:root {
    --bg-base: #0f172a;
    --bg-surface: rgba(30, 41, 59, 0.7);
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --accent: #3b82f6;
    --accent-hover: #2563eb;
    --danger: #ef4444;
    --success: #10b981;
    --border: rgba(255, 255, 255, 0.1);
    --glass-blur: blur(12px);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-base);
    color: var(--text-primary);
    min-height: 100vh;
    overflow: hidden;
    /* Smooth gradient background */
    background: radial-gradient(circle at top left, #1e293b 0%, #0f172a 100%);
}

#app-container {
    display: flex;
    height: 100vh;
    opacity: 0;
    transition: opacity 0.3s ease;
}

#app-container.authenticated {
    opacity: 1;
}

/* Typography */
h1, h2, h3 { font-weight: 600; }
.highlight { color: var(--accent); }

/* Glassmorphism utility */
.glass-panel {
    background: var(--bg-surface);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border: 1px solid var(--border);
    border-radius: 16px;
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
}

/* Sidebar */
.sidebar {
    width: 260px;
    margin: 16px;
    padding: 24px;
    display: flex;
    flex-direction: column;
}

.logo {
    margin-bottom: 40px;
}

.nav-links {
    list-style: none;
    flex: 1;
}

.nav-links li { margin-bottom: 8px; }

.nav-links a {
    display: block;
    padding: 12px 16px;
    color: var(--text-secondary);
    text-decoration: none;
    border-radius: 8px;
    transition: var(--transition);
}

.nav-links a:hover, .nav-links a.active {
    background: rgba(59, 130, 246, 0.1);
    color: var(--accent);
}

.user-profile {
    display: flex;
    align-items: center;
    gap: 12px;
    padding-top: 24px;
    border-top: 1px solid var(--border);
}

.avatar {
    width: 36px;
    height: 36px;
    background: var(--accent);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
}

/* Main Content */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    padding: 16px 16px 16px 0;
}

.top-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 24px;
    margin-bottom: 24px;
}

/* Buttons */
.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    font-family: 'Inter', sans-serif;
}

.btn.primary {
    background: var(--accent);
    color: white;
}

.btn.primary:hover {
    background: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

/* Views Container */
.view-container {
    flex: 1;
    position: relative;
    overflow-y: auto;
}

.view {
    display: none;
    animation: fadeIn 0.4s ease forwards;
}

.view.active {
    display: block;
}

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

/* Dashboard Stats */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 24px;
}

.stat-card {
    padding: 24px;
    text-align: center;
}

.stat-card h3 {
    color: var(--text-secondary);
    font-size: 14px;
    margin-bottom: 12px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.stat-value {
    font-size: 36px;
    font-weight: 700;
}

.stat-value.warning {
    color: var(--danger);
}

/* Data Table */
.table-container {
    padding: 24px;
    overflow-x: auto;
}

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

.data-table th, .data-table td {
    padding: 16px;
    text-align: left;
    border-bottom: 1px solid var(--border);
}

.data-table th {
    color: var(--text-secondary);
    font-size: 14px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.data-table tr {
    transition: var(--transition);
}

.data-table tr:hover {
    background: rgba(255, 255, 255, 0.03);
}

.clickable-row {
    cursor: pointer;
}

.status-badge {
    padding: 4px 10px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 600;
}

.status-badge.ok {
    background: rgba(16, 185, 129, 0.2);
    color: var(--success);
}

.status-badge.low {
    background: rgba(239, 68, 68, 0.2);
    color: var(--danger);
}

/* Modal Styles */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(8px);
    display: none; /* Hidden by default */
    justify-content: center;
    align-items: center;
    z-index: 1000;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.modal-overlay.active {
    display: flex;
    opacity: 1;
}

.modal-content {
    width: 100%;
    max-width: 500px;
    padding: 32px;
    position: relative;
    transform: scale(0.9);
    transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.modal-overlay.active .modal-content {
    transform: scale(1);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
}

.close-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 24px;
    cursor: pointer;
    transition: var(--transition);
}

.close-btn:hover {
    color: var(--text-primary);
}

/* Form Elements */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-size: 14px;
    color: var(--text-secondary);
}

.form-control {
    width: 100%;
    padding: 12px 16px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text-primary);
    font-family: inherit;
    transition: var(--transition);
}

.form-control:focus {
    outline: none;
    border-color: var(--accent);
    background: rgba(255, 255, 255, 0.1);
}

.form-actions {
    display: flex;
    justify-content: flex-end;
    gap: 12px;
    margin-top: 32px;
}

.placeholder-content {
    padding: 48px;
    text-align: center;
}

.placeholder-content h2 {
    margin-bottom: 16px;
}

.placeholder-content p {
    color: var(--text-secondary);
}