/* Main styles for Bible Timeline - Editorial Style */

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

/* ============================================
   Fixed Site Header
   ============================================ */

.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    padding: var(--space-sm) var(--space-md);
    background: linear-gradient(180deg, rgba(10, 10, 10, 0.9) 0%, rgba(10, 10, 10, 0) 100%);
    opacity: 0;
    transform: translateY(-10px);
    transition: opacity 0.4s ease-out, transform 0.4s ease-out;
    pointer-events: none;
}

.site-header.visible {
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
}

.site-header__title {
    font-family: var(--font-serif);
    font-size: 1rem;
    font-weight: 600;
    color: var(--color-accent);
    margin: 0;
    letter-spacing: 0.02em;
}

/* ============================================
   Book Background (full-screen hover effect)
   ============================================ */

.book-background {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 1;
    opacity: 0;
    transition: opacity 0.5s ease-out;
    pointer-events: none;
}

.book-background.visible {
    opacity: 1;
}

/* Image background child elements */
.book-background__blur,
.book-background__sharp,
.book-background__vignette {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    pointer-events: none;
}

/* Blurred background fill */
.book-background__blur {
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    filter: blur(30px) brightness(0.4) saturate(1.2);
    transform: scale(1.1); /* Prevent blur edges showing */
}

/* Sharp centered image on top */
.book-background__sharp {
    background-size: contain;
    background-position: center;
    background-repeat: no-repeat;
}

/* Subtle vignette overlay */
.book-background__vignette {
    background: radial-gradient(
        ellipse 100% 100% at center,
        transparent 0%,
        transparent 40%,
        rgba(10, 10, 10, 0.2) 70%,
        rgba(10, 10, 10, 0.5) 100%
    );
}

/* Era-based gradient backgrounds */
.book-background[data-era="primeval"] {
    background: radial-gradient(ellipse at 30% 20%, rgba(139, 90, 43, 0.4) 0%, transparent 50%),
                radial-gradient(ellipse at 70% 80%, rgba(101, 67, 33, 0.3) 0%, transparent 50%),
                linear-gradient(180deg, rgba(30, 20, 10, 0.8) 0%, rgba(10, 10, 10, 0.95) 100%);
}

.book-background[data-era="patriarchs"] {
    background: radial-gradient(ellipse at 20% 30%, rgba(194, 154, 97, 0.4) 0%, transparent 50%),
                radial-gradient(ellipse at 80% 70%, rgba(139, 90, 43, 0.3) 0%, transparent 50%),
                linear-gradient(180deg, rgba(40, 30, 15, 0.8) 0%, rgba(10, 10, 10, 0.95) 100%);
}

.book-background[data-era="exodus"] {
    background: radial-gradient(ellipse at 40% 20%, rgba(180, 60, 60, 0.35) 0%, transparent 50%),
                radial-gradient(ellipse at 70% 60%, rgba(139, 90, 43, 0.3) 0%, transparent 50%),
                linear-gradient(180deg, rgba(50, 20, 20, 0.8) 0%, rgba(10, 10, 10, 0.95) 100%);
}

.book-background[data-era="judges"] {
    background: radial-gradient(ellipse at 30% 40%, rgba(120, 100, 80, 0.4) 0%, transparent 50%),
                radial-gradient(ellipse at 60% 70%, rgba(80, 70, 60, 0.3) 0%, transparent 50%),
                linear-gradient(180deg, rgba(35, 30, 25, 0.8) 0%, rgba(10, 10, 10, 0.95) 100%);
}

.book-background[data-era="united-kingdom"] {
    background: radial-gradient(ellipse at 50% 30%, rgba(201, 169, 98, 0.4) 0%, transparent 50%),
                radial-gradient(ellipse at 30% 70%, rgba(160, 130, 70, 0.3) 0%, transparent 50%),
                linear-gradient(180deg, rgba(45, 35, 20, 0.8) 0%, rgba(10, 10, 10, 0.95) 100%);
}

