/* ===================================
   곽상훈 교수 홈페이지 - 한동대 블루 테마
   Professional Academic Website
   =================================== */

/* CSS Variables */
:root {
    /* Handong Blue Color Palette */
    --primary: #003876;
    --primary-light: #1E5A9A;
    --primary-dark: #002855;
    --secondary: #4A90C2;
    --accent: #0066CC;

    /* Neutral Colors */
    --white: #FFFFFF;
    --gray-50: #F8FAFC;
    --gray-100: #F1F5F9;
    --gray-200: #E2E8F0;
    --gray-300: #CBD5E1;
    --gray-400: #94A3B8;
    --gray-500: #64748B;
    --gray-600: #475569;
    --gray-700: #334155;
    --gray-800: #1E293B;
    --gray-900: #0F172A;

    /* Typography */
    --font-primary: 'Noto Sans KR', -apple-system, BlinkMacSystemFont, sans-serif;

    /* Spacing */
    --section-padding: 100px;
    --container-max: 1200px;

    /* Transitions */
    --transition: 0.3s ease;

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    font-size: 16px;
    line-height: 1.7;
    color: var(--gray-700);
    background-color: var(--white);
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

ul {
    list-style: none;
}

img {
    max-width: 100%;
    height: auto;
}

.container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 24px;
}

/* ===================================
   Header & Navigation
   =================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background-color: var(--white);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.header.scrolled {
    box-shadow: var(--shadow);
}

.header-container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 72px;
}

.logo {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.logo-university {
    font-size: 11px;
    font-weight: 500;
    letter-spacing: 1.5px;
    color: var(--gray-500);
    text-transform: uppercase;
}

.logo-name {
    font-size: 18px;
    font-weight: 700;
    color: var(--primary);
}

.nav-list {
    display: flex;
    gap: 32px;
}

.nav-link {
    font-size: 15px;
    font-weight: 500;
    color: var(--gray-600);
    padding: 8px 0;
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--primary);
    transition: var(--transition);
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

/* Language Switch */
.lang-switch {
    display: flex;
    align-items: center;
    gap: 6px;
    margin-left: 24px;
}

.lang-btn {
    font-size: 13px;
    font-weight: 600;
    color: var(--gray-400);
    padding: 4px 8px;
    border-radius: 4px;
    transition: var(--transition);
    letter-spacing: 0.5px;
}

.lang-btn:hover {
    color: var(--primary);
}

.lang-btn.active {
    color: var(--white);
    background-color: var(--primary);
}

.lang-divider {
    font-size: 13px;
    color: var(--gray-300);
    user-select: none;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background-color: var(--gray-700);
    transition: var(--transition);
}

/* ===================================
   Buttons
   =================================== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 28px;
    font-size: 15px;
    font-weight: 600;
    border-radius: 8px;
    cursor: pointer;
    transition: var(--transition);
    border: none;
}

.btn-primary {
    background-color: var(--primary);
    color: var(--white);
}

.btn-primary:hover {
    background-color: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-outline {
    background-color: transparent;
    color: var(--white);
    border: 2px solid var(--white);
}

.btn-outline:hover {
    background-color: var(--white);
    color: var(--primary);
}

/* ===================================
   Hero Section
   =================================== */
.hero {
    min-height: 100vh;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    display: flex;
    align-items: center;
    padding-top: 72px;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 50%;
    height: 100%;
    background: linear-gradient(135deg, transparent 0%, rgba(255,255,255,0.05) 100%);
    clip-path: polygon(20% 0, 100% 0, 100% 100%, 0% 100%);
}

.hero-container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 24px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
    position: relative;
    z-index: 1;
}

.hero-content {
    color: var(--white);
}

.hero-subtitle {
    font-size: 14px;
    font-weight: 500;
    letter-spacing: 2px;
    text-transform: uppercase;
    opacity: 0.9;
    margin-bottom: 16px;
}

.hero-title {
    font-size: 56px;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 16px;
}

.hero-tagline {
    font-size: 24px;
    font-weight: 300;
    font-style: italic;
    opacity: 0.95;
    margin-bottom: 24px;
}

.hero-description {
    font-size: 18px;
    line-height: 1.8;
    opacity: 0.9;
    margin-bottom: 32px;
}

