:root {
  --bg: #0f0f17;
  --text: #e0e0ff;
  --accent: #00d4ff;
  --card: rgba(20, 20, 40, 0.7);
  --border: rgba(0, 212, 255, 0.15);
}

[data-theme='light'] {
  --bg: #f8f9fc;
  --text: #1a1a3d;
  --accent: #0066cc;
  --card: rgba(255, 255, 255, 0.75);
  --border: rgba(0, 102, 204, 0.2);
}

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

body {
  font-family: 'Segoe UI', system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  transition:
    background 0.5s ease,
    color 0.5s ease;
}

html {
  scroll-behavior: smooth;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

header {
  position: fixed;
  top: 0;
  width: 100%;
  z-index: 1000;
  backdrop-filter: blur(12px);
  background: rgba(15, 15, 23, 0.6);
  border-bottom: 1px solid var(--border);
  transition: all 0.3s;
}

[data-theme='light'] header {
  background: rgba(248, 249, 252, 0.8);
}

nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.2rem 0;
}

.logo {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--accent);
}

.nav-links a {
  color: var(--text);
  text-decoration: none;
  margin-left: 2.2rem;
  font-weight: 500;
  transition: color 0.3s;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--accent);
}

.theme-toggle {
  background: none;
  border: none;
  color: var(--text);
  font-size: 1.3rem;
  cursor: pointer;
}

#hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: 6rem;
}

.hero-content {
  max-width: 700px;
}

.hero-content h1 {
  font-size: clamp(3.2rem, 8vw, 5.5rem);
  margin-bottom: 1.5rem;
  line-height: 1.1;
}

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

.hero-content p {
  font-size: 1.3rem;
  margin-bottom: 2.5rem;
  opacity: 0.9;
}

.btn {
  display: inline-block;
  background: var(--accent);
  color: #000;
  padding: 0.9rem 2.2rem;
  border-radius: 50px;
  text-decoration: none;
  font-weight: 600;
  transition: all 0.3s;
}

.btn:hover {
  transform: translateY(-3px);
  box-shadow: 0 10px 30px rgba(0, 212, 255, 0.3);
}

.btn-outline {
  background: transparent;
  border: 2px solid var(--accent);
  color: var(--accent);
  margin-left: 1.5rem;
}

.btn-outline:hover {
  background: var(--accent);
  color: #000;
}

section {
  padding: 8rem 0;
}

h2 {
  font-size: 3.5rem;
  text-align: center;
  margin-bottom: 4rem;
  background: linear-gradient(90deg, var(--accent), #a78bfa);
  -webkit-background-clip: text;
  -moz-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
  gap: 2.5rem;
}

.project-card {
  background: var(--card);
  border-radius: 16px;
  overflow: hidden;
  border: 1px solid var(--border);
  backdrop-filter: blur(10px);
  transition: all 0.4s ease;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.2);
}

.project-card:hover {
  transform: translateY(-12px);
  box-shadow: 0 20px 50px rgba(0, 212, 255, 0.15);
  border-color: var(--accent);
}

.project-img {
  height: 220px;
  background: #111;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  color: #444;
  border-bottom: 1px solid var(--border);
}

#robofriends .project-img {
  background: url(../images/RoboFriends.png);
  background-size: cover;
}

#smartbrain .project-img {
  background: url(../images/SmartBrain.png);
  background-size: cover;
}

.project-info {
  padding: 1.8rem;
}

.project-info h3 {
  font-size: 1.5rem;
  margin-bottom: 0.8rem;
}

.project-info a {
  color: var(--text);
  text-decoration: none;
  transition: color 0.3s;
}

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

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-top: 1rem;
}

.tag {
  background: rgba(0, 212, 255, 0.1);
  color: var(--accent);
  padding: 0.4rem 1rem;
  border-radius: 30px;
  font-size: 0.85rem;
}

#about,
#contact {
  text-align: center;
  max-width: 800px;
  margin: 0 auto;
}

.social-links {
  margin-top: 2.5rem;
}

.social-links a {
  color: var(--text);
  font-size: 1.8rem;
  text-decoration: none;
  margin: 0 1rem;
  transition: color 0.3s;
}

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

footer {
  text-align: center;
  padding: 3rem 0;
  opacity: 0.7;
  font-size: 0.95rem;
  border-top: 1px solid var(--border);
}

@media only screen and (max-width: 768px) {
  .nav-links {
    display: none;
  }

  h2 {
    font-size: 2.8rem;
  }

  .btn {
    font-size: 0.75rem;
  }

  .projects-grid {
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  }
}