/* ============================================================
   a6c.xyz — Art Deco Codex Stylesheet
   Palette: Kiln Black, Smoked Umber, Fired Terracotta,
            Oxidized Copper, Pale Gold, Warm Parchment,
            Amber, Sunburst Orange, Clay Rose
   Fonts: Poiret One (display), Space Grotesk (body),
          IBM Plex Mono (code)
   ============================================================ */

/* --- CSS Custom Properties --- */
:root {
    --kiln-black: #0D0906;
    --smoked-umber: #1A0F0A;
    --fired-terracotta: #C2703E;
    --oxidized-copper: #A0522D;
    --pale-gold: #E8C49A;
    --warm-parchment: #D4B896;
    --amber: #E0A86E;
    --sunburst-orange: #E8872A;
    --clay-rose: #8B4C2A;
    --scroll-progress: 0;
    --baseline: 24px;
    --section-gap: 120px;
    --column-width: 720px;
    --border-offset: 40px;
}

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

html {
    font-size: 17px;
    line-height: 1.75;
    scroll-behavior: smooth;
    background-color: var(--kiln-black);
}

body {
    font-family: 'Space Grotesk', sans-serif;
    font-weight: 400;
    color: var(--warm-parchment);
    background-color: var(--kiln-black);
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* --- Fixed Top Bar --- */
#top-bar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 48px;
    background-color: var(--kiln-black);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 24px;
    z-index: 1000;
    border-bottom: 1px solid rgba(194, 112, 62, 0.15);
}

#nav-title {
    font-family: 'Poiret One', cursive;
    font-size: 20px;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--pale-gold);
    -webkit-text-stroke: 0.3px var(--pale-gold);
}

#menu-toggle {
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: opacity 0.3s ease;
}

#menu-toggle:hover {
    opacity: 0.7;
}

/* --- Table of Contents Overlay --- */
#toc-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(13, 9, 6, 0.92);
    z-index: 2000;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 1;
    transition: opacity 0.5s ease;
}

#toc-overlay.hidden {
    opacity: 0;
    pointer-events: none;
}

#toc-panel {
    text-align: center;
    max-width: 400px;
    width: 90%;
    padding: 48px 32px;
    border: 1px solid var(--fired-terracotta);
    background-color: var(--smoked-umber);
    position: relative;
}

#toc-panel::before,
#toc-panel::after {
    content: '';
    position: absolute;
    left: 8px;
    right: 8px;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--fired-terracotta), transparent);
}

#toc-panel::before { top: 8px; }
#toc-panel::after { bottom: 8px; }

.toc-ornament {
    display: flex;
    justify-content: center;
    margin: 16px 0;
}

.toc-heading {
    font-family: 'Poiret One', cursive;
    font-size: 28px;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--pale-gold);
    -webkit-text-stroke: 0.3px var(--pale-gold);
    margin-bottom: 24px;
}

#toc-list {
    list-style: none;
    padding: 0;
}

#toc-list li {
    margin-bottom: 16px;
}

#toc-list a {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 16px;
    color: var(--warm-parchment);
    text-decoration: none;
    letter-spacing: 0.08em;
    transition: color 0.3s ease;
    display: inline-block;
    padding: 4px 0;
}

#toc-list a:hover {
    color: var(--sunburst-orange);
}

/* --- Decorative Border Rules --- */
.border-rule {
    position: fixed;
    top: 0;
    bottom: 0;
    width: 2px;
    z-index: 100;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.border-rule.visible {
    opacity: 1;
}

#border-left {
    left: calc(50% - var(--column-width) / 2 - var(--border-offset));
}

#border-right {
    right: calc(50% - var(--column-width) / 2 - var(--border-offset));
}

.border-svg {
    position: absolute;
    top: 0;
    left: 0;
    width: 2px;
    height: 100%;
}

.border-line {
    stroke-dasharray: 8 4;
    stroke-dashoffset: 3000;
    transition: stroke-dashoffset 1.5s cubic-bezier(0.16, 1, 0.3, 1);
}

.border-rule.visible .border-line {
    stroke-dashoffset: 0;
}

.border-nodes {
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 20px;
    height: 100%;
}

.border-node {
    position: absolute;
    left: 50%;
    transform: translate(-50%, -50%) scale(1);
    transition: transform 0.6s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.6s ease;
    animation: nodePulse 3s ease-in-out infinite;
}

.border-node.diamond {
    width: 8px;
    height: 8px;
    background: var(--fired-terracotta);
    transform: translate(-50%, -50%) rotate(45deg) scale(1);
    box-shadow: 0 0 0px var(--clay-rose);
}

.border-node.diamond.active {
    transform: translate(-50%, -50%) rotate(45deg) scale(1.3);
    box-shadow: 0 0 6px var(--clay-rose);
}

.border-node.circle {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--fired-terracotta);
    box-shadow: 0 0 0px var(--clay-rose);
}

.border-node.circle.active {
    transform: translate(-50%, -50%) scale(1.3);
    box-shadow: 0 0 6px var(--clay-rose);
}