.hero-buttons {
    display: flex;
    gap: 16px;
}

.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero-card {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 20px;
    padding: 48px;
    text-align: center;
    color: var(--white);
}

.hero-card-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 24px;
}

.hero-card-icon svg {
    width: 100%;
    height: 100%;
}

.hero-card h3 {
    font-size: 28px;
    font-weight: 700;
    margin-bottom: 8px;
}

.hero-card p {
    font-size: 16px;
    opacity: 0.9;
}

/* ===================================
   Section Common Styles
   =================================== */
section {
    padding: var(--section-padding) 0;
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-label {
    display: inline-block;
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 2px;
    text-transform: uppercase;
    color: var(--primary);
    margin-bottom: 12px;
}

.section-title {
    font-size: 36px;
    font-weight: 700;
    color: var(--gray-800);
}

.section-subtitle {
    font-size: 18px;
    color: var(--gray-500);
    margin-top: 12px;
    font-weight: 400;
}

/* ===================================
   About Section
   =================================== */
.about {
    background-color: var(--gray-50);
}

.about-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.about-card {
    background-color: var(--white);
    border-radius: 12px;
    padding: 32px;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.about-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-4px);
}

.about-card-intro {
    grid-column: span 3;
}

.about-card-title {
    font-size: 18px;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 20px;
    padding-bottom: 12px;
    border-bottom: 2px solid var(--gray-100);
}

.about-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.about-list li {
    display: flex;
    align-items: flex-start;
    gap: 12px;
}

.degree {
    flex-shrink: 0;
    width: 48px;
    padding: 4px 0;
    font-size: 12px;
    font-weight: 700;
    text-align: center;
    background-color: var(--primary);
    color: var(--white);
    border-radius: 4px;
}

.institution {
    font-size: 15px;
    color: var(--gray-600);
    line-height: 1.6;
    padding-top: 2px;
}

.position-info {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.position-main {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.position-title {
    display: inline-block;
    font-size: 14px;
    font-weight: 700;
    color: var(--white);
    background-color: var(--primary);
    padding: 4px 12px;
    border-radius: 4px;
    width: fit-content;
}

.position-dept {
    font-size: 16px;
    color: var(--gray-600);
}

.position-secondary {
    display: flex;
    flex-direction: column;
    gap: 4px;
    padding-top: 12px;
    border-top: 1px solid var(--gray-100);
}

.position-secondary .position-title {
    font-size: 14px;
    font-weight: 700;
}

.position-secondary .position-dept {
    font-size: 14px;
}

a.position-link {
    color: var(--primary);
    text-decoration: none;
    font-weight: 500;
    border-bottom: 1px dashed var(--primary);
    transition: color 0.2s, border-color 0.2s;
}

a.position-link:hover {
    color: var(--accent);
    border-color: var(--accent);
}

.position-field {
    font-size: 14px;
    color: var(--gray-500);
    padding: 12px 16px;
    background-color: var(--gray-50);
    border-radius: 8px;
}

/* Experience List */
.experience-list li {
    flex-direction: column;
    gap: 4px;
}

.experience-list .period {
    font-size: 12px;
    font-weight: 600;
    color: var(--primary);
    background: none;
    padding: 0;
    width: auto;
}

.experience-list .role {
    font-size: 15px;
    color: var(--gray-700);
}

.about-intro-text {
    font-size: 16px;
    line-height: 1.9;
    color: var(--gray-600);
}

/* ===================================
   Research Section
   =================================== */
.research {
    background-color: var(--white);
}

.research-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-bottom: 48px;
}

.research-card {
    background-color: var(--gray-50);
    border-radius: 12px;
    padding: 32px;
    text-align: center;
    transition: var(--transition);
    border: 1px solid var(--gray-100);
}

.research-card:hover {
    background-color: var(--primary);
    border-color: var(--primary);
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.research-card:hover .research-icon,
.research-card:hover .research-title,
.research-card:hover .research-desc {
    color: var(--white);
}

.research-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 20px;
    color: var(--primary);
    transition: var(--transition);
}

.research-icon svg {
    width: 100%;
    height: 100%;
}

.research-title {
    font-size: 20px;
    font-weight: 700;
    color: var(--gray-800);
    margin-bottom: 12px;
    transition: var(--transition);
}

