: 3rem;
    background-color: white;
    border-radius: 10px;
    box-shadow: var(--card-shadow);
    text-align: center;
    position: relative;
    overflow: hidden;
}

.philosophy-card::before {
    content: '\f5dc';
    font-family: 'Font Awesome 6 Free';
    font-weight: 900;
    position: absolute;
    top: -20px;
    right: -20px;
    font-size: 8rem;
    color: var(--primary-color);
    opacity: 0.03;
    transform: rotate(15deg);
}

.philosophy-card p {
    font-size: 1.2rem;
    line-height: 1.8;
    position: relative;
}

/* キーワードセクション */
.keywords-container {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    justify-content: center;
    margin-top: 2rem;
}

.keyword {
    background-color: white;
    color: var(--primary-color);
    padding: 0.7rem 1.5rem;
    border-radius: 30px;
    font-size: 1rem;
    box-shadow: var(--card-shadow);
    transition: all 0.3s;
    border: 1px solid var(--border-color);
}

.keyword:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.1);
    background-color: var(--primary-color);
    color: white;
}

/* 研究内容セクション */
.research-tabs {
    display: flex;
    justify-content: center;
    margin-bottom: 2rem;
}

.research-tab {
    padding: 0.8rem 1.5rem;
    cursor: pointer;
    border: none;
    background-color: transparent;
    font-family: 'Noto Sans JP', sans-serif;
    font-size: 1rem;
    color: var(--gray-text);
    transition: all 0.3s;
    position: relative;
    margin: 0 0.5rem;
}

.research-tab.active {
    color: var(--primary-color);
    font-weight: 500;
}

.research-tab::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background-color: var(--primary-color);
    transition: all 0.3s;
    transform: translateX(-50%);
}

.research-tab.active::after {
    width: 80%;
}

.research-content {
    display: none;
    animation: fadeIn 0.5s;
}

.research-content.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.research-card {
    background-color: white;
    border-radius: 10px;
    box-shadow: var(--card-shadow);
    padding: 2rem;
    margin-bottom: 2rem;
}

.research-card h4 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.3rem;
    border-left: 4px solid var(--primary-color);
    padding-left: 1rem;
}

.research-card ul {
    list-style-type: none;
}

.research-card li {
    margin-bottom: 0.8rem;
    padding-left: 1.5rem;
    position: relative;
}

.research-card li::before {
    content: '\f105';
    font-family: 'Font Awesome 6 Free';
    font-weight: 900;
    position: absolute;
    left: 0;
    color: var(--primary-color);
}

.member-list {
    list-style-type: none;
    padding: 0;
    margin: 0 0 2rem 0;
    column-count: 2;
    column-gap: 2rem;
}

.member-list li {
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    break-inside: avoid;
    border-bottom: 1px solid var(--border-color);
}

@media (max-width: 768px) {
    .member-list {
        column-count: 1;
    }
}

/* 問い合わせセクション */
.contact-card {
    background-color: white;
    border-radius: 10px;
    box-shadow: var(--card-shadow);
    padding: 0 3rem 3rem 3rem;
    text-align: center;
}

.contact-icon {
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 1.5rem;
}

.contact-info p {
    margin-bottom: 1rem;
    font-size: 1.1rem;
}

.contact-address {
    display: inline-block;
    margin-top: 1rem;
    padding: 1rem 2rem;
    background-color: var(--light-bg);
    border-radius: 5px;
}

/* フッター */
footer {
    background-color: var(--primary-dark);
    color: white;
    text-align: center;
    padding: 3rem 1rem;
}

.footer-logo {
    font-size: 1.3rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.footer-text {
    opacity: 0.7;
    font-size: 0.9rem;
    margin-bottom: 2rem;
}

.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 50px;
    height: 50px;
    background-color: var(--primary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    opacity: 0;
    transition: all 0.3s;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
    z-index: 100;
}

.back-to-top:hover {
    background-color: var(--primary-light);
    transform: translateY(-3px);
}

/* レスポンシブ対応 */
@media (max-width: 992px) {
    .representative-card {
        flex-direction: column;
        gap: 2rem;
    }

    section {
        padding: 4rem 1.5rem;
    }
}

@media (max-width: 768px) {
    .hero h1 {
        font-size: 2.2rem;
    }

    .hero h2 {
        font-size: 1.2rem;
    }

    .section-heading h3 {
        font-size: 1.7rem;
    }

    nav ul li a {
        padding: 0.5rem 0.8rem;
        font-size: 0.85rem;
    }

    .philosophy-card {
        padding: 2rem;
    }
}

@media (max-width: 576px) {
    .hero {
        padding: 5rem 1rem 4rem;
    }

    .hero h1 {
        font-size: 1.8rem;
    }

    section {
        padding: 3rem 1rem;
    }

    .research-tab {
        padding: 0.5rem 0.8rem;
        font-size: 0.9rem;
    }

    .contact-card {
        padding: 2rem 1rem;
    }
}