.border-node.stepped {
    width: 8px;
    height: 8px;
    background: var(--fired-terracotta);
    box-shadow: 0 0 0px var(--clay-rose);
    clip-path: polygon(25% 0%, 75% 0%, 100% 25%, 100% 75%, 75% 100%, 25% 100%, 0% 75%, 0% 25%);
}

.border-node.stepped.active {
    transform: translate(-50%, -50%) scale(1.3);
    box-shadow: 0 0 6px var(--clay-rose);
}

/* Border glow mask effect - follows scroll */
.border-rule::after {
    content: '';
    position: absolute;
    left: -6px;
    width: 14px;
    height: 140px;
    background: radial-gradient(ellipse, rgba(139, 76, 42, 0.4) 0%, transparent 70%);
    top: calc(var(--scroll-progress, 0.5) * 100%);
    transform: translateY(-50%);
    pointer-events: none;
    transition: top 0.15s linear;
}

/* --- Node Pulse Animation --- */
@keyframes nodePulse {
    0%, 100% { box-shadow: 0 0 0px var(--clay-rose); }
    50% { box-shadow: 0 0 6px var(--clay-rose); }
}

/* --- Hero Section --- */
#hero {
    height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    position: relative;
    padding-top: 48px;
}

#hero-sunburst {
    opacity: 0;
    margin-bottom: 48px;
    transition: opacity 1s ease;
}

#hero-sunburst.visible {
    opacity: 1;
}

.sunburst-line {
    stroke-dasharray: 200;
    stroke-dashoffset: 200;
    transition: stroke-dashoffset 1.2s cubic-bezier(0.16, 1, 0.3, 1);
}

.sunburst-line.drawn {
    stroke-dashoffset: 0;
}

.sunburst-diamond {
    opacity: 0;
    transition: opacity 0.8s ease;
}

.sunburst-diamond.visible {
    opacity: 1;
}

#hero-title {
    font-family: 'Poiret One', cursive;
    font-size: 64px;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--pale-gold);
    -webkit-text-stroke: 0.5px var(--pale-gold);
    text-align: center;
    min-height: 80px;
    position: relative;
}

#hero-title .char {
    display: inline-block;
    opacity: 0;
    animation: charReveal 0.3s ease forwards;
}

@keyframes charReveal {
    0% {
        opacity: 0;
        color: var(--sunburst-orange);
        text-shadow: 0 0 12px var(--sunburst-orange);
    }
    50% {
        opacity: 1;
        color: var(--sunburst-orange);
        text-shadow: 0 0 8px var(--sunburst-orange);
    }
    100% {
        opacity: 1;
        color: var(--pale-gold);
        text-shadow: none;
    }
}

#hero-subtitle {
    font-family: 'Space Grotesk', sans-serif;
    font-style: italic;
    font-size: 17px;
    color: var(--warm-parchment);
    opacity: 0;
    margin-top: 24px;
    text-align: center;
    transition: opacity 1s ease;
}

#hero-subtitle.visible {
    opacity: 0.6;
}

/* --- Watermark Sunburst --- */
#watermark-sunburst {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    opacity: 0;
    z-index: 0;
    pointer-events: none;
    transition: opacity 0.8s ease;
}

#watermark-sunburst.visible {
    opacity: 0.08;
}

/* --- Main Content Column --- */
#content-column {
    max-width: var(--column-width);
    margin: 0 auto;
    padding: 0 24px;
    position: relative;
    z-index: 1;
}

/* --- Codex Sections --- */
.codex-section {
    margin-bottom: var(--section-gap);
    padding-top: 24px;
}

/* Sunburst Dividers */
.sunburst-divider {
    display: flex;
    justify-content: center;
    margin-bottom: 48px;
    opacity: 0;
    transform: scale(0.9);
    transition: opacity 0.8s ease, transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}

.sunburst-divider.revealed {
    opacity: 1;
    transform: scale(1);
}

.sunburst-divider svg {
    overflow: visible;
}

/* Section Headings */
.section-heading {
    font-family: 'Poiret One', cursive;
    font-size: 48px;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--pale-gold);
    -webkit-text-stroke: 0.5px var(--pale-gold);
    text-align: center;
    margin-bottom: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
}

.chevron-left,
.chevron-right {
    font-size: 28px;
    color: var(--fired-terracotta);
    opacity: 0;
    transition: opacity 0.5s ease, transform 0.5s ease;
}

.chevron-left.animated {
    opacity: 1;
    animation: chevronLeft 0.6s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

.chevron-right.animated {
    opacity: 1;
    animation: chevronRight 0.6s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

@keyframes chevronLeft {
    from { transform: translateX(8px); opacity: 0; }
    to { transform: translateX(0); opacity: 1; }
}

@keyframes chevronRight {
    from { transform: translateX(-8px); opacity: 0; }
    to { transform: translateX(0); opacity: 1; }
}

.heading-text .heading-char {
    display: inline-block;
    opacity: 0;
    transform: translateY(8px);
    transition: opacity 0.3s ease, transform 0.3s ease;
}

.heading-text .heading-char.revealed {
    opacity: 1;
    transform: translateY(0);
}

/* Section Body */
.section-body {
    line-height: 1.75;
}

.section-body p {
    margin-bottom: var(--baseline);
    color: var(--warm-parchment);
}

