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

body {
  font-family: var(--font-sans);
  background-color: var(--bg-main);
  background-image: radial-gradient(circle at top right, var(--color-primary-glow) 0%, transparent 40%),
                    radial-gradient(circle at bottom left, var(--border-glow) 0%, transparent 40%);
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  line-height: 1.6;
  overflow-x: hidden;
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-title);
  color: var(--text-bright);
  font-weight: 700;
  letter-spacing: -0.02em;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  filter: brightness(1.2);
}

/* Scrollbar Styles */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}
::-webkit-scrollbar-track {
  background: var(--bg-main);
}
::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: var(--border-radius-sm);
}
::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}

/* Core Layout Container */
.container {
  width: 100%;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 20px;
}

.main-content {
  flex-grow: 1;
  display: flex;
  flex-direction: column;
  padding: 40px 0;
}

/* Header & Navigation */
header {
  background-color: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 100;
}

header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: var(--header-height);
}

.logo-link {
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo-text {
  font-family: var(--font-title);
  font-size: 1.4rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--color-x), var(--color-o));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  text-transform: uppercase;
  letter-spacing: 1px;
}

nav {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-link {
  color: var(--text-main);
  padding: 8px 16px;
  border-radius: var(--border-radius-sm);
  font-weight: 500;
  font-size: 0.95rem;
  transition: all var(--transition-fast);
}

.nav-link:hover, .nav-link.active {
  color: var(--text-bright);
  background-color: var(--border-color);
}

/* Action Controls (Theme, Sound, Install) */
.controls-group {
  display: flex;
  align-items: center;
  gap: 12px;
}

.btn-icon {
  background: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-main);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
  outline: none;
}

.btn-icon:hover {
  background-color: var(--border-color);
  color: var(--text-bright);
  border-color: var(--text-muted);
}

/* Burger Mobile Menu */
.burger-menu {
  display: none;
  background: transparent;
  border: none;
  cursor: pointer;
  flex-direction: column;
  gap: 6px;
  width: 30px;
  height: 24px;
  justify-content: space-between;
  outline: none;
}

.burger-line {
  width: 100%;
  height: 3px;
  background-color: var(--text-main);
  border-radius: 2px;
  transition: all var(--transition-normal);
}

/* Footer Section */
footer {
  background-color: var(--bg-card);
  border-top: 1px solid var(--border-color);
  padding: 40px 0 20px 0;
  margin-top: auto;
  font-size: 0.9rem;
  color: var(--text-muted);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}

.footer-brand p {
  margin-top: 12px;
  max-width: 320px;
}

.footer-links-title {
  color: var(--text-bright);
  font-weight: 600;
  margin-bottom: 16px;
  font-size: 1rem;
}

.footer-links-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-link {
  color: var(--text-muted);
  transition: color var(--transition-fast);
}

.footer-link:hover {
  color: var(--text-bright);
}

.footer-bottom {
  text-align: center;
  padding-top: 20px;
  border-top: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  gap: 10px;
}

/* Skip to Content for Accessibility */
.skip-link {
  position: absolute;
  top: -100px;
  left: 0;
  background: var(--color-primary);
  color: white;
  padding: 10px 20px;
  z-index: 1000;
  transition: top 0.2s;
}

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

/* Media Queries for Navigation */
@media (max-width: 992px) {
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 30px;
  }
}

@media (max-width: 768px) {
  nav {
    display: none; /* Controlled by JavaScript on Mobile */
    flex-direction: column;
    position: absolute;
    top: var(--header-height);
    left: 0;
    width: 100%;
    background-color: var(--bg-main);
    border-bottom: 1px solid var(--border-color);
    padding: 20px;
    box-shadow: 0 10px 15px rgba(0, 0, 0, 0.5);
  }

  nav.open {
    display: flex;
  }

  .burger-menu {
    display: flex;
  }

  .burger-menu.open .burger-line:nth-child(1) {
    transform: translateY(9px) rotate(45deg);
  }

  .burger-menu.open .burger-line:nth-child(2) {
    opacity: 0;
  }

  .burger-menu.open .burger-line:nth-child(3) {
    transform: translateY(-9px) rotate(-45deg);
  }
}