/* Design System & Visual Aesthetics for Lutz Bornmann Career Showcase */

:root {
    --bg-dark: #070913;
    --bg-panel: rgba(15, 22, 42, 0.65);
    --bg-card: rgba(30, 41, 59, 0.5);
    --bg-group: rgba(7, 10, 20, 0.4);
    --border-color: rgba(255, 255, 255, 0.08);
    --border-hover: rgba(255, 255, 255, 0.16);
    --border-group: rgba(255, 255, 255, 0.03);
    
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    
    /* Neon gradients & glow colors */
    --color-lead: #00f2fe; /* Glowing cyan */
    --color-lead-glow: rgba(0, 242, 254, 0.4);
    --color-co: #ec008c; /* Glowing magenta */
    --color-co-glow: rgba(236, 0, 140, 0.4);
    --color-accent: #8b5cf6; /* Violet */
    --color-accent-glow: rgba(139, 92, 246, 0.3);
    
    --bg-toggle: rgba(255, 255, 255, 0.03);
    --color-grid: rgba(255, 255, 255, 0.04);
    --color-grid-active: rgba(255, 255, 255, 0.15);
    --bg-theme-btn: rgba(255, 255, 255, 0.04);
    --bg-theme-btn-hover: rgba(255, 255, 255, 0.08);
    --bg-btn-hover: rgba(255, 255, 255, 0.03);
    
    --glow-color-lead: 0, 242, 254;
    --glow-color-co: 236, 0, 140;
    --glow-color-accent: 139, 92, 246;
    --glow-opacity-multiplier: 1;
    
    --shadow-inset: inset 0 1px 1px rgba(255, 255, 255, 0.05);

    /* Theme-specific control assets */
    --bg-slider-track: rgba(255, 255, 255, 0.1);
    --bg-slider-track-hover: rgba(255, 255, 255, 0.2);
    --bg-checkbox-track: rgba(255, 255, 255, 0.08);
    --border-panel-header: rgba(255, 255, 255, 0.05);
    --bg-ctrl-btn: rgba(255, 255, 255, 0.05);
    --bg-ctrl-btn-hover: rgba(255, 255, 255, 0.1);
    --border-ctrl-btn-hover: rgba(255, 255, 255, 0.2);
    --bg-accordion-hover: rgba(255, 255, 255, 0.02);
    --bg-stat-icon: rgba(255, 255, 255, 0.04);

    --font-heading: 'Outfit', 'Inter', sans-serif;
    --font-body: 'Inter', sans-serif;
    
    --transition-fast: 0.15s ease;
    --transition-smooth: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.light-theme {
    --bg-dark: #f8fafc; /* Slate 50 */
    --bg-panel: rgba(255, 255, 255, 0.75);
    --bg-card: rgba(15, 23, 42, 0.04);
    --bg-group: rgba(15, 23, 42, 0.02);
    --border-color: rgba(15, 23, 42, 0.08);
    --border-hover: rgba(15, 23, 42, 0.16);
    --border-group: rgba(15, 23, 42, 0.04);
    
    --text-primary: #0f172a; /* Slate 900 */
    --text-secondary: #475569; /* Slate 600 */
    --text-muted: #64748b; /* Slate 500 */
    
    --color-lead: #0284c7; /* Sky 600 */
    --color-lead-glow: rgba(2, 132, 199, 0.25);
    --color-co: #db2777; /* Pink 600 */
    --color-co-glow: rgba(219, 39, 119, 0.25);
    --color-accent: #7c3aed; /* Violet 600 */
    --color-accent-glow: rgba(124, 58, 237, 0.2);

    --bg-toggle: rgba(15, 23, 42, 0.04);
    --color-grid: rgba(15, 23, 42, 0.06);
    --color-grid-active: rgba(15, 23, 42, 0.2);
    --bg-theme-btn: rgba(15, 23, 42, 0.03);
    --bg-theme-btn-hover: rgba(15, 23, 42, 0.06);
    --bg-btn-hover: rgba(15, 23, 42, 0.03);
    
    --glow-color-lead: 14, 165, 233;
    --glow-color-co: 219, 39, 119;
    --glow-color-accent: 124, 58, 237;
    --glow-opacity-multiplier: 0.65;
    
