:root {
    --bg-main: #0f172a;
    --bg-card: #1e293b;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --accent-ceb: #eab308;
    --accent-water: #3b82f6;
    --border-color: #334155;
    --success: #10b981;
    --danger: #ef4444;
    --card-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.5), 0 4px 6px -2px rgba(0, 0, 0, 0.25);
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-main);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 2rem;
}

.dashboard {
    width: 100%;
    max-width: 900px;
}

.header {
    text-align: center;
    margin-bottom: 3rem;
}

.header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    background: linear-gradient(135deg, #f8fafc, #94a3b8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

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

.cards-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.card {
    background-color: var(--bg-card);
    border-radius: 16px;
    padding: 2rem;
    box-shadow: var(--card-shadow);
    border: 1px solid var(--border-color);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.card:hover {
    transform: translateY(-5px);
    border-color: #475569;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
}

#ceb-card::before {
    background: linear-gradient(90deg, var(--accent-ceb), #fef08a);
}

#water-card::before {
    background: linear-gradient(90deg, var(--accent-water), #93c5fd);
}

.card-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 2rem;
}

.icon {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.ceb-icon {
    background-color: rgba(234, 179, 8, 0.1);
    color: var(--accent-ceb);
}

.water-icon {
    background-color: rgba(59, 130, 246, 0.1);
    color: var(--accent-water);
}

.card-header h2 {
    font-size: 1.5rem;
    font-weight: 600;
}

.input-group {
    margin-bottom: 1.5rem;
}

.input-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
}

.input-group input {
    width: 100%;
    padding: 0.8rem 1rem;
    background-color: rgba(15, 23, 42, 0.6);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 1rem;
    font-family: 'Inter', sans-serif;
    transition: var(--transition);
}

.input-group input:focus {
    outline: none;
    border-color: #64748b;
    background-color: rgba(15, 23, 42, 0.9);
}

.btn {
    width: 100%;
    padding: 0.8rem;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    font-family: 'Inter', sans-serif;
}

.primary-btn {
    background-color: #334155;
    color: #f8fafc;
}

.primary-btn:hover {
    background-color: #475569;
}

.bill-details {
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px dashed var(--border-color);
    animation: fadeIn 0.5s ease;
}

.hidden {
    display: none;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.detail-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    font-size: 0.95rem;
}

.detail-row span:first-child {
    color: var(--text-secondary);
}

.amount {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
}

.highlight {
    font-weight: 600;
    color: #e2e8f0;
}

.status-badge {
    display: inline-block;
    padding: 0.3rem 0.8rem;
    border-radius: 9999px;
    font-size: 0.85rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-top: 0.5rem;
}

.status-paid {
    background-color: rgba(16, 185, 129, 0.1);
    color: var(--success);
}

.status-unpaid {
    background-color: rgba(239, 68, 68, 0.1);
    color: var(--danger);
}

/* Toast Notification */
.toast {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    background-color: var(--bg-card);
    color: var(--text-primary);
    padding: 1rem 1.5rem;
    border-radius: 8px;
    box-shadow: var(--card-shadow);
    border: 1px solid var(--border-color);
    z-index: 1000;
    transition: var(--transition);
    transform: translateY(100px);
    opacity: 0;
}

.toast.show {
    transform: translateY(0);
    opacity: 1;
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .cards-container {
        grid-template-columns: 1fr;
    }
    
    .header h1 {
        font-size: 2rem;
    }
}