:root {
  --bg: #ffffff;
  --text: #1a1a1a;
  --primary: #2563eb;
  --accent: #3b82f6;
  --gray: #64748b;
  --light: #f1f5f9;
  --card-bg: #ffffff;
  --border: #e2e8f0;
  --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1);
}
body.dark {
  --bg: #0f172a;
  --text: #f8fafc;
  --primary: #60a5fa;
  --accent: #3b82f6;
  --gray: #94a3b8;
  --light: #1e293b;
  --card-bg: #1e293b;
  --border: #334155;
}
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
html {
  scroll-behavior: smooth;
}
body {
  font-family: system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  transition: 0.3s;
}
a {
  text-decoration: none;
  color: inherit;
  transition: 0.2s;
}
ul {
  list-style: none;
}
button {
  cursor: pointer;
  border: none;
  background: none;
  font: inherit;
  color: inherit;
}
.container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 0 30px;
}
.btn {
  display: inline-block;
  padding: 10px 24px;
  border-radius: 6px;
  font-weight: 600;
}
.btn-primary {
  background: var(--primary);
  color: white;
}
.btn-primary:hover {
  opacity: 0.9;
  transform: translateY(-1px);
}
.btn-outline {
  border: 1px solid var(--border);
  color: var(--text);
}
.btn-outline:hover {
  border-color: var(--primary);
  color: var(--primary);
}

/* Header & Nav */
.header {
  position: fixed;
  top: 0;
  width: 100%;
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  z-index: 100;
  transition: 0.3s;
}
body.dark .header {
  background: rgba(15, 23, 42, 0.8);
}
.nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 70px;
}
.logo {
  font-size: 1.5rem;
  font-weight: 800;
}
.dot {
  color: var(--primary);
}
.nav-menu {
  display: flex;
  gap: 30px;
}
.nav-link {
  font-weight: 500;
  position: relative;
}
.nav-link:hover {
  color: var(--primary);
}
.nav-link::after {
  content: "";
  position: absolute;
  width: 0;
  height: 2px;
  bottom: -4px;
  left: 0;
  background: var(--primary);
  transition: 0.3s;
}
.nav-link:hover::after {
  width: 100%;
}
#theme-toggle {
  font-size: 1.2rem;
  padding: 8px;
  border-radius: 50%;
  background: var(--light);
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: 0.3s;
}
#theme-toggle:hover {
  background: var(--primary);
  color: white;
  transform: rotate(15deg);
}

/* Hero */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: 80px;
}
.hero-content {
  max-width: 800px;
}
.badge {
  background: var(--light);
  padding: 6px 12px;
  border-radius: 20px;
  font-size: 0.9rem;
  color: var(--primary);
  font-weight: 600;
}
.hero h1 {
  font-size: 3.5rem;
  line-height: 1.1;
  margin: 20px 0;
  letter-spacing: -1px;
}
.gradient-text {
  background: linear-gradient(to right, var(--primary), var(--accent));
  -webkit-background-clip: text;
  color: transparent;
}
.hero p {
  font-size: 1.2rem;
  color: var(--gray);
  margin-bottom: 30px;
}
.hero-actions {
  display: flex;
  gap: 15px;
  margin-bottom: 40px;
}
.stats {
  display: flex;
  gap: 40px;
  border-top: 1px solid var(--border);
  padding-top: 20px;
}
.stat strong {
  display: block;
  font-size: 1.5rem;
  color: var(--text);
}
.stat {
  color: var(--gray);
  font-size: 0.9rem;
}

/* Sections */
.section {
  padding: 80px 0;
}
.section-header {
  text-align: center;
  margin-bottom: 50px;
}
.section-header h2 {
  font-size: 2rem;
  margin-bottom: 10px;
}
.section-header p {
  color: var(--gray);
}

/* About */
.about-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 50px;
  align-items: center;
}
.skill-item {
  margin-bottom: 15px;
}
.skill-item span {
  display: block;
  margin-bottom: 5px;
  font-weight: 500;
}
.progress-bar {
  height: 8px;
  background: var(--light);
  border-radius: 4px;
  overflow: hidden;
}
.progress {
  height: 100%;
  background: var(--primary);
  border-radius: 4px;
}

/* Projects */
.filter-tabs {
  display: flex;
  justify-content: center;
  gap: 10px;
  margin-bottom: 40px;
}
.filter-tab {
  padding: 8px 20px;
  border-radius: 20px;
  background: var(--light);
  color: var(--gray);
  font-weight: 500;
  transition: 0.3s;
}
.filter-tab.active,
.filter-tab:hover {
  background: var(--primary);
  color: white;
}
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
}
.project-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  transition: 0.3s;
}
.project-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow);
}
.project-image {
  height: 200px;
  background: var(--light);
}
.project-info {
  padding: 20px;
}
.project-info h3 {
  margin-bottom: 8px;
}
.project-info p {
  color: var(--gray);
  font-size: 0.9rem;
  margin-bottom: 15px;
}
.tags {
  display: flex;
  gap: 8px;
}
.tags span {
  font-size: 0.75rem;
  padding: 4px 10px;
  background: var(--light);
  border-radius: 4px;
  color: var(--gray);
}

/* Contact */
.contact-form {
  max-width: 700px;
  margin: 0 auto;
}
.form-group {
  margin-bottom: 20px;
}
input,
textarea {
  width: 100%;
  padding: 12px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--card-bg);
  color: var(--text);
  font-family: inherit;
}
input:focus,
textarea:focus {
  outline: 2px solid var(--primary);
  border-color: transparent;
}
.form-status {
  margin-top: 15px;
  text-align: center;
  font-size: 0.9rem;
}

/* Footer */
.footer {
  background: var(--card-bg);
  border-top: 1px solid var(--border);
  padding: 80px 0 30px;
  margin-top: 100px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 60px;
  margin-bottom: 50px;
}
.footer-brand p {
  color: var(--gray);
  margin-top: 20px;
  line-height: 1.8;
  max-width: 350px;
}
.footer-logo {
  font-size: 1.8rem;
  font-weight: 800;
}
.footer h4 {
  font-size: 1.1rem;
  margin-bottom: 25px;
  color: var(--text);
  font-weight: 700;
}
.footer-links ul {
  display: flex;
  flex-direction: column;
  gap: 15px;
}
.footer-links a {
  color: var(--gray);
  transition: 0.2s;
}
.footer-links a:hover {
  color: var(--primary);
  padding-left: 5px;
}
.footer-contact p {
  color: var(--gray);
  margin-bottom: 15px;
}
.footer-social {
  display: flex;
  gap: 15px;
  margin-top: 25px;
}
.footer-social a {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--light);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text);
  transition: 0.3s;
}
.footer-social a:hover {
  background: var(--primary);
  color: white;
  transform: translateY(-3px);
}
.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: 30px;
  text-align: center;
  color: var(--gray);
  font-size: 0.9rem;
}

@media (max-width: 768px) {
  .hero h1 {
    font-size: 2.5rem;
  }
  .about-content,
  .footer-grid {
    grid-template-columns: 1fr;
  }
  .nav-menu {
    display: none;
  }
  .footer-grid {
    gap: 40px;
    text-align: center;
  }
  .footer-brand p {
    margin: 15px auto 0;
  }
  .footer-social {
    justify-content: center;
  }
}