    --shadow-inset: inset 0 1px 1px rgba(15, 23, 42, 0.02);

    /* Light theme control assets */
    --bg-slider-track: rgba(15, 23, 42, 0.12);
    --bg-slider-track-hover: rgba(15, 23, 42, 0.22);
    --bg-checkbox-track: rgba(15, 23, 42, 0.08);
    --border-panel-header: rgba(15, 23, 42, 0.06);
    --bg-ctrl-btn: rgba(15, 23, 42, 0.05);
    --bg-ctrl-btn-hover: rgba(15, 23, 42, 0.1);
    --border-ctrl-btn-hover: rgba(15, 23, 42, 0.18);
    --bg-accordion-hover: rgba(15, 23, 42, 0.02);
    --bg-stat-icon: rgba(15, 23, 42, 0.04);
}

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

body {
    background-color: var(--bg-dark);
    color: var(--text-primary);
    font-family: var(--font-body);
    min-height: 100vh;
    overflow-x: hidden;
    position: relative;
    line-height: 1.5;
}

/* Futuristic background glow effect */
.glow-bg {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: -1;
    background: 
        radial-gradient(circle at 10% 20%, rgba(var(--glow-color-lead), calc((0.05 + var(--audio-pulse, 0) * 0.12) * var(--glow-opacity-multiplier))) 0%, transparent calc(40% + var(--audio-pulse, 0) * 15%)),
        radial-gradient(circle at 90% 80%, rgba(var(--glow-color-co), calc((0.05 + var(--audio-pulse, 0) * 0.12) * var(--glow-opacity-multiplier))) 0%, transparent calc(45% + var(--audio-pulse, 0) * 15%)),
        radial-gradient(circle at 50% 50%, rgba(var(--glow-color-accent), calc((0.03 + var(--audio-pulse, 0) * 0.08) * var(--glow-opacity-multiplier))) 0%, transparent calc(60% + var(--audio-pulse, 0) * 20%));
    pointer-events: none;
    transition: background-image 0.1s ease;
}

/* App Layout Container */
.app-container {
    max-width: 1440px;
    margin: 0 auto;
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 24px;
}

/* Header styling */
.app-header {
    background: var(--bg-panel);
    border: 1px solid var(--border-color);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-radius: 16px;
    padding: 18px 24px;
    display: flex;
    align-items: center;
    gap: 16px;
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.3);
}



.header-text h1 {
    font-family: var(--font-heading);
    font-size: 1.8rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    background: linear-gradient(to right, #fff, var(--text-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.light-theme .header-text h1 {
    background: linear-gradient(to right, var(--text-primary), var(--text-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.header-text .subtitle {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.header-audio-controls {
    margin-left: auto;
    display: flex;
    align-items: center;
    gap: 16px;
    background: var(--bg-toggle);
    padding: 6px 16px;
    border-radius: 99px;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-inset);
}

.header-volume-control {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--text-secondary);
    font-size: 0.8rem;
    font-weight: 500;
}

.header-volume-control input[type="range"] {
    -webkit-appearance: none;
    appearance: none;
    width: 80px;
    height: 4px;
    border-radius: 2px;
    background: var(--bg-slider-track);
    outline: none;
    transition: background 0.3s;
}

.header-volume-control input[type="range"]:hover {
    background: var(--bg-slider-track-hover);
}

.header-volume-control input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--color-lead);
    cursor: pointer;
    box-shadow: 0 0 8px var(--color-lead-glow);
    transition: transform 0.1s;
}

.header-volume-control input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.2);
}

#volume-val {
    min-width: 20px;
    text-align: right;
    font-variant-numeric: tabular-nums;
    font-size: 0.8rem;
    color: var(--text-primary);
}

.header-audio-btn {
    background: linear-gradient(135deg, rgba(0, 242, 254, 0.08), rgba(139, 92, 246, 0.08));
    border: 1px solid rgba(0, 242, 254, 0.25);
    color: var(--color-lead);
    padding: 6px 14px;
    border-radius: 99px;
    cursor: pointer;
    font-size: 0.8rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 6px;
    transition: all 0.2s ease;
}

