:root {
    --primary: #667eea;
    --primary-dark: #5a6fd8;
    --secondary: #27ae60;
    --secondary-dark: #219653;
    --danger: #e74c3c;
    --danger-dark: #c0392b;
    --warning: #f39c12;
    --warning-dark: #d35400;
    --dark: #2c3e50;
    --light: #f8f9fa;
    --gray: #666666;
    --gray-light: #e9ecef;
    --white: #ffffff;

    /* Typography */
    --font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-md: 1rem;
    --font-size-lg: 1.25rem;
    --font-size-xl: 1.5rem;
    --font-size-2xl: 2rem;

    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;

    /* Borders & Shadows */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --shadow-sm: 0 5px 10px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 10px 20px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 20px 40px rgba(0, 0, 0, 0.1);

    /* Transitions */
    --transition: all 0.3s ease;
}

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

body {
    font-family: var(--font-family), sans-serif;
    background: #5568bd;
    color: var(--light);
    line-height: 1.6;
    padding: 0;
}

/* ===== TYPOGRAPHY ===== */
h1, h2, h3, h4, h5, h6 {
    margin-bottom: var(--space-md);
    font-weight: 600;
    line-height: 1.3;
}

h1 {
    font-size: var(--font-size-2xl);
}

h2 {
    font-size: var(--font-size-xl);
}

h3 {
    font-size: var(--font-size-lg);
    font-size: var(--font-size-lg);
}

h4 {
    font-size: var(--font-size-md);
}

h5 {
    font-size: var(--font-size-sm);
}

p {
    margin-bottom: var(--space-md);
}

/* ===== LAYOUT ===== */
.container {
    width: 100%;
    max-width: 1800px;
    margin: 0 auto;
    padding: var(--space-md);
}

.section {
    margin-bottom: var(--space-xl);
}

.grid {
    display: grid;
    gap: var(--space-md);
}

.grid-2 {
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
}

.grid-3 {
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
}

.grid-4 {
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
}

.flex {
    display: flex;
}

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

.flex-center {
    display: flex;
    justify-content: center;
    align-items: center;
}

.flex-left {
    display: flex;
    justify-content: left;
    align-items: center;
}

/* ===== CARDS ===== */
.card {
    background-color: var(--white);
    color: var(--dark);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    padding: var(--space-md);
    margin-bottom: var(--space-md);
    transition: var(--transition);
}

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

.card-header {
    font-size: var(--font-size-lg);
    font-weight: 600;
    margin-bottom: var(--space-md);
    padding-bottom: var(--space-sm);
    border-bottom: 1px solid var(--gray-light);
}

.card-body {
    padding: var(--space-sm) 0;
}

.stat-card {
    background: var(--white);
    margin: 0 var(--space-md);
    padding: var(--space-md);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    text-align: center;
    border-left: 4px solid var(--primary);
    font-weight: bold;
}

.stat-card-header {
    color: var(--dark);
    margin-bottom: var(--space-sm);
    font-size: var(--font-size-sm);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.stat-card-body {
    font-size: var(--font-size-2xl);
    color: var(--primary);
}

/* ===== FORMS ===== */
.form-group {
    margin-bottom: var(--space-md);
}

label {
    display: block;
    margin-bottom: var(--space-xs);
    font-weight: 500;
}

.form-hint {
    font-size: var(--font-size-sm);
    color: var(--gray);
    margin-top: var(--space-xs);
}

input[type="text"],
input[type="password"],
input[type="number"],
input[type="email"],
input[type="datetime-local"],
select,
textarea {
    width: 100%;
    padding: var(--space-sm);
    border: 1px solid var(--gray-light);
    border-radius: var(--radius-sm);
    font-size: var(--font-size-sm);
    transition: var(--transition);
    background-color: var(--white);
}

input[type="text"]:focus,
input[type="password"]:focus,
input[type="number"]:focus,
input[type="email"]:focus,
input[type="datetime-local"],
select:focus,
textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.2);
}

input[type="text"]:disabled,
input[type="password"]:disabled,
input[type="number"]:disabled,
input[type="email"]:disabled,
input[type="datetime-local"]:disabled,
select:disabled,
textarea:disabled {
    cursor: not-allowed;
    background-color: var(--light);
}

.input-with-icon {
    position: relative;
}

.input-icon {
    position: absolute;
    right: var(--space-sm);
    top: 50%;
    transform: translateY(-50%);
    cursor: pointer;
    color: var(--gray);
}

.input-icon:hover {
    color: var(--primary);
}

.error {
    border-color: var(--danger) !important;
    box-shadow: 0 0 0 3px rgba(231, 76, 60, 0.2) !important;
}

