body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: #fcfcfc;
    color: #333;
    display: flex;
    flex-direction: column; /* 세로 정렬을 위해 추가 */
    align-items: center; /* 가로 중앙 정렬 */
    min-height: 100vh;
    margin: 0;
    padding: 40px 20px;
    box-sizing: border-box;
}

.container {
    max-width: 900px;
    width: 100%;
}

/* --- 프로필 헤더 --- */
.profile-header {
    text-align: center;
    margin-bottom: 50px;
}
.profile-pic {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    object-fit: cover;
    margin-bottom: 20px;
}
.profile-header h1 {
    font-size: 3em;
    margin: 0;
}
.intro {
    font-size: 1.1em;
    line-height: 1.6;
    margin-top: 10px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}
.intro a {
    color: #333;
    font-weight: 500;
}
.social-links {
    margin-top: 15px;
}
.social-links a {
    font-size: 24px;
    color: #555;
    margin: 0 10px;
}

/* --- 콘텐츠 그리드 --- */
.content-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
    text-align: left;
    margin-bottom: 60px;
}
.content-grid h2 {
    font-size: 1.1em;
    font-weight: 600;
    border-bottom: 1px solid #eee;
    padding-bottom: 8px;
    margin-bottom: 15px;
}
.content-grid h2 i {
    margin-right: 8px;
    color: #555;
}
.content-grid ul {
    list-style: none;
    padding: 0;
    margin: 0;
    line-height: 1.6;
}
.content-grid li {
    margin-bottom: 15px;
}
.duration {
    font-size: 0.9em;
    color: #888;
}

/* Education 섹션 스타일 */
.education-item {
    padding-bottom: 15px;
    border-bottom: 1px solid #f0f0f0;
}
.education-item:last-child {
    border-bottom: none;
}
.education-item p { margin: 4px 0; }
.degree { font-weight: bold; }
.school a {
    color: #333; /* 링크 색상을 기본 글자색으로 변경 */
}
.advisor {
    font-size: 0.9em;
    color: #666;
    padding-left: 10px;
    border-left: 2px solid #eee;
}
.advisor a {
    color: #666; /* 링크 색상을 advisor 글자색으로 변경 */
}
/* Research Interests 태그 스타일 */
.tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}
.tag {
    background-color: #f0f0f0;
    padding: 5px 10px;
    border-radius: 5px;
    font-size: 0.9em;
}

/* --- 추가 정보 그리드 (Teaching, Awards) --- */
.additional-info-grid {
    display: grid;
    grid-template-columns: 1fr 1fr; /* 2개의 컬럼으로 나눔 */
    gap: 40px;
    margin-bottom: 60px;
}

.additional-info-grid h2 {
    font-size: 1.1em;
    font-weight: 600;
    border-bottom: 1px solid #eee;
    padding-bottom: 8px;
    margin-bottom: 15px;
}

.additional-info-grid h2 i {
    margin-right: 8px;
    color: #555;
}

.info-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.info-item {
    padding-bottom: 15px;
    margin-bottom: 15px;
    border-bottom: 1px solid #f0f0f0;
}

.info-item:last-child {
    border-bottom: none;
    margin-bottom: 0;
}

.info-title {
    display: block;
    font-weight: 600;
    margin-bottom: 5px;
}

.info-meta {
    display: block;
    font-size: 0.9em;
    color: #666;
}

/* --- 리서치 프로젝트 --- */
.projects-section { 
    width: 100%; 
    text-align: left; 
    margin-bottom: 60px;
}

.projects-section h2 { 
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.2em;
    font-weight: 700;
    margin-bottom: 10px;
    color: #2d3748;
}

.projects-section h2 i {
    margin-right: 15px;
    color: #667eea;
    font-size: 0.9em;
}

.section-description {
    font-size: 1.1em;
    color: #718096;
    margin-bottom: 40px;
    line-height: 1.6;
    font-style: italic;
    text-align: center;
}

.projects-list { 
    list-style: none; 
    padding: 0; 
    margin: 0; 
    display: flex; 
    flex-direction: column; 
    gap: 15px; 
}

/* --- 펼치기/접기 카드 스타일 --- */
.project-main-item details {
    background-color: #ffffff;
    padding: 0;
    border: 1px solid #e2e8f0;
    border-radius: 12px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    transition: all 0.3s ease;
    overflow: hidden;
}

.project-main-item:hover details {
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    transform: translateY(-2px);
}

.project-main-item summary {
    cursor: pointer;
    list-style: none; /* 기본 화살표 아이콘 제거 */
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 25px;
    background: linear-gradient(135deg, #f7fafc 0%, #edf2f7 100%);
    transition: background 0.3s ease;
}