.book-background[data-era="divided-kingdom"] {
    background: radial-gradient(ellipse at 25% 25%, rgba(140, 100, 70, 0.35) 0%, transparent 45%),
                radial-gradient(ellipse at 75% 75%, rgba(100, 80, 60, 0.3) 0%, transparent 45%),
                linear-gradient(180deg, rgba(40, 30, 20, 0.8) 0%, rgba(10, 10, 10, 0.95) 100%);
}

.book-background[data-era="exile"] {
    background: radial-gradient(ellipse at 50% 50%, rgba(70, 70, 90, 0.4) 0%, transparent 50%),
                radial-gradient(ellipse at 20% 80%, rgba(50, 50, 70, 0.3) 0%, transparent 50%),
                linear-gradient(180deg, rgba(20, 20, 30, 0.85) 0%, rgba(10, 10, 10, 0.95) 100%);
}

.book-background[data-era="post-exile"] {
    background: radial-gradient(ellipse at 60% 30%, rgba(100, 110, 90, 0.35) 0%, transparent 50%),
                radial-gradient(ellipse at 30% 70%, rgba(80, 90, 70, 0.3) 0%, transparent 50%),
                linear-gradient(180deg, rgba(25, 30, 25, 0.8) 0%, rgba(10, 10, 10, 0.95) 100%);
}

.book-background[data-era="intertestamental"] {
    background: radial-gradient(ellipse at 40% 40%, rgba(90, 90, 100, 0.35) 0%, transparent 50%),
                radial-gradient(ellipse at 70% 60%, rgba(70, 70, 80, 0.3) 0%, transparent 50%),
                linear-gradient(180deg, rgba(25, 25, 30, 0.8) 0%, rgba(10, 10, 10, 0.95) 100%);
}

.book-background[data-era="gospels"] {
    background: radial-gradient(ellipse at 50% 30%, rgba(201, 169, 98, 0.45) 0%, transparent 50%),
                radial-gradient(ellipse at 40% 70%, rgba(180, 150, 80, 0.3) 0%, transparent 50%),
                linear-gradient(180deg, rgba(40, 35, 20, 0.75) 0%, rgba(10, 10, 10, 0.95) 100%);
}

.book-background[data-era="apostolic"] {
    background: radial-gradient(ellipse at 30% 30%, rgba(100, 80, 140, 0.35) 0%, transparent 50%),
                radial-gradient(ellipse at 70% 70%, rgba(140, 100, 80, 0.3) 0%, transparent 50%),
                linear-gradient(180deg, rgba(30, 25, 35, 0.8) 0%, rgba(10, 10, 10, 0.95) 100%);
}

.book-background[data-era="wisdom"] {
    background: radial-gradient(ellipse at 50% 50%, rgba(120, 120, 140, 0.35) 0%, transparent 50%),
                radial-gradient(ellipse at 30% 30%, rgba(100, 100, 120, 0.25) 0%, transparent 50%),
                linear-gradient(180deg, rgba(25, 25, 30, 0.8) 0%, rgba(10, 10, 10, 0.95) 100%);
}

.book-background[data-era="church-age"] {
    background: radial-gradient(ellipse at 50% 70%, rgba(180, 160, 100, 0.3) 0%, transparent 50%),
                radial-gradient(ellipse at 30% 30%, rgba(100, 80, 60, 0.2) 0%, transparent 50%),
                linear-gradient(180deg, rgba(20, 18, 15, 0.85) 0%, rgba(10, 10, 10, 0.95) 100%);
}

html {
    font-size: 16px;
}

body {
    margin: 0;
    padding: 0;
    font-family: var(--font-sans);
    font-weight: 300;
    background-color: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ============================================
   Site Header (top left)
   ============================================ */

.site-header {
    position: fixed;
    top: var(--space-md);
    left: var(--space-md);
    z-index: 100;
}

