:root {
    --bg-color: #000000;
    --text-primary: #ffffff;
    --text-muted: rgba(255, 255, 255, 0.45);
    --accent-cyan: #00f2ff;
    --accent-magenta: #ff00ff;
    --glow-cyan: 0 0 20px rgba(0, 242, 255, 0.6);
    --glow-magenta: 0 0 20px rgba(255, 0, 255, 0.6);
    --hud-bg: rgba(10, 10, 12, 0.6);
    --hud-border: rgba(255, 255, 255, 0.08);
    --font-heading: 'Outfit', 'Helvetica Neue', sans-serif;
    --font-body: 'Space Grotesk', sans-serif;
}

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

body, html {
    background: var(--bg-color);
    color: var(--text-primary);
    font-family: var(--font-body);
    font-size: 16px;
    overflow-x: hidden;
    scrollbar-width: none;
    height: 100%;
    min-height: 100vh;
    min-height: 100dvh;
    width: 100%;
}

body::-webkit-scrollbar {
    display: none;
}

/* Background Canvas */
#webgl-canvas {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    height: 100vh;
    height: 100dvh;
    z-index: 1;
    pointer-events: none;
}

/* Glassmorphism utility */
.glass {
    background: var(--hud-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--hud-border);
    border-radius: 4px;
}

/* LOADER / START SCREEN */
.screen-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    height: 100vh;
    height: 100dvh;
    background: #000000;
    z-index: 2000;
    display: flex;
    justify-content: center;
    align-items: center;
    opacity: 0;
    pointer-events: none;
    transition: opacity 1s ease-in-out;
}

.screen-overlay.active {
    opacity: 1;
    pointer-events: all;
}

.loader-content {
    text-align: center;
    max-width: 600px;
    padding: 2rem;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.glitch-title {
    font-family: var(--font-heading);
    font-size: 5rem;
    font-weight: 900;
    letter-spacing: 0.25em;
    color: var(--text-primary);
    position: relative;
    margin-bottom: 0.5rem;
    text-shadow: 0 0 10px rgba(255, 255, 255, 0.2);
}

.subtitle {
    font-size: 0.85rem;
    letter-spacing: 0.5em;
    color: var(--accent-cyan);
    font-weight: 600;
    margin-bottom: 2rem;
    text-transform: uppercase;
}

.divider {
    width: 80px;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--accent-cyan), var(--accent-magenta), transparent);
    margin-bottom: 2rem;
}

.tagline {
    font-size: 1.1rem;
    color: var(--text-muted);
    font-weight: 300;
    line-height: 1.6;
    margin-bottom: 3rem;
}

.btn-primary {
    background: transparent;
    border: 1px solid var(--text-primary);
    color: var(--text-primary);
    padding: 1rem 2.5rem;
    font-family: var(--font-heading);
    font-size: 0.9rem;
    letter-spacing: 0.3em;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.4s ease;
    border-radius: 2px;
}

.btn-primary:hover {
    background: var(--text-primary);
    color: #000000;
    box-shadow: 0 0 30px rgba(255, 255, 255, 0.35);
    transform: translateY(-2px);
}

.hint {
    margin-top: 1.5rem;
    font-size: 0.75rem;
    letter-spacing: 0.1em;
    color: rgba(255, 255, 255, 0.25);
    text-transform: uppercase;
}

.hint .hint-touch {
    display: none;
}

.hint .hint-desktop {
    display: inline;
}

@media (hover: none) and (pointer: coarse) {
    .hint .hint-desktop {
        display: none;
    }
    .hint .hint-touch {
        display: inline;
    }
}

/* HUD STRUCTURE */
#hud {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    height: 100vh;
    height: 100dvh;
    z-index: 100;
    pointer-events: none;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

#hud * {
    pointer-events: all;
}

/* Header */
.hud-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.25rem 2.5rem;
    width: 95%;
    margin: 1.5rem auto 0;
    border-radius: 8px;
}

.hud-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
    color: inherit;
    cursor: pointer;
}

.logo-dot {
    width: 8px;
    height: 8px;
    background: var(--text-primary);
    border-radius: 50%;
    box-shadow: 0 0 10px #fff;
    animation: pulse-dot 2s infinite ease-in-out;
}

