:root {
  --bg-primary: #0a0a0a;
  --bg-secondary: #111111;
  --bg-card: #161616;
  --text-primary: #e0e0e0;
  --text-secondary: #b0b0b0;
  --text-dim: #555555;
  --accent-blue: #00d4ff;
  --accent-green: #00ff88;
  --border: #222222;
  --border-light: #333333;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Courier New', monospace;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  background: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-body);
  line-height: 1.6;
  min-height: 100vh;
}

body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image:
    linear-gradient(rgba(255,255,255,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.03) 1px, transparent 1px);
  background-size: 40px 40px;
  pointer-events: none;
  z-index: 0;
}

a {
  color: var(--accent-blue);
  text-decoration: none;
  transition: color 0.2s;
}

a:hover {
  color: var(--accent-green);
}

nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: rgba(10, 10, 10, 0.95);
  border-bottom: 1px solid var(--border);
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  z-index: 100;
  backdrop-filter: blur(10px);
}

nav .logo {
  font-family: var(--font-mono);
  font-size: 1.1rem;
  color: var(--accent-blue);
  font-weight: 700;
}

nav .logo span {
  color: var(--text-secondary);
}

nav ul {
  display: flex;
  list-style: none;
  gap: 2rem;
}

nav ul li a {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  color: var(--text-secondary);
  padding: 0.5rem 1rem;
  border: 1px solid transparent;
  transition: all 0.2s;
}

nav ul li a:hover,
nav ul li a.active {
  color: var(--accent-blue);
  border-color: var(--border-light);
  background: var(--bg-secondary);
}

.lang-toggle {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.3rem 0.6rem;
  border: 1px solid var(--border);
  background: var(--bg-card);
}

.lang-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-dim);
  transition: color 0.2s;
}

.switch {
  position: relative;
  display: inline-block;
  width: 36px;
  height: 18px;
}

.switch input {
  opacity: 0;
  width: 0;
  height: 0;
}

.slider {
  position: absolute;
  cursor: pointer;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: var(--border-light);
  transition: 0.3s;
  border-radius: 18px;
}

.slider::before {
  position: absolute;
  content: "";
  height: 12px;
  width: 12px;
  left: 3px;
  bottom: 3px;
  background-color: var(--text-secondary);
  transition: 0.3s;
  border-radius: 50%;
}

.switch input:checked + .slider {
  background-color: var(--accent-blue);
}

.switch input:checked + .slider::before {
  transform: translateX(18px);
  background-color: var(--bg-primary);
}

.lang-toggle:has(input:checked) .lang-label:last-of-type {
  color: var(--accent-blue);
}

.lang-toggle:has(input:not(:checked)) .lang-label:first-of-type {
  color: var(--accent-blue);
}

.container {
  max-width: 900px;
  margin: 0 auto;
  padding: 6rem 2rem 4rem;
  position: relative;
  z-index: 2;
}

section {
  margin-bottom: 4rem;
}

.prompt {
  font-family: var(--font-mono);
  color: var(--accent-green);
  margin-bottom: 1rem;
  font-size: 0.9rem;
  text-align: center;
}

.prompt::before {
  content: '> ';
  color: var(--text-dim);
}

.hero {
  display: flex;
  gap: 2rem;
  align-items: center;
  padding: 3rem 0;
  border-bottom: 1px solid var(--border);
}

.hero-photo {
  width: 230px;
  height: 230px;
  border-radius: 4px;
  border: 2px solid var(--accent-blue);
  background: var(--bg-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  overflow: hidden;
}

.hero-photo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-photo .placeholder {
  font-family: var(--font-mono);
  color: var(--text-dim);
  font-size: 0.75rem;
  text-align: center;
  padding: 0.5rem;
}

.hero-content h1 {
  font-family: var(--font-mono);
  font-size: 2rem;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.hero-content .tagline {
  font-family: var(--font-mono);
  color: var(--accent-blue);
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
}

.hero-content .tagline-en {
  color: var(--text-secondary);
  font-size: 1rem;
  max-width: 600px;
  margin-bottom: 1.2rem;
}

.hero-content .description {
  color: var(--text-secondary);
  font-size: 1rem;
  max-width: 600px;
  margin-bottom: 1.2rem;
}

.cv-btn {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--accent-blue);
  padding: 0.5rem 1rem;
  border: 1px solid var(--accent-blue);
  background: var(--bg-card);
  transition: all 0.2s;
  display: inline-block;
}