.header-audio-btn:hover {
    background: linear-gradient(135deg, rgba(0, 242, 254, 0.18), rgba(139, 92, 246, 0.18));
    border-color: var(--color-lead);
    box-shadow: 0 0 8px var(--color-lead-glow);
}

.header-audio-btn.active {
    background: rgba(0, 242, 254, 0.12);
    border-color: #00e676;
    color: #00e676;
    box-shadow: 0 0 8px rgba(0, 230, 118, 0.25);
}

.header-theme-btn {
    background: var(--bg-theme-btn);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    padding: 6px 14px;
    border-radius: 99px;
    cursor: pointer;
    font-size: 0.8rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 6px;
    transition: all 0.2s ease;
}

.header-theme-btn:hover {
    background: var(--bg-theme-btn-hover);
    border-color: var(--border-hover);
    color: var(--text-primary);
}

.vol-icon {
    color: var(--text-secondary);
    flex-shrink: 0;
}

/* Grid Layout for Panels */
.main-grid {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 24px;
}

/* Panels generic styles */
.panel {
    background: var(--bg-panel);
    border: 1px solid var(--border-color);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-radius: 16px;
    padding: 24px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.2);
    display: flex;
    flex-direction: column;
    gap: 16px;
    transition: border-color var(--transition-smooth);
    min-width: 0; /* Prevent grid items from stretching past screen width */
}

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

.panel-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border-panel-header);
    padding-bottom: 12px;
}

.panel-header h2 {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
}

.full-width {
    grid-column: 1 / -1;
}

/* 1. Timeline Panel styling */
.timeline-panel {
    grid-column: 1 / 2;
}

.layout-toggle-group {
    display: flex;
    gap: 4px;
    background: var(--bg-toggle);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 2px;
}

.layout-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 0.75rem;
    padding: 6px 12px;
    border-radius: 6px;
    cursor: pointer;
    font-weight: 500;
    transition: all 0.25s ease;
}

.layout-btn:hover {
    color: var(--text-primary);
    background: var(--bg-btn-hover);
}

.layout-btn.active {
    background: var(--text-primary);
    color: var(--bg-dark);
    font-weight: 600;
}

.legend {
    display: flex;
    gap: 16px;
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.dot-indicator {
    width: 10px;
    height: 10px;
    border-radius: 50%;
}

.lead-author-dot {
    background: var(--color-lead);
    box-shadow: 0 0 8px var(--color-lead-glow);
}

.co-author-dot {
    background: var(--color-co);
    box-shadow: 0 0 8px var(--color-co-glow);
}

.timeline-visualization-wrapper {
    position: relative;
    background: var(--bg-group);
    border: 1px solid var(--border-group);
    border-radius: 12px;
    overflow: hidden;
}

.svg-scroll-container {
    width: 100%;
    overflow-x: auto;
    overflow-y: hidden;
}

#timeline-svg {
    display: block;
    user-select: none;
}

/* Swarm dots hover & active styles */
.paper-node {
    cursor: pointer;
    transition: transform 0.2s cubic-bezier(0.175, 0.885, 0.32, 1.275), filter 0.2s ease;
    transform-origin: center;
    transform-box: fill-box;
}

.paper-node circle, .hover-ring {
    transition: 
        cx 0.8s cubic-bezier(0.16, 1, 0.3, 1), 
        cy 0.8s cubic-bezier(0.16, 1, 0.3, 1), 
        r 0.4s ease, 
        transform 0.15s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.echo-ripple {
    pointer-events: none;
    transition: r 0.8s cubic-bezier(0.1, 0.8, 0.3, 1), opacity 0.8s ease, stroke-width 0.8s ease;
}

.paper-node:hover {
    transform: scale(1.4);
    filter: brightness(1.2);
}

.paper-node.active-playing {
    animation: dot-pulse 1s infinite alternate;
}

@keyframes dot-pulse {
    0% { transform: scale(1); filter: brightness(1); }
    100% { transform: scale(1.6); filter: brightness(1.5); }
}

.year-grid-line {
    stroke: var(--color-grid);
    stroke-dasharray: 4 6;
}

.year-grid-line.active {
    stroke: var(--color-grid-active);
}

.year-label-svg {
    fill: var(--text-muted);
    font-family: var(--font-heading);
    font-size: 11px;
    font-weight: 500;
}

