:root {
    --bg-primary: #0a0e1a;
    --bg-secondary: #151b2e;
    --bg-tertiary: #1e2940;
    --text-primary: #e8ecf4;
    --text-secondary: #9ca3af;
    --accent-primary: #6366f1;
    --accent-hover: #4f46e5;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --border: #2d3748;
    --shadow: rgba(0, 0, 0, 0.3);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

header {
    text-align: center;
    margin-bottom: 3rem;
    padding: 2rem 0;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 0.5rem;
}

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

h1 {
    font-size: 2.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--accent-primary), #8b5cf6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

main {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.upload-section {
    background: var(--bg-secondary);
    border-radius: 1rem;
    padding: 2rem;
    border: 2px dashed var(--border);
}

.upload-area {
    text-align: center;
    padding: 2rem;
}

.upload-area svg {
    color: var(--accent-primary);
    margin-bottom: 1rem;
}

.upload-area h2 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.upload-area p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.btn-primary {
    background: var(--accent-primary);
    color: white;
    border: none;
    padding: 0.75rem 2rem;
    border-radius: 0.5rem;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-primary:hover {
    background: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.4);
}

.manual-input-section {
    background: var(--bg-secondary);
    border-radius: 1rem;
    padding: 2rem;
}

.manual-input-section h3 {
    margin-bottom: 1.5rem;
    font-size: 1.3rem;
}

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

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.form-group label {
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
}

.form-group input,
.form-group select {
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    color: var(--text-primary);
    padding: 0.75rem;
    border-radius: 0.5rem;
    font-size: 1rem;
    transition: all 0.2s;
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.results-section {
    animation: fadeIn 0.5s ease-in;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.results-section h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    text-align: center;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: var(--bg-secondary);
    border-radius: 1rem;
    padding: 1.5rem;
    display: flex;
    align-items: center;
    gap: 1rem;
    border: 1px solid var(--border);
    transition: all 0.3s;
}

.stat-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px var(--shadow);
    border-color: var(--accent-primary);
}

.stat-card.highlight {
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.1), rgba(139, 92, 246, 0.1));
    border-color: var(--accent-primary);
}

.stat-card.alert {
    background: linear-gradient(135deg, rgba(239, 68, 68, 0.1), rgba(245, 158, 11, 0.1));
    border-color: var(--danger);
}

.stat-icon {
    font-size: 2.5rem;
    flex-shrink: 0;
}

.stat-content {
    flex: 1;
}

.stat-label {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 0.25rem;
}

.stat-value {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--text-primary);
}

.stat-description {
    color: var(--text-secondary);
    font-size: 0.85rem;
    margin-top: 0.25rem;
}

.chart-container {
    background: var(--bg-secondary);
    border-radius: 1rem;
    padding: 2rem;
    margin-bottom: 2rem;
    border: 1px solid var(--border);
}

.chart-container h3 {
    margin-bottom: 1.5rem;
    font-size: 1.3rem;
}

#sleepChart {
    max-height: 300px;
}

.sessions-table {
    background: var(--bg-secondary);
    border-radius: 1rem;
    padding: 2rem;
    border: 1px solid var(--border);
}

.sessions-table h3 {
    margin-bottom: 1.5rem;
    font-size: 1.3rem;
}

.table-wrapper {
    overflow-x: auto;
}

table {
    width: 100%;
    border-collapse: collapse;
}

thead {
    background: var(--bg-tertiary);
}

th {
    padding: 1rem;
    text-align: left;
    font-weight: 600;
    color: var(--text-secondary);
    border-bottom: 2px solid var(--border);
}

td {
    padding: 1rem;
    border-bottom: 1px solid var(--border);
}

tbody tr {
    transition: background 0.2s;
}

tbody tr:hover {
    background: var(--bg-tertiary);
}

.quality-badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 0.25rem;
    font-size: 0.85rem;
    font-weight: 600;
}

.quality-excellent {
    background: rgba(16, 185, 129, 0.2);
    color: var(--success);
}

.quality-good {
    background: rgba(59, 130, 246, 0.2);
    color: #3b82f6;
}

.quality-normal {
    background: rgba(156, 163, 175, 0.2);
    color: var(--text-secondary);
}

.quality-bad {
    background: rgba(245, 158, 11, 0.2);
    color: var(--warning);
}

.quality-terrible {
    background: rgba(239, 68, 68, 0.2);
    color: var(--danger);
}

footer {
    text-align: center;
    padding: 2rem 0;
    margin-top: 3rem;
    color: var(--text-secondary);
    border-top: 1px solid var(--border);
}

@media (max-width: 768px) {
    .container {
        padding: 1rem;
    }

    h1 {
        font-size: 2rem;
    }

    .form-grid {
        grid-template-columns: 1fr;
    }

    .stats-grid {
        grid-template-columns: 1fr;
    }

    table {
        font-size: 0.9rem;
    }

    th, td {
        padding: 0.75rem 0.5rem;
    }
}