@keyframes pulse-dot {
    0%, 100% { transform: scale(1); opacity: 0.5; }
    50% { transform: scale(1.5); opacity: 1; }
}

.logo-text {
    font-family: var(--font-heading);
    font-size: 1.1rem;
    font-weight: 900;
    letter-spacing: 0.3em;
}

.hud-dimension {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-family: var(--font-heading);
    font-size: 0.85rem;
    letter-spacing: 0.2em;
}

.hud-dimension .act {
    color: var(--accent-magenta);
    font-weight: 700;
    text-shadow: 0 0 10px rgba(255, 0, 255, 0.5);
    margin-right: 1.25rem;
    font-size: 0.75rem;
}

.hud-dimension .label {
    color: var(--text-muted);
    font-weight: 300;
}

.hud-dimension #active-dimension-num {
    font-weight: 900;
    color: var(--accent-cyan);
    text-shadow: var(--glow-cyan);
}

.hud-dimension .dash {
    color: rgba(255, 255, 255, 0.15);
}

.hud-dimension #active-dimension-name {
    font-weight: 600;
    text-transform: uppercase;
}

.btn-icon {
    background: transparent;
    border: none;
    color: var(--text-primary);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-family: var(--font-heading);
    font-size: 0.75rem;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    transition: opacity 0.3s ease;
    opacity: 0.8;
}

.btn-icon:hover {
    opacity: 1;
}

.btn-icon .icon {
    width: 18px;
    height: 18px;
}

.btn-icon.muted {
    color: var(--text-muted);
}

.hidden {
    display: none !important;
}

/* Progress bar container */
.hud-progress-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: rgba(255, 255, 255, 0.05);
    z-index: 1000;
}

#hud-progress-bar {
    width: 0%;
    height: 100%;
    background: linear-gradient(90deg, var(--accent-cyan), var(--accent-magenta));
    box-shadow: 0 0 10px var(--accent-cyan);
    transition: width 0.1s ease-out;
}

/* NARRATIVE POSTERS */
#narrative-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    height: 100vh;
    height: 100dvh;
    z-index: 50;
    pointer-events: none;
}

.poster {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    height: 100vh;
    height: 100dvh;
    display: flex;
    flex-direction: column;
    padding: 12vh 10vw;
    opacity: 0;
    pointer-events: none;
}

.poster.active {
    opacity: 1;
}

.poster.layout-center {
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 10vh 15vw;
}

.poster.layout-left {
    justify-content: center;
    align-items: flex-start;
    text-align: left;
}

.poster.layout-right {
    justify-content: center;
    align-items: flex-end;
    text-align: right;
}

.poster.layout-bottom {
    justify-content: flex-end;
    align-items: center;
    text-align: center;
    padding-bottom: 12vh;
}

.poster h1 {
    font-family: var(--font-heading);
    font-size: 0.8rem;
    letter-spacing: 0.7em;
    color: var(--accent-cyan);
    text-transform: uppercase;
    margin-bottom: 1.5rem;
    text-shadow: var(--glow-cyan);
}

.poster h2 {
    font-family: var(--font-heading);
    font-size: 3.2rem;
    font-weight: 900;
    letter-spacing: -0.02em;
    line-height: 1.1;
    margin-bottom: 1.5rem;
}

.poster p {
    font-size: 1.15rem;
    font-weight: 300;
    line-height: 1.7;
    color: var(--text-muted);
    max-width: 500px;
    letter-spacing: 0.05em;
}

.poster.layout-center p {
    max-width: 600px;
}

.poster strong {
    color: var(--text-primary);
    font-weight: 700;
}

/* Dynamic sub-elements styled dynamically */
.choice-label {
    position: absolute;
    color: #fff;
    font-family: var(--font-heading);
    font-size: 0.8rem;
    letter-spacing: 0.2em;
    padding: 4px 8px;
    border: 1px solid rgba(255,255,255,0.2);
    border-radius: 4px;
    background: rgba(0,0,0,0.6);
    pointer-events: none;
    transform: translate(-50%, -50%);
    opacity: 0;
    transition: opacity 0.5s ease;
}