.site-title {
    font-family: var(--font-sans);
    font-size: 0.75rem;
    font-weight: 400;
    letter-spacing: 0.05em;
    color: var(--color-text-muted);
    text-transform: lowercase;
}

.title-line {
    display: block;
}

/* ============================================
   Timeline Track (left side vertical line)
   ============================================ */

.timeline-track {
    position: fixed;
    left: var(--timeline-left);
    top: 0;
    bottom: 0;
    width: 1px;
    z-index: 50;
    pointer-events: none;
}

.timeline-line {
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0;
    width: 1px;
    background: linear-gradient(
        to bottom,
        transparent 0%,
        var(--color-line) 10%,
        var(--color-line) 90%,
        transparent 100%
    );
}

.timeline-dot {
    position: absolute;
    top: 15%; /* JS controls this - moves from 15% (top) to 85% (bottom) */
    left: 50%;
    transform: translate(-50%, -50%);
    width: 8px;
    height: 8px;
    background: var(--color-text);
    border-radius: 50%;
    /* Transition scale and color, but not top (which follows scroll) */
    transition: transform var(--transition-normal), background var(--transition-normal);
}

.year-paused .timeline-dot {
    transform: translate(-50%, -50%) scale(1.5);
    background: var(--color-accent);
}

/* Timeline Ticks - appear as books start */
.timeline-ticks {
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0;
    width: 100%;
    pointer-events: none;
}

.timeline-tick {
    position: absolute;
    left: 4px; /* Position to right of the line */
    width: 12px;
    height: 2px;
    background: var(--color-text-dim);
    transform: translateY(-50%) scaleX(0);
    transform-origin: left center;
    opacity: 0;
    transition: transform 0.3s ease-out, opacity 0.3s ease-out;
}

.timeline-tick.visible {
    transform: translateY(-50%) scaleX(1);
    opacity: 1;
}

/* Canonization glow levels - ticks glow brighter with each council */
.timeline-ticks.canon-level-1 .timeline-tick.visible {
    box-shadow: 0 0 4px rgba(201, 169, 98, 0.3);
}

.timeline-ticks.canon-level-2 .timeline-tick.visible {
    box-shadow: 0 0 6px rgba(201, 169, 98, 0.4);
}

.timeline-ticks.canon-level-3 .timeline-tick.visible {
    box-shadow: 0 0 8px rgba(201, 169, 98, 0.5);
}

.timeline-ticks.canon-level-4 .timeline-tick.visible {
    box-shadow: 0 0 10px rgba(201, 169, 98, 0.6);
}

.timeline-ticks.canon-level-5 .timeline-tick.visible {
    box-shadow: 0 0 12px rgba(201, 169, 98, 0.7),
                0 0 20px rgba(201, 169, 98, 0.4);
}

/* Pulse animation when a new canonization level is reached */
.timeline-ticks.canon-pulse .timeline-tick.visible {
    animation: canon-pulse 0.6s ease-out;
}

@keyframes canon-pulse {
    0% {
        box-shadow: 0 0 20px rgba(201, 169, 98, 0.9),
                    0 0 40px rgba(201, 169, 98, 0.6);
    }
    100% {
        box-shadow: inherit;
    }
}

/* Era Dividers */
.timeline-eras {
    position: absolute;
    top: 0;
    bottom: 0;
    left: 0;
    width: 100%;
    pointer-events: none;
}

.era-divider {
    position: absolute;
    right: 4px; /* Position to left of the line */
    transform: translateY(-50%);
    display: flex;
    align-items: center;
    gap: 6px;
}

.era-divider__label {
    font-family: var(--font-sans);
    font-size: 0.625rem;
    font-weight: 400;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--color-accent);
    white-space: nowrap;
    text-align: right;
    opacity: 0;
    transition: opacity 0.4s ease-out;
}

