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

:root {
    --bg-gradient-start: #667eea;
    --bg-gradient-end: #764ba2;
    --text-primary: #333;
    --text-light: #666;
    --text-white: #fff;
    --container-bg: rgba(255, 255, 255, 0.95);
    --container-shadow: rgba(0, 0, 0, 0.3);
    --button-bg: rgba(102, 126, 234, 0.1);
    --button-border: rgba(102, 126, 234, 0.3);
    --button-hover-bg: rgba(102, 126, 234, 0.2);
    --button-text: #333;
    --control-bg: #667eea;
    --control-hover: #5568d3;
    --control-active: #764ba2;
    --checkbox-bg: rgba(102, 126, 234, 0.1);
    --checkbox-border: rgba(102, 126, 234, 0.3);
    --checkbox-hover-bg: rgba(102, 126, 234, 0.15);
    --checkbox-checked-bg: rgba(102, 126, 234, 0.3);
    --checkbox-checked-border: #667eea;
}

html[data-theme="dark"] {
    --bg-gradient-start: #1a1a2e;
    --bg-gradient-end: #16213e;
    --text-primary: #fff;
    --text-light: rgba(255, 255, 255, 0.7);
    --text-white: #fff;
    --container-bg: rgba(255, 255, 255, 0.05);
    --container-shadow: rgba(0, 0, 0, 0.6);
    --button-bg: rgba(255, 255, 255, 0.1);
    --button-border: rgba(255, 255, 255, 0.2);
    --button-hover-bg: rgba(255, 255, 255, 0.2);
    --button-text: white;
    --control-bg: #667eea;
    --control-hover: #5568d3;
    --control-active: #764ba2;
    --checkbox-bg: rgba(255, 255, 255, 0.1);
    --checkbox-border: rgba(255, 255, 255, 0.2);
    --checkbox-hover-bg: rgba(255, 255, 255, 0.15);
    --checkbox-checked-bg: rgba(102, 126, 234, 0.3);
    --checkbox-checked-border: #667eea;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, var(--bg-gradient-start) 0%, var(--bg-gradient-end) 100%);
    color: var(--text-primary);
    padding: 40px 20px;
    min-height: 100vh;
    transition: background 0.3s ease;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    background: var(--container-bg);
    border-radius: 20px;
    padding: 40px;
    backdrop-filter: blur(10px);
    box-shadow: 0 8px 32px 0 var(--container-shadow);
    transition: background 0.3s ease, box-shadow 0.3s ease;
}

.header-controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.back-btn {
    padding: 10px 20px;
    background: var(--button-bg);
    color: var(--button-text);
    text-decoration: none;
    border-radius: 10px;
    font-weight: bold;
    transition: all 0.3s ease;
    border: 2px solid var(--button-border);
}

.back-btn:hover {
    background: var(--button-hover-bg);
    transform: translateX(-5px);
}

.theme-toggle {
    padding: 10px 20px;
    background: var(--button-bg);
    color: var(--button-text);
    border: 2px solid var(--button-border);
    border-radius: 10px;
    font-size: 1.2em;
    cursor: pointer;
    transition: all 0.3s ease;
}

.theme-toggle:hover {
    background: var(--button-hover-bg);
    transform: scale(1.1);
}

h1 {
    text-align: center;
    font-size: 3em;
    margin-bottom: 10px;
    color: var(--text-primary);
}

html[data-theme="dark"] h1 {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    text-align: center;
    font-size: 1.2em;
    color: var(--text-light);
    margin-bottom: 30px;
}

.mode-selector {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-bottom: 30px;
}

.mode-btn {
    padding: 10px 25px;
    font-size: 1em;
    border: 2px solid var(--button-border);
    background: var(--button-bg);
    color: var(--button-text);
    border-radius: 25px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.mode-btn:hover {
    background: var(--button-hover-bg);
    border-color: var(--button-border);
}

.mode-btn.active {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-color: transparent;
    color: white;
}

