:root {
    /* Color Palette - Premium Dark */
    --bg-primary: #0a0a0c;
    --bg-secondary: #141419;
    --bg-glass: rgba(20, 20, 25, 0.7);

    --accent-primary: #6366f1;
    /* Indigo */
    --accent-secondary: #a855f7;
    /* Purple */
    --accent-glow: rgba(99, 102, 241, 0.3);

    --text-primary: #ffffff;
    --text-secondary: #94a3b8;
    --text-tertiary: #64748b;

    --border-color: rgba(255, 255, 255, 0.1);

    /* Spacing */
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 2rem;
    --spacing-xl: 4rem;

    /* Fonts */
    --font-heading: 'Space Grotesk', sans-serif;
    --font-body: 'Outfit', sans-serif;
}

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

html {
    scroll-behavior: smooth;
    /* Native smooth scroll for anchor links */
}

body {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-family: var(--font-body);
    overflow-x: hidden;
    min-height: 100vh;
    line-height: 1.6;
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
    background: var(--bg-secondary);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--accent-primary);
}

.main-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: var(--bg-primary);
    z-index: 100;
    border-bottom: 1px solid var(--border-color);
}

.header-top {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-sm) var(--spacing-md);
}

/* Time Controls (Secondary - Compact) */
.time-controls {
    display: flex;
    gap: 4px;
    background: rgba(255, 255, 255, 0.05);
    padding: 3px;
    border-radius: 6px;
}

.time-btn {
    background: none;
    border: none;
    color: var(--text-tertiary);
    padding: 4px 10px;
    border-radius: 4px;
    font-size: 0.75rem;
    cursor: pointer;
    font-family: var(--font-body);
    transition: all 0.2s ease;
}

.time-btn:hover {
    color: var(--text-primary);
}

.time-btn.active {
    background: var(--accent-primary);
    color: white;
}

/* Type Filters (Primary - Full Width Scroll) */
.type-filters {
    display: flex;
    gap: 8px;
    padding: var(--spacing-sm) var(--spacing-md);
    overflow-x: auto;
    scrollbar-width: none;
    -webkit-overflow-scrolling: touch;
}

.type-filters::-webkit-scrollbar {
    display: none;
}

.type-btn {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 0.85rem;
    white-space: nowrap;
    cursor: pointer;
    font-family: var(--font-heading);
    transition: all 0.2s ease;
}

.type-btn:hover {
    border-color: var(--accent-primary);
    color: var(--text-primary);
}

.type-btn.active {
    background: var(--accent-primary);
    border-color: var(--accent-primary);
    color: white;
}

/* Quick Nav Bar */
#quick-nav {
    position: fixed;
    top: 100px;
    /* Below new header */
    left: 0;
    width: 100%;
    z-index: 99;
    padding: 8px var(--spacing-md);
    display: flex;
    justify-content: center;
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    pointer-events: none;
}

#quick-nav-list {
    display: flex;
    gap: 8px;
    overflow-x: auto;
    padding: 10px 0;
    pointer-events: auto;
    /* Re-enable clicks */
    max-width: 800px;
    /* Hide scrollbar */
    scrollbar-width: none;
    -ms-overflow-style: none;
}

#quick-nav-list::-webkit-scrollbar {
    display: none;
}

.nav-pill {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    color: var(--text-tertiary);
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.8rem;
    white-space: nowrap;
    cursor: pointer;
    transition: all 0.2s ease;
    font-family: var(--font-heading);
}

.nav-pill:hover,
.nav-pill.active {
    background: var(--accent-primary);
    color: white;
    border-color: var(--accent-primary);
    transform: translateY(-1px);
}


.logo {
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 1.5rem;
    letter-spacing: -0.02em;
    display: flex;
    align-items: center;
    gap: 10px;
}

.header-logo {
    height: 32px;
    width: auto;
    border-radius: 6px;
    /* Soften edges */
}

.logo .accent {
    color: var(--accent-primary);
}

.nav-container {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
}

.view-controls {
    display: flex;
    gap: var(--spacing-sm);
    background: rgba(255, 255, 255, 0.05);
    padding: 4px;
    border-radius: 8px;
}

.filter-btn {
    background: none;
    border: none;
    color: var(--text-tertiary);
    padding: 6px 12px;
    border-radius: 6px;
    font-size: 0.85rem;
    cursor: pointer;
    font-family: var(--font-body);
    transition: all 0.2s ease;
}

