/* ── Reset ── */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { font-family: 'Sora', sans-serif; color: #000; background: #fff; -webkit-font-smoothing: antialiased; overflow-x: hidden; }
img { display: block; max-width: 100%; }
a { text-decoration: none; color: inherit; }
button { cursor: pointer; font-family: 'Sora', sans-serif; border: none; background: none; }

/* ── Layout ── */
.container { max-width: 1280px; margin: 0 auto; padding: 0 80px; }
section { padding: 96px 0; }

/* ── Buttons ── */
.btn { display: inline-flex; align-items: center; gap: 8px; border-radius: 4px; font-family: 'Sora', sans-serif; font-weight: 700; letter-spacing: 0.02em; cursor: pointer; transition: background 0.2s, color 0.2s, border-color 0.2s, transform 0.15s; }
.btn:active { transform: scale(0.97); }
.btn-primary { background: #000; color: #fff; border: 2px solid #000; }
.btn-primary:hover { background: #404040; border-color: #404040; }
.btn-outline { background: transparent; color: #000; border: 2px solid #000; }
.btn-outline:hover { background: #000; color: #fff; }
.btn-md { height: 56px; padding: 0 24px; font-size: 15px; }
.btn-sm { height: 44px; padding: 0 20px; font-size: 14px; }

/* ── Nav ── */
.nav { position: sticky; top: 0; z-index: 100; background: rgba(255,255,255,0.92); backdrop-filter: blur(10px); border-bottom: 1px solid #f1f1f1; height: 80px; display: flex; align-items: center; }
.nav .container { display: flex; justify-content: space-between; align-items: center; width: 100%; }
.logo { display: flex; align-items: center; gap: 10px; }
.logo-text { font-size: 18px; font-weight: 700; letter-spacing: -0.02em; color: #000; }
.nav-links { display: flex; gap: 36px; }
.nav-link { font-size: 14px; font-weight: 400; color: #71717a; padding: 4px 0; transition: color 0.2s, font-weight 0.1s; position: relative; }
.nav-link::after { content: ''; position: absolute; bottom: -4px; left: 0; right: 0; height: 2px; background: #000; transform: scaleX(0); transition: transform 0.2s; }
.nav-link:hover, .nav-link.active { color: #000; font-weight: 700; }
.nav-link:hover::after, .nav-link.active::after { transform: scaleX(1); }

.hamburger { display: none; flex-direction: column; gap: 5px; width: 32px; height: 32px; justify-content: center; align-items: center; }
.hamburger span { display: block; width: 22px; height: 2px; background: #000; transition: transform 0.3s, opacity 0.3s; }
.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

.mobile-menu { position: fixed; inset: 0; top: 80px; background: #fff; display: flex; flex-direction: column; justify-content: center; align-items: center; gap: 36px; z-index: 99; transform: translateY(-100%); opacity: 0; transition: transform 0.35s ease, opacity 0.35s ease; pointer-events: none; }
.mobile-menu.open { transform: translateY(0); opacity: 1; pointer-events: all; }
.mobile-menu .nav-link { font-size: 28px; font-weight: 700; color: #000; }