.year-label-svg.active {
    fill: var(--text-primary);
    font-weight: 700;
}



/* Playback bar beneath timeline */
.playback-bar {
    display: flex;
    align-items: center;
    gap: 20px;
    padding-top: 10px;
}

.play-controls {
    display: flex;
    align-items: center;
    gap: 8px;
}

.play-btn {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--color-lead), var(--color-co));
    border: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #070913;
    box-shadow: 0 0 15px rgba(0, 242, 254, 0.3);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.play-btn:hover {
    transform: scale(1.08);
    box-shadow: 0 0 25px rgba(0, 242, 254, 0.5);
}

.play-btn:active {
    transform: scale(0.96);
}

.ctrl-btn {
    width: 38px;
    height: 38px;
    border-radius: 50%;
    background: var(--bg-ctrl-btn);
    border: 1px solid var(--border-color);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-primary);
    transition: background-color 0.2s ease, color 0.2s ease;
}

.ctrl-btn:hover {
    background: var(--bg-ctrl-btn-hover);
    color: #fff;
    border-color: var(--border-ctrl-btn-hover);
}

.ctrl-btn:active {
    transform: scale(0.95);
}

.progress-container {
    flex-grow: 1;
    display: flex;
    align-items: center;
    gap: 12px;
}

.playback-year-label {
    font-size: 0.8rem;
    font-family: var(--font-heading);
    color: var(--text-secondary);
    min-width: 36px;
    text-align: center;
}

.slider-wrapper {
    flex-grow: 1;
    position: relative;
    display: flex;
    align-items: center;
}

input[type="range"] {
    -webkit-appearance: none;
    width: 100%;
    height: 6px;
    border-radius: 99px;
    background: var(--bg-slider-track);
    outline: none;
    cursor: pointer;
}

/* Slider Track custom fill trick */
.slider-progress {
    position: absolute;
    height: 6px;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    background: linear-gradient(to right, var(--color-lead), var(--color-co));
    border-radius: 99px;
    pointer-events: none;
    width: 0%;
}

input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: #fff;
    border: 2px solid var(--color-lead);
    box-shadow: 0 0 8px rgba(0, 242, 254, 0.8);
    transition: transform 0.1s ease;
}

input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.25);
}

.speed-control {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.custom-select {
    background: var(--bg-panel);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 6px 12px;
    border-radius: 8px;
    font-size: 0.8rem;
    outline: none;
    cursor: pointer;
    transition: border-color var(--transition-fast);
}

.custom-select:hover {
    border-color: var(--border-hover);
}



.settings-grid {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.settings-group {
    background: var(--bg-group);
    border: 1px solid var(--border-group);
    border-radius: 12px;
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.settings-group h3 {
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-secondary);
    border-bottom: 1px solid var(--border-group);
    padding-bottom: 6px;
    margin-bottom: 4px;
}

.setting-row {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.setting-row label {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.label-with-val {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.label-with-val span {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--color-lead);
}

/* Dual Range Sliders */
.dual-sliders {
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin-top: 4px;
}

.slider-with-label {
    display: flex;
    align-items: center;
    gap: 12px;
}

.slider-with-label span {
    font-size: 0.75rem;
    color: var(--text-secondary);
    min-width: 32px;
}

.slider-with-label input[type="range"] {
    flex: 1;
}

/* Toggle buttons */
.toggle-group {
    display: flex;
    background: var(--bg-toggle);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 2px;
}

.toggle-btn {
    flex: 1;
    background: none;
    border: none;
    color: var(--text-secondary);
    padding: 6px 10px;
    font-size: 0.75rem;
    font-weight: 500;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.toggle-btn:hover {
    color: var(--text-primary);
    background: var(--bg-btn-hover);
}

.toggle-btn.active {
    background: var(--text-primary);
    color: var(--bg-dark);
    font-weight: 600;
}

/* Toggle Switch Switch Styling */
.toggle-switch-label {
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    font-size: 0.8rem;
    color: var(--text-secondary);
    user-select: none;
    width: 100%;
}