.research-desc {
    font-size: 15px;
    color: var(--gray-500);
    line-height: 1.7;
    transition: var(--transition);
}

.research-interests {
    background-color: var(--gray-50);
    border-radius: 12px;
    padding: 40px;
    text-align: center;
}

.interests-title {
    font-size: 20px;
    font-weight: 700;
    color: var(--gray-800);
    margin-bottom: 24px;
}

.interests-tags {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 12px;
}

.tag {
    display: inline-block;
    padding: 10px 20px;
    font-size: 14px;
    font-weight: 500;
    color: var(--primary);
    background-color: var(--white);
    border: 1px solid var(--gray-200);
    border-radius: 50px;
    transition: var(--transition);
}

.tag:hover {
    background-color: var(--primary);
    color: var(--white);
    border-color: var(--primary);
}

/* ===================================
   Publications Section
   =================================== */
.publications {
    background-color: var(--gray-50);
}

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

.pub-category {
    margin-bottom: 48px;
}

.pub-category:last-child {
    margin-bottom: 0;
}

.pub-category-title {
    font-size: 20px;
    font-weight: 700;
    color: var(--gray-800);
    margin-bottom: 24px;
    padding-bottom: 12px;
    border-bottom: 2px solid var(--primary);
}

.pub-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.pub-item {
    background-color: var(--white);
    border-radius: 10px;
    padding: 24px;
    border-left: 4px solid var(--primary);
    transition: var(--transition);
}

.pub-item:hover {
    box-shadow: var(--shadow-md);
    transform: translateX(4px);
}

.pub-title {
    font-size: 17px;
    font-weight: 600;
    color: var(--gray-800);
    margin-bottom: 8px;
    line-height: 1.5;
}

.pub-authors {
    font-size: 14px;
    color: var(--gray-600);
    margin-bottom: 4px;
}

.pub-venue {
    font-size: 13px;
    color: var(--gray-400);
    font-style: italic;
}

/* ===================================
   Teaching Section
   =================================== */
.teaching {
    background-color: var(--white);
}

.teaching-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 32px;
}

.teaching-card {
    background-color: var(--gray-50);
    border-radius: 12px;
    padding: 32px;
}

a.teaching-card-link {
    display: block;
    text-decoration: none;
    color: inherit;
    cursor: pointer;
    transition: var(--transition);
    border: 2px solid transparent;
}

a.teaching-card-link:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary);
}

.teaching-level {
    font-size: 20px;
    font-weight: 700;
    color: var(--primary);
    text-align: center;
    margin-bottom: 8px;
    padding-bottom: 12px;
    border-bottom: 2px solid var(--gray-200);
}

.teaching-level-sub {
    display: inline;
}

.teaching-level-en {
    display: block;
    font-size: 14px;
    font-weight: 500;
    margin-top: 4px;
}

.teaching-desc {
    font-size: 16px;
    color: var(--gray-500);
    text-align: center;
    margin-bottom: 16px;
}

.course-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.course-item {
    background-color: var(--white);
    border-radius: 8px;
    padding: 20px;
    transition: var(--transition);
}

.course-item:hover {
    box-shadow: var(--shadow);
}

.course-name {
    font-size: 16px;
    font-weight: 600;
    color: var(--gray-800);
    margin-bottom: 8px;
}

.course-desc {
    font-size: 14px;
    color: var(--gray-500);
    line-height: 1.7;
}

.teaching-desc {
    font-size: 14px;
    color: var(--gray-500);
    text-align: center;
    margin-bottom: 20px;
}

/* ===================================
   Projects Section
   =================================== */
.projects {
    background-color: var(--gray-50);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.project-card {
    background-color: var(--white);
    border-radius: 12px;
    padding: 32px;
    transition: var(--transition);
    border: 1px solid var(--gray-100);
}

.project-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary);
}

a.project-card-link {
    display: block;
    text-decoration: none;
    color: inherit;
    cursor: pointer;
}

a.project-card-link:hover {
    border-color: var(--primary);
}

.card-detail-link {
    display: inline-block;
    margin-top: 16px;
    font-size: 13px;
    font-weight: 700;
    color: var(--primary);
    transition: gap var(--transition), color var(--transition);
}

a.project-card-link:hover .card-detail-link,
a.teaching-card-link:hover .card-detail-link {
    color: var(--primary-light);
    letter-spacing: 0.03em;
}