/* ── Hero ── */
.hero { position: relative; padding: 0; height: calc(100vh - 80px); display: flex; align-items: center; overflow: clip; }
.hero .container { display: flex; align-items: center; width: 100%; position: relative; z-index: 1; }
.hero-text { padding: 80px 0; width: 65%; flex-shrink: 0; position: relative; z-index: 2; }
.hero-greeting { font-size: 32px; font-weight: 400; color: #000; letter-spacing: -0.01em; margin-bottom: 12px; }
.hero-greeting strong { font-weight: 700; }
.hero-headline { font-size: 62px; font-weight: 800; letter-spacing: -0.03em; line-height: 1.05; margin-bottom: 32px; white-space: nowrap; }
.hero-headline .role { display: block; }
.hero-headline .solid { color: #000; }
.hero-headline .outlined { color: #fff; text-shadow: -3px 0 0 #000, 3px 0 0 #000, 0 -3px 0 #000, 0 3px 0 #000, -2px -2px 0 #000, 2px -2px 0 #000, -2px 2px 0 #000, 2px 2px 0 #000; font-weight: 800; }
.hero-headline .based { display: block; font-weight: 700; }
.split-line { overflow: hidden; }
.hero-headline .based .country { font-weight: 800; }
.hero-desc { font-size: 15px; line-height: 1.8; color: #6b6b73; margin-bottom: 40px; max-width: 520px; }
.hero-socials { display: flex; gap: 12px; }
.social-btn { width: 44px; height: 44px; border-radius: 6px; border: 1.5px solid #e4e4e7; display: flex; align-items: center; justify-content: center; background: transparent; transition: background 0.2s, border-color 0.2s, color 0.2s, transform 0.2s; color: #000; }
.social-btn.filled { background: #000; border-color: #000; color: #fff; }
.social-btn:hover { background: #000; border-color: #000; color: #fff; transform: translateY(-2px); }

/* Hero illustration */
.hero-illustration { position: absolute; right: 0; top: 0; bottom: 0; width: 55%; display: flex; align-items: center; justify-content: flex-end; transform: translateY(-6%); z-index: 1; }
.hero-img { height: 90%; width: auto; max-width: 100%; object-fit: contain; object-position: center right; }

/* ── Section title ── */
.section-title { font-size: 48px; font-weight: 800; letter-spacing: -0.03em; text-align: center; margin-bottom: 56px; }
.section-title .light-word { font-weight: 400; color: #71717a; }

/* ── Skills ── */
.skills-section { padding: 60px 0 96px; }
.skills-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 20px; }
.skill-card { border: 1.5px solid #e4e4e7; border-radius: 8px; padding: 32px 16px; display: flex; flex-direction: column; align-items: center; gap: 16px; cursor: pointer; transition: background 0.22s, border-color 0.22s, transform 0.22s, box-shadow 0.22s; background: #fff; min-height: 140px; }
.skill-card:hover { transform: translateY(-4px); box-shadow: 0 8px 20px rgba(0,0,0,0.06); border-color: #d4d4d8; }
.skill-card.selected { background: #f4f4f5; border-color: #a1a1aa; }
.skill-card.selected .skill-name { color: #18181b; }
.skill-card.selected .skill-icon { filter: none; }
.skill-icon { width: 44px; height: 44px; object-fit: contain; transition: filter 0.22s; }
.skill-name { font-size: 14px; font-weight: 700; color: #000; text-align: center; transition: color 0.22s; }

/* ── Experience ── */
.experience-section { background: #000; padding: 96px 0; }
.experience-section .section-title { color: #fff; }
.experience-section .section-title .light-word { color: #d4d4d8; font-weight: 400; }
.exp-list { display: flex; flex-direction: column; gap: 16px; max-width: 1100px; margin: 0 auto; }
.exp-card { background: transparent; border: 1px solid #2a2a2a; border-radius: 12px; padding: 28px 32px; transition: background 0.22s, border-color 0.22s, transform 0.22s; cursor: pointer; }
.exp-card:hover { background: #111; border-color: #3a3a3a; transform: translateY(-2px); }
.exp-card.dark-fill { background: #181818; border-color: #181818; }
.exp-header { display: flex; justify-content: space-between; align-items: center; gap: 16px; margin-bottom: 16px; }
.exp-title-row { display: flex; align-items: center; gap: 16px; }
.exp-logo { width: 32px; height: 32px; border-radius: 50%; display: flex; align-items: center; justify-content: center; flex-shrink: 0; font-weight: 800; font-size: 14px; }
.exp-title { font-size: 18px; font-weight: 700; color: #fff; }
.exp-dates { font-size: 13px; color: #a1a1aa; white-space: nowrap; font-weight: 500; }
.exp-desc { font-size: 13px; color: #a1a1aa; line-height: 1.7; }

