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

:root {
    --primary: #1a1a2e;
    --accent: #3a86ff;
    --text: #2d2d2d;
    --text-light: #666;
    --bg: #fafafa;
    --bg-alt: #fff;
    --border: #e8e8e8;
    --max-width: 900px;
}

body {
    font-family: "Hiragino Kaku Gothic ProN", "Hiragino Sans", "Noto Sans CJK JP", -apple-system, sans-serif;
    color: var(--text);
    background: var(--bg);
    line-height: 1.7;
    font-size: 15px;
}

/* Nav */
nav {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    z-index: 100;
}

.nav-inner {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 14px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-name {
    font-weight: 700;
    font-size: 16px;
    color: var(--primary);
    text-decoration: none;
}

.nav-links a {
    margin-left: 28px;
    text-decoration: none;
    color: var(--text-light);
    font-size: 14px;
    transition: color 0.2s;
}

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

.lang-switch {
    background: var(--accent);
    color: #fff !important;
    padding: 4px 12px;
    border-radius: 4px;
    font-weight: 600;
    font-size: 13px !important;
}

.lang-switch:hover {
    opacity: 0.85;
}

/* Hero */
#hero {
    padding: 140px 24px 80px;
    background: var(--bg-alt);
}

.hero-content {
    max-width: var(--max-width);
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 48px;
}

.hero-text h1 {
    font-size: 42px;
    font-weight: 800;
    color: var(--primary);
    letter-spacing: 0.08em;
    margin-bottom: 4px;
}

.hero-en {
    font-size: 18px;
    color: var(--text-light);
    margin-bottom: 20px;
}

.hero-affiliation {
    font-size: 14px;
    color: var(--text-light);
    line-height: 1.6;
    margin-bottom: 12px;
}

.hero-tagline {
    font-size: 16px;
    color: var(--accent);
    font-weight: 600;
}

.hero-photo {
    flex-shrink: 0;
}

.profile-img {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    object-fit: cover;
}

/* Sections */
section {
    padding: 72px 24px;
}

section:nth-child(odd) {
    background: var(--bg-alt);
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
}

h2 {
    font-size: 28px;
    font-weight: 800;
    color: var(--primary);
    margin-bottom: 32px;
    padding-bottom: 12px;
    border-bottom: 3px solid var(--accent);
    display: inline-block;
}

h3 {
    font-size: 18px;
    font-weight: 700;
    color: var(--primary);
    margin-top: 32px;
    margin-bottom: 16px;
}

/* Skills */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
}

.skill-item {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 16px;
    font-size: 14px;
    line-height: 1.6;
}

.skill-item strong {
    color: var(--primary);
    font-size: 13px;
    text-transform: uppercase;
    letter-spacing: 0.03em;
}

@media (max-width: 768px) {
    .skills-grid {
        grid-template-columns: 1fr;
    }
}

/* Timeline (Education) */
.timeline {
    position: relative;
    padding-left: 24px;
    border-left: 2px solid var(--border);
}

.timeline-item {
    margin-bottom: 24px;
    position: relative;
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -30px;
    top: 6px;
    width: 10px;
    height: 10px;
    background: var(--accent);
    border-radius: 50%;
}

.timeline-date {
    font-size: 13px;
    color: var(--accent);
    font-weight: 600;
}

.timeline-content {
    margin-top: 4px;
    font-size: 14px;
    line-height: 1.6;
}

/* Projects */
.project {
    display: flex;
    gap: 32px;
    margin-bottom: 48px;
    padding-bottom: 48px;
    border-bottom: 1px solid var(--border);
}

.project:last-child {
    border-bottom: none;
    margin-bottom: 0;
    padding-bottom: 0;
}

.project-info {
    flex: 1;
}

.project-info h3 {
    margin-top: 0;
    font-size: 20px;
}

.project-info h3 a {
    color: var(--primary);
    text-decoration: none;
    border-bottom: 2px solid var(--accent);
    transition: color 0.2s;
}

.project-info h3 a:hover {
    color: var(--accent);
}

.award-item a {
    color: inherit;
    text-decoration: none;
    border-bottom: 1px solid var(--accent);
    transition: color 0.2s;
}

.award-item a:hover {
    color: var(--accent);
}

.project-meta {
    font-size: 13px;
    color: var(--accent);
    font-weight: 600;
    display: block;
    margin-bottom: 12px;
}

.project-info p {
    font-size: 14px;
    color: var(--text);
    line-height: 1.75;
}

.project-media {
    flex-shrink: 0;
    width: 400px;
}

.media-placeholder {
    width: 100%;
    height: 180px;
    background: var(--border);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-light);
    font-size: 14px;
}

.video-embed {
    position: relative;
    width: 100%;
    padding-top: 56.25%;
    border-radius: 8px;
    overflow: hidden;
}

.video-embed iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

/* Publications */
.pub-list {
    padding-left: 24px;
    margin-bottom: 24px;
}

.pub-list li {
    margin-bottom: 16px;
    font-size: 14px;
    line-height: 1.7;
}

.pub-list li a {
    color: var(--accent);
    text-decoration: none;
    font-weight: 600;
    margin-left: 4px;
}

.pub-list li a:hover {
    text-decoration: underline;
}

.patent-list {
    list-style: none;
    padding-left: 0;
}

.patent-list li {
    margin-bottom: 8px;
    font-size: 14px;
    padding-left: 20px;
    position: relative;
}

.patent-list li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 10px;
    width: 8px;
    height: 8px;
    background: var(--accent);
    border-radius: 2px;
}

/* Awards */
.award-list {
    margin-bottom: 16px;
}

.award-item {
    display: flex;
    gap: 20px;
    padding: 12px 0;
    border-bottom: 1px solid var(--border);
    font-size: 14px;
    align-items: baseline;
}

.award-item:last-child {
    border-bottom: none;
}

.award-date {
    flex-shrink: 0;
    width: 90px;
    font-size: 13px;
    color: var(--accent);
    font-weight: 600;
}

/* Contact */
#contact {
    text-align: center;
    padding: 72px 24px;
}

.contact-email {
    font-size: 20px;
    font-weight: 600;
    color: var(--primary);
    margin-bottom: 20px;
}

.contact-links {
    display: flex;
    justify-content: center;
    gap: 24px;
}

.contact-links a {
    color: var(--accent);
    text-decoration: none;
    font-size: 14px;
    font-weight: 600;
    padding: 8px 20px;
    border: 2px solid var(--accent);
    border-radius: 24px;
    transition: all 0.2s;
}

.contact-links a:hover {
    background: var(--accent);
    color: #fff;
}

/* Footer */
footer {
    text-align: center;
    padding: 32px 24px;
    font-size: 13px;
    color: var(--text-light);
    border-top: 1px solid var(--border);
}

/* Responsive */
@media (max-width: 768px) {
    .hero-content {
        flex-direction: column-reverse;
        text-align: center;
    }

    .hero-text h1 {
        font-size: 32px;
    }

    .project {
        flex-direction: column;
    }

    .project-media {
        width: 100%;
    }

    .nav-links a {
        margin-left: 16px;
        font-size: 12px;
    }

    .award-item {
        flex-direction: column;
        gap: 4px;
    }

    .award-date {
        width: auto;
    }
}