/* ===== VARIABLES ===== */
:root {
    --primary: #0e7490;
    --primary-dark: #0c6280;
    --primary-light: #e0f7fa;
    --accent: #2563eb;
    --text-dark: #0f172a;
    --text-mid: #334155;
    --text-light: #64748b;
    --bg-white: #ffffff;
    --bg-light: #f8fafc;
    --border: #e2e8f0;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
    --shadow: 0 4px 12px rgba(0,0,0,0.08);
    --shadow-lg: 0 10px 30px rgba(0,0,0,0.1);
    --radius: 10px;
    --radius-lg: 16px;
    --nav-h: 68px;
}

/* ===== RESET & BASE ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; font-size: 16px; }

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    color: var(--text-dark);
    background: var(--bg-white);
    line-height: 1.7;
}

img { max-width: 100%; display: block; }
a { color: var(--primary); text-decoration: none; transition: color 0.2s; }
a:hover { color: var(--primary-dark); }

/* ===== LAYOUT ===== */
.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 24px;
}

.section { padding: 88px 0; }
.bg-white { background: var(--bg-white); }
.bg-light { background: var(--bg-light); }
.bg-primary { background: var(--primary); color: #fff; }

.section-title {
    font-family: 'Merriweather', Georgia, serif;
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 12px;
    position: relative;
    padding-bottom: 16px;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 52px;
    height: 3px;
    background: var(--primary);
    border-radius: 2px;
}

.section-sub {
    color: var(--text-light);
    font-size: 1.05rem;
    margin-bottom: 40px;
    margin-top: 8px;
}

.subsection-title {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--text-dark);
    margin: 40px 0 20px;
}

/* ===== BUTTONS ===== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 11px 24px;
    border-radius: 6px;
    font-size: 0.92rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    border: 2px solid transparent;
    white-space: nowrap;
}

.btn-primary {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}
.btn-primary:hover { background: var(--primary-dark); border-color: var(--primary-dark); color: #fff; }

.btn-outline {
    background: transparent;
    color: var(--primary);
    border-color: var(--primary);
}
.btn-outline:hover { background: var(--primary); color: #fff; }

.btn-outline-white {
    background: transparent;
    color: #fff;
    border-color: rgba(255,255,255,0.7);
}
.btn-outline-white:hover { background: rgba(255,255,255,0.15); color: #fff; }

.btn-white {
    background: #fff;
    color: var(--primary);
    border-color: #fff;
}
.btn-white:hover { background: #f0fdfa; color: var(--primary-dark); }

/* ===== NAVBAR ===== */
.navbar {
    position: fixed;
    top: 0; left: 0; right: 0;
    z-index: 1000;
    background: rgba(255,255,255,0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid transparent;
    transition: all 0.3s;
    height: var(--nav-h);
}

.navbar.scrolled {
    border-color: var(--border);
    box-shadow: var(--shadow-sm);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    font-weight: 700;
    font-size: 1.05rem;
    color: var(--text-dark);
    letter-spacing: -0.3px;
}
.nav-logo:hover { color: var(--primary); }

.nav-links {
    display: flex;
    list-style: none;
    gap: 4px;
    align-items: center;
}

.nav-links a {
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-mid);
    padding: 6px 10px;
    border-radius: 6px;
    transition: all 0.2s;
}
.nav-links a:hover, .nav-links a.active {
    color: var(--primary);
    background: var(--primary-light);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}
.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text-dark);
    border-radius: 2px;
    transition: all 0.3s;
}
.nav-toggle.active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.active span:nth-child(2) { opacity: 0; }
.nav-toggle.active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ===== HERO ===== */
.hero {
    min-height: 100vh;
    background: linear-gradient(135deg, #0f2944 0%, #0e7490 60%, #0c9aa8 100%);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    position: relative;
    padding: calc(var(--nav-h) + 40px) 24px 80px;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background: url('/intro.jpg') center/cover no-repeat;
    opacity: 0.12;
}

.hero-overlay {
    position: absolute;
    inset: 0;
    background: radial-gradient(ellipse at 70% 50%, transparent 30%, rgba(7,25,50,0.5) 100%);
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 1100px;
    width: 100%;
    display: flex;
    align-items: center;
    gap: 60px;
    margin: 0 auto;
}

.hero-text { flex: 1; }

.hero-label {
    font-size: 0.85rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    color: rgba(255,255,255,0.7);
    margin-bottom: 16px;
}

.hero-name {
    font-family: 'Merriweather', Georgia, serif;
    font-size: clamp(2.2rem, 5vw, 3.4rem);
    font-weight: 700;
    color: #fff;
    line-height: 1.2;
    margin-bottom: 12px;
    letter-spacing: -0.5px;
}