.project-header {
    margin-bottom: 16px;
}

.project-category {
    display: inline-block;
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 1px;
    text-transform: uppercase;
    color: var(--white);
    background-color: var(--primary);
    padding: 4px 10px;
    border-radius: 4px;
    margin-bottom: 12px;
}

.project-title {
    font-size: 18px;
    font-weight: 700;
    color: var(--gray-800);
    line-height: 1.4;
}

.project-desc {
    font-size: 14px;
    color: var(--gray-500);
    line-height: 1.7;
    margin-bottom: 20px;
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.project-tags span {
    font-size: 12px;
    color: var(--primary);
    background-color: var(--gray-50);
    padding: 4px 10px;
    border-radius: 4px;
    border: 1px solid var(--gray-200);
}

/* ===================================
   News Section
   =================================== */
.news {
    background-color: var(--white);
}

.news-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.news-card {
    display: block;
    background-color: var(--gray-50);
    border-radius: 12px;
    padding: 28px;
    transition: var(--transition);
    border: 1px solid var(--gray-100);
}

.news-card:hover {
    background-color: var(--primary);
    border-color: var(--primary);
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.news-card:hover .news-source,
.news-card:hover .news-title,
.news-card:hover .news-link {
    color: var(--white);
}

.news-source {
    font-size: 12px;
    font-weight: 600;
    color: var(--primary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 12px;
    transition: var(--transition);
}

.news-title {
    font-size: 16px;
    font-weight: 600;
    color: var(--gray-800);
    line-height: 1.5;
    margin-bottom: 16px;
    transition: var(--transition);
}

.news-link {
    font-size: 14px;
    font-weight: 500;
    color: var(--primary);
    transition: var(--transition);
}

/* ===================================
   News / Media Section
   =================================== */
.news {
    background-color: var(--white);
}

.news-list {
    list-style: none;
    border-top: 2px solid var(--primary);
}

.news-list-item a {
    display: flex;
    align-items: center;
    gap: 20px;
    padding: 18px 12px;
    border-bottom: 1px solid var(--gray-200);
    text-decoration: none;
    color: inherit;
    transition: background-color var(--transition);
}

.news-list-item a:hover {
    background-color: var(--gray-50);
}

.news-list-meta {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-shrink: 0;
    min-width: 220px;
}

.news-list-date {
    font-size: 13px;
    color: var(--gray-400);
    white-space: nowrap;
}

.news-list-source {
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.04em;
    color: var(--white);
    background-color: var(--primary);
    padding: 2px 8px;
    border-radius: 3px;
    white-space: nowrap;
}

.news-list-title {
    flex: 1;
    font-size: 15px;
    font-weight: 500;
    color: var(--gray-700);
    line-height: 1.5;
}

.news-list-item a:hover .news-list-title {
    color: var(--primary);
}

.news-list-arrow {
    font-size: 14px;
    color: var(--gray-300);
    flex-shrink: 0;
    transition: color var(--transition), transform var(--transition);
}

.news-list-item a:hover .news-list-arrow {
    color: var(--primary);
    transform: translateX(3px);
}

@media (max-width: 640px) {
    .news-list-meta {
        min-width: unset;
        flex-direction: column;
        align-items: flex-start;
        gap: 4px;
    }
    .news-list-item a {
        flex-wrap: wrap;
        gap: 8px;
    }
}

/* 메인 페이지 - 전체 게시판 이동 버튼 */
.news-view-all-wrap {
    text-align: center;
    margin-top: 28px;
}

.news-view-all {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 11px 28px;
    background-color: var(--primary);
    color: var(--white);
    text-decoration: none;
    border-radius: 6px;
    font-size: 14px;
    font-weight: 600;
    transition: background-color var(--transition);
}
.news-view-all:hover { background-color: var(--primary-light); }

/* ===================================
   News Board Page (news.php / news_en.php)
   =================================== */
.news-page-hero {
    background-color: var(--white);
    border-bottom: 1px solid var(--gray-200);
    padding: 48px 0 40px;
}

.news-page-back {
    display: inline-block;
    font-size: 13px;
    color: var(--gray-400);
    text-decoration: none;
    margin-bottom: 20px;
    transition: color var(--transition);
}
.news-page-back:hover { color: var(--primary); }

