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

body {
    font-family: 'Inter', "Hiragino Kaku Gothic Pro", "ヒラギノ角ゴ Pro W3", Meiryo, "メイリオ", sans-serif;
    line-height: 1.7;
    color: #34495e;
    background: #f8f9fa;
    min-height: 100vh;
}

/* ============================================================
   NAVIGATION
   ============================================================ */
.site-nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(44, 62, 80, 0.96);
    backdrop-filter: blur(12px);
    border-bottom: 2px solid #FFD700;
    transition: transform 0.3s ease;
}

.site-nav.nav-hidden {
    transform: translateY(-100%);
}

.nav-inner {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 40px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 56px;
}

.nav-logo {
    color: #FFD700;
    text-decoration: none;
    font-weight: 700;
    font-size: 1.05em;
    white-space: nowrap;
    letter-spacing: 0.01em;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 6px;
    align-items: center;
}

.nav-links a {
    color: rgba(255,255,255,0.88);
    text-decoration: none;
    font-size: 0.9em;
    font-weight: 500;
    padding: 6px 14px;
    border-radius: 20px;
    transition: background 0.2s, color 0.2s;
}

.nav-links a:hover,
.nav-links a:focus {
    background: rgba(255,215,0,0.15);
    color: #FFD700;
    outline: none;
}

.nav-toggle {
    display: none;
    background: none;
    border: none;
    color: white;
    font-size: 1.2em;
    cursor: pointer;
    padding: 6px;
}

/* ============================================================
   CONTAINER & WRAPPER
   ============================================================ */
.container {
    width: 100%;
    max-width: 100%;
    margin: 0;
    background: white;
    padding-top: 56px; /* nav height */
}

.content-wrapper {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 40px;
}

/* ============================================================
   HEADER / HERO
   ============================================================ */
.header-section {
    background: linear-gradient(rgba(44, 62, 80, 0.72), rgba(52, 73, 94, 0.85)),
                url('cosmic-language-map.png');
    background-size: cover;
    background-position: center;
    background-attachment: fixed;
    color: white;
    padding: 100px 0 80px;
    text-align: center;
    position: relative;
    border-bottom: 4px solid #FFD700;
}

.header-content {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 40px;
    position: relative;
    z-index: 2;
}

/* Dual-label tagline */
.hero-tagline {
    font-size: 1.25em;
    font-weight: 300;
    letter-spacing: 0.04em;
    color: rgba(255,215,0,0.92);
    margin-bottom: 14px;
    font-style: italic;
}

.hero-sub {
    max-width: 760px;
    margin: 18px auto 28px;
    font-size: 1.0em;
    line-height: 1.8;
    color: rgba(255,255,255,0.88);
}

.hero-sub strong {
    color: #FFD700;
    font-weight: 600;
}

.profile-image {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    background: rgba(255,255,255,0.1);
    backdrop-filter: blur(12px);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 25px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.3), 0 0 20px rgba(255,215,0,0.5);
    border: 3px solid #FFD700;
}

.profile-image i {
    font-size: 48px;
    color: white;
}

h1 {
    font-size: 3em;
    font-weight: 700;
    margin-bottom: 12px;
    text-shadow: 2px 2px 6px rgba(0,0,0,0.4);
}

.subtitle {
    font-size: 1.4em;
    font-weight: 400;
    min-height: 40px;
    text-shadow: 1px 1px 3px rgba(0,0,0,0.4);
    color: rgba(255,255,255,0.9);
    margin-bottom: 32px;
}

/* ============================================================
   LINKS
   ============================================================ */
.links {
    display: flex;
    justify-content: center;
    gap: 14px;
    margin-bottom: 0;
    flex-wrap: wrap;
}

.social-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    background: white;
    border: 2px solid #2c3e50;
    color: #2c3e50;
    text-decoration: none;
    border-radius: 30px;
    font-weight: 600;
    font-size: 0.9em;
    transition: all 0.3s ease;
    box-shadow: 0 4px 10px rgba(0,0,0,0.08);
}

.social-link:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(0,0,0,0.15);
    background: #2c3e50;
    color: white;
}