.hero-dept {
    font-size: 1rem;
    color: rgba(255,255,255,0.8);
    margin-bottom: 4px;
}

.hero-university {
    font-size: 1rem;
    font-weight: 600;
    color: #7dd3fc;
    margin-bottom: 24px;
}

.hero-tagline {
    font-size: 1.1rem;
    color: rgba(255,255,255,0.85);
    line-height: 1.6;
    margin-bottom: 36px;
    max-width: 540px;
}

.hero-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-bottom: 36px;
}

.hero-social {
    display: flex;
    gap: 14px;
}
.hero-social a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: 8px;
    background: rgba(255,255,255,0.12);
    color: rgba(255,255,255,0.8);
    transition: all 0.2s;
}
.hero-social a:hover { background: rgba(255,255,255,0.25); color: #fff; }
.hero-social svg { width: 18px; height: 18px; }

.hero-photo-wrap {
    flex-shrink: 0;
}
.hero-photo {
    width: 240px;
    height: 240px;
    border-radius: 50%;
    object-fit: cover;
    border: 4px solid rgba(255,255,255,0.25);
    box-shadow: 0 20px 60px rgba(0,0,0,0.3);
}

.hero-scroll {
    position: absolute;
    bottom: 32px;
    left: 50%;
    transform: translateX(-50%);
    color: rgba(255,255,255,0.5);
    animation: bounce 2s infinite;
    z-index: 1;
}
.hero-scroll svg { width: 28px; height: 28px; }
@keyframes bounce {
    0%, 100% { transform: translateX(-50%) translateY(0); }
    50% { transform: translateX(-50%) translateY(8px); }
}

/* ===== ABOUT ===== */
.about-grid {
    display: grid;
    grid-template-columns: 1fr 260px;
    gap: 60px;
    align-items: start;
    margin-top: 40px;
}
.about-text p { color: var(--text-mid); margin-bottom: 18px; }
.about-text p:last-of-type { margin-bottom: 0; }
.about-text strong { color: var(--text-dark); }

.about-cards {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    margin-top: 28px;
}
.about-card {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 16px;
    background: var(--bg-light);
    border-radius: var(--radius);
    border: 1px solid var(--border);
}
.about-card-icon { font-size: 1.3rem; }
.about-card strong { display: block; font-size: 0.85rem; color: var(--text-dark); }
.about-card span { font-size: 0.8rem; color: var(--text-light); }

.about-photo-col { position: sticky; top: calc(var(--nav-h) + 20px); }
.about-photo {
    width: 100%;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    object-fit: cover;
    aspect-ratio: 3/4;
}

/* ===== RESEARCH ===== */
.research-block {
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 36px;
    margin-top: 40px;
    box-shadow: var(--shadow-sm);
}
.research-block h3 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 20px;
    line-height: 1.4;
}
.research-block p {
    color: var(--text-mid);
    margin-bottom: 16px;
}
.research-block p:last-child { margin-bottom: 0; }
.research-block strong { color: var(--text-dark); }

.tags-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
}
.tag {
    padding: 6px 16px;
    background: var(--primary-light);
    color: var(--primary-dark);
    border-radius: 100px;
    font-size: 0.85rem;
    font-weight: 500;
    border: 1px solid rgba(14,116,144,0.2);
}

/* ===== PROJECTS ===== */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    margin-top: 40px;
}
.project-card {
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 28px;
    transition: all 0.25s;
    box-shadow: var(--shadow-sm);
}
.project-card:hover {
    border-color: var(--primary);
    box-shadow: var(--shadow);
    transform: translateY(-3px);
}
.project-icon { font-size: 2rem; margin-bottom: 16px; }
.project-card h3 {
    font-size: 1rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 10px;
    line-height: 1.4;
}
.project-card p {
    font-size: 0.9rem;
    color: var(--text-mid);
    margin-bottom: 18px;
    line-height: 1.6;
}
.project-tags { display: flex; flex-wrap: wrap; gap: 6px; }
.project-tags span {
    font-size: 0.75rem;
    font-weight: 500;
    padding: 3px 10px;
    background: var(--bg-light);
    color: var(--text-light);
    border-radius: 100px;
    border: 1px solid var(--border);
}

/* ===== EDUCATION ===== */
.edu-list {
    display: flex;
    flex-direction: column;
    gap: 0;
    margin-top: 40px;
    position: relative;
}
.edu-list::before {
    content: '';
    position: absolute;
    left: 24px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--border);
}
.edu-item {
    display: flex;
    gap: 28px;
    padding: 28px 0;
    position: relative;
}
.edu-item + .edu-item { border-top: 1px solid var(--border); }

