/* ============================================
   undo.quest - Muji x Arcade Glitch
   ============================================ */

/* CSS Custom Properties */
:root {
    --canvas: #FAFAF7;
    --deep-ground: #0A0E27;
    --primary-neon: #FF006E;
    --secondary-neon: #39FF14;
    --tertiary-neon: #00F0FF;
    --circuit-trace: #B8B5AD;
    --text-primary: #1A1A1A;
    --glitch-shadow: #7B2FBE;

    --font-headline: 'Caveat', cursive;
    --font-body: 'Inter', sans-serif;
    --font-accent: 'Inconsolata', monospace;

    --gutter: 48px;
    --margin-outer: 80px;
    --content-max: 640px;
}

/* Reset */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    background-color: var(--canvas);
    color: var(--text-primary);
    font-family: var(--font-body);
    font-weight: 400;
    font-size: clamp(1rem, 1.1vw, 1.15rem);
    line-height: 1.75;
    letter-spacing: 0.005em;
    overflow-x: hidden;
    position: relative;
}

/* Scanline Overlay */
.scanline-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 9999;
    background: repeating-linear-gradient(
        to bottom,
        rgba(0, 0, 0, 0.03) 0px,
        rgba(0, 0, 0, 0.03) 1px,
        transparent 1px,
        transparent 4px
    );
}

/* Scroll Progress Indicator */
.scroll-progress {
    position: fixed;
    bottom: 24px;
    left: 24px;
    width: 10px;
    height: 120px;
    z-index: 100;
}

.progress-circuit {
    width: 100%;
    height: 100%;
}

.progress-track {
    stroke: var(--circuit-trace);
    stroke-width: 1;
    opacity: 0.4;
}

.progress-fill {
    stroke: var(--primary-neon);
    stroke-width: 1.5;
    stroke-dasharray: 200;
    stroke-dashoffset: 200;
    transition: stroke-dashoffset 0.1s linear;
}

.progress-dot {
    fill: var(--primary-neon);
    opacity: 0;
    transition: opacity 0.3s;
}

.progress-dot.active {
    opacity: 1;
    filter: drop-shadow(0 0 4px var(--primary-neon));
}

/* Section Base */
.section {
    position: relative;
    min-height: 100vh;
    padding-left: var(--margin-outer);
    padding-right: var(--margin-outer);
}

/* Section Headlines */
.section-headline {
    font-family: var(--font-headline);
    font-weight: 700;
    font-size: clamp(2.2rem, 5.5vw, 4.8rem);
    letter-spacing: 0.01em;
    color: var(--text-primary);
    position: relative;
    display: inline-block;
}

.section-headline-light {
    color: var(--canvas);
}

/* Display Numerals */
.display-numeral {
    font-family: var(--font-headline);
    font-size: clamp(6rem, 15vw, 12rem);
    -webkit-text-stroke: 1.5px var(--primary-neon);
    -webkit-text-fill-color: transparent;
    color: transparent;
    line-height: 1;
    opacity: 0.3;
    user-select: none;
}

.display-numeral-light {
    -webkit-text-stroke-color: var(--tertiary-neon);
}

/* Accent Labels */
.accent-label {
    font-family: var(--font-accent);
    font-size: 0.85rem;
    color: var(--secondary-neon);
    text-transform: lowercase;
    margin-top: 4px;
    margin-bottom: 34px;
}

.accent-label-light {
    color: var(--secondary-neon);
}

/* Annotations */
.annotation {
    font-family: var(--font-headline);
    font-size: 0.75rem;
    color: var(--text-primary);
    opacity: 0.4;
    transition: opacity 0.3s ease;
    user-select: none;
    position: absolute;
}

.annotation:hover {
    opacity: 0.8;
}

/* Glitch Text Effect */
.glitch-text {
    position: relative;
}

.glitch-text::before,
.glitch-text::after {
    content: attr(data-text);
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    pointer-events: none;
}

.glitch-text::before {
    color: var(--primary-neon);
    z-index: -1;
}

.glitch-text::after {
    color: var(--tertiary-neon);
    z-index: -1;
}

.glitch-text.glitching::before {
    opacity: 0.7;
    animation: glitch-shift-left 200ms steps(2) forwards;
}