/* ============================================================
   CONTENT SECTIONS
   ============================================================ */
.content {
    padding: 80px 0;
}

h2 {
    font-size: 2.1em;
    margin: 80px 0 40px;
    color: #2c3e50;
    position: relative;
    padding-bottom: 18px;
    display: flex;
    align-items: center;
    gap: 14px;
}

h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 80px;
    height: 4px;
    background: linear-gradient(135deg, #FFD700 0%, #B8860B 100%);
    border-radius: 2px;
}

h2:first-child { margin-top: 0; }

.section-alt {
    background-color: #f8f9fa;
    padding: 80px 0;
}

/* ============================================================
   PROFILE INFO
   ============================================================ */
.profile-info {
    background: rgba(255,255,255,0.6);
    backdrop-filter: blur(12px);
    border: 1px solid rgba(0,0,0,0.05);
    padding: 40px;
    border-radius: 20px;
    margin-bottom: 40px;
    box-shadow: 0 16px 40px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.profile-info:hover {
    transform: translateY(-4px);
    box-shadow: 0 20px 50px rgba(0,0,0,0.15);
}

.info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 24px;
}

.info-item {
    display: flex;
    align-items: flex-start;
    font-size: 1.05em;
    color: #2c3e50;
}

.info-item i {
    width: 24px;
    color: #2c3e50;
    margin-right: 14px;
    margin-top: 4px;
    flex-shrink: 0;
}

.info-item a { color: #2c3e50; text-decoration: none; border-bottom: 1px solid #FFD700; }
.info-item a:hover { color: #B8860B; }

/* ============================================================
   CATEGORY BADGES
   ============================================================ */
.category-legend {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin: 0 0 30px;
}

.cat-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 18px;
    border-radius: 20px;
    font-size: 0.9em;
    font-weight: 500;
}

.cat-a { background: #eef7ee; border: 1px solid #a8d5a2; color: #2e6e2e; }
.cat-b { background: #eef3ff; border: 1px solid #a8bef0; color: #2a3fa0; }
.cat-d { background: #fff8ee; border: 1px solid #f0d5a0; color: #8a5500; }

.pub-cat, .card-cat {
    display: inline-block;
    padding: 2px 10px;
    border-radius: 10px;
    font-size: 0.78em;
    font-weight: 700;
    margin-bottom: 8px;
}

.pub-cat.cat-a, .card-cat.cat-a { background: #eef7ee; color: #2e6e2e; border: 1px solid #a8d5a2; }
.pub-cat.cat-b, .card-cat.cat-b { background: #eef3ff; color: #2a3fa0; border: 1px solid #a8bef0; }
.pub-cat.cat-d, .card-cat.cat-d { background: #fff8ee; color: #8a5500; border: 1px solid #f0d5a0; }

/* ============================================================
   CARDS: TIMELINE / THEME / NEWS
   ============================================================ */
.timeline, .research-themes, .news-section {
    display: grid;
    gap: 24px;
    margin-top: 40px;
}

.timeline { grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); }
.research-themes { grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.news-section { grid-template-columns: repeat(auto-fit, minmax(360px, 1fr)); }

.timeline-item, .theme-card, .news-item {
    background: white;
    border: 1px solid rgba(0,0,0,0.07);
    padding: 28px;
    border-radius: 14px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.06);
    transition: all 0.3s ease;
}

.timeline-item:hover, .theme-card:hover, .news-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 32px rgba(0,0,0,0.1);
}

.timeline-item { border-left: 4px solid #FFD700; }
.timeline-date { font-weight: 600; color: #2c3e50; margin-bottom: 8px; }

.theme-card { border-top: 4px solid #FFD700; position: relative; }
.theme-card h3 { color: #2c3e50; margin: 8px 0 12px; font-size: 1.2em; }
.theme-card h3 i { margin-right: 8px; }

.news-item { border-left: 4px solid #2c3e50; }
.news-item:hover { border-left-color: #FFD700; }
.news-date { display: flex; align-items: center; color: #2c3e50; font-weight: 600; font-size: 0.95em; margin-bottom: 10px; }
.news-date i { margin-right: 8px; }
.news-content a { color: #2c3e50; text-decoration: none; font-weight: 500; border-bottom: 1px solid rgba(255,215,0,0.5); transition: all 0.2s; }
.news-content a:hover { color: #B8860B; border-bottom-color: #B8860B; }