.edu-badge {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--primary);
    color: #fff;
    font-weight: 700;
    font-size: 1.1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    position: relative;
    z-index: 1;
    box-shadow: 0 0 0 4px var(--bg-light);
}

.edu-body { flex: 1; }
.edu-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 6px;
}
.edu-header h3 { font-size: 1.1rem; font-weight: 700; color: var(--text-dark); }
.edu-year {
    font-size: 0.78rem;
    font-weight: 600;
    padding: 3px 10px;
    background: var(--primary-light);
    color: var(--primary);
    border-radius: 100px;
}
.edu-degree { font-size: 0.95rem; font-weight: 600; color: var(--primary); margin-bottom: 4px; }
.edu-location { font-size: 0.85rem; color: var(--text-light); margin-bottom: 10px; }
.edu-desc { font-size: 0.9rem; color: var(--text-mid); }

/* ===== SKILLS ===== */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
    margin-top: 40px;
}
.skills-col {
    background: var(--bg-light);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 28px;
}
.skills-col h3 {
    font-size: 1rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 18px;
    padding-bottom: 12px;
    border-bottom: 2px solid var(--primary);
}
.skills-list { list-style: none; }
.skills-list li {
    font-size: 0.9rem;
    color: var(--text-mid);
    padding: 7px 0;
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    gap: 8px;
}
.skills-list li::before {
    content: '';
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--primary);
    flex-shrink: 0;
}
.skills-list li:last-child { border-bottom: none; }

/* ===== PUBLICATIONS ===== */
.pub-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
    margin-top: 40px;
}
.pub-col {
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 28px;
}
.pub-col h3 { font-size: 1rem; font-weight: 700; color: var(--text-dark); margin-bottom: 16px; }
.coming-soon { color: var(--text-light); font-style: italic; font-size: 0.9rem; }

/* ===== CV BLOCK ===== */
.cv-block {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 40px;
    flex-wrap: wrap;
}
.cv-text h2 {
    font-family: 'Merriweather', serif;
    font-size: 1.8rem;
    font-weight: 700;
    color: #fff;
    margin-bottom: 10px;
}
.cv-text p { color: rgba(255,255,255,0.85); max-width: 500px; }
.cv-actions { display: flex; gap: 14px; flex-wrap: wrap; }

/* ===== BLOG ===== */
.blog-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
    margin-top: 8px;
}
.blog-card {
    background: var(--bg-light);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 28px;
    transition: all 0.25s;
}
.blog-card:hover { border-color: var(--primary); box-shadow: var(--shadow); }
.blog-badge {
    display: inline-block;
    font-size: 0.72rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    padding: 3px 10px;
    background: var(--primary-light);
    color: var(--primary);
    border-radius: 100px;
    margin-bottom: 14px;
}
.blog-card h3 { font-size: 1rem; font-weight: 700; color: var(--text-dark); margin-bottom: 10px; line-height: 1.45; }
.blog-card p { font-size: 0.9rem; color: var(--text-mid); margin-bottom: 14px; }
.blog-tag { font-size: 0.78rem; color: var(--text-light); }

/* ===== GALLERY ===== */
.gallery-placeholder {
    margin-top: 40px;
    border: 2px dashed var(--border);
    border-radius: var(--radius-lg);
    padding: 60px 40px;
    text-align: center;
    color: var(--text-light);
}
.gallery-icon { font-size: 3rem; margin-bottom: 16px; }
.gallery-placeholder p { font-size: 1rem; margin-bottom: 24px; }
.gallery-cats { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; }
.gallery-cats span {
    padding: 6px 16px;
    background: var(--bg-white);
    border: 1px solid var(--border);
    border-radius: 100px;
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-mid);
}

/* ===== CONTACT ===== */
.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 48px;
    margin-top: 40px;
    align-items: start;
}
.contact-info { display: flex; flex-direction: column; gap: 20px; }
.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 16px;
}
.contact-icon {
    width: 44px;
    height: 44px;
    border-radius: 10px;
    background: var(--primary-light);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    color: var(--primary);
}
.contact-icon svg { width: 20px; height: 20px; }
.contact-item strong { display: block; font-size: 0.85rem; color: var(--text-dark); margin-bottom: 2px; }
.contact-item a, .contact-item span { font-size: 0.9rem; color: var(--text-mid); }
.contact-item a:hover { color: var(--primary); }
.contact-map iframe { border-radius: var(--radius-lg); box-shadow: var(--shadow); }