/* --- Blueprint Panels --- */
.blueprint-panel {
    position: relative;
    margin: 48px 0;
    padding: 32px 32px 32px 48px;
    background-color: var(--smoked-umber);
    border: 1px solid var(--oxidized-copper);
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out, border-color 0.3s ease;
}

.blueprint-panel.revealed {
    opacity: 1;
    transform: translateY(0);
}

.blueprint-panel:hover {
    border-color: var(--fired-terracotta);
}

/* Chevron Borders on Panels */
.chevron-border-left,
.chevron-border-right {
    position: absolute;
    top: 0;
    bottom: 0;
    width: 12px;
    overflow: hidden;
}

.chevron-border-left {
    left: 0;
}

.chevron-border-right {
    right: 0;
}

.chevron-border-left::before,
.chevron-border-right::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 200%;
    background: repeating-linear-gradient(
        180deg,
        transparent 0px,
        transparent 4px,
        rgba(160, 82, 45, 0.4) 4px,
        transparent 12px,
        transparent 16px
    );
    animation: chevronCascade 8s linear infinite;
}

.blueprint-panel:hover .chevron-border-left::before,
.blueprint-panel:hover .chevron-border-right::before {
    animation-duration: 3s;
}

@keyframes chevronCascade {
    0% { transform: translateY(0); }
    100% { transform: translateY(-50%); }
}

.chevron-border-left::after,
.chevron-border-right::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 200%;
    background: repeating-linear-gradient(
        180deg,
        transparent 0px,
        transparent 8px,
        rgba(160, 82, 45, 0.25) 8px,
        transparent 16px,
        transparent 20px
    );
    animation: chevronCascade 12s linear infinite reverse;
}

.panel-heading {
    font-family: 'Poiret One', cursive;
    font-size: 22px;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--pale-gold);
    margin-bottom: 16px;
}

.panel-text {
    font-family: 'Space Grotesk', sans-serif;
    font-size: 15px;
    line-height: 1.65;
    color: var(--warm-parchment);
    margin-bottom: 20px;
    opacity: 0.85;
}

/* --- Code Blocks --- */
.code-block {
    font-family: 'IBM Plex Mono', monospace;
    font-size: 14px;
    line-height: 1.6;
    font-weight: 400;
    color: var(--amber);
    background-color: var(--kiln-black);
    padding: 20px 24px;
    border-left: 2px solid var(--fired-terracotta);
    overflow-x: auto;
    white-space: pre;
}

.code-line {
    display: block;
    opacity: 0;
    transition: opacity 0.2s ease;
}

.code-line.revealed {
    opacity: 1;
}

/* --- Keystone Diagram --- */
.keystone-diagram {
    display: flex;
    justify-content: center;
    margin: 48px 0;
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.keystone-diagram.revealed {
    opacity: 1;
    transform: translateY(0);
}

/* --- Section Wave (Flowing Curves Motif) --- */
.section-wave {
    height: 40px;
    margin-top: 48px;
    position: relative;
    overflow: hidden;
    opacity: 0.15;
}

.section-wave::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 300%;
    height: 100%;
    background: repeating-linear-gradient(
        90deg,
        transparent 0px,
        transparent 40px,
        var(--oxidized-copper) 40px,
        transparent 80px
    );
    mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 200 40'%3E%3Cpath d='M0 20 Q25 0 50 20 Q75 40 100 20 Q125 0 150 20 Q175 40 200 20' fill='none' stroke='black' stroke-width='12'/%3E%3C/svg%3E");
    -webkit-mask-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 200 40'%3E%3Cpath d='M0 20 Q25 0 50 20 Q75 40 100 20 Q125 0 150 20 Q175 40 200 20' fill='none' stroke='black' stroke-width='12'/%3E%3C/svg%3E");
    mask-size: 200px 40px;
    -webkit-mask-size: 200px 40px;
    mask-repeat: repeat-x;
    -webkit-mask-repeat: repeat-x;
    animation: waveFlow 12s linear infinite;
}

@keyframes waveFlow {
    0% { transform: translateX(0); }
    100% { transform: translateX(200px); }
}

/* --- Final Ornament --- */
.final-ornament {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-top: 72px;
    padding-bottom: 96px;
}

.colophon {
    font-family: 'Poiret One', cursive;
    font-size: 14px;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--fired-terracotta);
    margin-top: 24px;
    opacity: 0.6;
}

/* --- Responsive --- */
@media (max-width: 860px) {
    :root {
        --column-width: 100%;
        --border-offset: 12px;
    }

    #hero-title {
        font-size: 40px;
    }

    .section-heading {
        font-size: 32px;
        letter-spacing: 0.1em;
    }

    .blueprint-panel {
        padding: 24px 24px 24px 32px;
    }

    .border-rule {
        display: none;
    }
}

@media (max-width: 480px) {
    #hero-title {
        font-size: 28px;
    }

    .section-heading {
        font-size: 24px;
    }

    .panel-heading {
        font-size: 18px;
    }

    .code-block {
        font-size: 12px;
        padding: 16px;
    }
}