/* ── Research ── */
.research-section { padding: 80px 0 96px; background: #fff; }
.research-list { display: flex; flex-direction: column; gap: 16px; }
.research-card { border: 1.5px solid #e4e4e7; border-radius: 10px; padding: 24px 28px; display: flex; align-items: flex-start; justify-content: space-between; gap: 24px; background: #fff; transition: box-shadow 0.22s, transform 0.22s, border-color 0.22s; text-decoration: none; color: inherit; }
.research-card:hover { transform: translateY(-3px); box-shadow: 0 8px 24px rgba(0,0,0,0.07); border-color: #d4d4d8; }
.research-title { font-size: 16px; font-weight: 700; color: #18181b; line-height: 1.45; margin-bottom: 6px; }
.research-authors { font-size: 13px; color: #71717a; line-height: 1.5; }
.research-meta { display: flex; flex-direction: column; align-items: flex-end; gap: 8px; flex-shrink: 0; min-width: 80px; }
.research-cited { font-size: 13px; font-weight: 700; color: #18181b; white-space: nowrap; }
.research-cited span { font-weight: 400; color: #71717a; }
.research-year { font-size: 13px; font-weight: 600; color: #a1a1aa; }

/* ── About ── */
.about-section { padding: 100px 0; }
.about-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 80px; align-items: center; }
.about-frame { border: 2px solid #000; border-radius: 12px; overflow: hidden; aspect-ratio: 1/1.05; background: #f5f5f5; }
.about-photo { width: 100%; height: 100%; object-fit: cover; object-position: top center; display: block; }
.about-content h2 { font-size: 48px; font-weight: 400; letter-spacing: -0.03em; margin-bottom: 24px; }
.about-content h2 strong { font-weight: 800; }
.about-content p { font-size: 14px; line-height: 1.85; color: #6b6b73; margin-bottom: 16px; }

/* ── Projects ── */
.projects-section { background: #000; padding: 100px 0; color: #fff; }
.projects-section .section-title { color: #fff; }
.projects-section .section-title .light-word { color: #d4d4d8; font-weight: 400; }
.projects-list { display: flex; flex-direction: column; gap: 80px; max-width: 1100px; margin: 0 auto; }
.project-item { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: center; }
.project-img-wrap { border-radius: 16px; overflow: hidden; aspect-ratio: 4/3; background: linear-gradient(135deg, #fef08a, #fb923c); display: flex; align-items: center; justify-content: center; transition: transform 0.3s; cursor: pointer; }
.project-img-wrap:hover { transform: scale(1.02); }
.project-img-wrap.p2 { background: linear-gradient(135deg, #f3e8ff, #fbbf24, #34d399); }
.project-img-wrap.p3 { background: linear-gradient(135deg, #ec4899, #8b5cf6, #fbbf24); }
.project-num { font-size: 56px; font-weight: 800; letter-spacing: -0.04em; color: #fff; margin-bottom: 16px; }
.project-title { font-size: 24px; font-weight: 700; color: #fff; margin-bottom: 16px; line-height: 1.25; }
.project-desc { font-size: 13px; color: #a1a1aa; line-height: 1.75; margin-bottom: 24px; }
.project-link-btn { width: 40px; height: 40px; border-radius: 8px; border: 1px solid #2a2a2a; display: flex; align-items: center; justify-content: center; transition: background 0.2s, border-color 0.2s; }
.project-link-btn:hover { background: #fff; border-color: #fff; }
.project-link-btn:hover svg { stroke: #000; }
.project-item.reverse .project-info-wrap { grid-row: 1; }
.project-item.reverse .project-img-wrap { grid-row: 1; grid-column: 2; }

/* Mock screenshot styles */
.proj-real-img { width: 100%; height: 100%; object-fit: cover; display: block; }