/* SCROLL PROMPT */
#scroll-prompt {
    position: fixed;
    bottom: 2.5rem;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    opacity: 0.6;
    animation: pulse-scroll-prompt 2.5s infinite ease-in-out;
}

@keyframes pulse-scroll-prompt {
    0%, 100% { opacity: 0.35; transform: translate(-50%, 0); }
    50% { opacity: 0.8; transform: translate(-50%, -5px); }
}

.mouse-icon {
    width: 20px;
    height: 32px;
    border: 1.5px solid var(--text-primary);
    border-radius: 12px;
    position: relative;
}

.mouse-icon .wheel {
    width: 3px;
    height: 6px;
    background: var(--accent-cyan);
    border-radius: 50%;
    position: absolute;
    top: 6px;
    left: 50%;
    transform: translateX(-50%);
    animation: scroll-wheel-anim 1.6s infinite ease-in-out;
    box-shadow: var(--glow-cyan);
}

@keyframes scroll-wheel-anim {
    0% { top: 6px; opacity: 1; }
    80% { top: 18px; opacity: 0; }
    100% { top: 6px; opacity: 0; }
}

#scroll-prompt .text {
    font-size: 0.65rem;
    letter-spacing: 0.4em;
    text-transform: uppercase;
    font-weight: 700;
}

/* CREDITS OVERLAY (THE LOOP / BEYOND) */
.credits-container {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 10vh 15vw;
    box-sizing: border-box;
    pointer-events: none;
    transition: opacity 1.5s ease-in-out;
}

.credits-main {
    font-family: var(--font-heading);
    font-size: clamp(1.4rem, 4.2vw, 2.5rem);
    font-weight: 900;
    line-height: 1.25;
    letter-spacing: -0.01em;
    color: var(--text-primary);
    margin-bottom: 1.25rem;
    max-width: 700px;
    text-shadow: 0 0 25px rgba(255, 255, 255, 0.45);
    word-break: break-word;
}

.credits-sub {
    font-family: var(--font-body);
    font-size: clamp(0.75rem, 2vw, 0.95rem);
    letter-spacing: 0.35em;
    text-transform: uppercase;
    color: var(--accent-cyan);
    font-weight: 600;
    margin-bottom: 1.75rem;
    text-shadow: var(--glow-cyan);
}

.credits-link-wrap {
    margin-top: 0.25rem;
}

.credits-link {
    pointer-events: auto;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 44px;
    padding: 0.65rem 1.5rem;
    font-family: var(--font-heading);
    font-size: clamp(0.75rem, 1.8vw, 0.85rem);
    letter-spacing: 0.2em;
    text-transform: uppercase;
    font-weight: 600;
    color: var(--text-primary);
    text-decoration: none;
    border: 1px solid rgba(0, 242, 255, 0.5);
    background: rgba(0, 242, 255, 0.08);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border-radius: 4px;
    box-shadow: 0 0 15px rgba(0, 242, 255, 0.25);
    transition: all 0.3s ease;
}

.credits-link:hover {
    background: var(--accent-cyan);
    color: #000000;
    box-shadow: 0 0 25px rgba(0, 242, 255, 0.7);
    transform: translateY(-2px);
}

/* SCROLL ENGINE PROXY */
#scroll-engine {
    height: 5214vh; /* 13 segments * 357.14vh (dur 10) + ending 571.43vh (dur 16) */
    width: 100%;
    position: absolute;
    top: 0;
    left: 0;
    pointer-events: none;
    z-index: 0;
}

/* RESPONSIVE MEDIA QUERIES (MOBILE OPTIMIZATIONS) */
@media (max-width: 768px) {
    /* a) Loader scaling */
    .loader-content {
        padding: 1.5rem 1rem;
        width: 100%;
        max-width: 100%;
    }

    .glitch-title {
        font-size: clamp(2rem, 9.2vw, 3.2rem);
        letter-spacing: 0.08em;
        margin-bottom: 0.5rem;
    }

    .subtitle {
        font-size: clamp(0.65rem, 2.5vw, 0.75rem);
        letter-spacing: 0.2em;
        margin-bottom: 1.25rem;
    }

    .divider {
        margin-bottom: 1.25rem;
    }

    .tagline {
        font-size: clamp(0.85rem, 3.5vw, 1rem);
        line-height: 1.5;
        margin-bottom: 1.75rem;
        padding: 0 0.5rem;
    }