/* ============================================================
   TAGS
   ============================================================ */
.tag {
    display: inline-block;
    padding: 7px 16px;
    background: #eef2ff;
    border: 1px solid #d1d9ff;
    border-radius: 20px;
    font-size: 0.88em;
    font-weight: 500;
    color: #2c3e50;
    margin: 4px 6px 4px 0;
    transition: all 0.3s ease;
}
.tag:hover { background: #FFD700; border-color: #B8860B; color: #2c3e50; transform: translateY(-2px); }

/* ============================================================
   TEACHING
   ============================================================ */
.teaching-card {
    background: white; border: 1px solid rgba(0,0,0,0.07); padding: 40px; border-radius: 14px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.06);
}
.teaching-card h3 { color: #2c3e50; margin-bottom: 20px; font-size: 1.4em; }
.teaching-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 20px; margin-top: 20px; }
.teaching-grid > div { background: #f8f9fa; padding: 24px; border-radius: 10px; border-left: 4px solid #FFD700; }
.teaching-grid i { font-size: 1.8em; margin-bottom: 12px; display: block; color: #2c3e50; }
.teaching-grid strong { display: block; margin-bottom: 5px; color: #2c3e50; }
.teaching-grid span { font-size: 0.92em; color: #5a6c7d; }
.external-link-area { margin-top: 28px; }
.external-link-area a { color: #3498db; text-decoration: none; font-weight: 500; }
.external-link-area a:hover { text-decoration: underline; }

/* ============================================================
   PUBLICATIONS
   ============================================================ */
.publications {
    background: white; border: 1px solid rgba(0,0,0,0.07); padding: 40px; border-radius: 14px;
    margin-top: 40px; box-shadow: 0 4px 20px rgba(0,0,0,0.06);
}
.publications h3 { color: #2c3e50; margin: 32px 0 20px; font-size: 1.4em; display: flex; align-items: center; gap: 10px; }
.publications h3:first-child { margin-top: 0; }
.publications ul { list-style: none; }
.publications li {
    background: #f8f9fa; border: 1px solid rgba(0,0,0,0.05); padding: 20px; margin-bottom: 14px;
    border-radius: 10px; border-left: 4px solid #FFD700; transition: all 0.3s ease;
}
.publications li:hover { transform: translateX(4px); box-shadow: 0 5px 15px rgba(0,0,0,0.08); border-left-color: #2c3e50; }
.pub-link { margin-top: 10px; display: flex; align-items: center; flex-wrap: wrap; gap: 12px; }
.pub-link a { display: inline-flex; align-items: center; gap: 6px; font-size: 0.88em; color: #3498db; text-decoration: none; }
.pub-link a:hover { text-decoration: underline; }
.pub-link img { height: 18px; }
.grant-note { margin-top: 5px; font-size: 0.88em; color: #5a6c7d; }

/* ============================================================
   DATA & CODE
   ============================================================ */
.data-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
    gap: 28px;
    margin-top: 20px;
}

.data-card {
    background: white;
    border: 1px solid rgba(0,0,0,0.07);
    border-radius: 14px;
    padding: 32px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.06);
    transition: all 0.3s ease;
    border-top: 4px solid #2c3e50;
}

.data-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 32px rgba(0,0,0,0.1);
}

.data-card-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 16px;
}

.data-card-header i {
    font-size: 1.6em;
    color: #2c3e50;
}

.data-card-header h3 {
    font-size: 1.1em;
    color: #2c3e50;
    font-weight: 600;
}

.data-card p {
    color: #5a6c7d;
    font-size: 0.95em;
    line-height: 1.7;
    margin-bottom: 16px;
}

.data-card-meta {
    display: flex;
    gap: 16px;
    font-size: 0.85em;
    color: #7f8c8d;
    margin-bottom: 16px;
}

.data-card-meta span {
    display: flex;
    align-items: center;
    gap: 6px;
}

