:root {
    --bg-color: #0F1115;
    --surface-color: #171A21;
    --elevated-surface: #1D222B;
    --border-color: #2B313C;
    
    --text-primary: #F3F5F7;
    --text-secondary: #A5AFBC;
    --text-muted: #707887;
    
    --accent-primary: #6FAE8E;
    --accent-hover: #84C6A2;
    
    --success: #58B86D;
    --warning: #D7A04A;
    --error: #CF6666;
    
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    
    --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-family: var(--font-family);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
}

#app {
    display: flex;
    min-height: 100vh;
}

/* Sidebar */
.sidebar {
    width: 280px;
    background-color: var(--surface-color);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    position: fixed;
    height: 100vh;
    overflow-y: auto;
    z-index: 10;
}

.sidebar::-webkit-scrollbar {
    width: 6px;
}
.sidebar::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: var(--radius-sm);
}

.brand {
    padding: 32px 24px;
}

.brand h1 {
    font-size: 1.25rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    color: var(--text-primary);
}

.brand .subtitle {
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-top: 4px;
    display: block;
}

.nav-links {
    display: flex;
    flex-direction: column;
    padding: 0 16px;
    gap: 8px;
}

.nav-btn {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 16px;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 0.875rem;
    font-weight: 500;
    font-family: inherit;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
    text-align: left;
}

.nav-btn:hover {
    background-color: var(--elevated-surface);
    color: var(--text-primary);
}

.nav-btn.active {
    background-color: var(--elevated-surface);
    color: var(--accent-primary);
}

.filters-section {
    padding: 32px 24px;
    margin-top: auto;
    border-top: 1px solid var(--border-color);
}

.filters-section h3 {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    margin-bottom: 16px;
}

.filter-group {
    margin-bottom: 16px;
}

.filter-group label {
    display: block;
    font-size: 0.75rem;
    color: var(--text-secondary);
    margin-bottom: 8px;
}

input[type="text"], select {
    width: 100%;
    background-color: var(--bg-color);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 8px 12px;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-family: inherit;
    transition: var(--transition);
    outline: none;
}

input[type="text"]:focus, select:focus {
    border-color: var(--accent-primary);
}

input[type="range"] {
    width: 100%;
    accent-color: var(--accent-primary);
}

.btn-secondary {
    width: 100%;
    padding: 8px 16px;
    background-color: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    cursor: pointer;
    transition: var(--transition);
    margin-top: 8px;
}

.btn-secondary:hover {
    background-color: var(--elevated-surface);
    color: var(--text-primary);
    border-color: var(--text-muted);
}

.data-notice {
    margin-top: 24px;
    padding-top: 16px;
    border-top: 1px solid var(--border-color);
    font-size: 0.725rem;
    color: var(--text-muted);
    display: flex;
    gap: 8px;
    align-items: flex-start;
    line-height: 1.5;
}

/* Main Content */
.main-content {
    flex: 1;
    margin-left: 280px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.top-header {
    padding: 16px 48px 24px;
}

.header-brand {
    margin-bottom: 24px;
    display: block;
    text-align: center;
    background: transparent;
    border: none;
    cursor: pointer;
    font-family: inherit;
    margin-left: auto;
    margin-right: auto;
    transition: var(--transition);
}
.header-brand:hover .brand-title {
    color: var(--accent-hover);
}
.brand-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.02em;
}
.brand-subtitle {
    font-size: 0.75rem;
    color: var(--text-secondary);
    display: block;
    margin-top: 4px;
}
.author-name {
    font-weight: 500;
    color: var(--text-primary);
}
.emoji-tag {
    font-size: 0.95em;
    margin-left: 2px;
}
.redacted-tag {
    font-size: 0.82em;
    color: var(--text-muted);
    font-weight: 400;
    margin-left: 4px;
}

.header-titles h2 {
    font-size: 2rem;
    font-weight: 600;
    letter-spacing: -0.03em;
    margin-bottom: 8px;
}

.header-titles p {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.content-area {
    padding: 0 48px 48px;
    flex: 1;
}

.hidden {
    display: none !important;
}

/* Splash Screen */
.splash-screen {
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background-color: var(--bg-color);
    z-index: 9999;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-direction: column;
    transition: opacity 0.6s cubic-bezier(0.4, 0, 0.2, 1), visibility 0.6s;
}
.splash-screen.fade-out {
    opacity: 0;
    visibility: hidden;
}
.splash-content {
    text-align: center;
    animation: splash-pop 0.8s cubic-bezier(0.4, 0, 0.2, 1) forwards;
}
@keyframes splash-pop {
    0% { transform: scale(0.95); opacity: 0; }
    100% { transform: scale(1); opacity: 1; }
}
.splash-loader {
    width: 60px;
    height: 4px;
    background: var(--border-color);
    border-radius: 4px;
    margin: 32px auto 0;
    overflow: hidden;
    position: relative;
}
.splash-loader::after {
    content: '';
    position: absolute;
    left: 0; top: 0; bottom: 0;
    width: 50%;
    background: var(--accent-primary);
    border-radius: 4px;
    animation: load-slide 1s ease-in-out infinite alternate;
}
@keyframes load-slide {
    0% { transform: translateX(-20%); }
    100% { transform: translateX(120%); }
}

/* Grid Layouts for Dashboards */
.kpi-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 16px;
    margin-bottom: 32px;
}

.kpi-card {
    background-color: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 8px;
    transition: var(--transition);
}

.kpi-card:hover {
    transform: translateY(-2px);
    border-color: var(--text-muted);
    box-shadow: 0 4px 20px rgba(0,0,0,0.2);
}

