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

:root {
  --color-bg: #ffffff;
  --color-text: #1a1a1a;
  --color-text-secondary: #555555;
  --color-accent: #1a1a1a;
  --color-border: #e5e5e5;
  --color-card-bg: #f7f7f7;
  --color-hover: #f0f0f0;
  --font-main: 'DM Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-display: 'DM Serif Display', Georgia, serif;
  --max-width: 1200px;
  --spacing-sm: 1rem;
  --spacing-md: 2rem;
  --spacing-lg: 4rem;
  --spacing-xl: 6rem;
  --transition: 0.3s ease;
}

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

body {
  font-family: var(--font-main);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: inherit;
  text-decoration: none;
}

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

/* Container */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

/* Header / Nav */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
}

.nav {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.nav-logo {
  font-weight: 700;
  font-size: 1.125rem;
  letter-spacing: -0.02em;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-link {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  transition: color var(--transition);
  position: relative;
}

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

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--color-text);
  border-radius: 1px;
}

.nav-link--external {
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.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(--color-text);
  border-radius: 2px;
  transition: var(--transition);
}

/* Mobile Menu */
.mobile-menu {
  display: none;
  position: fixed;
  top: 64px;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--color-bg);
  z-index: 99;
  flex-direction: column;
  padding: var(--spacing-lg) var(--spacing-md);
  gap: 1.5rem;
}

.mobile-menu.open {
  display: flex;
}

.mobile-menu-link {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--color-text-secondary);
  transition: color var(--transition);
}

.mobile-menu-link:hover,
.mobile-menu-link.active {
  color: var(--color-text);
}

/* Hero */
.hero {
  padding: var(--spacing-xl) 0;
  border-bottom: 1px solid var(--color-border);
}

.hero-title {
  font-family: var(--font-display);
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 400;
  letter-spacing: -0.01em;
  line-height: 1.1;
  max-width: 850px;
  margin-bottom: var(--spacing-md);
}

.hero-subtitle {
  font-size: clamp(1rem, 1.5vw, 1.25rem);
  color: var(--color-text-secondary);
  max-width: 640px;
  line-height: 1.7;
  margin-bottom: 1rem;
}

.hero-ai-line {
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  font-style: italic;
}

/* Projects */
.projects {
  padding: var(--spacing-xl) 0;
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-md);
}

.project-card {
  display: block;
  border-radius: 12px;
  overflow: hidden;
  background: var(--color-card-bg);
  transition: transform var(--transition), box-shadow var(--transition);
}

.project-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.08);
}

.project-image {
  width: 100%;
  aspect-ratio: 4 / 3;
  overflow: hidden;
  background: #e0e0e0;
}

.project-image--placeholder {
  background: linear-gradient(135deg, #1a1a1a 0%, #3a3a3a 100%);
  display: flex;
  align-items: center;
  justify-content: center;
}

.project-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.project-card:hover .project-image img {
  transform: scale(1.03);
}

.project-info {
  padding: 1.5rem;
}

.project-tag {
  display: block;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  color: var(--color-text-secondary);
  margin-bottom: 0.5rem;
}

/* Wide card — spans full grid width, image left / text right */
.project-card--wide {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: stretch;
}

.project-card--wide .project-image {
  aspect-ratio: unset;
  min-height: 280px;
}

.project-card--wide .project-info {
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 2.5rem;
}

.project-card--wide .project-title {
  font-size: 1.375rem;
}

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

  .project-card--wide .project-image {
    aspect-ratio: 4 / 3;
    min-height: unset;
  }
}

.project-title {
  font-size: 1.125rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: 0.5rem;
  line-height: 1.3;
}

.project-desc {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* CTA */
.cta {
  padding: var(--spacing-xl) 0;
  text-align: center;
  border-top: 1px solid var(--color-border);
}

.cta-title {
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  font-weight: 400;
  letter-spacing: -0.01em;
  margin-bottom: var(--spacing-md);
}

.cta-links {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
}

.cta-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-bg);
  background: var(--color-text);
  padding: 0.75rem 1.5rem;
  border: 2px solid var(--color-text);
  border-radius: 8px;
  transition: background var(--transition), color var(--transition);
}

.cta-link:hover {
  background: transparent;
  color: var(--color-text);
}

.cta-link--secondary {
  background: transparent;
  color: var(--color-text);
}

.cta-link--secondary:hover {
  background: var(--color-text);
  color: var(--color-bg);
}

.cta-link--secondary:hover svg path {
  stroke: var(--color-bg);
}

/* Footer */
.footer {
  padding: 1.75rem 0;
  border-top: 1px solid var(--color-border);
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.footer-left {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.footer-name {
  font-size: 0.9375rem;
  font-weight: 700;
}

.footer-role {
  font-size: 0.8125rem;
  color: var(--color-text-secondary);
}

.footer-center {
  display: flex;
  gap: 1.5rem;
}

.footer-link {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  transition: color var(--transition);
}

.footer-link:hover {
  color: var(--color-text);
}

.footer-right {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 0.25rem;
}

.footer-meta {
  font-size: 0.8125rem;
  color: var(--color-text-secondary);
}

.back-to-top {
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  transition: color var(--transition);
}

.back-to-top:hover {
  color: var(--color-text);
}

/* Animations */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Responsive */
@media (max-width: 768px) {
  .nav-links {
    display: none;
  }

  .nav-toggle {
    display: flex;
  }

  .hero {
    padding: var(--spacing-lg) 0;
  }

  .projects-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .cta {
    padding: var(--spacing-lg) 0;
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 2rem;
  }

  .container {
    padding: 0 1rem;
  }
}