.controls {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 40px;
}

.topic-controls {
    margin-bottom: 40px;
}

.topic-selection {
    background: var(--checkbox-bg);
    border-radius: 15px;
    padding: 25px;
    margin-bottom: 20px;
    border: 1px solid var(--checkbox-border);
}

.topic-selection label {
    display: block;
    font-size: 1.1em;
    font-weight: bold;
    margin-bottom: 20px;
    color: var(--text-primary);
}

.topic-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 12px;
    margin-bottom: 20px;
}

.topic-checkbox {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 16px;
    background: var(--checkbox-bg);
    border: 2px solid var(--checkbox-border);
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: normal;
    font-size: 0.95em;
    color: var(--text-primary);
}

.topic-checkbox:hover {
    background: var(--checkbox-hover-bg);
    border-color: var(--checkbox-border);
    transform: translateY(-2px);
}

.topic-checkbox input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
}

.topic-checkbox input[type="checkbox"]:checked + span {
    font-weight: bold;
}

.topic-checkbox:has(input:checked) {
    background: var(--checkbox-checked-bg);
    border-color: var(--checkbox-checked-border);
}

.load-btn {
    width: 100%;
    padding: 15px 30px;
    font-size: 1.1em;
    font-weight: bold;
    border: none;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-radius: 30px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.load-btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(102, 126, 234, 0.4);
}

.load-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    background: rgba(255, 255, 255, 0.2);
}

.time-range-section {
    background: var(--checkbox-bg);
    border: 1px solid var(--checkbox-border);
    border-radius: 15px;
    padding: 25px;
    margin-bottom: 30px;
}

.time-range-section h3 {
    color: var(--text-primary);
    margin-bottom: 20px;
    font-size: 1.3em;
}

.period-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 20px;
}

.period-btn {
    padding: 10px 20px;
    background: var(--button-bg);
    color: var(--button-text);
    border: 2px solid var(--button-border);
    border-radius: 20px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-size: 0.9em;
    font-weight: 500;
}

.period-btn:hover {
    background: var(--button-hover-bg);
    transform: translateY(-2px);
}

.period-btn.active {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-color: transparent;
    color: white;
    font-weight: bold;
}

.custom-range {
    background: var(--checkbox-hover-bg);
    padding: 15px;
    border-radius: 10px;
    margin-bottom: 20px;
}

.custom-range label {
    display: block;
    color: var(--text-primary);
    font-weight: bold;
    margin-bottom: 10px;
}

.range-inputs {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
}

.range-inputs input {
    padding: 8px 12px;
    border: 2px solid var(--checkbox-border);
    border-radius: 8px;
    background: var(--container-bg);
    color: var(--text-primary);
    font-size: 1em;
    width: 120px;
}

.range-inputs span {
    color: var(--text-primary);
    font-weight: 500;
}

.apply-range-btn {
    padding: 8px 20px;
    background: #667eea;
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-weight: bold;
    transition: all 0.3s ease;
}

.apply-range-btn:hover {
    background: #5568d3;
    transform: scale(1.05);
}

.zoom-controls {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
}

.zoom-controls label {
    color: var(--text-primary);
    font-weight: bold;
}

.zoom-btn {
    padding: 8px 16px;
    background: var(--button-bg);
    color: var(--button-text);
    border: 2px solid var(--button-border);
    border-radius: 8px;
    cursor: pointer;
    font-weight: 500;
    transition: all 0.3s ease;
}

.zoom-btn:hover {
    background: var(--button-hover-bg);
    transform: scale(1.05);
}

.controls button {
    padding: 12px 30px;
    font-size: 1.1em;
    border: 2px solid var(--button-border);
    background: var(--control-bg);
    color: white;
    border-radius: 30px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.controls button:hover {
    background: var(--control-hover);
    border-color: var(--button-border);
    transform: translateY(-2px);
}

.controls button.active {
    background: var(--control-active);
    border-color: transparent;
    color: white;
}

.timeline-wrapper {
    margin: 40px 0;
}

.timeline-row {
    display: flex;
    align-items: center;
    margin-bottom: 30px;
}