.filter-btn:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
}

.filter-btn.active {
    background: var(--accent-primary);
    color: white;
}

.nav-label {
    display: none;
    /* Hidden on small screens or just generally cleaner without */
}

.divider-vertical {
    width: 1px;
    height: 24px;
    background: var(--border-color);
}

.nav-link {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-family: var(--font-heading);
    font-weight: 500;
    cursor: pointer;
    transition: color 0.3s ease;
}

.nav-link:hover,
.nav-link.active {
    color: var(--text-primary);
}

/* Timeline Container */
/* Type Colors */
:root {
    --color-model: #818cf8;
    --color-model-bg: rgba(99, 102, 241, 0.15);

    --color-video: #f43f5e;
    --color-video-bg: rgba(244, 63, 94, 0.15);

    --color-image: #fb923c;
    --color-image-bg: rgba(251, 146, 60, 0.15);

    --color-tool: #22d3ee;
    --color-tool-bg: rgba(6, 182, 212, 0.15);

    --color-hardware: #f472b6;
    --color-hardware-bg: rgba(236, 72, 153, 0.15);

    --color-news: #c084fc;
    --color-news-bg: rgba(168, 85, 247, 0.15);

    --color-benchmark: #4ade80;
    --color-benchmark-bg: rgba(34, 197, 94, 0.15);
}

/* Timeline Container */
#timeline-container {
    position: relative;
    padding-top: 180px;
    /* Header (~100px) + Quick Nav (~45px) + buffer */
    padding-bottom: 10vh;
    min-height: 100vh;
    width: 100%;
}

#timeline-track {
    position: relative;
    z-index: 1;
    max-width: 600px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

/* Group Headers */
.group-header {
    position: sticky;
    top: 145px;
    /* Below header + quick nav */
    background: rgba(10, 10, 12, 0.95);
    padding: 6px 16px;
    margin: var(--spacing-md) 0;
    border-bottom: 1px solid var(--border-color);
    font-family: var(--font-heading);
    font-size: 1rem;
    font-weight: 700;
    color: var(--accent-secondary);
    z-index: 50;
    /* Lower than Quick Nav (99) */
    backdrop-filter: blur(10px);
    width: fit-content;
    align-self: flex-start;
    border-radius: 20px;
    border: 1px solid var(--border-color);
    scroll-margin-top: 120px;
    /* For anchor scroll offset */
}

/* Month Divider (All mode - subtle separator) */
.month-divider {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin: var(--spacing-lg) 0 var(--spacing-sm) 0;
    color: var(--text-tertiary);
    font-size: 0.75rem;
    font-family: var(--font-heading);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.month-divider::before,
.month-divider::after {
    content: '';
    flex: 1;
    height: 1px;
    background: var(--border-color);
}

.month-divider span {
    padding: 0 var(--spacing-sm);
}

/* Event Node */
.event-row {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-md);
    opacity: 0;
    transform: translateY(20px);
    animation: fadeInUp 0.5s forwards;
    position: relative;
}

/* Stagger animation */
.event-row:nth-child(1) {
    animation-delay: 0.1s;
}

.event-row:nth-child(2) {
    animation-delay: 0.15s;
}

.event-row:nth-child(3) {
    animation-delay: 0.2s;
}

.event-row:nth-child(4) {
    animation-delay: 0.25s;
}

.event-row:nth-child(5) {
    animation-delay: 0.3s;
}

.event-marker {
    width: 12px;
    height: 12px;
    min-width: 12px;
    background: var(--text-tertiary);
    /* fallback */
    border-radius: 50%;
    margin-top: 20px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.3);
    z-index: 2;
    position: relative;
}

/* Marker coloring based on type class added by JS */
.event-row.type-model .event-marker {
    background: var(--color-model);
    box-shadow: 0 0 10px var(--color-model-bg);
}

.event-row.type-video .event-marker {
    background: var(--color-video);
    box-shadow: 0 0 10px var(--color-video-bg);
}

.event-row.type-image .event-marker {
    background: var(--color-image);
    box-shadow: 0 0 10px var(--color-image-bg);
}

.event-row.type-tool .event-marker {
    background: var(--color-tool);
    box-shadow: 0 0 10px var(--color-tool-bg);
}

.event-row.type-hardware .event-marker {
    background: var(--color-hardware);
    box-shadow: 0 0 10px var(--color-hardware-bg);
}

.event-row.type-news .event-marker {
    background: var(--color-news);
    box-shadow: 0 0 10px var(--color-news-bg);
}