.project-main-item summary:hover {
    background: linear-gradient(135deg, #edf2f7 0%, #e2e8f0 100%);
}

.project-main-item summary::-webkit-details-marker {
    display: none; /* 기본 화살표 아이콘 제거 (Safari) */
}

.project-main-title {
    display: flex;
    align-items: center;
    font-weight: 600;
    font-size: 1.4em;
    margin: 0;
    color: #2d3748;
}

.project-main-title i {
    margin-right: 12px;
    color: #667eea;
    font-size: 0.8em;
}

/* --- 펼치기/접기 아이콘 (+/-) --- */
.project-main-item summary::after {
    content: '+'; /* 닫혔을 때 아이콘 */
    font-size: 2em;
    font-weight: 300;
    color: #aaa;
    transition: transform 0.2s;
}
.project-main-item details[open] summary::after {
    content: '−'; /* 열렸을 때 아이콘 */
    transform: rotate(180deg);
}

/* --- 펼쳐지는 하위 내용 스타일 --- */
.sub-projects-list {
    list-style: none;
    padding: 0;
    margin: 25px 0 0 0;
    border-top: 2px solid #f0f0f0;
}
.sub-project-item {
    padding: 25px 30px 0 30px;
}

.sub-project-header {
    display: flex;
    align-items: center;
    margin-bottom: 15px;
}

.sub-project-header i {
    margin-right: 10px;
    color: #764ba2;
    font-size: 0.9em;
}

.sub-project-title {
    font-weight: bold;
    font-size: 1.1em;
    margin: 0;
    color: #2d3748;
}
.project-description, .publication-info { /* 공통 스타일 */
    font-size: 0.95em;
    color: #555;
    margin: 0 0 15px 0;
    line-height: 1.6;
}

/* --- 논문 정보 및 링크 스타일 (기존과 유사) --- */
.related-publications strong {
    display: flex;
    align-items: center;
    font-size: 0.9em;
    color: #333;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 10px;
}

.related-publications strong i {
    margin-right: 8px;
    color: #667eea;
    font-size: 1.1em;
}
.related-publications ul {
    list-style: none;
    padding: 10px 0 0 0;
    margin: 0;
}
.publication-info {
    font-size: 0.95em;
    color: #555;
    margin: 0 0 15px 0;
    line-height: 1.6;
}

/* --- 전체 링크 스타일 --- */
a {
    color: #333;
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

a:hover {
    color: #007bff;
    text-decoration: underline;
}

/* --- 아이콘이 포함된 링크의 세부 스타일 --- */
.social-links a {
    font-size: 24px;
    margin: 0 10px;
}

.project-links a {
    display: inline-block;
    margin-right: 20px;
    font-size: 0.9em;
}

/* 아이콘 스타일 */
.social-links a i,
.project-links a i {
    color: #888;
    margin-right: 5px;
    transition: color 0.2s;
}

/* 아이콘 hover 효과 */
.social-links a:hover i,
.project-links a:hover i {
    color: #007bff;
}


/* --- 섹션 구분선 --- */
.section-divider {
    width: 100%;
    height: 1px;
    background: linear-gradient(to right, transparent, #e2e8f0, transparent);
    margin: 60px 0;
    position: relative;
}

.section-divider::before {
    content: '';
    position: absolute;
    left: 50%;
    top: -2px;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: linear-gradient(135deg, #667eea, #764ba2);
    border-radius: 2px;
}

/* 모바일에서 구분선 간격 조정 */
@media (max-width: 600px) {
    .section-divider {
        margin: 40px 0;
    }
}
.site-footer {
    width: 100%;
    text-align: center;
    padding-top: 20px;
    margin-top: 50px;
    border-top: 1px solid #eee;
    font-size: 0.9em;
    color: #888;
}

/* --- 반응형 디자인 --- */

/* 태블릿 - 2열 레이아웃 (768px ~ 1024px) */
@media (max-width: 1024px) and (min-width: 769px) {
    .content-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 30px;
    }
    .projects-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 25px;
    }
    .additional-info-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 25px;
    }
}

/* 작은 태블릿 - 2열 레이아웃 (600px ~ 768px) */
@media (max-width: 768px) and (min-width: 601px) {
    .content-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 25px;
    }
    .projects-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 20px;
    }
    .additional-info-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 20px;
    }
    
    .main-content {
        padding: 60px 30px;
    }
}

/* 모바일 - 1열 레이아웃 (600px 이하) */
@media (max-width: 600px) {
    .content-grid {
        grid-template-columns: 1fr;
        gap: 25px;
    }
    .projects-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    .additional-info-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .main-content {
        padding: 50px 20px;
    }
}



