:root {
  --white: #ffffff;
  --slate: #1e293b;
  --slate-light: #475569;
  --emerald: #10b981;
  --emerald-dark: #059669;
  --bg-alt: #f8fafc;
  --border: #e2e8f0;
  --shadow: 0 4px 20px rgba(15, 23, 42, 0.06);
  --radius: 14px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: "Segoe UI", system-ui, -apple-system, Roboto, Helvetica, Arial, sans-serif;
  background: var(--white);
  color: var(--slate);
  line-height: 1.6;
}

.container {
  width: 100%;
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
}

a {
  text-decoration: none;
  color: inherit;
}

/* Navbar */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
  z-index: 1000;
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}

.logo {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--slate);
}

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

.nav-links {
  display: flex;
  gap: 32px;
}

.nav-links a {
  font-weight: 500;
  color: var(--slate-light);
  transition: color 0.2s ease;
}

.nav-links a:hover {
  color: var(--emerald-dark);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 32px;
  height: 32px;
  background: none;
  border: none;
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  height: 2px;
  background: var(--slate);
  border-radius: 2px;
}

/* Hero */
.hero {
  padding: 160px 0 100px;
  background: linear-gradient(180deg, #f0fdf9 0%, #ffffff 100%);
}

.hero-inner {
  text-align: center;
  max-width: 720px;
}

.eyebrow {
  color: var(--emerald-dark);
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  font-size: 0.85rem;
  margin-bottom: 12px;
}

.hero h1 {
  font-size: 3.2rem;
  font-weight: 800;
  color: var(--slate);
  margin-bottom: 10px;
}

.hero-title {
  font-size: 1.5rem;
  font-weight: 600;
  color: var(--emerald-dark);
  margin-bottom: 18px;
}

.hero-text {
  font-size: 1.1rem;
  color: var(--slate-light);
  margin-bottom: 34px;
}

.hero-buttons {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  padding: 14px 30px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.95rem;
  transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.btn-primary {
  background: var(--emerald);
  color: #ffffff;
  box-shadow: 0 8px 20px rgba(16, 185, 129, 0.25);
}

.btn-primary:hover {
  background: var(--emerald-dark);
  transform: translateY(-2px);
}

.btn-outline {
  background: transparent;
  color: var(--slate);
  border: 2px solid var(--border);
}

.btn-outline:hover {
  border-color: var(--emerald);
  color: var(--emerald-dark);
  transform: translateY(-2px);
}

/* Sections */
.section {
  padding: 90px 0;
}

.section-alt {
  background: var(--bg-alt);
}

.section-label {
  color: var(--emerald-dark);
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  font-size: 0.85rem;
  margin-bottom: 10px;
}

.section-title {
  font-size: 2.1rem;
  font-weight: 700;
  color: var(--slate);
  margin-bottom: 28px;
}

.about-text {
  max-width: 760px;
  color: var(--slate-light);
  font-size: 1.05rem;
}

/* Skills */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 16px;
}

.skill-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  text-align: center;
  font-weight: 600;
  color: var(--slate);
  box-shadow: var(--shadow);
  transition: transform 0.2s ease, border-color 0.2s ease, color 0.2s ease;
}

.skill-card:hover {
  transform: translateY(-4px);
  border-color: var(--emerald);
  color: var(--emerald-dark);
}

/* Projects */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.project-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--shadow);
  transition: transform 0.2s ease;
}

.project-card:hover {
  transform: translateY(-6px);
}

.project-icon {
  font-size: 2rem;
  margin-bottom: 14px;
}

.project-card h3 {
  font-size: 1.2rem;
  margin-bottom: 10px;
  color: var(--slate);
}

.project-card p {
  color: var(--slate-light);
  font-size: 0.98rem;
}

/* Contact */
.contact-text {
  color: var(--slate-light);
  margin-bottom: 24px;
  font-size: 1.05rem;
}

.contact-email {
  display: inline-block;
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--emerald-dark);
  margin-bottom: 30px;
  border-bottom: 2px solid var(--emerald);
  padding-bottom: 2px;
}

.social-links {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.social-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 22px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--white);
  font-weight: 600;
  color: var(--slate);
  transition: all 0.2s ease;
}

.social-link:hover {
  border-color: var(--emerald);
  color: var(--emerald-dark);
  transform: translateY(-2px);
}

.social-icon {
  font-size: 1rem;
}

/* Footer */
.footer {
  background: var(--slate);
  color: #cbd5e1;
  padding: 26px 0;
  text-align: center;
  font-size: 0.9rem;
}

/* Back to top */
.back-to-top {
  position: fixed;
  bottom: 28px;
  right: 28px;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: none;
  background: var(--emerald);
  color: #fff;
  font-size: 1.2rem;
  cursor: pointer;
  box-shadow: 0 8px 20px rgba(16, 185, 129, 0.3);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: all 0.25s ease;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  background: var(--emerald-dark);
}

/* Mobile */
@media (max-width: 768px) {
  .nav-links {
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    background: var(--white);
    border-bottom: 1px solid var(--border);
    flex-direction: column;
    padding: 20px 24px;
    gap: 18px;
    display: none;
  }

  .nav-links.open {
    display: flex;
  }

  .nav-toggle {
    display: flex;
  }

  .hero {
    padding: 130px 0 70px;
  }

  .hero h1 {
    font-size: 2.3rem;
  }

  .hero-title {
    font-size: 1.2rem;
  }

  .section-title {
    font-size: 1.7rem;
  }
}