.era-divider.label-visible .era-divider__label {
    opacity: 1;
}

.era-divider__tick {
    width: 16px;
    height: 2px;
    background: var(--color-accent);
    flex-shrink: 0;
    opacity: 0;
    transform: scaleX(0);
    transform-origin: right center;
    transition: opacity 0.3s ease-out, transform 0.3s ease-out;
}

.era-divider.tick-visible .era-divider__tick {
    opacity: 1;
    transform: scaleX(1);
}

/* ============================================
   Milestone Markers (left side timeline labels)
   ============================================ */

.milestone-marker {
    position: absolute;
    right: 4px;
    transform: translateY(-50%);
    display: flex;
    align-items: center;
    gap: 6px;
    pointer-events: none;
}

.milestone-marker__label {
    font-family: var(--font-sans);
    font-size: 0.5625rem;
    font-weight: 500;
    letter-spacing: 0.05em;
    color: rgba(201, 169, 98, 0.8);
    white-space: nowrap;
    text-align: right;
    opacity: 0;
    transition: opacity 0.4s ease-out;
}

.milestone-marker.label-visible .milestone-marker__label {
    opacity: 1;
}

.milestone-marker__year {
    font-family: var(--font-sans);
    font-size: 0.5rem;
    font-weight: 400;
    color: rgba(201, 169, 98, 0.5);
    white-space: nowrap;
    opacity: 0;
    transition: opacity 0.4s ease-out;
}

.milestone-marker.label-visible .milestone-marker__year {
    opacity: 1;
}

/* Tick mark for milestone (next to timeline) */
.milestone-marker::after {
    content: '';
    width: 10px;
    height: 2px;
    background: rgba(201, 169, 98, 0.6);
    flex-shrink: 0;
    opacity: 0;
    transform: scaleX(0);
    transform-origin: right center;
    transition: opacity 0.3s ease-out, transform 0.3s ease-out;
}

.milestone-marker.tick-visible::after {
    opacity: 1;
    transform: scaleX(1);
}

/* ============================================
   Milestone Cards (right side, in book grid)
   ============================================ */

.milestone-card {
    background: linear-gradient(145deg, rgba(30, 25, 18, 0.98) 0%, rgba(15, 12, 8, 0.99) 100%);
    border: 1px solid var(--color-accent);
    border-radius: 6px;
    padding: var(--space-md) var(--space-lg);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    min-height: 120px;
    /* Transform, opacity, and z-index controlled by JS for stacking */
    transform-origin: center bottom;
    transition: transform 0.4s ease-out, opacity 0.4s ease-out, box-shadow 0.3s ease;
}

.milestone-card:first-of-type,
.milestone-card[style*="z-index: 1"] {
    /* Newest card gets subtle glow */
    box-shadow: 0 4px 20px rgba(201, 169, 98, 0.15);
}

.milestone-card__year {
    font-family: var(--font-sans);
    font-size: 0.75rem;
    font-weight: 500;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--color-accent);
    margin-bottom: var(--space-xs);
}

.milestone-card__title {
    font-family: var(--font-serif);
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-text);
    margin: 0 0 var(--space-sm);
    line-height: 1.3;
}

.milestone-card__description {
    font-family: var(--font-sans);
    font-size: 0.875rem;
    font-weight: 300;
    color: var(--color-text-muted);
    margin: 0;
    line-height: 1.5;
}

/* Large milestone variant (e.g., The Living Tradition) */
.milestone-card--large {
    min-height: 120px;
    padding: var(--space-md) var(--space-lg);
}

.milestone-card--large .milestone-card__title {
    font-size: 1.25rem;
    margin-bottom: var(--space-sm);
}

.milestone-card--large .milestone-card__description {
    font-size: 0.9rem;
    line-height: 1.6;
}

/* ============================================
   Message Container & Floating Callouts
   ============================================ */