.glitch-text.glitching::after {
    opacity: 0.7;
    animation: glitch-shift-right 200ms steps(2) forwards;
}

@keyframes glitch-shift-left {
    0% { transform: translate(-2px, 0); }
    50% { transform: translate(-4px, 1px); }
    100% { transform: translate(0, 0); }
}

@keyframes glitch-shift-right {
    0% { transform: translate(2px, 0); }
    50% { transform: translate(4px, -1px); }
    100% { transform: translate(0, 0); }
}

/* ============================================
   Section 1: The Buffer (Hero)
   ============================================ */
.section-buffer {
    display: flex;
    align-items: center;
    justify-content: flex-start;
    height: 100vh;
    padding-top: 0;
    padding-bottom: 0;
}

.buffer-content {
    position: relative;
    max-width: var(--content-max);
    margin-left: calc(8.333vw);
}

.buffer-word-container {
    display: inline-flex;
    align-items: baseline;
}

.buffer-word {
    font-family: var(--font-headline);
    font-weight: 700;
    font-size: clamp(3rem, 8vw, 6rem);
    letter-spacing: 0.01em;
    color: var(--text-primary);
    position: relative;
    min-height: 1.2em;
    display: inline-block;
}

.buffer-cursor {
    font-family: var(--font-accent);
    font-size: clamp(3rem, 8vw, 6rem);
    color: var(--primary-neon);
    animation: cursor-blink 1s step-end infinite;
    margin-left: 2px;
}

@keyframes cursor-blink {
    0%, 100% { opacity: 1; }
    50% { opacity: 0; }
}

.buffer-annotation {
    right: -60px;
    top: -20px;
}

/* Strikethrough animation for erasing words */
.buffer-word.erasing {
    text-decoration: line-through;
    text-decoration-color: var(--primary-neon);
    text-decoration-thickness: 2px;
}

/* ============================================
   Section 2: The Stack
   ============================================ */
.section-stack {
    padding-top: 89px;
    padding-bottom: 144px;
}

.section-number {
    position: absolute;
    right: var(--margin-outer);
    top: 40px;
}

.stack-content {
    max-width: var(--content-max);
    margin-left: calc(8.333vw);
    position: relative;
}

.stack-entries {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.stack-entry {
    position: relative;
    background: rgba(250, 250, 247, 0.85);
    border: 1px solid var(--circuit-trace);
    border-radius: 2px;
    padding: 20px 24px;
    transition: transform 0.4s cubic-bezier(0.23, 1, 0.32, 1), opacity 0.4s ease, box-shadow 0.3s ease;
    cursor: default;
    overflow: hidden;
}

.stack-entry::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    border: 1px solid transparent;
    border-radius: 2px;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
    pointer-events: none;
}

.stack-entry:hover::before {
    border-color: var(--tertiary-neon);
    box-shadow: 0 0 8px rgba(0, 240, 255, 0.15);
}

.stack-entry.faded {
    opacity: 0.35;
    transform: scale(0.98);
}

.entry-circuit-border {
    position: absolute;
    top: 0;
    left: 0;
    width: 3px;
    height: 100%;
    background: var(--circuit-trace);
    transition: background 0.3s ease;
}

.stack-entry:hover .entry-circuit-border {
    background: var(--tertiary-neon);
    box-shadow: 0 0 6px rgba(0, 240, 255, 0.4);
}

.entry-timestamp {
    font-family: var(--font-accent);
    font-size: 0.75rem;
    color: var(--circuit-trace);
    display: block;
    margin-bottom: 8px;
}

.entry-text {
    font-family: var(--font-body);
    font-size: clamp(0.9rem, 1vw, 1rem);
    line-height: 1.65;
    color: var(--text-primary);
}

.stack-annotation {
    bottom: -40px;
    right: 0;
}

/* ============================================
   Section 3: The Fork
   ============================================ */
.section-fork {
    padding-top: 89px;
    padding-bottom: 144px;
}

.fork-content {
    max-width: 900px;
    margin-left: calc(8.333vw);
    position: relative;
}

.fork-panels {
    display: flex;
    gap: 0;
    align-items: stretch;
    margin-top: 34px;
}