    .btn-primary {
        padding: 0.85rem 1.8rem;
        font-size: 0.8rem;
        letter-spacing: 0.18em;
        min-height: 44px;
        display: inline-flex;
        align-items: center;
        justify-content: center;
    }

    .hint {
        margin-top: 1rem;
        font-size: 0.7rem;
        letter-spacing: 0.05em;
        padding: 0 0.5rem;
    }

    /* b) HUD header compact one-row layout */
    .hud-header {
        width: calc(100% - 16px);
        margin: 8px auto 0;
        padding: 0.35rem 0.6rem;
        gap: 0.4rem;
        border-radius: 6px;
    }

    .hud-brand {
        gap: 0.4rem;
        flex-shrink: 0;
    }

    .hud-brand .logo-text {
        font-size: 0.8rem;
        letter-spacing: 0.15em;
    }

    .hud-dimension {
        gap: 0.3rem;
        font-size: 0.7rem;
        letter-spacing: 0.05em;
        overflow: hidden;
        text-overflow: ellipsis;
        white-space: nowrap;
        flex: 1;
        justify-content: center;
        min-width: 0;
    }

    .hud-dimension .act {
        display: none !important;
    }

    .hud-dimension .dash {
        margin: 0 2px;
    }

    .hud-dimension #active-dimension-name {
        overflow: hidden;
        text-overflow: ellipsis;
        white-space: nowrap;
    }

    .hud-audio {
        flex-shrink: 0;
    }

    #btn-audio-toggle {
        min-width: 44px;
        min-height: 44px;
        padding: 0;
        display: inline-flex;
        align-items: center;
        justify-content: center;
    }

    #audio-status-text {
        display: none;
    }

    /* c) Narrative posters scaling */
    .poster {
        padding: 4.8rem 1.25rem 2rem;
    }

    .poster.layout-center {
        padding: 4.8rem 1.25rem 2rem;
    }

    .poster.layout-left,
    .poster.layout-right {
        padding: 4.8rem 1.25rem 2rem;
        text-align: left;
        align-items: flex-start;
    }

    .poster.layout-bottom {
        padding: 4.8rem 1.25rem 4.5rem;
    }

    .poster h1 {
        font-size: 0.65rem;
        letter-spacing: 0.35em;
        margin-bottom: 0.75rem;
    }

    .poster h2 {
        font-size: clamp(1.75rem, 6.2vw, 2.4rem);
        line-height: 1.15;
        margin-bottom: 0.75rem;
        word-break: break-word;
    }

    .poster p {
        font-size: clamp(0.9rem, 3.4vw, 1.05rem);
        line-height: 1.55;
        max-width: 100%;
        word-break: break-word;
    }

    /* Credits mobile styling */
    .credits-container {
        padding: 4.8rem 1.25rem 2rem;
        width: 100%;
        max-width: 100%;
    }

    .credits-main {
        font-size: clamp(1.25rem, 5.2vw, 1.85rem);
        line-height: 1.25;
        margin-bottom: 1rem;
    }

    .credits-sub {
        font-size: clamp(0.7rem, 2.6vw, 0.85rem);
        letter-spacing: 0.2em;
        margin-bottom: 1.25rem;
    }

    .credits-link {
        font-size: clamp(0.7rem, 2.4vw, 0.8rem);
        letter-spacing: 0.12em;
        padding: 0.6rem 1rem;
    }

    /* Scroll indicator prompt */
    #scroll-prompt {
        bottom: 1.25rem;
        gap: 0.35rem;
    }

    .mouse-icon {
        width: 16px;
        height: 26px;
    }

    #scroll-prompt .text {
        font-size: 0.55rem;
        letter-spacing: 0.25em;
    }
}

/* Very compact mobile phones (e.g. 360x800) */
@media (max-width: 380px) {
    .hud-brand .logo-text {
        display: none;
    }

    .hud-dimension {
        font-size: 0.65rem;
        letter-spacing: 0.03em;
    }

    .glitch-title {
        font-size: clamp(1.85rem, 8.5vw, 2.2rem);
        letter-spacing: 0.06em;
    }
}