/* --- 우측 고정 내비게이션 (밝은 반투명 스타일) --- */
.right-nav {
    position: fixed;
    top: 30px;
    right: 0;
    z-index: 2000;
    background: rgba(255, 255, 255, 0.7);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(0, 0, 0, 0.08);
    border-radius: 15px 0 0 15px;
    box-shadow: -6px 0 25px rgba(0, 0, 0, 0.08);
    padding: 15px 0 15px 10px;
    min-width: 85px;
    transform: scale(0.6) translateX(0);
    transform-origin: top right;
    transition: all 0.3s ease;
}

.right-nav:hover {
    transform: scale(0.6) translateX(-5px);
    background: rgba(255, 255, 255, 0.85);
    box-shadow: -10px 0 35px rgba(0, 0, 0, 0.12);
}

.right-nav .skip-link {
    position: absolute;
    left: -9999px;
}

.right-nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

.right-nav li {
    margin-bottom: 6px;
}

.right-nav li:last-child {
    margin-bottom: 0;
}

.right-nav a {
    display: block;
    padding: 10px 15px 10px 12px;
    font-size: 14px;
    font-weight: 500;
    line-height: 1.3;
    color: #4a5568;
    text-decoration: none;
    text-align: left;
    transition: all 0.3s ease;
    border-radius: 10px 0 0 10px;
    position: relative;
    overflow: hidden;
}

.right-nav a::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 3px;
    height: 100%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 50%, #f093fb 100%);
    transform: scaleY(0);
    transition: transform 0.3s ease;
}

.right-nav a:hover,
.right-nav a:focus {
    background: rgba(102, 126, 234, 0.1);
    color: #5a67d8;
    transform: translateX(-6px);
    box-shadow: -4px 0 15px rgba(102, 126, 234, 0.15);
}

.right-nav a:hover::before,
.right-nav a:focus::before,
.right-nav a.active::before {
    transform: scaleY(1);
}

.right-nav a.active {
    background: rgba(102, 126, 234, 0.15);
    color: #5a67d8;
    font-weight: 600;
}

/* 반응형 */
@media (max-width: 768px) {
    .right-nav {
        top: 20px;
        min-width: 75px;
        padding: 12px 0 12px 8px;
        transform: scale(0.55) translateX(0);
        background: rgba(255, 255, 255, 0.8);
    }
    
    .right-nav:hover {
        transform: scale(0.55) translateX(-3px);
    }
    
    .right-nav a {
        padding: 8px 12px 8px 10px;
        font-size: 13px;
    }
}

@media (max-width: 480px) {
    .right-nav {
        top: 15px;
        min-width: 70px;
        padding: 10px 0 10px 6px;
        transform: scale(0.5) translateX(0);
        background: rgba(255, 255, 255, 0.85);
    }
    
    .right-nav:hover {
        transform: scale(0.5) translateX(-2px);
    }
    
    .right-nav a {
        padding: 6px 10px 6px 8px;
        font-size: 12px;
    }
}

/* Hide Posts and Archives */
.archive__subtitle,
.list__item,
.entries-list,
.taxonomy__section,
.archive,
h3.archive__subtitle {
    display: none !important;
}

/* Hide any leftover follow button if present */
.btn.btn--inverse,
button[aria-label="Follow"] {
    display: none !important;
}

/* --- 메인 콘텐츠와 섹션 --- */
.main-content {
    width: 100%;
}
.page-section {
    padding-top: 50px; /* 내비게이션 클릭 시 헤더에 가려지지 않도록 여백 추가 */
}



/* --- Contact 섹션 --- */
.contact-section {
    background-color: #f8f9fa;
    padding: 60px 20px;
    margin-top: 60px;
    margin-left: calc(-50vw + 50%);
    margin-right: calc(-50vw + 50%);
    width: 100vw;
}
.contact-content {
    max-width: 900px;
    margin: 0 auto;
    text-align: center;
}
.contact-content h2 {
    margin-bottom: 30px;
}
.contact-content ul {
    list-style: none;
    padding: 0;
    margin: 0;
    display: inline-block; /* 내용만큼만 너비 차지 (중앙 정렬에 중요) */
    text-align: left;    /* 목록 내 텍스트는 왼쪽 정렬 */
}
.contact-content li {
    margin-bottom: 15px;
    font-size: 1.1em;
}
.contact-content li i {
    margin-right: 15px;
    width: 20px;
    color: #555;
}
/* optional map block, uncomment and adjust selector if you add a map element */
/*
.map {
    height: 350px;
    border-radius: 8px;
}
*/

/* smooth scroll to anchors */
html { scroll-behavior: smooth; }

.app-item img {
    max-width: 50%; /* 이미지 크기를 반으로 줄임 */
    height: auto;
    display: block;
    margin: 0 auto;
}