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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-primary);
  background: linear-gradient(to bottom, var(--color-bg-dark), var(--color-bg-medium));
  color: var(--color-text-light);
  line-height: 1.6;
  overflow-x: hidden;
  min-height: 100vh;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  top: -100px;
  left: var(--spacing-md);
  background: var(--color-secondary);
  color: var(--color-text-light);
  padding: var(--spacing-sm) var(--spacing-md);
  text-decoration: none;
  font-weight: 700;
  border-radius: var(--border-radius-sm);
  z-index: 10000;
}

.skip-link:focus {
  top: var(--spacing-md);
}

header {
  background-color: var(--color-primary);
  padding: var(--spacing-sm) 0;
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: var(--shadow-md);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--spacing-md);
}

header h1 {
  font-size: clamp(1.5rem, 4vw, 2rem);
  color: var(--color-text-dark);
  font-weight: 900;
  margin: 0;
}

.hamburger {
  display: none;
  background: none;
  border: none;
  color: var(--color-text-dark);
  cursor: pointer;
  padding: var(--spacing-xs);
  font-size: 1.75rem;
  line-height: 1;
  transition: transform var(--transition-speed);
  z-index: 1001;
}

.hamburger:hover {
  transform: scale(1.1);
}

.hamburger[aria-expanded="true"] {
  color: var(--color-secondary);
}

nav {
  flex: 1;
  display: flex;
  justify-content: flex-end;
}

.nav-menu {
  list-style: none;
  display: flex;
  gap: clamp(0.75rem, 2vw, 1.5rem);
  align-items: center;
  flex-wrap: wrap;
}

.nav-menu a {
  color: var(--color-text-dark);
  text-decoration: none;
  font-weight: 700;
  font-size: clamp(0.9rem, 1.5vw, 1rem);
  transition: all var(--transition-speed);
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--border-radius-sm);
  white-space: nowrap;
}

.nav-menu a:hover,
.nav-menu a:focus {
  color: var(--color-text-light);
  background-color: rgba(255, 255, 255, 0.1);
  outline: 2px solid transparent;
}

.nav-menu a:focus-visible {
  outline: 2px solid var(--color-secondary);
  outline-offset: 2px;
}

.section {
  padding: clamp(3rem, 8vw, 5rem) 0;
  text-align: center;
}

.section h2 {
  color: var(--color-primary);
  font-size: clamp(2rem, 5vw, 2.8rem);
  margin-bottom: var(--spacing-lg);
  text-shadow: 2px 2px 6px rgba(0, 0, 0, 0.5);
  line-height: 1.2;
}

.section h3 {
  color: var(--color-secondary);
  font-size: clamp(1.3rem, 3vw, 1.8rem);
  margin: var(--spacing-lg) 0 var(--spacing-md);
  text-shadow: 1px 1px 3px rgba(0, 0, 0, 0.5);
}

.section p {
  font-size: clamp(1rem, 2vw, 1.1rem);
  max-width: 800px;
  margin: 0 auto var(--spacing-md);
  line-height: 1.8;
}

.btn {
  background-color: var(--color-secondary);
  color: var(--color-text-light);
  border: none;
  padding: clamp(0.75rem, 2vw, 1rem) clamp(1.5rem, 4vw, 2rem);
  font-size: clamp(0.95rem, 2vw, 1.1rem);
  font-weight: 700;
  cursor: pointer;
  border-radius: var(--border-radius-full);
  transition: all var(--transition-speed);
  box-shadow: 0 4px 12px rgba(255, 0, 0, 0.4);
  text-decoration: none;
  display: inline-block;
  text-align: center;
  white-space: nowrap;
}

.btn:hover,
.btn:focus {
  background-color: var(--color-accent);
  color: var(--color-text-dark);
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(0, 255, 0, 0.5);
}

.btn:focus-visible {
  outline: 3px solid var(--color-text-light);
  outline-offset: 4px;
}

.btn:active {
  transform: translateY(0);
}

.btn-primary {
  background-color: var(--color-primary);
  color: var(--color-text-dark);
  box-shadow: 0 4px 12px rgba(0, 184, 217, 0.4);
}

.btn-primary:hover,
.btn-primary:focus {
  background-color: var(--color-accent);
  box-shadow: 0 6px 16px rgba(0, 255, 0, 0.5);
}

.btn-secondary {
  background-color: transparent;
  border: 2px solid var(--color-primary);
  color: var(--color-primary);
  box-shadow: none;
}

.btn-secondary:hover,
.btn-secondary:focus {
  background-color: var(--color-primary);
  color: var(--color-text-dark);
  border-color: var(--color-primary);
}

.btn-group {
  display: flex;
  gap: var(--spacing-md);
  justify-content: center;
  flex-wrap: wrap;
  margin: var(--spacing-xl) 0;
}

footer {
  background-color: var(--color-bg-medium);
  padding: var(--spacing-xl) 0;
  text-align: center;
  box-shadow: 0 -4px 12px rgba(0, 0, 0, 0.3);
  margin-top: var(--spacing-2xl);
}

footer p {
  font-size: clamp(0.85rem, 1.8vw, 0.95rem);
  margin-bottom: var(--spacing-md);
  color: rgba(255, 255, 255, 0.8);
}

.social-links {
  display: flex;
  gap: var(--spacing-lg);
  justify-content: center;
  flex-wrap: wrap;
}

footer a {
  color: var(--color-accent);
  text-decoration: none;
  font-size: clamp(1rem, 2vw, 1.2rem);
  font-weight: 700;
  transition: all var(--transition-speed);
  padding: var(--spacing-xs) var(--spacing-md);
  border-radius: var(--border-radius-sm);
}

footer a:hover,
footer a:focus {
  color: var(--color-primary);
  background-color: rgba(255, 255, 255, 0.1);
  transform: translateY(-2px);
}

footer a:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

ol, ul {
  text-align: left;
  max-width: 800px;
  margin: var(--spacing-lg) auto;
  padding-left: var(--spacing-xl);
  font-size: clamp(0.95rem, 2vw, 1.1rem);
  line-height: 1.8;
}

li {
  margin-bottom: var(--spacing-sm);
}

li strong {
  color: var(--color-accent);
}

@media (max-width: 767px) {
  .hamburger {
    display: block;
  }

  nav {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    width: min(280px, 80vw);
    background: linear-gradient(135deg, var(--color-bg-medium), var(--color-bg-dark));
    transform: translateX(100%);
    transition: transform var(--transition-speed) ease-in-out;
    z-index: 999;
    box-shadow: -4px 0 12px rgba(0, 0, 0, 0.5);
    overflow-y: auto;
  }

  nav.active {
    transform: translateX(0);
  }

  .nav-menu {
    flex-direction: column;
    padding: var(--spacing-xl) var(--spacing-lg);
    align-items: flex-start;
    gap: var(--spacing-md);
    margin-top: 60px;
  }

  .nav-menu a {
    color: var(--color-text-light);
    width: 100%;
    font-size: 1.1rem;
    padding: var(--spacing-md);
    border-radius: var(--border-radius-sm);
    background-color: rgba(255, 255, 255, 0.05);
  }

  .nav-menu a:hover,
  .nav-menu a:focus {
    background-color: var(--color-primary);
    color: var(--color-text-dark);
  }

  .btn-group {
    flex-direction: column;
    align-items: stretch;
  }

  .btn {
    width: 100%;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}