.toggle-switch-label input[type="checkbox"] {
    -webkit-appearance: none;
    appearance: none;
    width: 38px;
    height: 20px;
    background: var(--bg-checkbox-track);
    border-radius: 99px;
    position: relative;
    cursor: pointer;
    transition: background-color 0.3s, border-color 0.3s;
    border: 1px solid var(--border-color);
    outline: none;
    box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.4);
}

.toggle-switch-label input[type="checkbox"]:checked {
    background: linear-gradient(135deg, var(--color-lead), var(--color-accent));
    border-color: rgba(0, 242, 254, 0.4);
    box-shadow: 0 0 8px var(--color-lead-glow);
}

.toggle-switch-label input[type="checkbox"]::before {
    content: '';
    position: absolute;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: #fff;
    top: 2px;
    left: 2px;
    transition: transform 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.4);
}

.toggle-switch-label input[type="checkbox"]:checked::before {
    transform: translateX(18px);
}

/* Action button (audio enable) */
.action-btn {
    background: linear-gradient(135deg, rgba(0, 242, 254, 0.1), rgba(139, 92, 246, 0.1));
    border: 1px solid var(--color-lead);
    color: var(--color-lead);
    padding: 10px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.85rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    transition: all 0.2s ease;
}

.action-btn:hover {
    background: linear-gradient(135deg, rgba(0, 242, 254, 0.25), rgba(139, 92, 246, 0.25));
    box-shadow: 0 0 10px var(--color-lead-glow);
}

.action-btn.active {
    background: var(--color-lead);
    color: #000;
    border-color: var(--color-lead);
}

.btn-icon {
    flex-shrink: 0;
}

/* 3. Synthesizer Settings Accordion styling */
.accordion-group {
    background: var(--bg-group);
    border: 1px solid var(--border-group);
    border-radius: 12px;
    margin-top: 16px;
    overflow: hidden;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.accordion-group[open] {
    border-color: var(--color-accent);
    box-shadow: 0 0 15px var(--color-accent-glow);
}

.accordion-header {
    padding: 16px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    user-select: none;
    list-style: none; /* Hide default triangle on Chrome/Firefox */
    transition: background 0.2s ease;
}

.accordion-header::-webkit-details-marker {
    display: none; /* Hide default triangle on Safari */
}

.accordion-header:hover {
    background: var(--bg-accordion-hover);
}

.accordion-header h3 {
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-secondary);
    margin: 0;
}

.accordion-icon {
    color: var(--text-muted);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1), color 0.3s ease;
}

.accordion-group[open] .accordion-icon {
    transform: rotate(180deg);
    color: var(--color-accent);
}

.accordion-content {
    padding: 0 16px 16px 16px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    border-top: 1px solid var(--border-group);
    padding-top: 16px;
}

/* 4. Selected Paper Details Card styling */
.details-panel {
    grid-column: 2 / 3;
}

.details-content {
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    background: var(--bg-group);
    border: 1px solid var(--border-group);
    border-radius: 12px;
    padding: 16px;
    min-height: 180px;
}

.no-selection-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    text-align: center;
    color: var(--text-muted);
    font-size: 0.85rem;
    padding: 20px;
}

.empty-icon {
    color: var(--text-muted);
    opacity: 0.4;
}

.paper-details {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.detail-badge-row {
    display: flex;
    gap: 8px;
}

.author-badge {
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: 3px 8px;
    border-radius: 4px;
}

.author-badge.is-lead {
    background: rgba(0, 242, 254, 0.15);
    color: var(--color-lead);
    border: 1px solid rgba(0, 242, 254, 0.3);
}

.author-badge.is-co {
    background: rgba(236, 0, 140, 0.15);
    color: var(--color-co);
    border: 1px solid rgba(236, 0, 140, 0.3);
}

.year-badge {
    font-size: 0.7rem;
    font-weight: 600;
    background: var(--bg-ctrl-btn);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    padding: 3px 8px;
    border-radius: 4px;
}

.paper-title-id {
    font-family: var(--font-heading);
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--text-primary);
    word-break: break-all;
}

.detail-meta-grid {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 12px;
}

.meta-item {
    display: flex;
    flex-direction: column;
}

.meta-label {
    font-size: 0.7rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.02em;
}