/* ── Lightbox ── */
.lb-overlay { position: fixed; inset: 0; background: rgba(0,0,0,0.92); display: flex; align-items: center; justify-content: center; z-index: 9999; opacity: 0; pointer-events: none; transition: opacity 0.25s; }
.lb-overlay.active { opacity: 1; pointer-events: all; }
.lb-img-wrap { max-width: 88vw; max-height: 82vh; display: flex; align-items: center; justify-content: center; }
.lb-img { max-width: 100%; max-height: 82vh; border-radius: 12px; box-shadow: 0 24px 80px rgba(0,0,0,0.6); object-fit: contain; display: block; }
.lb-close { position: absolute; top: 20px; right: 24px; background: none; border: none; color: #fff; font-size: 32px; line-height: 1; cursor: pointer; opacity: 0.7; transition: opacity 0.15s; z-index: 10000; }
.lb-close:hover { opacity: 1; }
.lb-arrow { position: absolute; top: 50%; transform: translateY(-50%); background: rgba(255,255,255,0.12); border: none; color: #fff; font-size: 22px; width: 48px; height: 48px; border-radius: 50%; cursor: pointer; display: flex; align-items: center; justify-content: center; transition: background 0.15s; z-index: 10000; }
.lb-arrow:hover { background: rgba(255,255,255,0.25); }
.lb-prev { left: 20px; }
.lb-next { right: 20px; }
.lb-dots { position: absolute; bottom: 20px; left: 50%; transform: translateX(-50%); display: flex; gap: 8px; }
.lb-dot { width: 8px; height: 8px; border-radius: 50%; background: rgba(255,255,255,0.35); transition: background 0.15s; }
.lb-dot.active { background: #fff; }
.proj-mock { width: 100%; height: 100%; padding: 32px; display: flex; align-items: center; justify-content: center; }
.proj-mock-card { background: #fff; border-radius: 12px; padding: 16px; box-shadow: 0 12px 30px rgba(0,0,0,0.15); transform: rotate(-4deg); width: 80%; }
.proj-mock-card .row { height: 8px; background: #000; border-radius: 4px; margin-bottom: 6px; }
.proj-mock-card .row.short { width: 60%; }
.proj-mock-card .pill { display: inline-block; padding: 4px 10px; background: #000; color: #fff; font-size: 9px; border-radius: 12px; font-weight: 700; margin-top: 4px; }

/* ── Testimonials ── */
.testimonials-section { padding: 100px 0; overflow: hidden; }
.testimonials-track { display: flex; gap: 24px; will-change: transform; }
.testi-card { border-radius: 20px; padding: 36px 28px; display: flex; flex-direction: column; align-items: center; gap: 18px; transition: transform 0.22s, box-shadow 0.22s; cursor: pointer; background: #fff; box-shadow: 0 8px 24px -8px rgba(0,0,0,0.12); flex-shrink: 0; width: 380px; text-decoration: none; color: inherit; }
.testi-card:hover { transform: translateY(-4px); box-shadow: 0 12px 32px -6px rgba(0,0,0,0.16); }
.testi-card.dark { background: #000; }
.testi-avatar-wrap { position: relative; width: 80px; height: 80px; }
.testi-avatar { width: 80px; height: 80px; border-radius: 50%; background: #f4f4f5; overflow: hidden; display: flex; align-items: flex-end; justify-content: center; }
.testi-quote-bubble { position: absolute; bottom: -2px; right: -8px; width: 28px; height: 28px; border-radius: 50%; background: #000; display: flex; align-items: center; justify-content: center; }
.testi-card.dark .testi-quote-bubble { background: #fff; }
.testi-quote-bubble svg { fill: #fff; }
.testi-card.dark .testi-quote-bubble svg { fill: #000; }
.testi-quote { font-size: 13px; line-height: 1.7; text-align: center; color: #6b6b73; }
.testi-card.dark .testi-quote { color: #d4d4d8; }
.testi-divider { width: 60px; height: 1.5px; background: #d4d4d8; margin: 4px 0; }
.testi-card.dark .testi-divider { background: #52525b; }
.testi-name { font-size: 16px; font-weight: 700; color: #000; }
.testi-card.dark .testi-name { color: #fff; }
.testi-role { font-size: 13px; color: #6b6b73; }
.testi-card.dark .testi-role { color: #a1a1aa; }

