:root {
  --bg: #0f1116;
  --card: #161922;
  --card-hover: #1e222d;
  --text: #f3f4f6;
  --text-dim: #9ca3af;
  --accent: #3b82f6;
  --accent-hover: #2563eb;
  --border: #262a33;
  --success: #22c55e;
  --error: #ef4444;
}

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

html {
  scroll-behavior: smooth;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: rgba(15, 17, 22, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  z-index: 100;
  padding: 16px 0;
}

nav .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

nav .logo {
  font-weight: 600;
  font-size: 18px;
  color: var(--text);
}

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

nav ul {
  display: flex;
  list-style: none;
  gap: 32px;
}

nav ul li a {
  color: var(--text-dim);
  font-size: 14px;
  font-weight: 500;
  transition: color 0.2s;
}

nav ul li a:hover,
nav ul li a.active {
  color: var(--text);
}

.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 120px 0 80px;
}

.hero h1 {
  font-size: clamp(40px, 8vw, 72px);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: 16px;
}

.hero h1 .accent {
  color: var(--accent);
}

.hero .tagline {
  font-size: 20px;
  color: var(--text-dim);
  margin-bottom: 32px;
  max-width: 600px;
}

.hero .cta {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--accent);
  color: white;
  padding: 14px 28px;
  border-radius: 8px;
  font-weight: 600;
  font-size: 16px;
  transition: background 0.2s, transform 0.2s;
}

.hero .cta:hover {
  background: var(--accent-hover);
  color: white;
  transform: translateY(-2px);
}

section {
  padding: 100px 0;
}

section h2 {
  font-size: 36px;
  font-weight: 700;
  margin-bottom: 48px;
  letter-spacing: -0.02em;
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 24px;
}

.project-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  transition: transform 0.2s, border-color 0.2s;
}

.project-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent);
}

.project-card .card-image {
  width: 100%;
  height: 200px;
  background: var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

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

.project-card .card-image .placeholder {
  color: var(--text-dim);
  font-size: 14px;
}

.project-card .card-content {
  padding: 24px;
}

.project-card h3 {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 8px;
}

.project-card p {
  color: var(--text-dim);
  font-size: 14px;
  margin-bottom: 20px;
  line-height: 1.5;
}

.project-card .card-buttons {
  display: flex;
  gap: 12px;
}

.project-card .btn {
  flex: 1;
  padding: 10px 16px;
  border-radius: 6px;
  font-size: 14px;
  font-weight: 500;
  text-align: center;
  transition: all 0.2s;
}

.project-card .btn-demo {
  background: var(--accent);
  color: white;
}

.project-card .btn-demo:hover {
  background: var(--accent-hover);
  color: white;
}

.project-card .btn-code {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text);
}

.project-card .btn-code:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.project-detail {
  padding: 140px 0 80px;
  min-height: 100vh;
}

.project-detail .back {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--text-dim);
  font-size: 14px;
  margin-bottom: 32px;
}

.project-detail .back:hover {
  color: var(--text);
}

.project-detail h1 {
  font-size: 48px;
  font-weight: 700;
  margin-bottom: 24px;
}

.project-detail .demo-screenshot {
  width: 100%;
  max-width: 900px;
  height: 500px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  margin-bottom: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.project-detail .demo-screenshot img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.project-detail .links {
  display: flex;
  gap: 16px;
  margin-bottom: 48px;
}

.project-detail .links .btn {
  padding: 12px 24px;
  border-radius: 8px;
  font-weight: 600;
}

.project-detail .description {
  max-width: 800px;
  color: var(--text-dim);
  font-size: 18px;
  line-height: 1.7;
}

.about {
  background: var(--card);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.about .about-content {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 64px;
  align-items: start;
}

.about h2 {
  margin-bottom: 24px;
}

.about .bio {
  color: var(--text-dim);
  font-size: 18px;
  line-height: 1.7;
  margin-bottom: 32px;
}

.about .skills {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.about .skill {
  background: var(--bg);
  border: 1px solid var(--border);
  padding: 8px 16px;
  border-radius: 6px;
  font-size: 14px;
  font-weight: 500;
}

.about .photo {
  width: 300px;
  height: 300px;
  background: var(--border);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

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

.contact {
  min-height: 80vh;
  display: flex;
  align-items: center;
}

.contact h2 {
  margin-bottom: 16px;
}

.contact .intro {
  color: var(--text-dim);
  margin-bottom: 48px;
  max-width: 500px;
}

.contact form {
  max-width: 500px;
}

.form-group {
  margin-bottom: 24px;
}

.form-group label {
  display: block;
  font-size: 14px;
  font-weight: 500;
  margin-bottom: 8px;
}

.form-group input,
.form-group textarea {
  width: 100%;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 14px 16px;
  font-size: 16px;
  color: var(--text);
  font-family: inherit;
  transition: border-color 0.2s;
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--accent);
}

.form-group textarea {
  min-height: 150px;
  resize: vertical;
}

.btn-primary {
  background: var(--accent);
  color: white;
  border: none;
  padding: 14px 28px;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s, transform 0.2s;
}

.btn-primary:hover {
  background: var(--accent-hover);
  transform: translateY(-2px);
}

.btn-primary:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none;
}

.success-message,
.error-message {
  padding: 16px 20px;
  border-radius: 8px;
  margin-bottom: 24px;
  font-size: 14px;
}

.success-message {
  background: rgba(34, 197, 94, 0.1);
  border: 1px solid var(--success);
  color: var(--success);
}

.error-message {
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid var(--error);
  color: var(--error);
}

footer {
  border-top: 1px solid var(--border);
  padding: 48px 0;
  text-align: center;
  color: var(--text-dim);
  font-size: 14px;
}

@media (max-width: 768px) {
  .about .about-content {
    grid-template-columns: 1fr;
  }

  .about .photo {
    width: 100%;
    height: 250px;
  }

  nav ul {
    gap: 20px;
  }

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

  .project-detail h1 {
    font-size: 32px;
  }

  .project-detail .demo-screenshot {
    height: 300px;
  }
}