/* Prevent FOUC by hiding content until stylesheets load */
html {
    visibility: hidden;
    opacity: 0;
}

html.loaded {
    visibility: visible;
    opacity: 1;
    transition: opacity 0.1s ease-in;
}

/* Legend dots for content guide */
.legend-dot {
    display: inline-block;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    margin-right: 0.3rem;
    vertical-align: middle;
}

/* Reading progress indicator */
.reading-progress {
    position: fixed;
    top: 0;
    left: 0;
    width: 0%;
    height: 2px;
    background: #333;
    z-index: 1000;
    transition: width 0.1s ease-out;
}

/* Header and nav z-index for dropdown stacking */
header {
    position: relative;
    z-index: 9999;
}

nav {
    position: relative;
    z-index: 9999;
}

nav > a, nav > .nav-dropdown {
    margin-right: 1rem;
}

.nav-dropdown {
    position: relative;
    display: inline-block;
}

.nav-dropdown-trigger {
    cursor: pointer;
    color: inherit;
    text-decoration: underline;
    padding-bottom: 1rem;
    display: inline-block;
}

.nav-dropdown-content {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background: white;
    border: 1px solid #ddd;
    border-radius: 4px;
    min-width: 250px;
    max-width: 400px;
    max-height: 500px;
    overflow-y: auto;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    z-index: 10000;
    padding: 0.75rem;
}

.nav-dropdown:hover .nav-dropdown-content,
.nav-dropdown-content:hover {
    display: block;
}

.tree-item {
    padding: 0.35rem 0;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.tree-item-icon {
    flex-shrink: 0;
    width: 18px;
    height: 18px;
}

.tree-item a {
    color: #333;
    text-decoration: none;
    flex: 1;
}

.tree-item a:hover {
    text-decoration: underline;
}

.tree-folder a {
    font-weight: 500;
}

body.dark-mode .nav-dropdown-content {
    background: #1a1a1a;
    border-color: #333;
}

body.dark-mode .tree-item a {
    color: #ccc;
}

@media (prefers-color-scheme: dark) {
    .nav-dropdown-content {
        background: #1a1a1a;
        border-color: #333;
    }

    .tree-item a {
        color: #ccc;
    }
}

.github-corner {
    position: absolute;
    top: 0;
    right: 0;
    z-index: 9998;
    opacity: 0.85;
    transition: opacity 0.3s ease;
}

.github-corner:hover {
    opacity: 0.8;
}

.github-corner-img {
    width: 80px;
    height: 80px;
}

body.dark-mode .github-corner {
    opacity: 0.25;
}

body.dark-mode .github-corner-img {
    filter: invert(1);
}

@media (max-width: 760px) {
    .github-corner-img {
        width: 50px;
        height: 50px;
    }
}

.theme-toggle {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 1.5rem;
    padding: 0.5rem;
    margin: 0;
    opacity: 0.15;
    transition: opacity 0.3s ease;
    line-height: 1;
    z-index: 9999;
}

.theme-toggle:hover {
    opacity: 0.8;
}

.sun-icon,
.moon-icon {
    display: none;
}

body.light-mode .sun-icon {
    display: inline;
}

body.dark-mode .moon-icon {
    display: inline;
}

/* Dark mode styles using body class */
body.dark-mode {
    background-color: #0d1117;
    color: #c9d1d9;
}

/* Light mode styles to override media query */
body.light-mode {
    background-color: #fffff8;
    color: #111;
}

@media (max-width: 760px) {
    .theme-toggle {
        font-size: 1.3rem;
        bottom: 1rem;
        right: 1rem;
        padding: 0.4rem;
    }
}

main {
    position: relative;
    z-index: 1;
}

article {
    position: relative;
    z-index: 1;
}

/* Dropdown navigation styles */
.nav-dropdown {
    position: relative;
    display: inline-block;
    padding: 0.5rem;
    margin: -0.5rem;
    z-index: 9999;
}

.nav-dropdown .dropdown-content {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    background-color: #fff;
    border: 1px solid #ddd;
    border-radius: 4px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
    z-index: 999999;
    min-width: 280px;
    padding: 0.5rem 0;
    margin-top: -1px;
}

.nav-dropdown:hover .dropdown-content {
    display: block;
}

.nav-dropdown .dropdown-content a {
    display: block;
    padding: 0.5rem 1rem;
    color: #333;
    text-decoration: none;
    border-bottom: none;
    font-size: 0.9rem;
    line-height: 1.4;
}

.nav-dropdown .dropdown-content a:hover {
    background-color: #f5f5f5;
}

.nav-dropdown .dropdown-content a .index-description {
    display: block;
    font-size: 0.75rem;
    color: #666;
    margin-top: 0.1rem;
}

.nav-dropdown > a::after {
    content: "\00a0\25BC";
    font-size: 0.7rem;
    color: #999;
}