.fork-panel {
    flex: 1;
    padding: 32px;
    background: rgba(250, 250, 247, 0.7);
    border: 1px solid var(--circuit-trace);
    position: relative;
    transition: transform 0.6s cubic-bezier(0.23, 1, 0.32, 1);
}

.fork-panel-before {
    border-radius: 2px 0 0 2px;
    transform: translateX(0);
}

.fork-panel-after {
    border-radius: 0 2px 2px 0;
    transform: translateX(0);
}

.fork-panel-before.split {
    transform: translateX(-20px);
}

.fork-panel-after.split {
    transform: translateX(20px);
}

.panel-label {
    font-family: var(--font-accent);
    font-size: 0.75rem;
    color: var(--secondary-neon);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: 16px;
    display: block;
}

.panel-text {
    font-family: var(--font-body);
    font-size: clamp(0.9rem, 1vw, 1rem);
    line-height: 1.65;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.panel-text:last-child {
    margin-bottom: 0;
}

.fork-connector {
    width: 40px;
    flex-shrink: 0;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}

.connector-line {
    width: 100%;
    height: 100%;
}

.fork-annotation {
    bottom: -40px;
    left: 50%;
    transform: translateX(-50%);
}

/* ============================================
   Section 4: The Merge
   ============================================ */
.section-merge {
    padding-top: 55px;
    padding-bottom: 0;
    min-height: 80vh;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
}

.merge-content {
    max-width: var(--content-max);
    margin-left: calc(8.333vw);
    position: relative;
    padding-bottom: 89px;
}

.merge-visual {
    position: relative;
    height: 200px;
    width: 100%;
    margin: 34px 0;
}

.merge-line {
    position: absolute;
    height: 2px;
    background: var(--circuit-trace);
    top: 50%;
    transition: transform 0.8s cubic-bezier(0.23, 1, 0.32, 1), width 0.8s ease;
}

.merge-line-left {
    left: 0;
    width: 45%;
    transform-origin: right center;
    transform: rotate(-10deg);
}

.merge-line-right {
    right: 0;
    width: 45%;
    transform-origin: left center;
    transform: rotate(10deg);
}

.merge-line-left.merged {
    transform: rotate(0deg);
    width: 50%;
}

.merge-line-right.merged {
    transform: rotate(0deg);
    width: 50%;
}

.merge-point {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%) scale(0);
    width: 12px;
    height: 12px;
    background: var(--primary-neon);
    border-radius: 50%;
    transition: transform 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
    box-shadow: 0 0 12px var(--primary-neon), 0 0 24px rgba(255, 0, 110, 0.3);
}

.merge-point.visible {
    transform: translate(-50%, -50%) scale(1);
}

.merge-text {
    font-family: var(--font-body);
    font-weight: 400;
    line-height: 1.75;
    color: var(--text-primary);
}

/* Glitch Band Transition */
.glitch-band {
    width: 100%;
    height: 4px;
    position: relative;
    overflow: hidden;
    margin-top: auto;
}

.glitch-band::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(
        90deg,
        var(--primary-neon),
        var(--secondary-neon),
        var(--tertiary-neon),
        var(--glitch-shadow),
        var(--primary-neon)
    );
    animation: glitch-band-sweep 3s ease-in-out infinite;
}

@keyframes glitch-band-sweep {
    0% { left: -100%; }
    50% { left: 100%; }
    100% { left: 100%; }
}

/* ============================================
   Section 5: The Engine Room (Dark)
   ============================================ */
.section-engine {
    background: var(--deep-ground);
    padding-top: 89px;
    padding-bottom: 144px;
    overflow: hidden;
}

.engine-circuits {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 0;
}

.circuit-line {
    stroke: var(--circuit-trace);
    stroke-width: 0.5;
    opacity: 0.15;
}

.circuit-junction {
    fill: var(--circuit-trace);
    opacity: 0.3;
    transition: fill 0.3s ease, opacity 0.3s ease;
}

.circuit-junction.glowing {
    fill: var(--primary-neon);
    opacity: 1;
    filter: drop-shadow(0 0 4px var(--primary-neon));
}

.circuit-pulse {
    fill: var(--secondary-neon);
    opacity: 0.8;
    filter: drop-shadow(0 0 8px var(--secondary-neon));
}