/* ===== FOOTER ===== */
.footer {
    background: #0f172a;
    color: rgba(255,255,255,0.65);
    padding: 60px 0 0;
}
.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 48px;
    padding-bottom: 48px;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}
.footer-name { font-size: 1.1rem; font-weight: 700; color: #fff; margin-bottom: 8px; }
.footer p { font-size: 0.88rem; line-height: 1.6; }
.footer-heading { font-size: 0.78rem; font-weight: 600; text-transform: uppercase; letter-spacing: 1px; color: rgba(255,255,255,0.4); margin-bottom: 14px; }
.footer-links { display: flex; flex-direction: column; gap: 8px; }
.footer-links a { font-size: 0.88rem; color: rgba(255,255,255,0.6); }
.footer-links a:hover { color: #fff; }
.footer-bottom {
    text-align: center;
    padding: 20px 0;
    font-size: 0.82rem;
    color: rgba(255,255,255,0.35);
}

/* ===== VISITOR WIDGET ===== */
.visitor-widget {
    position: fixed !important;
    bottom: 24px !important;
    right: 24px !important;
    left: auto !important;
    top: auto !important;
    z-index: 9999;
    background: #0f172a;
    border: 1px solid rgba(255,255,255,0.12);
    border-radius: 14px;
    padding: 12px 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    box-shadow: 0 4px 24px rgba(0,0,0,0.35);
    width: 100px;
    max-width: 100px;
}
.visitor-eye {
    width: 16px;
    height: 16px;
    color: var(--primary);
}
.visitor-num {
    font-size: 1.5rem;
    font-weight: 800;
    color: #fff;
    line-height: 1;
    letter-spacing: -0.5px;
}
.visitor-label {
    font-size: 0.68rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1.2px;
    color: rgba(255,255,255,0.4);
}

/* ===== CERTIFICATIONS ===== */
.cert-list {
    display: flex;
    flex-direction: column;
    gap: 0;
    margin-top: 40px;
}
.cert-item {
    display: flex;
    gap: 28px;
    padding: 24px 0;
    border-bottom: 1px solid var(--border);
}
.cert-item:last-child { border-bottom: none; }
.cert-year {
    min-width: 120px;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--primary);
    padding-top: 3px;
    flex-shrink: 0;
}
.cert-body h3 { font-size: 0.98rem; font-weight: 700; color: var(--text-dark); margin-bottom: 4px; }
.cert-org { font-size: 0.83rem; color: var(--text-light); margin-bottom: 6px; }
.cert-body p { font-size: 0.88rem; color: var(--text-mid); }

.award-block {
    display: flex;
    align-items: flex-start;
    gap: 20px;
    margin-top: 40px;
    background: linear-gradient(135deg, #fef9c3, #fef3c7);
    border: 1px solid #fde68a;
    border-radius: var(--radius-lg);
    padding: 28px;
}
.award-icon { font-size: 2.2rem; flex-shrink: 0; }
.award-block h3 { font-size: 1rem; font-weight: 700; color: #92400e; margin-bottom: 8px; }
.award-block p { font-size: 0.9rem; color: #78350f; }

/* ===== RESPONSIVE ===== */
@media (max-width: 900px) {
    .nav-toggle { display: flex; }
    .nav-links {
        display: none;
        position: absolute;
        top: var(--nav-h);
        left: 0; right: 0;
        background: #fff;
        border-bottom: 1px solid var(--border);
        flex-direction: column;
        padding: 16px;
        gap: 4px;
        box-shadow: var(--shadow);
    }
    .nav-links.open { display: flex; }
    .nav-links a { padding: 10px 16px; }

    .hero-content { flex-direction: column-reverse; text-align: center; gap: 36px; }
    .hero-photo { width: 180px; height: 180px; }
    .hero-buttons { justify-content: center; }
    .hero-social { justify-content: center; }

    .about-grid { grid-template-columns: 1fr; }
    .about-photo-col { display: none; }
    .about-cards { grid-template-columns: 1fr 1fr; }

    .projects-grid { grid-template-columns: repeat(2, 1fr); }
    .skills-grid { grid-template-columns: 1fr; }
    .pub-grid { grid-template-columns: 1fr; }
    .blog-grid { grid-template-columns: 1fr; }
    .contact-grid { grid-template-columns: 1fr; }
    .footer-grid { grid-template-columns: 1fr; gap: 32px; }
    .cv-block { flex-direction: column; }
}

@media (max-width: 600px) {
    .section { padding: 64px 0; }
    .section-title { font-size: 1.6rem; }
    .hero-name { font-size: 2rem; }
    .projects-grid { grid-template-columns: 1fr; }
    .about-cards { grid-template-columns: 1fr; }
    .edu-list::before { display: none; }
}