/* ===== BUTTONS ===== */
.btn {
    display: inline-block;
    padding: var(--space-sm) var(--space-md);
    border: none;
    border-radius: var(--radius-sm);
    font-size: var(--font-size-sm);
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    text-align: center;
    text-decoration: none;
}

.btn-sm {
    padding: var(--space-xs) var(--space-md);
    font-size: var(--font-size-sm);
}

.btn-lg {
    padding: var(--space-md) var(--space-lg);
    font-size: var(--font-size-md);
}

.btn-block {
    display: block;
    width: 100%;
}

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

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

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

.btn-secondary:hover {
    background-color: var(--secondary-dark);
}

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

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

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

.btn-warning:hover {
    background-color: var(--warning-dark);
}

.btn-outline {
    background-color: transparent;
    border: 1px solid currentColor;
}

.btn-outline-primary {
    color: var(--primary);
    border-color: var(--primary);
}

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

.btn:disabled,
.btn.disabled {
    opacity: 0.6;
    cursor: not-allowed;
    box-shadow: none;
}

.btn-primary:disabled,
.btn-primary.disabled {
    background-color: var(--gray-light);
    border-color: var(--gray-light);
    color: var(--gray);
}

.btn-secondary:disabled,
.btn-secondary.disabled {
    background-color: color-mix(in srgb, var(--secondary) 40%, transparent 60%);
    border-color: color-mix(in srgb, var(--secondary) 40%, transparent 60%);
    color: color-mix(in srgb, var(--secondary) 60%, white 40%);
}

.btn-danger:disabled,
.btn-danger.disabled {
    background-color: color-mix(in srgb, var(--danger) 40%, transparent 60%);
    border-color: color-mix(in srgb, var(--danger) 40%, transparent 60%);
    color: color-mix(in srgb, var(--danger) 60%, white 40%);
}

.btn-warning:disabled,
.btn-warning.disabled {
    background-color: color-mix(in srgb, var(--warning) 40%, transparent 60%);
    border-color: color-mix(in srgb, var(--warning) 40%, transparent 60%);
    color: color-mix(in srgb, var(--warning) 60%, white 40%);
}

.btn-outline-primary:disabled,
.btn-outline-primary.disabled {
    background-color: transparent;
    border-color: color-mix(in srgb, var(--primary) 40%, transparent 60%);
    color: color-mix(in srgb, var(--primary) 40%, transparent 60%);
}

.btn-outline-secondary:disabled,
.btn-outline-secondary.disabled {
    background-color: transparent;
    border-color: color-mix(in srgb, var(--secondary) 40%, transparent 60%);
    color: color-mix(in srgb, var(--secondary) 40%, transparent 60%);
}

@supports not (background-color: color-mix(in srgb, red 50%, blue 50%)) {
    .btn-primary:disabled,
    .btn-primary.disabled {
        background-color: #bdc3c7;
        border-color: #bdc3c7;
        color: #7f8c8d;
    }

    .btn-secondary:disabled,
    .btn-secondary.disabled {
        background-color: rgba(46, 204, 113, 0.4);
        border-color: rgba(46, 204, 113, 0.4);
        color: rgba(46, 204, 113, 0.6);
    }

    .btn-danger:disabled,
    .btn-danger.disabled {
        background-color: rgba(231, 76, 60, 0.4);
        border-color: rgba(231, 76, 60, 0.4);
        color: rgba(231, 76, 60, 0.6);
    }

    .btn-warning:disabled,
    .btn-warning.disabled {
        background-color: rgba(243, 156, 18, 0.4);
        border-color: rgba(243, 156, 18, 0.4);
        color: rgba(243, 156, 18, 0.6);
    }

    .btn-outline-primary:disabled,
    .btn-outline-primary.disabled {
        background-color: transparent;
        border-color: rgba(52, 152, 219, 0.4);
        color: rgba(52, 152, 219, 0.4);
    }

    .btn-outline-secondary:disabled,
    .btn-outline-secondary.disabled {
        background-color: transparent;
        border-color: rgba(46, 204, 113, 0.4);
        color: rgba(46, 204, 113, 0.4);
    }
}

.btn:disabled:focus,
.btn.disabled:focus {
    outline: none;
    box-shadow: none;
}

.btn:disabled:hover,
.btn.disabled:hover {
    transform: none;
    box-shadow: none;
}

/* ===== TOGGLE SWITCHES ===== */
.switch {
    position: relative;
    display: inline-block;
    width: 42px;
    height: 22px;
}

.switch input {
    opacity: 0;
    width: 0;
    height: 0;
}

.slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--gray);
    transition: var(--transition);
    border-radius: 34px;
}

