/* ===== CSS Variables ===== */
:root {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --bg-card: #1e293b;
    --bg-input: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --accent: #3b82f6;
    --accent-hover: #2563eb;
    --success: #22c55e;
    --warning: #f59e0b;
    --danger: #ef4444;
    --border: #334155;
    --shadow: 0 4px 6px -1px rgba(0,0,0,0.3);
    --radius: 8px;
}

/* ===== Reset & Base ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

body {
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ===== Login Page ===== */
.login-container {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    padding: 1rem;
}

.login-box {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 2.5rem;
    width: 100%;
    max-width: 420px;
    box-shadow: var(--shadow);
}

.login-box h1 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    text-align: center;
}

.login-box .subtitle {
    color: var(--text-secondary);
    text-align: center;
    margin-bottom: 2rem;
    font-size: 0.875rem;
}

.logo-area {
    text-align: center;
    margin-bottom: 1.5rem;
}

.logo-area .icon {
    width: 64px;
    height: 64px;
    background: var(--accent);
    border-radius: 16px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: white;
    margin-bottom: 0.5rem;
}

/* ===== Form Elements ===== */
.form-group {
    margin-bottom: 1.25rem;
}

.form-group label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
    color: var(--text-secondary);
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 0.75rem 1rem;
    background: var(--bg-input);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    color: var(--text-primary);
    font-size: 0.9375rem;
    outline: none;
    transition: border-color 0.2s;
}

.form-group input:focus {
    border-color: var(--accent);
}

.form-group input::placeholder {
    color: var(--text-secondary);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    font-size: 0.9375rem;
    font-weight: 600;
    border: none;
    border-radius: var(--radius);
    cursor: pointer;
    transition: background 0.2s, transform 0.1s;
}

.btn:active { transform: scale(0.98); }

.btn-primary {
    background: var(--accent);
    color: white;
    width: 100%;
}

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

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

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

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.8125rem;
}

.alert {
    padding: 0.75rem 1rem;
    border-radius: var(--radius);
    margin-bottom: 1rem;
    font-size: 0.875rem;
    display: none;
}

.alert-error { background: rgba(239,68,68,0.15); color: #fca5a5; border: 1px solid rgba(239,68,68,0.3); }
.alert-success { background: rgba(34,197,94,0.15); color: #86efac; border: 1px solid rgba(34,197,94,0.3); }
.alert-info { background: rgba(59,130,246,0.15); color: #93c5fd; border: 1px solid rgba(59,130,246,0.3); }

.form-footer {
    text-align: center;
    margin-top: 1.5rem;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

/* ===== 2FA Section ===== */
.twofa-section {
    display: none;
    text-align: center;
}

.twofa-section p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    font-size: 0.875rem;
}

.code-input {
    text-align: center;
    font-size: 1.5rem;
    letter-spacing: 0.5rem;
    font-weight: 700;
}

/* ===== Dashboard Layout ===== */
.app-layout {
    display: flex;
    min-height: 100vh;
}

.sidebar {
    width: 260px;
    background: var(--bg-secondary);
    border-right: 1px solid var(--border);
    padding: 1.5rem 1rem;
    display: flex;
    flex-direction: column;
    flex-shrink: 0;
}

.sidebar-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0 0.5rem 1.5rem;
    border-bottom: 1px solid var(--border);
    margin-bottom: 1.5rem;
}

.sidebar-brand .brand-icon {
    width: 36px;
    height: 36px;
    background: var(--accent);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    color: white;
    font-size: 0.875rem;
}

.sidebar-brand span {
    font-weight: 600;
    font-size: 1rem;
}

.nav-section {
    margin-bottom: 1.5rem;
}

.nav-section-title {
    font-size: 0.6875rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--text-secondary);
    padding: 0 0.75rem;
    margin-bottom: 0.5rem;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.625rem 0.75rem;
    border-radius: var(--radius);
    color: var(--text-secondary);
    font-size: 0.875rem;
    cursor: pointer;
    transition: background 0.15s, color 0.15s;
}

.nav-item:hover {
    background: var(--bg-input);
    color: var(--text-primary);
    text-decoration: none;
}

.nav-item.active {
    background: rgba(59,130,246,0.15);
    color: var(--accent);
}

.nav-item .nav-icon {
    width: 20px;
    text-align: center;
    font-size: 1rem;
}

.sidebar-footer {
    margin-top: auto;
    padding-top: 1rem;
    border-top: 1px solid var(--border);
}

