:root {
  --bg: #ffffff;
  --text: #222222;
  --muted: #666666;
  --accent: #1e88e5;
  --surface: #f6f7fb;
  --border: #e6e9ef;
}
/* Dark theme */
.dark {
  --bg: #0f172a;
  --text: #e2e8f0;
  --muted: #94a3b8;
  --accent: #3b82f6;
  --surface: #1e293b;
  --border: #334155;
}
* {
  box-sizing: border-box;
  scroll-behavior: smooth;
}
html, body {
  margin: 0;
  padding: 0;
  font-family: 'Poppins', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Ubuntu, sans-serif;
  background: var(--bg);
  color: var(--text);
}
.container {
  width: 100%;
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.25rem;
}
.section {
  padding: 5rem 0 4rem;
}
.section.alt {
  background: var(--surface);
}
.section-title {
  font-size: 2rem;
  margin-bottom: 2rem;
  position: relative;
}
.section-title::after {
  content: "";
  display: block;
  width: 60px;
  height: 4px;
  background: var(--accent);
  margin-top: 0.5rem;
  border-radius: 2px;
}
.header {
  position: sticky;
  top: 0;
  z-index: 999;
  background: rgba(255,255,255,0.75);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.dark .header {
  background: rgba(15,23,42,0.75);
}
.nav-wrapper {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}
.logo {
  font-size: 1.5rem;
  font-weight: 700;
}
.logo span {
  color: var(--accent);
}
.nav {
  display: flex;
  gap: 1rem;
  align-items: center;
}
.nav a {
  text-decoration: none;
  color: var(--text);
  font-weight: 500;
  transition: color .2s;
}
.nav a:hover {
  color: var(--accent);
}
#themeToggle {
  border: none;
  background: transparent;
  font-size: 1.1rem;
  cursor: pointer;
  margin-left: 0.5rem;
}
.hamburger {
  display: none;
  background: transparent;
  border: none;
  cursor: pointer;
}
.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text);
  margin: 5px 0;
  transition: transform .2s;
}
.hero {
  display: grid;
  place-items: center;
  min-height: calc(100vh - 64px);
  background: linear-gradient(135deg, var(--surface) 0%, transparent 100%);
}
.hero-inner {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  text-align: center;
}
.hero h1 {
  font-size: 3rem;
  line-height: 1.1;
}
.hero h2 {
  font-size: 1.2rem;
  color: var(--muted);
  font-weight: 500;
}
.accent {
  color: var(--accent);
}
.cta {
  margin-top: 1.5rem;
  display: flex;
  gap: 1rem;
  justify-content: center;
  flex-wrap: wrap;
}
.btn {
  display: inline-block;
  padding: 0.75rem 1.25rem;
  background: var(--accent);
  color: #fff;
  border-radius: 8px;
  text-decoration: none;
  transition: opacity .2s;
  border: none;
  cursor: pointer;
}
.btn:hover { opacity: .9; }
.btn.ghost {
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent);
}
.timeline {
  list-style: none;
  border-left: 2px solid var(--border);
  margin: 2rem 0;
  padding-left: 1.5rem;
}
.timeline li {
  margin-bottom: 1.5rem;
  position: relative;
}
.timeline .time {
  color: var(--muted);
  font-size: 0.85rem;
}
.timeline li::before {
  content: "";
  position: absolute;
  left: -10px;
  top: 4px;
  width: 12px;
  height: 12px;
  background: var(--accent);
  border-radius: 50%;
}
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 1rem;
}
.skill-card {
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  text-align: center;
  background: #fff;
}
.dark .skill-card {
  background: var(--surface);
}
.exp-item .meta {
  color: var(--muted);
  font-size: 0.9rem;
}
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}
.project-card {
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.25rem 1.25rem 1rem;
  background: #fff;
}
.dark .project-card {
  background: var(--surface);
}
.contact-form {
  max-width: 560px;
}
.form-group {
  display: flex;
  flex-direction: column;
  margin-bottom: 1rem;
  gap: 0.35rem;
}
input, textarea {
  width: 100%;
  padding: 0.75rem 0.9rem;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text);
  border-radius: 8px;
  outline: none;
}
input:focus, textarea:focus {
  border-color: var(--accent);
}
.footer {
  border-top: 1px solid var(--border);
  padding: 2rem 0;
  text-align: center;
  background: var(--surface);
}
.form-status {
  margin-top: 0.75rem;
  color: var(--muted);
}

/* Responsive */
@media (max-width: 900px) {
  .nav {
    position: fixed;
    top: 64px;
    left: 0;
    right: 0;
    padding: 1rem;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    flex-direction: column;
    gap: 1rem;
    transform: translateY(-150%);
    transition: transform .2s;
  }
  .nav.open {
    transform: translateY(0);
  }
  .hamburger {
    display: block;
  }
  /* Dropdown styling */
.dropdown {
  position: relative;
  display: inline-block;
}

.dropdown-content {
  display: none;
  position: absolute;
  background-color: #ffffff;
  min-width: 160px;
  box-shadow: 0px 8px 16px rgba(0,0,0,0.2);
  z-index: 1;
  padding: 10px 0;
  border-radius: 8px;
}

.dropdown-content a {
  color: #333;
  padding: 10px 20px;
  text-decoration: none;
  display: block;
}

.dropdown-content a:hover {
  background-color: #f0f0f0;
}

.dropdown:hover .dropdown-content {
  display: block;
}
}