:root {
  --bg-dark: #0b132b;
  --bg-light: #1c2541;
  --primary: #00ff91;
  --text-light: #ffffff;
  --text-gray: #b0b3c7;
  --accent: #5bc0be;
}

body {
  margin: 0;
  font-family: "Poppins", sans-serif;
  background: var(--bg-dark);
  color: var(--text-light);
  scroll-behavior: smooth;
}

/* HEADER */
.header {
  position: fixed;
  width: 100%;
  background: rgba(11, 19, 43, 0.9);
  backdrop-filter: blur(8px);
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 4rem;
  z-index: 1000;
}

.logo {
  font-weight: 700;
  font-size: 1.5rem;
  color: var(--primary);
}

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

.navbar a {
  margin-left: 2rem;
  color: var(--text-gray);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.3s;
}

.navbar a:hover {
  color: var(--primary);
}

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

/* HERO */
.hero {
  height: 100vh;
  background: linear-gradient(135deg, #0b132b, #1c2541);
  display: flex;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding-top: 5rem;
}

.hero-content h1 {
  font-size: 2.8rem;
  margin-bottom: 0.5rem;
}

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

.hero-content h2 {
  font-size: 1.5rem;
  color: var(--text-gray);
}

.hero-content p {
  max-width: 600px;
  margin: 1.5rem auto;
}

.btn {
  display: inline-block;
  background: var(--primary);
  color: #000;
  padding: 0.8rem 1.8rem;
  border-radius: 50px;
  font-weight: 600;
  text-decoration: none;
  transition: 0.3s;
}

.btn:hover {
  background: var(--accent);
}

/* ABOUT */
.about {
  display: flex;
  flex-wrap: wrap;
  gap: 2rem;
  padding: 6rem 4rem;
  align-items: center;
}

.about-img img {
  width: 280px;
  border-radius: 15px;
  box-shadow: 0 0 20px rgba(0,0,0,0.3);
}

.about-text {
  flex: 1;
  min-width: 300px;
}

/* PROJECTS */
.projects {
  padding: 5rem 4rem;
  text-align: center;
}

.project-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
  margin-top: 2rem;
}

.project-card {
  position: relative;
  overflow: hidden;
  border-radius: 12px;
}

.project-card img {
  width: 100%;
  border-radius: 12px;
  transition: 0.3s;
}

.project-card:hover img {
  transform: scale(1.05);
  opacity: 0.7;
}

.project-card .overlay {
  position: absolute;
  bottom: 0;
  background: rgba(0,0,0,0.6);
  width: 100%;
  padding: 1rem;
  color: var(--text-light);
}

/* SKILLS */
.skills {
  padding: 5rem 4rem;
  text-align: center;
}

.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1.5rem;
  margin-top: 2rem;
}

.skill {
  background: var(--bg-light);
  border-radius: 10px;
  padding: 1.5rem;
  transition: 0.3s;
}

.skill:hover {
  transform: translateY(-8px);
  background: var(--accent);
}

/* CONTACT */
.contact {
  text-align: center;
  padding: 5rem 4rem;
}

.contact-links a {
  color: var(--text-light);
  margin: 0.8rem;
  font-size: 1.5rem;
  transition: color 0.3s;
}

.contact-links a:hover {
  color: var(--primary);
}

/* FOOTER */
footer {
  text-align: center;
  padding: 1.5rem;
  background: #101836;
  color: var(--text-gray);
}

@media (max-width: 768px) {
  .header {
    padding: 1rem 2rem;
  }

  .about {
    padding: 4rem 2rem;
    flex-direction: column;
  }

  .projects, .skills, .contact {
    padding: 4rem 2rem;
  }
}

body.light-mode {
  background: #f8f9fb;
  color: #111;
}

body.light-mode .header {
  background: rgba(255,255,255,0.9);
}

body.light-mode .navbar a {
  color: #444;
}

body.light-mode .btn {
  background: #111;
  color: #fff;
}