.user-info {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.5rem;
}

.user-avatar {
    width: 32px;
    height: 32px;
    background: var(--accent);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.75rem;
    color: white;
}

.user-details {
    flex: 1;
    min-width: 0;
}

.user-details .name {
    font-size: 0.8125rem;
    font-weight: 600;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.user-details .role {
    font-size: 0.6875rem;
    color: var(--text-secondary);
}

/* ===== Main Content ===== */
.main-content {
    flex: 1;
    padding: 2rem;
    overflow-y: auto;
}

.page-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
}

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

.header-actions {
    display: flex;
    gap: 0.75rem;
}

/* ===== Stats Cards ===== */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.25rem;
}

.stat-card .stat-label {
    font-size: 0.75rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 0.5rem;
}

.stat-card .stat-value {
    font-size: 1.75rem;
    font-weight: 700;
}

.stat-card .stat-change {
    font-size: 0.75rem;
    margin-top: 0.25rem;
}

.stat-change.up { color: var(--success); }
.stat-change.down { color: var(--danger); }

/* ===== Data Cards ===== */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    margin-bottom: 1.5rem;
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 1.25rem;
    border-bottom: 1px solid var(--border);
}

.card-header h3 {
    font-size: 1rem;
    font-weight: 600;
}

.card-body {
    padding: 1.25rem;
}

/* ===== Tables ===== */
.table-container {
    overflow-x: auto;
}

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

th, td {
    padding: 0.75rem 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border);
    font-size: 0.875rem;
}

th {
    color: var(--text-secondary);
    font-weight: 600;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

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

tr:hover td { background: rgba(59,130,246,0.05); }

/* ===== Status Badges ===== */
.badge {
    display: inline-block;
    padding: 0.25rem 0.625rem;
    border-radius: 9999px;
    font-size: 0.6875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.03em;
}

.badge-success { background: rgba(34,197,94,0.15); color: #4ade80; }
.badge-warning { background: rgba(245,158,11,0.15); color: #fbbf24; }
.badge-danger { background: rgba(239,68,68,0.15); color: #f87171; }
.badge-info { background: rgba(59,130,246,0.15); color: #60a5fa; }

/* ===== Grid Layout ===== */
.grid-2 {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

/* ===== Live indicator ===== */
.live-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--success);
    display: inline-block;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.4; }
}

/* ===== Connection Status ===== */
.connection-status {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.8125rem;
    color: var(--text-secondary);
}

.ws-status {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--danger);
}

.ws-status.connected { background: var(--success); }

/* ===== Spinner ===== */
.spinner {
    width: 20px;
    height: 20px;
    border: 2px solid var(--border);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
    display: inline-block;
}

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

/* ===== Section Views ===== */
.section-view { display: none; }
.section-view.active { display: block; }

/* ===== Tag value display ===== */
.tag-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 0.75rem;
}

.tag-item {
    background: var(--bg-input);
    border-radius: var(--radius);
    padding: 0.75rem 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.tag-item .tag-name {
    font-size: 0.8125rem;
    color: var(--text-secondary);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    max-width: 60%;
}

.tag-item .tag-value {
    font-size: 0.9375rem;
    font-weight: 600;
    font-variant-numeric: tabular-nums;
}

/* ===== Nav Sub Items ===== */
.nav-sub {
    display: flex;
    flex-direction: column;
    padding-left: 1.25rem;
}

.nav-sub .nav-sub-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 0.75rem;
    border-radius: var(--radius);
    color: var(--text-secondary);
    font-size: 0.8125rem;
    cursor: pointer;
    transition: background 0.15s, color 0.15s;
    width: 100%;
    text-decoration: none;
}

.nav-sub .nav-sub-item:hover {
    background: var(--bg-input);
    color: var(--text-primary);
    text-decoration: none;
}

.nav-sub .nav-sub-item.active {
    background: rgba(59,130,246,0.15);
    color: var(--accent);
}

.nav-sub .nav-sub-dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--success);
    flex-shrink: 0;
}

/* ===== PLC Status Card ===== */
.plc-status-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1rem 1.25rem;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.plc-status-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.plc-status-header .plc-name {
    font-weight: 600;
    font-size: 1rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.plc-status-header .plc-indicator {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--success);
    display: inline-block;
    animation: pulse 2s infinite;
}