.slider:before {
    position: absolute;
    content: "";
    height: 16px;
    width: 16px;
    left: 3px;
    bottom: 3px;
    background-color: var(--white);
    transition: var(--transition);
    border-radius: 50%;
}

input:checked + .slider {
    background-color: var(--primary);
}

input:checked + .slider:before {
    transform: translateX(20px);
}

/* ===== RADIO & CHECKBOX GROUPS ===== */
.radio-group, .checkbox-group {
    display: flex;
    gap: var(--space-lg);
    margin-bottom: var(--space-md);
}

.radio-option, .checkbox-option {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
}

input[type="radio"], input[type="checkbox"] {
    cursor: pointer;
    width: 18px;
    height: 18px;
}

input[type="radio"]:disabled, input[type="checkbox"]:disabled {
    cursor: not-allowed;
}

/* ===== NAVIGATION ===== */
.navbar {
    background-color: var(--white);
    box-shadow: var(--shadow-sm);
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand {
    font-size: var(--font-size-xl);
    font-weight: 700;
    color: var(--primary);
    text-decoration: none;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: var(--space-xl);
}

.nav-item {
    color: var(--dark);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
}

.nav-item:hover {
    color: var(--primary);
}

/* ===== TABLES ===== */
.table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: var(--space-lg);
    box-shadow: var(--shadow-sm);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.table th, .table td {
    padding: var(--space-sm);
    text-align: left;
    border-bottom: 1px solid var(--gray-light);
}

.table th {
    background-color: var(--gray-light);
    color: var(--dark);
    font-weight: 600;
}

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

.table tr:hover {
    background-color: rgba(102, 126, 234, 0.05);
}

/* ===== TABS ===== */
.tab {
    padding: var(--space-sm) var(--space-md);
    cursor: pointer;
    font-weight: 500;
    border-bottom: 2px solid transparent;
}

.tab.active {
    border-bottom-color: var(--primary);
    color: var(--primary);
}

.tab-content {
    display: block;
}

/* ===== UTILITY CLASSES ===== */
.text-center {
    text-align: center;
}

.text-left {
    text-align: left;
}

.text-right {
    text-align: right;
}

.mt-xs {
    margin-top: var(--space-xs);
}

.mt-sm {
    margin-top: var(--space-sm);
}

.mt-md {
    margin-top: var(--space-md);
}

.mt-lg {
    margin-top: var(--space-lg);
}

.mt-xl {
    margin-top: var(--space-xl);
}

.mb-xs {
    margin-bottom: var(--space-xs);
}

.mb-sm {
    margin-bottom: var(--space-sm);
}

.mb-md {
    margin-bottom: var(--space-md);
}

.mb-lg {
    margin-bottom: var(--space-lg);
}

.mb-xl {
    margin-bottom: var(--space-xl);
}

.hidden {
    display: none;
}

.visible {
    display: block;
}

/* ===== STATUS COLORS ===== */
.status-up {
    color: var(--secondary);
}

.status-down {
    color: var(--danger);
}

/* ===== LOADING SPINNER ===== */
.loading-spinner {
    display: inline-block;
    width: 2rem;
    height: 2rem;
    border: 3px solid rgba(102, 126, 234, 0.3);
    border-radius: 50%;
    border-top-color: var(--primary);
    animation: spin 1s ease-in-out infinite;
}

.loading-spinner-sm {
    width: 1rem;
    height: 1rem;
    border-width: 2px;
}

.loading-spinner-lg {
    width: 3rem;
    height: 3rem;
    border-width: 4px;
}

.loading-spinner-secondary {
    border-top-color: var(--secondary);
}

.loading-spinner-danger {
    border-top-color: var(--danger);
}

.loading-spinner-warning {
    border-top-color: var(--warning);
}

.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(255, 255, 255, 0.8);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 9999;
}

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

.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 9999;
}

.modal-overlay .modal {
    width: 90%;
    max-width: 500px;
    margin: var(--space-lg);
}

.modal-overlay .modal .card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.form-control {
    width: 100%;
    padding: var(--space-sm);
    border: 1px solid var(--gray-light);
    border-radius: var(--radius-sm);
    font-size: var(--font-size-sm);
}

.form-control:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.2);
}

.form-control:disabled {
    background-color: var(--light);
    cursor: not-allowed;
}

/* ===== RESPONSIVE DESIGN ===== */
@media (max-width: 768px) {
    .grid-2, .grid-3 {
        grid-template-columns: 1fr;
    }

    .radio-group, .checkbox-group {
        flex-direction: column;
        gap: var(--space-sm);
    }

    .nav-menu {
        gap: var(--space-md);
    }
}