.cv-btn:hover {
  color: var(--accent-green);
  border-color: var(--accent-green);
  background: var(--bg-secondary);
}

.skills-list {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  padding: 1rem 0;
}

.skill-category {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.skill-category-title {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: 0.25rem;
  text-align: center;
}

.skill-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  justify-content: center;
}

.skill-tag {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-secondary);
  padding: 0.4rem 0.8rem 0.4rem 1.2rem;
  border: 1px solid var(--border);
  background: var(--bg-card);
  transition: all 0.2s;
  position: relative;
}

.skill-tag::before {
  content: '>';
  position: absolute;
  left: 0.4rem;
  color: var(--text-dim);
  font-size: 0.85rem;
}

.skill-tag:hover {
  color: var(--accent-green);
  border-color: var(--accent-green);
}

.skill-tag:hover::before {
  color: var(--accent-green);
}

.projects-grid {
  display: grid;
  gap: 2rem;
}

.project-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  padding: 1.5rem;
  transition: all 0.2s;
  position: relative;
}

.project-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background: var(--accent-blue);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.3s;
}

.project-card:hover::before {
  transform: scaleX(1);
}

.project-card:hover {
  border-color: var(--border-light);
  transform: translateY(-2px);
}

.project-image {
  width: 100%;
  height: 300px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  color: var(--text-dim);
  font-size: 0.8rem;
  overflow: hidden;
}

.project-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: top;
}

.project-card h3 {
  font-family: var(--font-mono);
  font-size: 1.2rem;
  color: var(--accent-blue);
  margin-bottom: 0.5rem;
  text-align: center;
}

.project-card p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  margin-bottom: 1rem;
  text-align: center;
}

.project-links {
  display: flex;
  gap: 1rem;
  justify-content: center;
}

.project-links a {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  padding: 0.4rem 0.8rem;
  border: 1px solid var(--border);
  transition: all 0.2s;
}

.project-links a:hover {
  border-color: var(--accent-green);
  color: var(--accent-green);
}

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

.contact-link {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  padding: 0.6rem 1.2rem;
  border: 1px solid var(--border);
  background: var(--bg-card);
  transition: all 0.2s;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.contact-icon {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}

.contact-link:hover {
  border-color: var(--accent-green);
  color: var(--accent-green);
  transform: translateY(-2px);
}

footer {
  text-align: center;
  padding: 2rem;
  border-top: 1px solid var(--border);
  color: var(--text-dim);
  font-family: var(--font-mono);
  font-size: 0.8rem;
}

footer span {
  color: var(--accent-blue);
}

@media (max-width: 768px) {
  nav {
    flex-direction: column;
    gap: 0.75rem;
    padding: 0.75rem 1rem;
  }

  nav ul {
    gap: 0.5rem;
    flex-wrap: wrap;
    justify-content: center;
  }

  nav ul li a {
    padding: 0.4rem 0.6rem;
    font-size: 0.8rem;
  }

  .lang-toggle {
    padding: 0.3rem 0.4rem;
  }

  .lang-label {
    font-size: 0.7rem;
  }

  .switch {
    width: 30px;
    height: 15px;
  }

  .slider::before {
    height: 10px;
    width: 10px;
  }

  .switch input:checked + .slider::before {
    transform: translateX(15px);
  }

  .container {
    padding: 7rem 0.75rem 2rem;
  }

  .prompt {
    font-size: 0.8rem;
    overflow: hidden;
  }

  .hero {
    flex-direction: column;
    text-align: center;
    padding: 2rem 0;
  }

  .hero-photo {
    width: 150px;
    height: 150px;
  }

  .hero-content h1 {
    font-size: 1.3rem;
  }

  .hero-content .tagline {
    font-size: 0.9rem;
  }

  .hero-content .description {
    font-size: 0.9rem;
  }

  .skill-category-title {
    font-size: 0.7rem;
  }

  .skill-tag {
    font-size: 0.75rem;
    padding: 0.3rem 0.6rem 0.3rem 1rem;
  }

  .projects-grid {
    gap: 1.5rem;
  }

  .project-card {
    padding: 1rem;
  }

  .project-image {
    height: 180px;
  }

  .project-card h3 {
    font-size: 1rem;
  }

  .project-card p {
    font-size: 0.85rem;
  }

  .project-links {
    flex-direction: column;
    gap: 0.5rem;
  }

  .project-links a {
    text-align: center;
    padding: 0.5rem;
  }

  .contact-links {
    flex-direction: column;
    gap: 0.75rem;
  }

  .contact-link {
    justify-content: center;
  }
}