.timeline-label {
    width: 150px;
    font-weight: bold;
    font-size: 1.2em;
    padding-right: 20px;
    color: var(--text-primary);
}

.timeline-track {
    flex: 1;
    position: relative;
    height: 80px;
    background: var(--checkbox-bg);
    border-radius: 10px;
    border: 1px solid var(--checkbox-border);
}

.timeline-axis {
    position: absolute;
    width: 100%;
    height: 2px;
    background: var(--checkbox-border);
    top: 50%;
    transform: translateY(-50%);
}

.event {
    position: absolute;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    cursor: pointer;
    transition: all 0.3s ease;
    border: 3px solid white;
    z-index: 10;
}

.event:hover {
    transform: translate(-50%, -50%) scale(1.8);
    z-index: 20;
}

.event.europe {
    background: #667eea;
}

.event.asia {
    background: #f093fb;
}

.event.americas {
    background: #4facfe;
}

.event.africa {
    background: #43e97b;
}

/* Dynamic topic colors */
.event.topic-0 { background: #667eea; }
.event.topic-1 { background: #f093fb; }
.event.topic-2 { background: #4facfe; }
.event.topic-3 { background: #43e97b; }
.event.topic-4 { background: #fa709a; }
.event.topic-5 { background: #fee140; }
.event.topic-6 { background: #30cfd0; }
.event.topic-7 { background: #a8edea; }

.event-title, .event-year {
    position: absolute;
    white-space: nowrap;
    font-size: 0.75em;
    opacity: 0;
    transition: opacity 0.3s ease;
    pointer-events: none;
}

.event-title {
    bottom: 25px;
    left: 50%;
    transform: translateX(-50%);
    font-weight: bold;
}

.event-year {
    top: 25px;
    left: 50%;
    transform: translateX(-50%);
    color: var(--text-light);
}

.event:hover .event-title,
.event:hover .event-year {
    opacity: 1;
}

.year-markers {
    display: flex;
    justify-content: space-between;
    margin-left: 150px;
    color: var(--text-light);
    font-size: 0.9em;
    padding: 0 10px;
}

.legend {
    display: flex;
    justify-content: center;
    gap: 30px;
    margin-top: 40px;
    flex-wrap: wrap;
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 10px;
}

.legend-color {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    border: 2px solid white;
}

.legend-color.europe {
    background: #667eea;
}

.legend-color.asia {
    background: #f093fb;
}

.legend-color.americas {
    background: #4facfe;
}

.legend-color.africa {
    background: #43e97b;
}

/* Dynamic topic legend colors */
.legend-color.topic-0 { background: #667eea; }
.legend-color.topic-1 { background: #f093fb; }
.legend-color.topic-2 { background: #4facfe; }
.legend-color.topic-3 { background: #43e97b; }
.legend-color.topic-4 { background: #fa709a; }
.legend-color.topic-5 { background: #fee140; }
.legend-color.topic-6 { background: #30cfd0; }
.legend-color.topic-7 { background: #a8edea; }

#tooltip {
    position: fixed;
    background: rgba(0, 0, 0, 0.9);
    color: white;
    padding: 12px 16px;
    border-radius: 8px;
    font-size: 0.9em;
    pointer-events: none;
    z-index: 1000;
    max-width: 300px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
    display: none;
}

/* Mobile Responsive Styles */
@media (max-width: 768px) {
    body {
        padding: 10px;
    }

    .container {
        padding: 20px 15px;
        border-radius: 15px;
    }

    h1 {
        font-size: 1.75rem;
    }

    .subtitle {
        font-size: 0.9rem;
    }

    /* Header controls */
    .header-controls {
        margin-bottom: 15px;
    }

    .back-btn,
    .theme-toggle {
        padding: 8px 12px;
        font-size: 0.9em;
    }

    /* Mode selector buttons */
    .mode-selector {
        flex-direction: column;
        gap: 8px;
    }

    .mode-btn {
        width: 100%;
        padding: 10px 15px;
        font-size: 0.9rem;
    }

    /* Default control buttons */
    .controls {
        flex-direction: column;
        gap: 8px;
    }

