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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  line-height: 1.6;
  color: #1a1a2e;
  background-color: #fafafa;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: #0066cc;
  text-decoration: none;
  transition: color 0.2s ease;
}

a:hover {
  color: #004a99;
}

ul {
  list-style: none;
}

.skip-link {
  position: absolute;
  top: -100%;
  left: 0;
  background: #0066cc;
  color: #ffffff;
  padding: 0.75rem 1.5rem;
  z-index: 1000;
  font-weight: 600;
  transition: top 0.2s ease;
}

.skip-link:focus {
  top: 0;
}

.container {
  width: 100%;
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background: #ffffff;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.08);
  z-index: 900;
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 1100px;
  margin: 0 auto;
  padding: 1rem 1.5rem;
}

.nav-logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: #1a1a2e;
  letter-spacing: -0.02em;
}

.nav-logo:hover {
  color: #0066cc;
}

.nav-menu {
  display: flex;
  gap: 2rem;
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: #444444;
  padding: 0.25rem 0;
  position: relative;
}

.nav-link::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: #0066cc;
  transition: width 0.25s ease;
}

.nav-link:hover {
  color: #0066cc;
}

.nav-link:hover::after {
  width: 100%;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.25rem;
}

.nav-toggle-bar {
  display: block;
  width: 24px;
  height: 2px;
  background: #1a1a2e;
  border-radius: 2px;
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.nav-toggle.active .nav-toggle-bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle.active .nav-toggle-bar:nth-child(2) {
  opacity: 0;
}

.nav-toggle.active .nav-toggle-bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.hero {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  text-align: center;
  padding: 6rem 1.5rem 4rem;
  background: linear-gradient(135deg, #f5f7fa 0%, #e4e9f0 100%);
}

.hero-title {
  font-size: 3rem;
  font-weight: 800;
  color: #1a1a2e;
  line-height: 1.2;
  margin-bottom: 1rem;
}

.highlight {
  color: #0066cc;
}

.hero-subtitle {
  font-size: 1.25rem;
  color: #555555;
  margin-bottom: 2rem;
  max-width: 500px;
  margin-left: auto;
  margin-right: auto;
}

.btn {
  display: inline-block;
  padding: 0.75rem 2rem;
  font-size: 1rem;
  font-weight: 600;
  border-radius: 6px;
  border: 2px solid transparent;
  cursor: pointer;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.btn-primary {
  background: #0066cc;
  color: #ffffff;
  border-color: #0066cc;
}

.btn-primary:hover {
  background: #004a99;
  border-color: #004a99;
  color: #ffffff;
}

.section {
  padding: 5rem 0;
}

.section-title {
  font-size: 2rem;
  font-weight: 700;
  color: #1a1a2e;
  margin-bottom: 1.5rem;
  text-align: center;
}

.about {
  background: #ffffff;
}

.about-text {
  font-size: 1.1rem;
  color: #444444;
  max-width: 700px;
  margin: 0 auto;
  text-align: center;
  line-height: 1.8;
}

.projects {
  background: #f5f7fa;
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 2rem;
  margin-top: 2rem;
}

.project-card {
  background: #ffffff;
  border-radius: 10px;
  padding: 2rem;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.project-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.1);
}

.project-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: #1a1a2e;
  margin-bottom: 0.75rem;
}

.project-description {
  font-size: 0.95rem;
  color: #555555;
  margin-bottom: 1.25rem;
  line-height: 1.7;
}

.project-link {
  font-weight: 600;
  font-size: 0.95rem;
  color: #0066cc;
}

.project-link:hover {
  color: #004a99;
}

.contact {
  background: #ffffff;
}

.contact-text {
  text-align: center;
  color: #555555;
  font-size: 1.1rem;
  margin-bottom: 2.5rem;
}

.contact-form {
  max-width: 600px;
  margin: 0 auto;
}

.form-group {
  margin-bottom: 1.25rem;
}

.form-group label {
  display: block;
  font-size: 0.9rem;
  font-weight: 600;
  color: #1a1a2e;
  margin-bottom: 0.4rem;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 0.75rem 1rem;
  font-size: 1rem;
  font-family: inherit;
  border: 1px solid #d0d5dd;
  border-radius: 6px;
  background: #fafafa;
  color: #1a1a2e;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: #0066cc;
  box-shadow: 0 0 0 3px rgba(0, 102, 204, 0.15);
}

.form-group textarea {
  resize: vertical;
}

.footer {
  text-align: center;
  padding: 2rem 0;
  background: #1a1a2e;
  color: #aaaaaa;
  font-size: 0.9rem;
}

@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }

  .nav-menu {
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    flex-direction: column;
    background: #ffffff;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
    padding: 1rem 1.5rem;
    gap: 0;
    display: none;
  }

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

  .nav-link {
    padding: 0.75rem 0;
    border-bottom: 1px solid #f0f0f0;
  }

  .hero-title {
    font-size: 2rem;
  }

  .hero-subtitle {
    font-size: 1.05rem;
  }

  .section {
    padding: 3.5rem 0;
  }

  .projects-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 1.65rem;
  }

  .section-title {
    font-size: 1.5rem;
  }

  .btn {
    width: 100%;
    text-align: center;
  }
}