.news-page-body {
    padding-top: 0;
    min-height: 50vh;
    padding-bottom: var(--section-padding);
}

.news-total-count {
    font-size: 13px;
    color: var(--gray-400);
    margin-bottom: 4px;
    text-align: right;
}

/* ===================================
   Publications Section
   =================================== */
.pub-section {
    background-color: var(--gray-50);
}

.pub-list {
    list-style: none;
    border-top: 2px solid var(--primary);
}

.pub-row {
    display: flex;
    align-items: flex-start;
    gap: 20px;
    padding: 18px 12px;
    border-bottom: 1px solid var(--gray-200);
}

.pub-row-link {
    text-decoration: none;
    color: inherit;
    transition: background-color var(--transition);
}
.pub-row-link:hover { background-color: var(--gray-100); }

.pub-year {
    flex-shrink: 0;
    font-size: 12px;
    font-weight: 700;
    color: var(--white);
    background-color: var(--secondary);
    padding: 2px 10px;
    border-radius: 3px;
    white-space: nowrap;
    min-width: 52px;
    text-align: center;
    margin-top: 2px;
}

.pub-title {
    flex: 1;
    font-size: 15px;
    font-weight: 500;
    color: var(--gray-700);
    line-height: 1.6;
}

/* ===================================
   Contact Section
   =================================== */
.contact {
    background-color: var(--gray-50);
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 48px;
}

.contact-info {
    background-color: var(--white);
    border-radius: 12px;
    padding: 40px;
}

.contact-info-title {
    font-size: 20px;
    font-weight: 700;
    color: var(--gray-800);
    margin-bottom: 28px;
}

.info-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
    margin-bottom: 24px;
}

.info-item {
    display: flex;
    gap: 16px;
}

.info-label {
    flex-shrink: 0;
    width: 80px;
    font-size: 13px;
    font-weight: 600;
    color: var(--gray-500);
}

.info-value {
    font-size: 15px;
    color: var(--gray-700);
}

.info-value a {
    color: var(--accent);
}

.info-value a:hover {
    text-decoration: underline;
}

.address-box {
    background-color: var(--gray-50);
    border-radius: 8px;
    padding: 20px;
    margin-top: 24px;
}

.address-box .info-label {
    display: block;
    margin-bottom: 8px;
}

.address-box p {
    font-size: 15px;
    color: var(--gray-700);
}

.contact-form-wrapper {
    background-color: var(--white);
    border-radius: 12px;
    padding: 40px;
}

.contact-form-title {
    font-size: 20px;
    font-weight: 700;
    color: var(--gray-800);
    margin-bottom: 28px;
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.form-group label {
    font-size: 14px;
    font-weight: 500;
    color: var(--gray-600);
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 14px 16px;
    font-size: 15px;
    font-family: var(--font-primary);
    border: 1px solid var(--gray-200);
    border-radius: 8px;
    transition: var(--transition);
    background-color: var(--gray-50);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
    background-color: var(--white);
    box-shadow: 0 0 0 3px rgba(0, 56, 118, 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

.btn-submit {
    width: 100%;
    padding: 16px;
    font-size: 16px;
}

/* ===================================
   Footer
   =================================== */
.footer {
    background-color: var(--gray-900);
    color: var(--gray-300);
    padding: 60px 0 40px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 48px;
    margin-bottom: 40px;
    padding-bottom: 40px;
    border-bottom: 1px solid var(--gray-700);
}

.footer-logo {
    display: flex;
    flex-direction: column;
    gap: 4px;
    margin-bottom: 12px;
}

.footer-university {
    font-size: 12px;
    font-weight: 500;
    letter-spacing: 1.5px;
    color: var(--gray-400);
    text-transform: uppercase;
}

.footer-name {
    font-size: 20px;
    font-weight: 700;
    color: var(--white);
}

.footer-dept {
    font-size: 14px;
    color: var(--gray-400);
}

.footer-lab {
    font-size: 13px;
    color: var(--gray-500);
    margin-top: 4px;
}

.footer-links h4,
.footer-external h4 {
    font-size: 14px;
    font-weight: 600;
    color: var(--white);
    margin-bottom: 20px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.footer-links ul,
.footer-external ul {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.footer-links a,
.footer-external a {
    font-size: 14px;
    color: var(--gray-400);
}