    .controls button {
        width: 100%;
        padding: 12px 15px;
        font-size: 0.85rem;
    }

    /* Topic controls */
    .topic-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 8px;
    }

    .topic-checkbox {
        padding: 8px 10px;
        font-size: 0.85rem;
    }

    .topic-checkbox span {
        font-size: 0.85rem;
    }

    .load-btn {
        width: 100%;
        padding: 12px;
        font-size: 0.9rem;
        margin-top: 10px;
    }

    /* Time range controls */
    .time-range-section h3 {
        font-size: 1.1rem;
    }

    .period-buttons {
        flex-direction: column;
        gap: 8px;
    }

    .period-btn {
        width: 100%;
        padding: 10px;
        font-size: 0.85rem;
    }

    .custom-range {
        flex-direction: column;
        gap: 10px;
    }

    .range-inputs {
        flex-direction: column;
        gap: 8px;
        width: 100%;
    }

    .range-inputs input {
        width: 100%;
        padding: 10px;
        font-size: 0.9rem;
    }

    .apply-range-btn {
        width: 100%;
        padding: 10px;
        font-size: 0.9rem;
    }

    .zoom-controls {
        flex-direction: column;
        gap: 8px;
    }

    .zoom-btn {
        width: 100%;
        padding: 10px;
        font-size: 0.9rem;
    }

    /* Timeline wrapper */
    .timeline-wrapper {
        margin: 20px 0;
    }

    .timeline-container {
        padding: 15px 10px;
    }

    .timeline-row {
        min-height: 60px;
    }

    .timeline-label {
        font-size: 0.75rem;
        padding: 8px;
        min-width: 80px;
    }

    .timeline-track {
        margin-left: 85px;
    }

    .event-block {
        min-height: 30px;
        font-size: 0.75rem;
        padding: 4px 6px;
    }

    .event-year {
        font-size: 0.65rem;
    }

    /* Year markers */
    .year-markers {
        margin-left: 85px;
        font-size: 0.7rem;
    }

    .year-marker {
        font-size: 0.7rem;
    }

    /* Legend */
    .legend {
        padding: 15px;
    }

    .legend-item {
        font-size: 0.85rem;
    }

    .legend-color {
        width: 12px;
        height: 12px;
    }

    /* Tooltip */
    #tooltip {
        max-width: 200px;
        font-size: 0.8em;
        padding: 10px 12px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 15px 10px;
    }

    h1 {
        font-size: 1.5rem;
    }

    .subtitle {
        font-size: 0.85rem;
    }

    .back-btn,
    .theme-toggle {
        padding: 6px 10px;
        font-size: 0.85em;
    }

    .mode-btn {
        padding: 8px 12px;
        font-size: 0.85rem;
    }

    .controls button {
        padding: 10px 12px;
        font-size: 0.8rem;
    }

    /* Topic grid - single column on very small screens */
    .topic-grid {
        grid-template-columns: 1fr;
    }

    .topic-checkbox {
        padding: 10px;
        font-size: 0.9rem;
    }

    .period-btn {
        padding: 8px;
        font-size: 0.8rem;
    }

    .timeline-label {
        font-size: 0.7rem;
        padding: 6px;
        min-width: 70px;
    }

    .timeline-track {
        margin-left: 75px;
    }

    .event-block {
        min-height: 25px;
        font-size: 0.7rem;
        padding: 3px 5px;
    }

    .event-year {
        font-size: 0.6rem;
    }

    .year-markers {
        margin-left: 75px;
        font-size: 0.65rem;
    }

    .legend {
        padding: 12px;
    }

    .legend-item {
        font-size: 0.8rem;
    }
}

/* Landscape orientation on mobile */
@media (max-width: 768px) and (orientation: landscape) {
    .topic-grid {
        grid-template-columns: repeat(3, 1fr);
    }

    .period-buttons {
        flex-direction: row;
        flex-wrap: wrap;
    }

    .period-btn {
        flex: 1 1 calc(50% - 8px);
        min-width: 0;
    }
}