.event-row.type-benchmark .event-marker {
    background: var(--color-benchmark);
    box-shadow: 0 0 10px var(--color-benchmark-bg);
}

/* Connecting line */
.event-row:not(:last-child)::after {
    content: '';
    position: absolute;
    top: 32px;
    left: 5px;
    width: 2px;
    height: calc(100% + var(--spacing-lg));
    background: var(--border-color);
    /* Neutral line */
    z-index: 0;
    opacity: 0.5;
}

.event-card {
    flex: 1;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    padding: var(--spacing-md);
    border-radius: 12px;
    cursor: pointer;
    transition: transform 0.2s ease, border-color 0.2s ease;
    border-left: 3px solid transparent;
    /* Type strip */
}

.event-card:hover {
    transform: translateX(4px);
    border-color: var(--accent-primary);
}

/* Card coloring based on type class */
.event-row.type-model .event-card:hover {
    border-color: var(--color-model);
}

.event-row.type-model .event-card {
    border-left-color: var(--color-model);
}

.event-row.type-video .event-card:hover {
    border-color: var(--color-video);
}

.event-row.type-video .event-card {
    border-left-color: var(--color-video);
}

.event-row.type-image .event-card:hover {
    border-color: var(--color-image);
}

.event-row.type-image .event-card {
    border-left-color: var(--color-image);
}

.event-row.type-tool .event-card:hover {
    border-color: var(--color-tool);
}

.event-row.type-tool .event-card {
    border-left-color: var(--color-tool);
}

.event-row.type-hardware .event-card:hover {
    border-color: var(--color-hardware);
}

.event-row.type-hardware .event-card {
    border-left-color: var(--color-hardware);
}

.event-row.type-news .event-card:hover {
    border-color: var(--color-news);
}

.event-row.type-news .event-card {
    border-left-color: var(--color-news);
}

.event-row.type-benchmark .event-card:hover {
    border-color: var(--color-benchmark);
}

.event-row.type-benchmark .event-card {
    border-left-color: var(--color-benchmark);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-sm);
}

.card-date {
    font-size: 0.8rem;
    color: var(--text-tertiary);
    font-family: var(--font-heading);
}

.event-title {
    font-family: var(--font-heading);
    font-weight: 700;
    margin-bottom: 6px;
    color: var(--text-primary);
    font-size: 1.1rem;
    line-height: 1.3;
}

.event-desc {
    font-size: 0.9rem;
    color: var(--text-secondary);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    line-height: 1.5;
}

/* Tags - use variables */
.tag {
    display: inline-block;
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
}

.tag.model {
    background: var(--color-model-bg);
    color: var(--color-model);
}

.tag.news {
    background: var(--color-news-bg);
    color: var(--color-news);
}

.tag.hardware {
    background: var(--color-hardware-bg);
    color: var(--color-hardware);
}

.tag.benchmark {
    background: var(--color-benchmark-bg);
    color: var(--color-benchmark);
}

.tag.image {
    background: var(--color-image-bg);
    color: var(--color-image);
}

.tag.video {
    background: var(--color-video-bg);
    color: var(--color-video);
}

.tag.tool {
    background: var(--color-tool-bg);
    color: var(--color-tool);
}

/* Fallback/Others */
.tag.iot,
.tag.wearable,
.tag.service,
.tag.cloud,
.tag.browser,
.tag.agent {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-secondary);
}

/* Modal */
#modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    backdrop-filter: blur(8px);
}

#modal-overlay.hidden {
    display: none;
}

.glass-panel {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    padding: var(--spacing-xl);
    border-radius: 16px;
    width: 90%;
    max-width: 600px;
    position: relative;
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.5);
}

#modal-close {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 2rem;
    cursor: pointer;
}

@keyframes fadeInUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Footer */
.main-footer {
    text-align: center;
    padding: var(--spacing-xl) var(--spacing-md);
    margin-top: var(--spacing-xl);
    border-top: 1px solid var(--border-color);
    background: linear-gradient(to top, var(--bg-primary) 0%, rgba(10, 10, 12, 0) 100%);
    position: relative;
    z-index: 10;
}

.footer-content {
    color: var(--text-tertiary);
    font-size: 0.9rem;
    font-family: var(--font-body);
}

.footer-content p {
    margin-bottom: 0.5rem;
}

.footer-content .brand {
    color: var(--text-secondary);
    font-weight: 600;
}

.footer-content .creator .highlight {
    color: var(--accent-primary);
    font-weight: 700;
}