.message-container {
    position: fixed;
    top: 0;
    left: var(--content-left);
    width: var(--content-width);
    bottom: 0;
    z-index: 25;
    pointer-events: none;
    display: flex;
    align-items: center;
    justify-content: center;
}

.message-box {
    width: 100%;
    max-width: 500px;
    padding: var(--space-lg);
    background: linear-gradient(145deg, rgba(30, 25, 18, 0.95) 0%, rgba(15, 12, 8, 0.98) 100%);
    border: 1px solid var(--color-accent);
    border-radius: 6px;
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.5s ease-out, transform 0.5s ease-out;
    pointer-events: none;
    text-align: center;
}

.message-box.visible {
    opacity: calc(var(--message-opacity, 1));
    transform: translateY(0);
    pointer-events: auto;
}

.message-box__title {
    font-family: var(--font-serif);
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--color-accent);
    margin: 0 0 var(--space-md);
    line-height: 1.3;
}

.message-box__content {
    font-family: var(--font-sans);
    font-size: 1rem;
    font-weight: 300;
    color: var(--color-text-muted);
    margin: 0;
    line-height: 1.7;
}

/* You Are Here marker on timeline */
.timeline-you-are-here {
    position: absolute;
    top: 85%; /* Same position where the scrolling dot ends */
    left: 50%;
    transform: translate(-50%, -50%); /* Center the dot on this position */
    opacity: 0;
    transition: opacity 0.5s ease-out;
    pointer-events: none;
}

.timeline-you-are-here.visible {
    opacity: 1;
}

.you-are-here-dot {
    width: 12px;
    height: 12px;
    background: var(--color-accent);
    border-radius: 50%;
    box-shadow: 0 0 12px var(--color-accent),
                0 0 24px rgba(201, 169, 98, 0.4);
    animation: pulse-glow 2s ease-in-out infinite;
}

@keyframes pulse-glow {
    0%, 100% {
        box-shadow: 0 0 12px var(--color-accent),
                    0 0 24px rgba(201, 169, 98, 0.4);
    }
    50% {
        box-shadow: 0 0 16px var(--color-accent),
                    0 0 32px rgba(201, 169, 98, 0.6);
    }
}

.you-are-here-label {
    position: absolute;
    top: 50%;
    right: 100%; /* Position to the left of the dot */
    transform: translateY(-50%);
    margin-right: 12px;
    font-family: var(--font-sans);
    font-size: 0.625rem;
    font-weight: 400;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--color-accent);
    white-space: nowrap;
}

/* ============================================
   Year Display (large serif numbers)
   ============================================ */

.year-display {
    position: fixed;
    left: calc(var(--timeline-left) + 2.5rem);
    top: 50%;
    transform: translateY(-50%);
    z-index: 60;
    pointer-events: none;
    /* Prevent year from overlapping book columns */
    max-width: calc(var(--content-left) - var(--timeline-left) - 4rem);
}

.year-number {
    display: block;
    font-family: var(--font-serif);
    font-size: var(--year-font-size);
    font-weight: 400;
    font-style: italic;
    line-height: var(--year-line-height);
    color: var(--color-text);
    transition: color var(--transition-normal);
    /* Padding for italic overhang */
    padding-left: 0.15em;
}

.year-suffix {
    display: block;
    font-family: var(--font-sans);
    font-size: 1rem;
    font-weight: 300;
    letter-spacing: 0.2em;
    color: var(--color-text-muted);
    margin-top: var(--space-xs);
}

.year-paused .year-number {
    color: var(--color-accent);
}

/* ============================================
   Era Label (right side, rotated)
   ============================================ */

.era-label {
    position: fixed;
    right: var(--era-right);
    top: 50%;
    transform: translateY(-50%);
    z-index: 60;
    pointer-events: none;
}

