:root {
  --bg-color: #f0f2f5;
  --text-color: #333;
  --card-bg: white;
  --header-bg: #333;
  --accent-color: #0056b3;
}

[data-theme="dark"] {
  --bg-color: #1e1e1e;
  --text-color: #f0f0f0;
  --card-bg: #2c2c2c;
  --header-bg: #111;
  --accent-color: #0056b3;
}

body {
  background: var(--bg-color);
  color: var(--text-color);
  transition: background 0.3s, color 0.3s;
}

/* Header styling */
header {
  background-color: var(--header-bg);
  padding: 15px 30px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.logo a {
  color: white;
  text-decoration: none; /* optional, removes underline */
  font-size: 28px;
  font-weight: bold;
}

.logo a:hover {
  color: var(--accent-color); /* optional, adds hover effect */
}


.header-right {
  display: flex;
  align-items: center;
  gap: 20px;
}

nav {
  display: none;
  flex-direction: column;
  background-color: #444;
  position: absolute;
  top: 100%;
  left: 0;
  width: fit-content;
  min-width: 150px;
  border: 1px solid #333;
}

nav a {
  margin: 0 15px;
  padding: 5px;
  text-decoration: none;
  color: white;
  font-weight: bold;
  transition: color 0.3s;
  white-space: nowrap;
}

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

.menu-toggle {
  flex-direction: column;
  cursor: pointer;
}

.bar {
  height: 3px;
  width: 25px;
  background-color: white;
  margin: 4px 0;
  border-radius: 3px;
}

.theme-toggle {
  cursor: pointer;
  font-size: 18px;
  transition: transform 0.3s;
}

.theme-toggle:hover {
  transform: rotate(20deg);
}

/* Submenu styling */
.submenu-container {
  position: relative;
  height: auto;
  margin: 4px 0;
  padding: 5px;
  border-bottom: 1px solid #555;
}

.submenu {
  display: none;
  flex-direction: column;
  background-color: #555;
  position: relative;
  left: 10px;
  margin-top: 5px;
  border-left: 2px solid var(--accent-color);
  border-radius: 4px;
}

.submenu a {
  padding-left: 20px;
  border: none;
}

.submenu-container.open .submenu {
  display: flex;
}

.card-link {
  text-decoration: none;
  color: inherit;
  display: block;
}
.card-icon {
  margin-bottom: 0.5rem;
}
.card-icon img {
  width: 64px;
  height: 64px;
}


/* Mobile */
@media (max-width: 768px) {
  .header-right {
    flex-direction: column;
    align-items: flex-end;
  }

  nav {
    display: none;
    flex-direction: column;
    background: var(--header-bg);
    position: absolute;
    top: 60px;
    right: 20px;
    width: fit-content;
    border-radius: 8px;
  }

  nav a {
    padding: 5px;
    margin: 5px 0;
  }

  .menu-toggle {
    display: flex;
  }

  nav.active {
    display: flex;
  }

  .theme-toggle {
    margin-top: 10px;
  }
}

/* Dark Mode Table Fixes */
body[data-theme="dark"] table,
body[data-theme="dark"] td,
body[data-theme="dark"] th {
  background-color: var(--card-bg);
  color: var(--text-color);
}

body[data-theme="dark"] tr:nth-child(even) {
  background-color: #2a2a2a;
}

html {
  scroll-behavior: smooth;
}