/* --- Grid Canvas Background (Task 12) --- */
#grid-canvas {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    pointer-events: none;
    opacity: 1;
    transition: opacity 0.6s ease-out;
}

#grid-canvas.grid-hidden {
    opacity: 0;
}

/* --- System Layers (Task 18) --- */

/* Layer 1: Digital Grid */
.sys-grid {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
    pointer-events: none;
    background-image:
        linear-gradient(rgba(0, 128, 128, 0.05) 1px, transparent 1px),
        linear-gradient(90deg, rgba(0, 128, 128, 0.05) 1px, transparent 1px);
    background-size: 40px 40px;
    opacity: 0;
    transition: opacity 0.8s ease;
}

/* Layer 2: Parallax Watermarks */
.sys-watermarks {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
    pointer-events: none;
    overflow: hidden;
    opacity: 0;
    transition: opacity 0.8s ease;
}

.watermark {
    position: absolute;
    font-family: var(--font-heading);
    font-size: clamp(3rem, 8vw, 6rem);
    color: rgba(0, 128, 128, 0.06);
    white-space: nowrap;
    letter-spacing: 0.2em;
    will-change: transform;
    user-select: none;
}

.wm-1 {
    top: 15%;
    left: -5%;
    transform: rotate(-12deg);
}

.wm-2 {
    top: 50%;
    right: -10%;
    transform: rotate(8deg);
}

.wm-3 {
    bottom: 10%;
    left: 10%;
    transform: rotate(-5deg);
}

/* Activation class — toggled by JS after scrolling past hero */
.layers-active .sys-grid,
.layers-active .sys-watermarks {
    opacity: 1;
}

/* Mobile: tone down layers */
@media (max-width: 768px) {
    .watermark {
        font-size: clamp(1.5rem, 5vw, 3rem);
        opacity: 0.7;
    }

    .sys-grid {
        background-size: 30px 30px;
    }
}

/* --- Easter Egg Bug (Task 12) --- */
.easter-bug {
    position: fixed;
    z-index: 5;
    font-size: 18px;
    line-height: 1;
    opacity: 0;
    pointer-events: auto;
    cursor: pointer;
    filter: drop-shadow(0 0 0px transparent);
    transition: opacity 0.3s ease, filter 0.3s ease;
    animation: bug-drift 4s ease-in-out infinite;
}

.easter-bug.bug-hidden {
    opacity: 0 !important;
    filter: none !important;
    animation-play-state: paused;
}

.easter-bug.bug-glow {
    filter: drop-shadow(0 0 8px var(--color-accent)) drop-shadow(0 0 16px var(--color-accent));
}

.easter-bug.bug-pulse {
    animation: bug-drift 4s ease-in-out infinite, bug-pulse-glow 2s ease-in-out infinite;
}

.easter-bug.bug-caught {
    animation: none !important;
    transform: scale(0) rotate(180deg) !important;
    opacity: 0 !important;
    pointer-events: none;
    transition: transform 0.4s ease-in, opacity 0.4s ease-out;
}

@keyframes bug-drift {

    0%,
    100% {
        transform: translate(0, 0);
    }

    25% {
        transform: translate(2px, -3px);
    }

    50% {
        transform: translate(-1px, 2px);
    }

    75% {
        transform: translate(3px, 1px);
    }
}

@keyframes bug-pulse-glow {

    0%,
    100% {
        filter: drop-shadow(0 0 2px rgba(45, 212, 191, 0.1));
    }

    50% {
        filter: drop-shadow(0 0 6px rgba(45, 212, 191, 0.35));
    }
}

/* --- Toast Notification --- */
.toast {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    background: rgba(17, 24, 32, 0.95);
    color: var(--color-accent);
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    border: 1px solid var(--color-accent);
    font-family: var(--font-mono);
    font-size: 0.9rem;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
    z-index: 1000;
    opacity: 0;
    transform: translateY(10px);
    transition: opacity 0.3s ease, transform 0.3s ease;
    pointer-events: none;
}

.toast.show {
    opacity: 1;
    transform: translateY(0);
}

/* --- Reduced Motion --- */
@media (prefers-reduced-motion: reduce) {

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}