.era-text {
    display: block;
    font-family: var(--font-serif);
    font-size: 1.25rem;
    font-weight: 400;
    font-style: italic;
    color: var(--color-text-dim);
    writing-mode: vertical-rl;
    text-orientation: mixed;
    letter-spacing: 0.1em;
    transition: color var(--transition-normal);
}

.year-paused .era-text {
    color: var(--color-text-muted);
}

/* ============================================
   Main Content Area
   ============================================ */

.timeline-content {
    position: relative;
    margin-left: var(--content-left);
    width: var(--content-width);
    min-height: 100vh;
}

/* ============================================
   Introduction Section
   ============================================ */

.timeline-intro {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: var(--space-xl) 0;
}

.intro-content {
    text-align: left;
    max-width: 500px;
}

.intro-title {
    font-family: var(--font-serif);
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 400;
    font-style: italic;
    line-height: 1.1;
    margin: 0 0 var(--space-md);
    color: var(--color-text);
}

.intro-subtitle {
    font-size: 1.125rem;
    font-weight: 300;
    color: var(--color-text-muted);
    margin: 0 0 var(--space-lg);
    line-height: 1.7;
}

.scroll-hint {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-xs);
    color: var(--color-text-dim);
    font-size: 0.875rem;
    letter-spacing: 0.05em;
}

.scroll-arrow {
    width: 24px;
    height: 24px;
    animation: float 2s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(8px); }
}

/* ============================================
   Scroll Spacer (creates scrollable area)
   ============================================ */

.scroll-spacer {
    height: 8000px; /* Default, will be set by JS */
    position: relative;
}

/* ============================================
   Book Grid (sticky container)
   ============================================ */

.book-columns {
    position: fixed;
    top: 50%;
    left: var(--content-left);
    width: var(--content-width);
    /* Fixed height container - rows always take equal space */
    height: 360px;
    transform: translateY(-50%);
    display: grid;
    gap: var(--space-sm);
    z-index: 40;
    pointer-events: none;
    opacity: 0;
    transition: opacity var(--transition-normal);
    overflow: visible;
    /* Fixed 4-column x 3-row grid (max 12 books) */
    grid-template-columns: repeat(4, 1fr);
    grid-template-rows: repeat(3, 1fr);
    align-items: start;
}

.book-columns.visible {
    opacity: 1;
}

/* ============================================
   Book Cards
   ============================================ */

.book-card {
    padding: var(--space-sm);
    border-left: 2px solid var(--color-accent);
    background: var(--color-bg);
    pointer-events: auto;
    cursor: pointer;
    transition: border-color 0.2s ease, background 0.2s ease;
}

.book-card:hover {
    border-color: var(--color-text);
    background: rgba(255, 255, 255, 0.05);
}

.book-card__title {
    font-family: var(--font-serif);
    font-size: 1.5rem;
    font-weight: 400;
    font-style: italic;
    line-height: 1.2;
    margin: 0 0 var(--space-xs);
    color: var(--color-text);
}

.book-card__date {
    font-size: 0.875rem;
    font-weight: 300;
    color: var(--color-text-muted);
    margin: 0 0 var(--space-xs);
}

.book-card__meta {
    font-size: 0.75rem;
    font-weight: 300;
    color: var(--color-text-dim);
    margin: 0;
}

/* ============================================
   Closing Section
   ============================================ */

.timeline-closing {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: var(--space-xl) 0;
}

.closing-content {
    max-width: 400px;
}

/* ============================================
   Book Steps - Single Book (Legacy)
   ============================================ */

.book-title {
    font-family: var(--font-serif);
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 400;
    font-style: italic;
    line-height: 1.2;
    margin: 0 0 var(--space-sm);
    color: var(--color-text);
}

.book-description {
    font-size: 1rem;
    font-weight: 300;
    color: var(--color-text-muted);
    margin: 0 0 var(--space-sm);
}

.book-meta {
    font-size: 0.875rem;
    font-weight: 300;
    color: var(--color-text-dim);
    margin: 0;
    letter-spacing: 0.02em;
}

