:root {
    --primary-color: #3498db;
    --primary-dark: #2980b9;
    --secondary-color: #95a5a6;
    --success-color: #27ae60;
    --danger-color: #e74c3c;
    --warning-color: #f39c12;
    --background-color: #ecf0f1;
    --card-background: #ffffff;
    --text-color: #2c3e50;
    --border-color: #bdc3c7;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --border-radius: 8px;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

/* Header */
header {
    text-align: center;
    margin-bottom: 30px;
    padding: 30px 0;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
}

header h1 {
    font-size: 2.5em;
    margin-bottom: 10px;
}

header p {
    font-size: 1.1em;
    opacity: 0.9;
}

/* Tabs */
.tabs {
    display: flex;
    margin-bottom: 20px;
    background: var(--card-background);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    overflow: hidden;
}

.tab-button {
    flex: 1;
    padding: 15px 20px;
    border: none;
    background: var(--card-background);
    color: var(--text-color);
    font-size: 1em;
    cursor: pointer;
    transition: all 0.3s ease;
}

.tab-button:hover {
    background: var(--background-color);
}

.tab-button.active {
    background: var(--primary-color);
    color: white;
}

/* Tab Content */
.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

/* Sections */
.section {
    background: var(--card-background);
    border-radius: var(--border-radius);
    padding: 25px;
    margin-bottom: 20px;
    box-shadow: var(--shadow);
}

.section h2 {
    margin-bottom: 20px;
    color: var(--primary-color);
    font-size: 1.5em;
}

/* Forms */
.form-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    align-items: end;
}

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

.form-group label {
    margin-bottom: 5px;
    font-weight: 500;
    color: var(--text-color);
}

.form-group input,
.form-group select {
    padding: 10px;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1em;
    transition: border-color 0.3s ease;
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
}

/* Buttons */
.btn {
    padding: 10px 20px;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1em;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 500;
}

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

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

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

.btn-secondary:hover {
    background: #7f8c8d;
}

.btn-danger {
    background: var(--danger-color);
    color: white;
    padding: 5px 10px;
    font-size: 0.9em;
}

.btn-danger:hover {
    background: #c0392b;
}

/* Controls */
.controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    flex-wrap: wrap;
    gap: 10px;
}

.search-group {
    display: flex;
    gap: 10px;
    align-items: center;
}

.search-group input {
    padding: 8px 12px;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    min-width: 200px;
}

/* Data Grid */
.data-grid {
    display: grid;
    gap: 15px;
}

.employee-card {
    background: #f8f9fa;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 20px;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.employee-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.employee-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
}

.employee-name {
    font-size: 1.2em;
    font-weight: 600;
    color: var(--primary-color);
}

.employee-details {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 10px;
    margin-bottom: 15px;
}

.employee-detail {
    display: flex;
    flex-direction: column;
}

.employee-detail strong {
    font-size: 0.9em;
    color: var(--secondary-color);
    margin-bottom: 2px;
}

/* Organization Tree */
.org-tree {
    padding: 20px;
}

.org-unit {
    margin: 10px 0;
    padding: 15px;
    background: #f8f9fa;
    border-left: 4px solid var(--primary-color);
    border-radius: var(--border-radius);
}

.org-unit.level-0 {
    background: var(--primary-color);
    color: white;
    border-left: 4px solid var(--primary-dark);
}

.org-unit.level-1 {
    margin-left: 20px;
    border-left-color: var(--success-color);
}

.org-unit.level-2 {
    margin-left: 40px;
    border-left-color: var(--warning-color);
}

.org-unit-name {
    font-weight: 600;
    font-size: 1.1em;
    margin-bottom: 5px;
}

.org-unit-info {
    font-size: 0.9em;
    opacity: 0.8;
}

/* Loading and Messages */
.loading {
    text-align: center;
    padding: 20px;
    font-size: 1.1em;
    color: var(--secondary-color);
}

.message {
    padding: 15px;
    border-radius: var(--border-radius);
    margin: 20px 0;
    font-weight: 500;
}

.message.success {
    background: rgba(39, 174, 96, 0.1);
    color: var(--success-color);
    border: 1px solid var(--success-color);
}

.message.error {
    background: rgba(231, 76, 60, 0.1);
    color: var(--danger-color);
    border: 1px solid var(--danger-color);
}

.message.warning {
    background: rgba(243, 156, 18, 0.1);
    color: var(--warning-color);
    border: 1px solid var(--warning-color);
}

.hidden {
    display: none !important;
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 10px;
    }

    header {
        padding: 20px 0;
    }

    header h1 {
        font-size: 2em;
    }

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

    .controls {
        flex-direction: column;
        align-items: stretch;
    }

    .search-group {
        justify-content: center;
    }

    .search-group input {
        min-width: 150px;
        flex: 1;
    }

    .employee-details {
        grid-template-columns: 1fr;
    }

    .employee-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }
}

@media (max-width: 480px) {
    .tabs {
        flex-direction: column;
    }

    .section {
        padding: 15px;
    }
}