.plc-status-metrics {
    display: flex;
    gap: 1.25rem;
}

.plc-status-metrics .metric {
    display: flex;
    flex-direction: column;
}

.plc-status-metrics .metric-label {
    font-size: 0.6875rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.plc-status-metrics .metric-value {
    font-size: 1.125rem;
    font-weight: 700;
    font-variant-numeric: tabular-nums;
}

/* ===== PLC Tag Section (collapsible) ===== */
.plc-tag-section {
    margin-bottom: 1rem;
}

.plc-tag-section .section-toggle {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.875rem 1.25rem;
    cursor: pointer;
    user-select: none;
    border-bottom: 1px solid var(--border);
}

.plc-tag-section .section-toggle:hover {
    background: rgba(59,130,246,0.05);
}

.plc-tag-section .toggle-title {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-weight: 600;
}

.plc-tag-section .toggle-arrow {
    transition: transform 0.2s;
    color: var(--text-secondary);
}

.plc-tag-section.collapsed .toggle-arrow {
    transform: rotate(-90deg);
}

.plc-tag-section.collapsed .section-content {
    display: none;
}

.plc-tag-section .section-content {
    padding: 1rem 1.25rem;
}

.tag-category-label {
    font-size: 0.6875rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin: 0.75rem 0 0.5rem;
    padding-bottom: 0.25rem;
    border-bottom: 1px solid var(--border);
}

.tag-category-label:first-child {
    margin-top: 0;
}

/* ===== Mobile Menu Button ===== */
.mobile-menu-btn {
    display: none;
    position: fixed;
    bottom: 1.25rem;
    right: 1.25rem;
    z-index: 1000;
    width: 52px;
    height: 52px;
    border-radius: 50%;
    border: none;
    background: var(--accent);
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
    box-shadow: 0 4px 12px rgba(0,0,0,0.4);
    align-items: center;
    justify-content: center;
    transition: opacity 0.2s;
}

.mobile-menu-btn.hidden {
    opacity: 0;
    pointer-events: none;
}

.sidebar-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1001;
}

.sidebar-overlay.visible {
    display: block;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
    .mobile-menu-btn {
        display: flex;
    }

    .sidebar {
        position: fixed;
        top: 0;
        left: 0;
        bottom: 0;
        width: 280px;
        z-index: 1002;
        transform: translateX(-100%);
        transition: transform 0.25s ease;
    }

    .sidebar.open {
        transform: translateX(0);
    }

    .main-content {
        padding: 1rem;
    }

    .grid-2 {
        grid-template-columns: 1fr;
    }

    .stats-grid {
        grid-template-columns: repeat(2, 1fr) !important;
    }

    .page-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.75rem;
    }

    .page-header h2 {
        font-size: 1.25rem;
    }

    .header-actions {
        width: 100%;
        flex-wrap: wrap;
    }

    .tag-grid {
        grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    }

    #plcStatusRow {
        grid-template-columns: 1fr !important;
    }

    .plc-status-metrics {
        flex-wrap: wrap;
        gap: 0.75rem;
    }

    .card-body {
        overflow-x: auto;
    }

    /* Modals: full-width */
    [style*="position:fixed"][style*="z-index:1000"] > div,
    [style*="position: fixed"][style*="z-index: 1000"] > div {
        width: 95vw !important;
        max-width: 95vw !important;
        max-height: 85vh;
        overflow-y: auto;
        margin: 1rem;
    }

    /* Stack modal fieldsets vertically */
    [id$="Modal"] > div > div[style*="display:flex"],
    #tlModal > div > div[style*="display:flex"] {
        flex-direction: column !important;
    }

    fieldset {
        padding: 0.75rem;
    }

    /* Array Mapping: stack layout */
    #section-arraymapping > div[style*="display: flex"] {
        flex-direction: column !important;
        min-height: auto !important;
    }

    #section-arraymapping > div[style*="display: flex"] > div[style*="width: 200px"] {
        width: 100% !important;
    }
}

@media (max-width: 480px) {
    .stats-grid {
        grid-template-columns: 1fr !important;
    }

    .stat-card .stat-value {
        font-size: 1.25rem;
    }

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

    th, td {
        padding: 0.5rem 0.625rem;
        font-size: 0.75rem;
    }

    .tag-item {
        padding: 0.5rem 0.75rem;
    }

    .tag-item .tag-name {
        font-size: 0.75rem;
    }

    .tag-item .tag-value {
        font-size: 0.8125rem;
    }
}