/* ==========================================
   CSS Variables & WCAG 2.1 Theming
   ========================================== */
:root {
    --bg-color: #ffffff;
    --text-color: #0f172a; /* Slate 900 for high contrast */
    --text-muted: #475569; /* Slate 600 */
    --card-bg: #f8fafc;
    --border-color: #e2e8f0;
    --accent: #2563eb; /* Accessible Blue */
    --focus-ring: #3b82f6;
}

body.dark-mode {
    --bg-color: #0f172a; /* Slate 900 */
    --text-color: #f8fafc; /* Slate 50 */
    --text-muted: #94a3b8; /* Slate 400 */
    --card-bg: #1e293b; /* Slate 800 */
    --border-color: #334155; /* Slate 700 */
    --accent: #60a5fa; 
    --focus-ring: #93c5fd;
}

/* ==========================================
   Base & Typography (WCAG Compliant)
   ========================================== */
body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
    font-size: 16px; /* Base scalable size */
    line-height: 1.6; /* WCAG requires at least 1.5 */
    transition: background-color 0.3s ease, color 0.3s ease, font-size 0.3s ease;
    margin: 0;
    padding: 0;
}

/* WCAG Focus States for Keyboard Navigation */
*:focus-visible {
    outline: 3px solid var(--focus-ring);
    outline-offset: 3px;
    border-radius: 4px;
}

/* Container limits width for readability (WCAG cognitive guidance) */
.content {
    max-width: 800px;
    margin: 0 auto;
    padding: 4rem 2rem;
}

/* Headings */
h1, h2, h3 {
    line-height: 1.2;
    margin-top: 2rem;
    margin-bottom: 1rem;
    color: var(--text-color);
}

h1 {
    font-size: 2.5rem;
    font-weight: 800;
    text-align: center;
    letter-spacing: -0.025em;
}

p {
    margin-bottom: 1.5rem;
    color: var(--text-muted);
}

hr {
    border: 0;
    height: 1px;
    background-color: var(--border-color);
    margin: 3rem 0;
}

/* ==========================================
   Navigation
   ========================================== */
.top-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    background-color: var(--bg-color);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-brand {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-color);
}

.nav-links {
    list-style: none;
    display: flex;
    gap: 2rem;
    margin: 0;
    padding: 0;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-muted);
    font-weight: 500;
    transition: color 0.2s ease;
}

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

/* ==========================================
   Modern Components (Cards & Callouts)
   ========================================== */
.callout {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-left: 4px solid var(--accent);
    padding: 2rem;
    border-radius: 8px;
    margin: 2rem 0;
    text-align: center;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
}

.callout h2 {
    margin-top: 0;
    color: var(--text-color);
    font-size: 1.5rem;
}

.callout p {
    margin-bottom: 0;
    font-size: 1.125rem;
    font-weight: 500;
    color: var(--text-muted);
}

/* Modern Card Grid */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    margin-top: 1.5rem;
}

.card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    padding: 1.5rem;
    border-radius: 8px;
}

/* ==========================================
   Top Right Floating Controls (Like Video)
   ========================================== */
/* ==========================================
   Bottom Right Floating Controls
   ========================================== */
.floating-controls {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    display: flex;
    flex-direction: row; /* Keeps the neat horizontal pill layout */
    gap: 0.5rem;
    z-index: 1001; 
}

.floating-controls button {
    background-color: var(--bg-color);
    color: var(--text-color);
    border: 1px solid var(--border-color);
    width: 40px;
    height: 40px;
    border-radius: 50%; /* Circle buttons */
    cursor: pointer;
    font-weight: 600;
    font-size: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}

.floating-controls button:hover {
    background-color: var(--card-bg);
    transform: translateY(-2px);
}

.floating-controls button[aria-pressed="true"] {
    background-color: var(--text-color);
    color: var(--bg-color);
    border-color: var(--text-color);
}

/* ==========================================
   Cursor Dot Trailer
   ========================================== */
.cursor-dot {
    position: fixed;
    width: 8px;
    height: 8px;
    background-color: var(--accent);
    box-shadow: 0 0 12px var(--accent);
    border-radius: 50%;
    pointer-events: none;
    transform: translate(-50%, -50%);
    animation: fadeOutDot 3.5s ease-out forwards;
    z-index: 9999;
    will-change: transform, opacity;
}

@keyframes fadeOutDot {
    0% { opacity: 1; transform: translate(-50%, -50%) scale(var(--start-scale, 1)); }
    100% { opacity: 0; transform: translate(-50%, -50%) scale(0); }
}

/* ==========================================
   Responsive Images & Captions
   ========================================== */
.responsive-img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    display: block;
    margin: 1.5rem auto 0.5rem auto;
}

.image-caption {
    font-size: 0.875rem;
    color: var(--text-muted);
    text-align: center;
    font-style: italic;
    margin-bottom: 2.5rem;
}