:root {
  --color-primary: #0077cc;
  --color-primary-dark: #005fa3;
  --color-background: #f4f6f8;
  --color-text: #333;
  --color-accent: #ff6600;
  --font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  --transition: 0.3s ease;
}

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

body {
  font-family: var(--font-family);
  background-color: var(--color-background);
  color: var(--color-text);
  line-height: 1.6;
}

.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 1rem;
}

.header {
  background-color: var(--color-primary);
  color: white;
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 1000;
}

.logo {
  font-size: 1.8rem;
  font-weight: 700;
  letter-spacing: 1px;
}

.nav ul {
  list-style: none;
  display: flex;
  gap: 1rem;
}

.nav a {
  color: white;
  text-decoration: none;
  font-weight: 600;
  transition: color var(--transition);
}

.nav a:hover,
.nav a:focus {
  color: var(--color-accent);
}

.menu-btn {
  display: none;
  font-size: 2rem;
  background: none;
  border: none;
  color: white;
  cursor: pointer;
}

.main {
  padding: 2rem 0;
}

.section {
  margin-bottom: 3rem;
}

.section h2 {
  color: var(--color-primary-dark);
  margin-bottom: 1rem;
  border-bottom: 3px solid var(--color-accent);
  display: inline-block;
  padding-bottom: 0.25rem;
}

.project-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.7rem;
}

.project-link {
  display: inline-block;
  padding: 0.6rem 1rem;
  background: white;
  border-radius: 5px;
  color: var(--color-primary-dark);
  text-decoration: none;
  box-shadow: 0 1px 5px rgb(0 0 0 / 0.1);
  transition: background-color var(--transition), box-shadow var(--transition);
}

.project-link:hover,
.project-link:focus {
  background-color: var(--color-accent);
  color: white;
  box-shadow: 0 3px 12px rgb(0 0 0 / 0.2);
}

.footer {
  background-color: var(--color-primary);
  color: white;
  text-align: center;
  padding: 1rem 0;
  font-size: 0.9rem;
  margin-top: 4rem;
}

/* Responsive */

@media (max-width: 700px) {
  .nav ul {
    display: none;
    flex-direction: column;
    background-color: var(--color-primary);
    position: absolute;
    top: 60px;
    right: 1rem;
    border-radius: 5px;
    padding: 1rem;
    width: 180px;
  }

  .nav ul.show {
    display: flex;
  }

  .menu-btn {
    display: block;
  }
}