.data-badge img {
    height: 20px;
}

/* ============================================================
   CONTACT
   ============================================================ */
.contact-card {
    background: white;
    border: 1px solid rgba(0,0,0,0.07);
    border-radius: 14px;
    padding: 40px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.06);
}

.contact-card > p {
    font-size: 1.05em;
    color: #34495e;
    margin-bottom: 32px;
    line-height: 1.8;
}

.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 20px;
    margin-bottom: 36px;
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 16px;
    background: #f8f9fa;
    border-left: 4px solid #FFD700;
    padding: 20px;
    border-radius: 10px;
}

.contact-item i {
    font-size: 1.4em;
    color: #2c3e50;
    margin-top: 2px;
    flex-shrink: 0;
}

.contact-item a {
    color: #3498db;
    text-decoration: none;
}
.contact-item a:hover { text-decoration: underline; }

.inquiry-template {
    background: #f4f6f8;
    border-radius: 10px;
    padding: 24px;
    border-left: 4px solid #2c3e50;
}

.inquiry-template h4 {
    color: #2c3e50;
    margin-bottom: 14px;
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.05em;
}

.inquiry-template pre {
    font-size: 0.88em;
    color: #34495e;
    white-space: pre-wrap;
    font-family: "Hiragino Kaku Gothic Pro", Meiryo, sans-serif;
    line-height: 1.8;
}

/* ============================================================
   RESEARCH TREE
   ============================================================ */
.research-tree-card {
    background: white;
    border: 1px solid rgba(0,0,0,0.07);
    border-radius: 14px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.06);
    overflow: hidden;
    transition: all 0.3s ease;
    margin-top: 40px;
}

.research-tree-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 32px rgba(0,0,0,0.1);
}

.research-tree-link {
    text-decoration: none;
    color: inherit;
    display: block;
}

.research-tree-thumbnail {
    position: relative;
    overflow: hidden;
    height: 220px;
    background: linear-gradient(135deg, #2c3e50 0%, #34495e 100%);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
}

.thumbnail-content .thumbnail-icon { font-size: 3.5em; margin-bottom: 12px; }
.thumbnail-content h4 { font-size: 1.6em; margin-bottom: 8px; font-weight: 600; }
.thumbnail-content p { font-size: 1em; opacity: 0.88; }

.research-tree-content { padding: 28px 30px; }
.research-tree-content h4 { color: #2c3e50; margin-bottom: 12px; font-size: 1.25em; }
.research-tree-content p { color: #5a6c7d; line-height: 1.7; margin-bottom: 18px; }
.research-tree-content ul { list-style: none; padding: 0; color: #5a6c7d; font-size: 0.93em; }
.research-tree-content li { margin-bottom: 10px; }
.research-tree-content li i { color: #27ae60; margin-right: 10px; }

.external-link-button { margin-top: 22px; color: #3498db; font-weight: 600; }

/* ============================================================
   FOOTER
   ============================================================ */
.footer {
    background: #2c3e50;
    color: white;
    padding: 40px 0;
    text-align: center;
    margin-top: 0;
}
.footer p { opacity: 0.8; font-size: 0.9em; line-height: 1.8; }

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 768px) {
    .nav-toggle { display: block; }
    .nav-links {
        display: none;
        flex-direction: column;
        position: absolute;
        top: 56px;
        left: 0;
        right: 0;
        background: rgba(44,62,80,0.98);
        padding: 16px 0 24px;
        gap: 4px;
        align-items: flex-start;
    }
    .nav-links.open { display: flex; }
    .nav-links li { width: 100%; }
    .nav-links a { display: block; padding: 12px 30px; border-radius: 0; }
    .nav-inner { padding: 0 20px; position: relative; }

    .content-wrapper { padding: 0 20px; }
    .header-section { padding: 60px 0 50px; }
    .content, .section-alt { padding: 60px 0; }
    h1 { font-size: 2.2em; }
    h2 { font-size: 1.8em; margin: 60px 0 28px; }
    .hero-tagline { font-size: 1.1em; }
    .hero-sub { font-size: 0.92em; }
    .links { gap: 10px; }
    .social-link { padding: 9px 16px; font-size: 0.85em; }
    .info-grid, .teaching-grid, .contact-grid { grid-template-columns: 1fr; gap: 16px; }
    .category-legend { gap: 8px; }
    .publications { padding: 24px; }
    .contact-card { padding: 24px; }
    .data-cards { grid-template-columns: 1fr; }
    .inquiry-template pre { font-size: 0.82em; }
}

