/* Dark & Vibrant Theme for Portfolio */
[data-theme="dark"] {
  --bg: #121212;
  --card-bg: #1e1e1e;
  --nav-bg: #1b1b1b;
  --text: #e0e0e0;
  --text-secondary: #a0a0a0;
  --accent: #bb86fc;
  --accent-hover: #9e6cff;
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.5);
  --transition: all 0.3s ease;
  --hero-bg: linear-gradient(135deg, #272727 0%, #1e1e1e 100%);
}

[data-theme="light"] {
  --bg: #9a61d0;
  --card-bg: #f5edf6;
  --nav-bg: #f8f8f8;
  --text: #121212;
  --text-secondary: #423e3e;
  --accent: #4a00e0;
  --accent-hover: #6a00ff;
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
  --transition: all 0.3s ease;
  --hero-bg: linear-gradient(135deg, #f1e7ef 0%, #f4ecf2 100%);
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  background-color: var(--bg);
  color: var(--text);
  font-family: 'Inter', sans-serif;
  margin: 0;
  padding: 0;
  line-height: 1.6;
}

a, a:visited {
  color: var(--accent);
  text-decoration: none;
  transition: color var(--transition);
}
a:hover {
  color: var(--accent-hover);
}

/* Scroll Progress Indicator */
.scroll-indicator {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: rgba(255, 255, 255, 0.05);
  z-index: 999;
}
.scroll-progress {
  height: 100%;
  width: 0;
  background: var(--accent);
  transition: width 0.25s ease;
}

/* Theme Toggle */
.theme-toggle {
  position: fixed;
  top: 1rem;
  right: 1rem;
  background: var(--card-bg);
  color: var(--text);
  border: none;
  border-radius: 50%;
  width: 40px;
  height: 40px;
  box-shadow: var(--shadow);
  cursor: pointer;
  z-index: 1000;
  transition: var(--transition);
}
.theme-toggle:hover {
  background: var(--accent);
  color: var(--bg);
}

/* Navigation */
nav.navbar {
  background-color: var(--nav-bg);
  box-shadow: var(--shadow);
  position: sticky;
  top: 0;
  z-index: 100;
}
.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 1200px;
  margin: auto;
  padding: 0.8rem 1.5rem;
}
.nav-logo h2 {
  color: var(--accent);
  margin: 0;
}
.nav-menu {
  display: flex;
  gap: 1.2rem;
}
.nav-link {
  color: var(--text);
  font-weight: 500;
  position: relative;
}
.nav-link::after {
  content: '';
  display: block;
  height: 2px;
  background: var(--accent);
  width: 0;
  transition: width var(--transition);
}
.nav-link:hover::after {
  width: 100%;
}

/* Hamburger */
.hamburger {
  display: none;
  flex-direction: column;
  cursor: pointer;
}
.hamburger .bar {
  display: block;
  width: 25px;
  height: 3px;
  margin: 5px;
  background: var(--text);
  transition: var(--transition);
}
@media (max-width: 768px) {
  .hamburger {
    display: flex;
  }
  .nav-menu {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 60px;
    right: 20px;
    background: var(--nav-bg);
    padding: 1rem;
    border-radius: 10px;
    box-shadow: var(--shadow);
  }
  .nav-menu.active {
    display: flex;
  }
}

/* Hero */
.hero {
  background: var(--hero-bg);
  padding: 4rem 1.5rem;
  text-align: center;
}
.hero-title {
  font-size: 3rem;
  color: var(--accent);
  margin: 0;
}
.hero-subtitle {
  font-size: 1.5rem;
  color: var(--text-secondary);
  margin: 0.5rem 0 1.5rem;
}
.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  margin: 0.5rem;
  border-radius: 30px;
  font-weight: 600;
  transition: var(--transition);
}
.btn-primary {
  background: var(--accent);
  color: var(--bg);
}
.btn-primary:hover {
  background: var(--accent-hover);
}
.btn-secondary {
  border: 2px solid var(--accent);
  color: var(--text);
}
.btn-secondary:hover {
  background: var(--accent);
  color: var(--bg);
}
.social-links a {
  font-size: 1.4rem;
  margin: 0 0.5rem;
  color: var(--text);
  transition: color var(--transition);
}
.social-links a:hover {
  color: var(--accent);
}

/* Sections */
section {
  padding: 4rem 1.5rem;
}
.section-title {
  font-size: 2rem;
  color: var(--accent);
  text-align: center;
  margin-bottom: 2rem;
  position: relative;
}
.section-title::after {
  content: '';
  display: block;
  width: 60px;
  height: 3px;
  background: var(--accent);
  margin: 0.5rem auto 0;
}
.container {
  max-width: 1100px;
  margin: auto;
}

/* Cards & Grid */
.projects-grid, .skills-grid {
  display: grid;
  gap: 1.5rem;
}
.projects-grid {
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
}
.project-card, .skill-category, .timeline-item {
  background: var(--card-bg);
  border-radius: 12px;
  box-shadow: var(--shadow);
  padding: 1.5rem;
  transition: transform var(--transition), box-shadow var(--transition);
}
.project-card:hover, .skill-category:hover, .timeline-item:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 30px rgba(0,0,0,0.6);
}
.project-header h3, .skill-category h3 {
  margin-top: 0;
  color: var(--accent);
}
.project-tech, .skill-tags {
  margin-top: 1rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}
.tech-tag, .skill-tag {
  background: rgba(187, 134, 252, 0.2);
  color: var(--accent);
  padding: 0.35rem 0.8rem;
  border-radius: 20px;
  font-size: 0.9rem;
}

/* Timeline */
.timeline {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}
.timeline-item {
  display: flex;
  position: relative;
  padding-left: 2rem;
}
.timeline-dot {
  position: absolute;
  left: 0;
  top: 0.5rem;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--accent);
}
.timeline-content h3 {
  margin-bottom: 0.3rem;
}
.timeline-date {
  display: block;
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 1rem;
}

/* Skills Grid */
.skills-grid {
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}
.skill-tags span {
  background: rgba(255,255,255,0.05);
}

/* Contact */
.contact-content {
  display: flex;
  gap: 2rem;
  flex-wrap: wrap;
}
.contact-info {
  flex: 1;
}
.contact-item {
  display: flex;
  align-items: center;
  margin-bottom: 1rem;
  color: var(--text);
}
.contact-item i {
  font-size: 1.5rem;
  margin-right: 1rem;
  color: var(--accent);
}
.contact-form {
  flex: 1;
}
.form-group input, .form-group textarea {
  width: 100%;
  padding: 0.8rem;
  border: 1px solid var(--text-secondary);
  border-radius: 6px;
  background: var(--bg);
  color: var(--text);
  margin-bottom: 1rem;
  transition: border-color var(--transition);
}
.form-group input:focus, .form-group textarea:focus {
  outline: none;
  border-color: var(--accent);
}

/* Footer */
.footer {
  background: var(--nav-bg);
  padding: 2rem 1.5rem;
  text-align: center;
}
.footer-content p {
  margin: 0 0 1rem;
  color: var(--text-secondary);
}
.footer-links a {
  margin: 0 0.5rem;
  color: var(--text);
  transition: color var(--transition);
}
.footer-links a:hover {
  color: var(--accent-hover);
}

/* Fade-in Animation */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  animation: fadeIn 0.8s ease-out forwards;
}
@keyframes fadeIn {
  to {
    opacity: 1;
    transform: none;
  }
}

/* Responsive */
@media (max-width: 768px) {
  .contact-content {
    flex-direction: column;
  }
}