/* Font */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;600;700&display=swap');

/* base styles */
:root {
  --primary-color: #1e3a8a;
  --accent-color: #3b82f6;
  --text-color: #333;
  --background-color: #f9fafb;
  --card-bg: #ffffff;
  --footer-bg: #1f2937;
  --footer-text-color: #cbd5e1;
  --border-radius: 14px;
  --box-shadow: 0 6px 20px rgba(0, 0, 0, 0.08);

  --dark-bg: #1a1a1a;
  --dark-header-bg: #1e293b;
  --dark-card-bg: #2c2c2c;
  --dark-text: #e5e5e5;
  --dark-primary: #60a5fa;
  --dark-accent: #93c5fd;
}

body {
  margin: 0;
  font-family: 'Inter', sans-serif;
  background: var(--background-color);
  color: var(--text-color);
  line-height: 1.6;
  transition: background 0.3s, color 0.3s;
}

section {
  background: var(--card-bg);
  margin: 40px auto;
  padding: 32px;
  border-radius: var(--border-radius);
  box-shadow: var(--box-shadow);
  transition: background 0.3s, color 0.3s;
  max-width: 900px;
}

section h2 {
  color: var(--primary-color);
  font-size: 1.85rem;
  margin-bottom: 20px;
}

section h3 {
  color: var(--accent-color);
  margin-top: 24px;
}

ul {
  padding-left: 20px;
}

ul li {
  margin-bottom: 10px;
}

header {
  background: var(--primary-color);
  color: white;
  text-align: center;
  padding: 70px 30px;
  box-shadow: var(--box-shadow);
}

header h1 {
  font-size: 2.75rem;
  margin: 0;
}

header p {
  margin: 10px 0;
  font-size: 1.1rem;
}

header a {
  color: var(--footer-text-color);
  text-decoration: none;
}

header a:hover {
  text-decoration: underline;
}

nav {
  background: white;
  box-shadow: var(--box-shadow);
  display: flex;
  justify-content: center;
  gap: 24px;
  flex-wrap: wrap;
  padding: 16px 0;
  position: sticky;
  top: 0;
  z-index: 1000;
  transition: background 0.3s;
}

nav a {
  color: var(--primary-color);
  font-weight: 600;
  text-decoration: none;
  padding: 8px 14px;
  border-radius: 6px;
  transition: background 0.3s;
}

nav a:hover {
  background: var(--accent-color);
  color: white;
}

footer {
  background: var(--footer-bg);
  color: var(--footer-text-color);
  text-align: center;
  padding: 24px 0;
  font-size: 0.95rem;
  margin-top: 40px;
}

/* Dark mode toggle */
#toggle-theme {
  position: fixed;
  top: 20px;
  right: 20px;
  background: var(--primary-color);
  color: white;
  border: none;
  padding: 10px 14px;
  border-radius: 8px;
  cursor: pointer;
  font-size: 0.95rem;
  box-shadow: var(--box-shadow);
  transition: background 0.3s, color 0.3s;
  z-index: 1100;
}

#toggle-theme:hover {
  background: var(--accent-color);
}

/* Dark mode styles */
body.dark {
  background: var(--dark-bg);
  color: var(--dark-text);
}

body.dark nav {
  background: var(--dark-card-bg);
}

body.dark nav a {
  color: var(--dark-primary);
}

body.dark nav a:hover {
  background: var(--dark-accent);
  color: var(--text-color);
}

body.dark section {
  background: var(--dark-card-bg);
}

body.dark section h2 {
  color: var(--dark-primary);
}

body.dark section h3 {
  color: var(--dark-accent);
}

body.dark header {
  background: var(--dark-header-bg);
  color: var(--dark-text);
}

body.dark header a {
  color: var(--dark-accent);
}

body.dark footer {
  background: var(--dark-card-bg);
  color: var(--dark-text);
}

body.dark #toggle-theme {
  background: var(--dark-primary);
  color: black;
}

/* Hamburger menu styles */
#menu-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.75rem;
  padding: 10px 20px;
  cursor: pointer;
  color: var(--primary-color);
  z-index: 1100;
}

#nav-links {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
  justify-content: center;
}

@media (max-width: 768px) {
  nav {
    flex-direction: column;
    align-items: flex-start;
    padding: 10px 20px;
  }

  #menu-toggle {
    display: block;
    align-self: flex-start;
  }

  #nav-links {
    display: none;
    flex-direction: column;
    width: 100%;
    margin-top: 10px;
  }

  #nav-links.show {
    display: flex;
  }

  #nav-links a {
    padding: 10px 14px;
  }

  body.dark #menu-toggle {
    color: var(--dark-primary);
  }
}