.circuit-pulse-secondary {
    fill: var(--tertiary-neon);
    opacity: 0.6;
    filter: drop-shadow(0 0 6px var(--tertiary-neon));
}

.engine-content {
    position: relative;
    z-index: 1;
    max-width: var(--content-max);
    margin-left: calc(8.333vw);
}

.engine-text-block {
    margin-top: 55px;
}

.engine-text {
    font-family: var(--font-body);
    font-weight: 400;
    color: rgba(250, 250, 247, 0.85);
    line-height: 1.85;
    margin-bottom: 34px;
}

.engine-text:last-child {
    margin-bottom: 0;
}

.engine-annotation {
    color: var(--secondary-neon);
    bottom: -50px;
    right: 0;
}

/* ============================================
   Section 6: The Commit (Close)
   ============================================ */
.section-commit {
    display: flex;
    align-items: center;
    justify-content: flex-start;
    min-height: 80vh;
}

.commit-content {
    max-width: var(--content-max);
    margin-left: calc(8.333vw);
    position: relative;
}

.commit-text-wrapper {
    position: relative;
}

.commit-text {
    font-family: var(--font-headline);
    font-weight: 700;
    font-size: clamp(1.8rem, 4vw, 3.2rem);
    letter-spacing: 0.01em;
    color: var(--text-primary);
    line-height: 1.4;
}

.commit-text .dissolving {
    display: inline;
    transition: opacity 0.3s ease;
}

.commit-text .dissolved {
    opacity: 0;
}

.commit-annotation {
    top: -30px;
    right: -40px;
}

/* ============================================
   Circuit Bus Line (Left Edge)
   ============================================ */
.circuit-bus {
    position: fixed;
    left: 32px;
    top: 10%;
    height: 80%;
    width: 20px;
    z-index: 50;
    pointer-events: none;
}

.bus-svg {
    width: 100%;
    height: 100%;
}

.bus-line {
    stroke: var(--circuit-trace);
    stroke-width: 1;
    opacity: 0.25;
}

.bus-junction {
    position: absolute;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 8px;
    height: 8px;
    background: var(--circuit-trace);
    border-radius: 50%;
    opacity: 0.4;
    transition: background 0.3s ease, opacity 0.3s ease, box-shadow 0.3s ease;
}

.bus-junction.active {
    background: var(--primary-neon);
    opacity: 1;
    box-shadow: 0 0 6px var(--primary-neon);
}

/* ============================================
   Scroll-linked visibility
   ============================================ */
.stack-entry,
.fork-panel,
.merge-text,
.engine-text-block {
    opacity: 0;
    transform: translateX(-30px);
    transition: opacity 0.6s ease, transform 0.6s cubic-bezier(0.23, 1, 0.32, 1);
}

.stack-entry.visible,
.fork-panel.visible,
.merge-text.visible,
.engine-text-block.visible {
    opacity: 1;
    transform: translateX(0);
}

/* Stack entry staggering */
.stack-entry:nth-child(2) { transition-delay: 0.08s; }
.stack-entry:nth-child(3) { transition-delay: 0.16s; }
.stack-entry:nth-child(4) { transition-delay: 0.24s; }
.stack-entry:nth-child(5) { transition-delay: 0.32s; }

/* ============================================
   Responsive
   ============================================ */
@media (max-width: 768px) {
    :root {
        --margin-outer: 24px;
        --gutter: 24px;
    }

    .section-number {
        position: relative;
        right: auto;
        top: auto;
        margin-bottom: 16px;
    }

    .buffer-content,
    .stack-content,
    .fork-content,
    .merge-content,
    .engine-content,
    .commit-content {
        margin-left: 0;
    }

    .fork-panels {
        flex-direction: column;
        gap: 16px;
    }

    .fork-connector {
        width: 100%;
        height: 40px;
    }

    .fork-panel-before,
    .fork-panel-after {
        border-radius: 2px;
    }

    .fork-panel-before.split {
        transform: translateY(-10px);
    }

    .fork-panel-after.split {
        transform: translateY(10px);
    }

    .circuit-bus {
        display: none;
    }

    .display-numeral {
        font-size: clamp(4rem, 12vw, 8rem);
    }
}