/* ============================================================
   REDUCED MOTION
   ============================================================ */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
    .header-section { background-attachment: scroll; }
}

/* ============================================================
   CONCEPT DIAGRAM: Spatial Cultural Dynamics
   ============================================================ */
.concept-diagram {
    background: var(--white, #fff);
    border: 1px solid rgba(0,0,0,0.07);
    border-radius: 16px;
    padding: 36px 40px;
    margin: 32px 0 48px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.06);
}

.concept-title {
    text-align: center;
    margin-bottom: 32px;
}
.concept-title strong {
    display: block;
    font-size: 1.35em;
    color: #2c3e50;
    letter-spacing: 0.02em;
    margin-bottom: 6px;
}
.concept-title span {
    font-size: 0.9em;
    color: #7f8c8d;
    font-style: italic;
}

.concept-flow {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0;
}

.concept-layer {
    width: 100%;
    max-width: 680px;
    border-radius: 10px;
    padding: 16px 24px;
    text-align: center;
    border: 1.5px solid transparent;
}

.layer-label {
    font-weight: 700;
    font-size: 0.95em;
    margin-bottom: 6px;
    letter-spacing: 0.01em;
}
.layer-items {
    font-size: 0.83em;
    opacity: 0.85;
    line-height: 1.6;
}
.layer-cycle {
    font-weight: 600;
    opacity: 1;
    font-size: 0.88em;
}

/* Layer colours */
.layer-space    { background: #eef3ff; border-color: #a8bef0; }
.layer-space .layer-label    { color: #1c3fa0; }

.layer-affective { background: #fdf0ff; border-color: #d8a8f0; }
.layer-affective .layer-label { color: #7a1aaa; }

.layer-traits   { background: #e8f7ee; border-color: #90cc90; }
.layer-traits .layer-label   { color: #1a6a1a; }

.layer-evo      { background: #fff4e0; border-color: #f0c880; }
.layer-evo .layer-label      { color: #8a4800; }

.layer-niche    { background: #f0f4f8; border-color: #aabbd0; }
.layer-niche .layer-label    { color: #2c3e50; }

.concept-arrow {
    font-size: 1.4em;
    color: #b0bec5;
    line-height: 1;
    padding: 4px 0;
    user-select: none;
}

@media (max-width: 600px) {
    .concept-diagram { padding: 24px 16px; }
    .concept-layer { padding: 14px 16px; }
    .layer-items { font-size: 0.8em; }
}

/* ============================================================
   LANGUAGE SWITCHER
   ============================================================ */
.lang-switch {
    display: flex;
    align-items: center;
    gap: 4px;
    margin-left: auto;
    flex-shrink: 0;
}
.lang-btn {
    padding: 4px 10px;
    border-radius: 12px;
    font-size: 0.78em;
    font-weight: 700;
    letter-spacing: 0.04em;
    text-decoration: none;
    border: 1.5px solid rgba(255,255,255,0.25);
    color: rgba(255,255,255,0.6);
    transition: all 0.2s;
    line-height: 1;
}
.lang-btn:hover {
    border-color: var(--gold, #c9a84c);
    color: var(--gold, #c9a84c);
}
.lang-btn.active {
    background: var(--gold, #c9a84c);
    border-color: var(--gold, #c9a84c);
    color: #1a2535;
}

/* ============================================================
   AOS FAILSAFE — show content even if AOS.js fails to load
   ============================================================ */
html:not(.aos-initialized) [data-aos] {
    opacity: 1 !important;
    transform: none !important;
}