/* ── Contact ── */
.contact-section { padding: 60px 0 100px; }
.contact-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 100px; align-items: start; max-width: 1100px; margin: 0 auto; }
.contact-form { display: flex; flex-direction: column; gap: 16px; }
.form-input, .form-textarea { font-family: 'Sora', sans-serif; font-size: 14px; border: 1.5px solid #e4e4e7; border-radius: 8px; padding: 16px 20px; outline: none; transition: border-color 0.2s; width: 100%; background: #fff; color: #000; }
.form-input::placeholder, .form-textarea::placeholder { color: #a1a1aa; }
.form-input:focus, .form-textarea:focus { border-color: #000; }
.form-textarea { resize: none; height: 130px; }
.contact-form-actions { display: flex; gap: 12px; align-items: center; margin-top: 4px; flex-wrap: wrap; }
.contact-headline { font-size: 48px; font-weight: 800; letter-spacing: -0.03em; line-height: 1.1; margin-bottom: 28px; }
.contact-headline .talk { -webkit-text-stroke: 1.5px #000; color: transparent; padding: 0 4px; }
.contact-desc { font-size: 14px; color: #6b6b73; line-height: 1.8; margin-bottom: 28px; max-width: 380px; }
.contact-info-line { font-size: 18px; font-weight: 700; color: #000; margin-bottom: 6px; }

/* ── Footer ── */
.footer { background: #000; color: #fff; padding: 28px 0; }
.footer .container { display: flex; justify-content: space-between; align-items: center; width: 100%; }
.footer-logo { display: flex; align-items: center; gap: 10px; }
.footer-logo-text { font-size: 16px; font-weight: 700; color: #fff; }
.footer-meta { font-size: 13px; color: #a1a1aa; text-align: right; line-height: 1.6; }

/* ── Animations ── */
.fade-up { opacity: 0; transform: translateY(28px); transition: opacity 0.6s ease, transform 0.6s ease; }
.fade-up.visible { opacity: 1; transform: translateY(0); }
.fade-up-d1 { transition-delay: 0.1s; }
.fade-up-d2 { transition-delay: 0.2s; }
.fade-up-d3 { transition-delay: 0.3s; }
.fade-up-d4 { transition-delay: 0.4s; }

/* ── Responsive ── */
@media (max-width: 1100px) {
  .container { padding: 0 40px; }
  .hero-headline { font-size: 60px; }
  .hero-greeting { font-size: 26px; }
  .skills-grid { grid-template-columns: repeat(4, 1fr); }
}

@media (max-width: 900px) {
  .container { padding: 0 24px; }
  .nav-links, .nav .container > .btn { display: none; }
  .hamburger { display: flex; }
  .hero { height: auto; min-height: auto; padding-bottom: 48px; }
  .hero .container { flex-direction: column; }
  .hero-text { width: 100%; padding: 48px 0 0; }
  .hero-illustration { position: relative; width: 100%; height: 300px; }
  .hero-img { width: 100%; height: 100%; object-position: bottom center; }
  .hero-headline { font-size: 42px; }
  .hero-greeting { font-size: 22px; }
  .section-title { font-size: 36px; }
  .skills-grid { grid-template-columns: repeat(3, 1fr); }
  section { padding: 72px 0; }
  .exp-header { flex-direction: column; align-items: flex-start; gap: 6px; }
  .about-grid { grid-template-columns: 1fr; gap: 48px; }
  .project-item { grid-template-columns: 1fr; gap: 24px; }
  .project-item.reverse .project-img-wrap { grid-column: 1; }
  .testi-card { width: 340px; }
  .contact-grid { grid-template-columns: 1fr; gap: 48px; }
  .contact-headline { font-size: 36px; }
  .footer .container { flex-direction: column; gap: 20px; text-align: center; }
  .footer-meta { text-align: center; }
}

@media (max-width: 540px) {
  .hero-headline { font-size: 34px; }
  .skills-grid { grid-template-columns: repeat(2, 1fr); }
  section { padding: 56px 0; }
}