:root {
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary: #64748b;
    --bg: #f1f5f9;
    --card-bg: #ffffff;
    --text: #1e293b;
    --text-light: #64748b;
    --border: #e2e8f0;
    --success: #22c55e;
    --warning: #f59e0b;
    --danger: #ef4444;
    --info: #3b82f6;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --radius: 16px;
    --radius-sm: 8px;
}

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

body {
    font-family: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
    width: 100%;
}

/* Header */
header {
    background: var(--card-bg);
    padding: 1rem 0;
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.logo {
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--primary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.logo i { font-size: 1.6rem; }

/* Upload Zone */
.upload-zone {
    display: flex;
    align-items: center;
    gap: 1rem;
    background: var(--bg);
    padding: 0.75rem 1.25rem;
    border-radius: var(--radius);
    border: 2px dashed var(--border);
    transition: border-color 0.2s;
}

.upload-zone.dragover {
    border-color: var(--primary);
    background: #eff6ff;
}

.upload-btn {
    background: var(--primary);
    color: white;
    padding: 0.6rem 1.2rem;
    border-radius: var(--radius-sm);
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 500;
    transition: background 0.2s;
    border: none;
}

.upload-btn:hover { background: var(--primary-hover); }

#fileName {
    color: var(--text-light);
    font-size: 0.9rem;
    max-width: 200px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

#analyzeBtn {
    background: var(--success);
    color: white;
    padding: 0.6rem 1.2rem;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-weight: 600;
    transition: opacity 0.2s;
}

#analyzeBtn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

#analyzeBtn:not(:disabled):hover {
    background: #16a34a;
}

/* Main Content */
main {
    flex: 1;
    padding: 2rem 0;
}

.hidden { display: none !important; }

/* Loading */
.loading {
    text-align: center;
    padding: 4rem 2rem;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 4px solid var(--border);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto 1.5rem;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

.loading-subtext {
    color: var(--text-light);
    font-size: 0.9rem;
    margin-top: 0.5rem;
}

/* Error */
.error {
    background: #fef2f2;
    color: var(--danger);
    padding: 1rem 1.25rem;
    border-radius: var(--radius);
    margin-bottom: 1.5rem;
    border-left: 4px solid var(--danger);
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.error::before {
    content: "⚠️";
    font-size: 1.2rem;
}

/* Cards */
.card {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 1.5rem;
    box-shadow: var(--shadow);
    margin-bottom: 1.5rem;
    transition: box-shadow 0.2s;
}

.card:hover { box-shadow: var(--shadow-lg); }

.card h2, .card h3 {
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text);
    font-size: 1.2rem;
}

.card h2 i, .card h3 i { color: var(--primary); }

/* Summary */
.summary-card p {
    color: var(--text-light);
    line-height: 1.7;
}

/* Metrics Grid */
.metrics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.metric-card {
    text-align: center;
    padding: 1.25rem;
}

.metric-card .value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary);
    margin: 0.5rem 0;
}

.bar-container {
    height: 6px;
    background: var(--border);
    border-radius: 3px;
    margin-top: 0.5rem;
    overflow: hidden;
}

.bar {
    height: 100%;
    background: var(--success);
    width: 0%;
    transition: width 0.8s ease;
    border-radius: 3px;
}

.bar.neg { background: var(--danger); }

/* Two Column Layout */
.two-col {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

/* Lists */
.list-group {
    list-style: none;
    padding: 0;
}

.list-group li {
    padding: 0.75rem 1rem;
    border-bottom: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 0.75rem;
}

.list-group li:last-child { border-bottom: none; }

.list-group li .badge {
    background: var(--info);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 999px;
    font-size: 0.8rem;
    font-weight: 600;
}

.list-group li .badge.high { background: var(--danger); }
.list-group li .badge.medium { background: var(--warning); color: #1e293b; }
.list-group li .badge.low { background: var(--success); }

.list-group.urgent li {
    background: #fef2f2;
    color: var(--danger);
    font-weight: 500;
    border-left: 3px solid var(--danger);
}

/* Actions List */
.actions-list {
    padding-left: 1.5rem;
    color: var(--text-light);
}

.actions-list li {
    margin-bottom: 0.5rem;
}

/* Trends */
.trend-box {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.trend-box div {
    padding: 0.5rem 0;
    border-bottom: 1px dashed var(--border);
}

.trend-box div:last-child { border-bottom: none; }

.trend-box strong {
    color: var(--primary);
    margin-right: 0.5rem;
}

/* Chart */
.chart-container {
    display: flex;
    align-items: flex-end;
    gap: 0.5rem;
    height: 180px;
    padding-top: 1rem;
    overflow-x: auto;
    padding-bottom: 0.5rem;
}

.chart-bar-wrapper {
    display: flex;
    flex-direction: column;
    align-items: center;
    flex: 1;
    min-width: 50px;
    max-width: 80px;
}

.chart-bar {
    background: linear-gradient(to top, var(--primary), #60a5fa);
    border-radius: 6px 6px 0 0;
    width: 100%;
    min-height: 4px;
    transition: height 0.5s ease;
}

.chart-label {
    font-size: 0.7rem;
    color: var(--text-light);
    margin-top: 0.5rem;
    text-align: center;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: 100%;
}

/* Keyword Cloud */
.keyword-cloud {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.keyword-tag {
    background: var(--bg);
    padding: 0.4rem 0.8rem;
    border-radius: 999px;
    font-size: 0.85rem;
    display: flex;
    align-items: center;
    gap: 0.4rem;
    border: 1px solid var(--border);
}

.keyword-tag .count {
    background: var(--primary);
    color: white;
    padding: 0.1rem 0.5rem;
    border-radius: 999px;
    font-size: 0.75rem;
    font-weight: 600;
}

/* Footer */
footer {
    background: var(--card-bg);
    padding: 1rem 0;
    text-align: center;
    color: var(--text-light);
    font-size: 0.85rem;
    border-top: 1px solid var(--border);
    margin-top: auto;
}

footer a {
    color: var(--primary);
    text-decoration: none;
}

footer a:hover { text-decoration: underline; }

/* Responsive */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        align-items: stretch;
    }
    
    .upload-zone {
        flex-direction: column;
        width: 100%;
    }
    
    .upload-btn, #analyzeBtn {
        width: 100%;
        justify-content: center;
    }
    
    #fileName {
        max-width: 100%;
        text-align: center;
    }
    
    .two-col {
        grid-template-columns: 1fr;
    }
    
    .metrics-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .card {
        padding: 1.25rem;
    }
}

@media (max-width: 480px) {
    .metrics-grid {
        grid-template-columns: 1fr;
    }
    
    .metric-card .value {
        font-size: 1.75rem;
    }
    
    .container {
        padding: 0 1rem;
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus states */
.upload-btn:focus, #analyzeBtn:focus {
    outline: 2px solid var(--primary);
    outline-offset: 2px;
}

input[type="file"]:focus + label {
    outline: 2px solid var(--primary);
}