/* ============================================
   Book Steps - Multiple Books (Side by Side)
   ============================================ */

.step-content--multi {
    max-width: none;
}

.book-group {
    display: flex;
    flex-direction: row;
    flex-wrap: nowrap;
    gap: var(--space-lg);
    align-items: flex-start;
    margin-bottom: var(--space-sm);
}

.book-item {
    flex: 0 0 auto;
    min-width: 160px;
    max-width: 220px;
    padding: var(--space-sm);
    border-left: 2px solid var(--color-text-dim);
    transition: border-color var(--transition-normal);
}

/* Stagger: each subsequent book steps down to show chronological sequence */
.book-item:nth-child(2) { margin-top: 1.5rem; }
.book-item:nth-child(3) { margin-top: 3rem; }
.book-item:nth-child(4) { margin-top: 4.5rem; }

.timeline-step.is-active .book-item {
    border-color: var(--color-accent);
}

.book-item__title {
    font-family: var(--font-serif);
    font-size: 1.5rem;
    font-weight: 400;
    font-style: italic;
    line-height: 1.2;
    margin: 0 0 var(--space-xs);
    color: var(--color-text);
}

.book-item__date {
    font-size: 0.875rem;
    font-weight: 300;
    color: var(--color-text-muted);
    margin: 0 0 var(--space-xs);
}

.book-item__meta {
    font-size: 0.75rem;
    font-weight: 300;
    color: var(--color-text-dim);
    margin: 0;
}

.group-meta {
    font-size: 0.75rem;
    font-weight: 300;
    color: var(--color-text-dim);
    margin: 0;
    font-style: italic;
}

/* ============================================
   Highlighted State (when book is in focus)
   ============================================ */

.year-highlighted .year-number {
    color: var(--color-accent);
}

.year-highlighted .timeline-dot {
    transform: translate(-50%, -50%) scale(1.5);
    background: var(--color-accent);
}

.year-highlighted .era-text {
    color: var(--color-text-muted);
}

/* ============================================
   Legacy Closing Styles (kept for compatibility)
   ============================================ */

.step-content--closing {
    max-width: 400px;
}

/* You Are Here section (closing) */
.you-are-here-title {
    font-family: var(--font-serif);
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 400;
    font-style: italic;
    line-height: 1.1;
    color: var(--color-accent);
    margin: 0 0 var(--space-lg);
    text-shadow: 0 0 40px rgba(201, 169, 98, 0.3);
}

.closing-text {
    font-family: var(--font-serif);
    font-size: 1.5rem;
    font-style: italic;
    color: var(--color-text-muted);
    margin: 0;
    line-height: 1.5;
}

.closing-link {
    display: inline-flex;
    align-items: center;
    gap: var(--space-xs);
    color: var(--color-accent);
    text-decoration: none;
    font-size: 0.875rem;
    letter-spacing: 0.05em;
    transition: color var(--transition-fast);
}

.closing-link:hover {
    color: var(--color-text);
}

.closing-link svg {
    width: 16px;
    height: 16px;
}

/* ============================================
   Footer
   ============================================ */

.site-footer {
    position: fixed;
    bottom: var(--space-md);
    left: var(--space-md);
    z-index: 100;
}

.site-footer a {
    font-size: 0.75rem;
    color: var(--color-text-dim);
    text-decoration: none;
    letter-spacing: 0.05em;
    transition: color var(--transition-fast);
}

.site-footer a:hover {
    color: var(--color-text-muted);
}

/* ============================================
   Error State
   ============================================ */

.error-message {
    padding: var(--space-xl);
    text-align: center;
    color: #ff6b6b;
}

.error-message h2 {
    font-family: var(--font-serif);
    font-weight: 400;
    margin: 0 0 var(--space-sm);
}

.error-message p {
    margin: 0;
    opacity: 0.8;
}