.kpi-label {
    font-size: 0.8rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.kpi-value {
    font-size: 1.75rem;
    font-weight: 600;
    color: var(--text-primary);
}

.kpi-sub {
    font-size: 0.75rem;
    color: var(--accent-primary);
}

.charts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 24px;
    margin-bottom: 32px;
}

.chart-card {
    background-color: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 24px;
    display: flex;
    flex-direction: column;
}

.chart-card h3 {
    font-size: 1rem;
    font-weight: 500;
    margin-bottom: 20px;
    color: var(--text-primary);
}

.chart-container {
    position: relative;
    height: 300px;
    width: 100%;
}

/* Data Tables */
.table-container {
    background-color: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    overflow: hidden;
    overflow-x: auto;
}

table {
    width: 100%;
    border-collapse: collapse;
    text-align: left;
}

th, td {
    padding: 14px 20px;
    font-size: 0.875rem;
}

th {
    background-color: var(--elevated-surface);
    color: var(--text-secondary);
    font-weight: 500;
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
}

td {
    border-bottom: 1px solid var(--border-color);
    color: var(--text-primary);
}

tr:last-child td {
    border-bottom: none;
}

tr:hover td {
    background-color: rgba(29, 34, 43, 0.5);
}

/* Insights Card */
.insight-card {
    background: linear-gradient(145deg, var(--surface-color), var(--elevated-surface));
    border-left: 3px solid var(--accent-primary);
    padding: 20px;
    border-radius: var(--radius-md);
    margin-bottom: 24px;
}
.insight-card h4 {
    font-size: 0.875rem;
    color: var(--accent-primary);
    margin-bottom: 8px;
    display: flex;
    align-items: center;
    gap: 8px;
}
.insight-card p {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* Pagination */
.pagination {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 20px;
    background-color: var(--surface-color);
    border-top: 1px solid var(--border-color);
}
.pagination-controls {
    display: flex;
    gap: 8px;
}
.page-btn {
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 6px 12px;
    border-radius: var(--radius-sm);
    cursor: pointer;
}
.page-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* Responsive */
.mobile-menu-btn {
    display: none;
    position: fixed;
    top: 24px;
    right: 24px;
    z-index: 50;
    background: var(--elevated-surface);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 8px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
}
.mobile-menu-btn:hover {
    background: var(--border-color);
}

.mobile-overlay {
    display: none;
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(0,0,0,0.7);
    z-index: 5;
}

/* Session Landing Page */
.session-landing {
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background: var(--bg-color);
    z-index: 999;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}
.landing-content {
    text-align: center;
    max-width: 800px;
    width: 100%;
}
.landing-content h2 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}
.session-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
    margin-top: 2rem;
}
.session-card {
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 40px 24px;
    cursor: pointer;
    transition: var(--transition);
    text-align: center;
    position: relative;
    overflow: hidden;
}
.session-card:hover {
    transform: translateY(-5px);
    border-color: var(--accent-primary);
    box-shadow: 0 10px 25px rgba(0,0,0,0.5);
}
.session-card h3 {
    font-size: 1.75rem;
    color: var(--text-primary);
    margin-bottom: 8px;
}
.session-card p {
    color: var(--text-secondary);
}
.session-card.featured {
    background: var(--elevated-surface);
    border-color: var(--accent-hover);
}
.session-card .badge {
    position: absolute;
    top: 16px;
    right: 16px;
    background: var(--success);
    color: #fff;
    font-size: 0.75rem;
    font-weight: 600;
    padding: 4px 10px;
    border-radius: 20px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* Modals */
.modal {
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(0,0,0,0.8);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}
.modal-content {
    background: var(--surface-color);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    width: 100%;
    max-width: 600px;
    position: relative;
    padding: 24px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.7);
}
.close-btn {
    position: absolute;
    top: 16px;
    right: 16px;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 1.5rem;
    cursor: pointer;
    transition: color 0.2s;
}
.close-btn:hover { color: var(--text-primary); }

.hidden { display: none !important; }

@media (max-width: 1024px) {
    .charts-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .mobile-menu-btn {
        display: flex;
        align-items: center;
        justify-content: center;
    }
    .mobile-overlay.open {
        display: block;
    }
    .sidebar {
        transform: translateX(-100%);
        transition: transform 0.3s ease;
        box-shadow: 2px 0 10px rgba(0,0,0,0.5);
    }
    .sidebar.open {
        transform: translateX(0);
    }
    .main-content {
        margin-left: 0;
    }
    .top-header {
        padding: 60px 24px 24px;
    }
    .content-area {
        padding-left: 24px;
        padding-right: 24px;
    }

    /* Responsive Tables */
    table, thead, tbody, th, td, tr {
        display: block;
    }
    thead tr {
        display: none;
    }
    .table-container {
        background-color: transparent;
        border: none;
        overflow: visible;
    }
    tr {
        background-color: var(--surface-color);
        border: 1px solid var(--border-color);
        border-radius: var(--radius-md);
        margin-bottom: 16px;
        padding: 8px 0;
    }
    td {
        border-bottom: 1px solid var(--border-color);
        display: flex;
        justify-content: space-between;
        align-items: center;
        text-align: right;
        padding: 12px 20px;
    }
    tr td:last-child {
        border-bottom: none;
    }
    td::before {
        content: attr(data-label);
        font-weight: 500;
        color: var(--text-secondary);
        text-align: left;
        margin-right: 16px;
    }
    tr:hover td {
        background-color: transparent;
    }
    .pagination {
        flex-direction: column;
        gap: 16px;
    }
}