.meta-val {
    font-size: 0.85rem;
    color: var(--text-primary);
    font-weight: 500;
}

.detail-divider {
    border: 0;
    height: 1px;
    background: var(--border-panel-header);
}

.audio-metrics-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
}

.metric-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 10px;
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.metric-header {
    display: flex;
    flex-direction: column;
    font-size: 0.7rem;
    color: var(--text-secondary);
}

.sound-map-label {
    color: var(--text-muted);
    font-size: 0.65rem;
    margin-top: 1px;
}

.metric-value {
    margin: 4px 0;
}

.val-num {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    font-weight: 700;
}

.prestige-card .val-num {
    color: var(--color-lead);
}

.success-card .val-num {
    color: var(--color-co);
}

.sound-feedback {
    font-size: 0.7rem;
    color: var(--text-muted);
    display: flex;
    gap: 4px;
}

.sound-val {
    color: var(--text-secondary);
    font-weight: 500;
}

.hidden {
    display: none !important;
}

/* 5. Career Analytics Panel */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}

.stat-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 18px;
    display: flex;
    align-items: center;
    gap: 16px;
    transition: transform 0.25s var(--transition-smooth), border-color 0.25s ease;
}

.stat-card:hover {
    transform: translateY(-4px);
    border-color: var(--border-hover);
}

.stat-icon {
    width: 44px;
    height: 44px;
    border-radius: 10px;
    background: var(--bg-stat-icon);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-accent);
}

.stat-icon.text-cyan {
    color: var(--color-lead);
}

.stat-icon.text-purple {
    color: #a78bfa;
}

.stat-icon.text-amber {
    color: #fbbf24;
}

.stat-data {
    display: flex;
    flex-direction: column;
}

.stat-label {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.stat-val {
    font-family: var(--font-heading);
    font-size: 1.35rem;
    font-weight: 700;
}

/* Footer & Guide sections */
.app-footer {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    background: var(--bg-panel);
    border: 1px solid var(--border-color);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-radius: 16px;
    padding: 20px 24px;
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.concept-block {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.concept-block h3 {
    font-family: var(--font-heading);
    font-size: 0.9rem;
    color: var(--text-primary);
    font-weight: 600;
}

/* Responsive Overrides */
@media (max-width: 1024px) {
    .main-grid {
        grid-template-columns: 1fr;
    }
    
    .timeline-panel, .details-panel {
        grid-column: 1 / -1;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .app-footer {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .app-container {
        padding: 16px;
        gap: 16px;
    }

    .app-header {
        flex-direction: column;
        align-items: stretch;
        gap: 16px;
        padding: 16px 20px;
    }

    .header-text {
        text-align: center;
    }

    .header-audio-controls {
        margin-left: 0;
        justify-content: center;
        width: 100%;
        box-sizing: border-box;
        flex-wrap: wrap;
        border-radius: 16px;
        padding: 12px;
        gap: 10px;
    }

    .header-volume-control {
        width: 100%;
        justify-content: center;
        margin-top: 4px;
    }

    .panel-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 14px;
    }

    .layout-toggle-group {
        width: 100%;
        display: flex;
    }

    .layout-btn {
        flex: 1;
        text-align: center;
        padding: 8px 6px;
        font-size: 0.7rem;
    }

    .legend {
        width: 100%;
        justify-content: flex-start;
        flex-wrap: wrap;
        gap: 12px;
    }
}

@media (max-width: 640px) {
    .panel {
        padding: 18px;
        gap: 12px;
    }

    .stats-grid {
        grid-template-columns: 1fr;
        gap: 12px;
    }
    
    .playback-bar {
        flex-direction: column;
        align-items: stretch;
        gap: 14px;
    }

    .play-controls {
        justify-content: center;
    }

    .progress-container {
        width: 100%;
    }

    .speed-control {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .app-header h1 {
        font-size: 1.5rem;
    }

    .audio-metrics-grid {
        grid-template-columns: 1fr;
        gap: 8px;
    }

    .stat-card {
        padding: 12px 14px;
        gap: 12px;
    }

    .stat-icon {
        width: 38px;
        height: 38px;
        border-radius: 8px;
        flex-shrink: 0;
    }

    .stat-val {
        font-size: 1.15rem;
    }


}