/* ============================================================
   THEORY DIAGRAM (新理論図: 情動×言語→文化進化→計算モデル)
   ============================================================ */
.theory-diagram .concept-title span {
    font-size: 0.92em;
    color: rgba(255,255,255,0.7);
}
.theory-flow {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0;
    padding: 8px 0;
}
.theory-inputs {
    display: flex;
    align-items: center;
    gap: 16px;
    width: 100%;
    max-width: 680px;
    justify-content: center;
}
.theory-connector-h {
    font-size: 1.6em;
    font-weight: 700;
    color: #b0bec5;
    flex-shrink: 0;
}
.theory-node {
    background: white;
    border: 1.5px solid rgba(0,0,0,0.1);
    border-radius: 12px;
    padding: 16px 20px;
    text-align: center;
    flex: 1;
    max-width: 280px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
    transition: transform 0.2s;
}
.theory-node:hover { transform: translateY(-2px); }
.node-icon { font-size: 1.8em; margin-bottom: 6px; }
.node-label {
    font-weight: 700;
    font-size: 1em;
    color: #2c3e50;
    line-height: 1.3;
    margin-bottom: 6px;
}
.node-label span { display: block; font-size: 0.78em; font-weight: 400; color: #7f8c8d; }
.node-sub { font-size: 0.78em; color: #7f8c8d; line-height: 1.5; }

.node-emotion { border-color: #d8a8f0; background: linear-gradient(135deg, #fdf0ff 0%, #fff 100%); }
.node-language { border-color: #a8bef0; background: linear-gradient(135deg, #eef0ff 0%, #fff 100%); }
.node-core {
    border-color: #90cc90;
    background: linear-gradient(135deg, #e8f5e8 0%, #fff 100%);
    width: 100%;
    max-width: 480px;
}
.node-model {
    border-color: #f0c880;
    background: linear-gradient(135deg, #fff4e0 0%, #fff 100%);
    width: 100%;
    max-width: 480px;
}

.theory-arrow-down {
    display: flex;
    flex-direction: column;
    align-items: center;
    color: #b0bec5;
    font-size: 1.4em;
    line-height: 1;
    padding: 6px 0;
    gap: 2px;
}
.theory-arrow-down span {
    font-size: 0.5em;
    color: #aabbc8;
    letter-spacing: 0.03em;
    font-weight: 500;
}

.theory-data-row {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    justify-content: center;
    max-width: 680px;
    margin-top: 4px;
}
.data-chip {
    background: #f0f4f8;
    border: 1px solid #d0dce8;
    border-radius: 20px;
    padding: 7px 16px;
    font-size: 0.85em;
    color: #2c3e50;
    font-weight: 500;
}

/* ============================================================
   LAYERED RESEARCH THEMES (理論層/方法層/データ層)
   ============================================================ */
.research-layers {
    display: flex;
    flex-direction: column;
    gap: 32px;
    margin-top: 32px;
}
.layer-row {
    display: grid;
    grid-template-columns: 140px 1fr;
    gap: 20px;
    align-items: start;
}
.layer-row-label {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
    padding-top: 28px;
}
.layer-row-tag {
    display: inline-block;
    padding: 5px 12px;
    border-radius: 20px;
    font-size: 0.82em;
    font-weight: 700;
    letter-spacing: 0.04em;
    white-space: nowrap;
}
.tag-theory  { background: #e8f5e8; color: #1a6a1a; border: 1px solid #90cc90; }
.tag-method  { background: #eef0ff; color: #1c3fa0; border: 1px solid #a8b8f0; }
.tag-data    { background: #fff4e0; color: #8a4800; border: 1px solid #f0c880; }
.layer-row-desc { font-size: 0.75em; color: #7f8c8d; }
.layer-row-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 16px;
}

/* theory note in data cards */
.data-theory-note {
    font-size: 0.85em;
    color: #5a6c7d;
    background: #f0f4f8;
    border-left: 3px solid #2c3e50;
    padding: 8px 12px;
    border-radius: 0 6px 6px 0;
    margin-bottom: 12px;
    line-height: 1.55;
}
.data-theory-note i { margin-right: 6px; color: #2c3e50; }

@media (max-width: 768px) {
    .theory-inputs { flex-direction: column; gap: 8px; }
    .theory-connector-h { transform: rotate(90deg); }
    .theory-node { max-width: 100%; }
    .layer-row { grid-template-columns: 1fr; gap: 12px; }
    .layer-row-label { flex-direction: row; align-items: center; padding-top: 0; }
}