.footer-links a:hover,
.footer-external a:hover {
    color: var(--white);
}

.footer-bottom {
    text-align: center;
}

.footer-bottom p {
    font-size: 14px;
    color: var(--gray-500);
}

.footer-contact {
    margin-top: 8px;
    font-size: 13px;
}

/* ===================================
   Mobile Navigation Active State
   =================================== */
.nav.active .nav-list {
    display: flex;
}

.nav-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.nav-toggle.active span:nth-child(2) {
    opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* ===================================
   Responsive Design
   =================================== */
@media screen and (max-width: 1024px) {
    :root {
        --section-padding: 80px;
    }

    .hero-title {
        font-size: 44px;
    }

    .hero-container {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-buttons {
        justify-content: center;
    }

    .hero-visual {
        display: none;
    }

    .about-grid {
        grid-template-columns: 1fr 1fr;
    }

    .about-card-intro {
        grid-column: span 2;
    }

    .research-grid {
        grid-template-columns: repeat(3, 1fr);
    }

    .projects-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .news-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

.mobile-br {
    display: none;
}

.desktop-br {
    display: inline;
}

@media screen and (max-width: 768px) {
    .mobile-br {
        display: inline;
    }

    .teaching-level-sub {
        display: block;
    }

    .subtitle-en {
        font-size: 14px;
    }

    .desktop-br {
        display: none;
    }

    :root {
        --section-padding: 60px;
    }

    .header-container {
        height: 64px;
    }

    .nav {
        position: fixed;
        top: 64px;
        left: 0;
        width: 100%;
        background-color: var(--white);
        box-shadow: var(--shadow-md);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: var(--transition);
    }

    .nav.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .nav-list {
        flex-direction: column;
        padding: 24px;
        gap: 0;
    }

    .nav-link {
        display: block;
        padding: 16px 0;
        border-bottom: 1px solid var(--gray-100);
    }

    .nav-link::after {
        display: none;
    }

    .nav-toggle {
        display: flex;
    }

    .logo-university {
        font-size: 10px;
        letter-spacing: 1px;
    }

    .logo-name {
        font-size: 15px;
    }

    .lang-switch {
        margin-left: auto;
        margin-right: 12px;
    }

    .hero {
        min-height: auto;
        padding: 120px 0 80px;
    }

    .hero-title {
        font-size: 36px;
    }

    .hero-tagline {
        font-size: 20px;
    }

    .hero-description {
        font-size: 16px;
        text-align: center;
    }

    .hero-buttons {
        flex-direction: column;
        gap: 12px;
    }

    .btn {
        width: 100%;
    }

    .section-title {
        font-size: 28px;
    }

    .about-grid {
        grid-template-columns: 1fr;
    }

    .about-card-intro {
        grid-column: span 1;
    }

    .research-grid {
        grid-template-columns: 1fr;
    }

    .projects-grid {
        grid-template-columns: 1fr;
    }

    .news-grid {
        grid-template-columns: 1fr;
    }

    .teaching-grid {
        grid-template-columns: 1fr;
    }

    .contact-grid {
        grid-template-columns: 1fr;
    }

    .footer-content {
        grid-template-columns: 1fr 1fr;
        gap: 24px 16px;
    }

    .footer-main {
        grid-column: span 2;
    }
}

@media screen and (max-width: 480px) {
    .logo-university {
        font-size: 9px;
        letter-spacing: 0.5px;
    }

    .logo-name {
        font-size: 14px;
    }

    .container {
        padding: 0 16px;
    }

    .hero-title {
        font-size: 28px;
    }

    .hero-tagline {
        font-size: 18px;
    }

    .about-card,
    .contact-info,
    .contact-form-wrapper {
        padding: 24px;
    }

    .research-card,
    .teaching-card,
    .project-card,
    .news-card {
        padding: 24px;
    }

    .pub-item {
        padding: 20px;
    }

    .interests-tags {
        gap: 8px;
    }

    .tag {
        padding: 8px 16px;
        font-size: 13px;
    }
}

/* ===================================
   Animation & Utilities
   =================================== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in-up {
    animation: fadeInUp 0.6s ease forwards;
}

/* Scroll reveal animation classes */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.active {
    opacity: 1;
    transform: translateY(0);
}