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

:root {
    --primary-color: #4a90e2;
    --primary-dark: #357abd;
    --secondary-color: #50c878;
    --danger-color: #e74c3c;
    --warning-color: #f39c12;
    --success-color: #27ae60;
    --text-color: #333;
    --text-light: #666;
    --border-color: #e0e0e0;
    --bg-color: #ffffff;
    --bg-light: #f8f9fa;
    --shadow: 0 2px 4px rgba(0,0,0,0.1);
    --shadow-hover: 0 4px 8px rgba(0,0,0,0.15);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    color: var(--text-color);
    background-color: var(--bg-color);
    line-height: 1.6;
}

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

/* Навигация */
.navbar {
    background-color: var(--bg-color);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow);
}

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

.nav-brand a {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-color);
    text-decoration: none;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
    align-items: center;
}

.nav-menu a {
    color: var(--text-color);
    text-decoration: none;
    transition: color 0.3s;
}

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

.nav-user {
    display: flex;
    gap: 1rem;
    align-items: center;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    gap: 4px;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background-color: var(--text-color);
    transition: all 0.3s;
}

/* Основной контент */
.main-content {
    min-height: calc(100vh - 200px);
    padding: 2rem 0;
}

/* Заголовки страниц */
.page-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.page-header h1 {
    font-size: 2rem;
    color: var(--text-color);
}

/* Карточки */
.card {
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow);
}

/* Кнопки */
.btn {
    display: inline-block;
    padding: 0.5rem 1.5rem;
    background-color: var(--primary-color);
    color: white;
    text-decoration: none;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 1rem;
    transition: background-color 0.3s, box-shadow 0.3s;
}

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

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

.btn-sm {
    padding: 0.25rem 0.75rem;
    font-size: 0.875rem;
}

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

/* Формы */
.form {
    max-width: 800px;
}

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

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
}

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

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

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

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
}

.form-actions {
    display: flex;
    gap: 1rem;
    margin-top: 2rem;
}

/* Таблицы */
.table-responsive {
    overflow-x: auto;
}

.table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 1rem;
}

.table thead {
    background-color: var(--bg-light);
}

.table th,
.table td {
    padding: 0.75rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.table tbody tr:hover {
    background-color: var(--bg-light);
}

/* Бейджи */
.badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    border-radius: 12px;
    font-size: 0.875rem;
    font-weight: 500;
}

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

.badge-inactive {
    background-color: var(--text-light);
    color: white;
}

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

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

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

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

.badge-pending {
    background-color: var(--text-light);
    color: white;
}

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

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

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

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

/* Алерты */
.alert {
    padding: 1rem;
    border-radius: 4px;
    margin-bottom: 1rem;
}

.alert-error {
    background-color: #fee;
    color: var(--danger-color);
    border: 1px solid var(--danger-color);
}

.alert-success {
    background-color: #efe;
    color: var(--success-color);
    border: 1px solid var(--success-color);
}

/* Авторизация */
.auth-container {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 80vh;
}

.auth-card {
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 2rem;
    width: 100%;
    max-width: 500px;
    box-shadow: var(--shadow);
}

.auth-card h1 {
    margin-bottom: 1.5rem;
    text-align: center;
}

.auth-link {
    text-align: center;
    margin-top: 1rem;
}

.auth-link a {
    color: var(--primary-color);
    text-decoration: none;
}

/* Дашборд */
.dashboard {
    padding: 1rem 0;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: var(--shadow);
}

.stat-card h3 {
    font-size: 0.875rem;
    color: var(--text-light);
    margin-bottom: 0.5rem;
}

.stat-number {
    font-size: 2rem;
    font-weight: bold;
    color: var(--primary-color);
}

.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 2rem;
}

.dashboard-section {
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
    box-shadow: var(--shadow);
}

.dashboard-section h2 {
    margin-bottom: 1rem;
    font-size: 1.25rem;
}

/* Списки */
.lessons-list,
.tasks-list,
.homework-list {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.lesson-card,
.task-card {
    background: var(--bg-light);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
}

.lesson-info,
.task-content {
    flex: 1;
}

.lesson-date {
    font-size: 0.875rem;
    color: var(--text-light);
}

.task-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    background: var(--bg-light);
    border-radius: 8px;
    border-left: 4px solid var(--primary-color);
}

.task-item.priority-high {
    border-left-color: var(--danger-color);
}

.task-item.priority-medium {
    border-left-color: var(--warning-color);
}

.task-item.priority-low {
    border-left-color: var(--secondary-color);
}

.task-date {
    font-size: 0.875rem;
    color: var(--text-light);
}

/* Календарь */
.calendar-nav {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.calendar {
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1.5rem;
    margin-bottom: 2rem;
}

.calendar-header {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 0.5rem;
    margin-bottom: 0.5rem;
}

.calendar-day-name {
    text-align: center;
    font-weight: 600;
    padding: 0.5rem;
}

.calendar-body {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 0.5rem;
}

.calendar-day {
    min-height: 100px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    padding: 0.5rem;
    background: var(--bg-color);
}

.calendar-day.today {
    background-color: #e3f2fd;
    border-color: var(--primary-color);
}

.calendar-day.empty {
    background-color: var(--bg-light);
    border: none;
}

.calendar-day-number {
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.calendar-lessons {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.calendar-lesson {
    font-size: 0.75rem;
    padding: 0.25rem;
    background: var(--primary-color);
    color: white;
    border-radius: 2px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.calendar-lesson-more {
    font-size: 0.75rem;
    color: var(--text-light);
    font-style: italic;
}

/* Информация */
.info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.info-item {
    padding: 0.5rem 0;
}

.info-section {
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
}

/* Вкладки */
.tabs {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.tab {
    padding: 0.75rem 1.5rem;
    text-decoration: none;
    color: var(--text-color);
    border-bottom: 2px solid transparent;
    transition: border-color 0.3s;
}

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

.tab-content {
    margin-top: 1.5rem;
}

/* Фильтры */
.filters {
    background: var(--bg-light);
    padding: 1.5rem;
    border-radius: 8px;
    margin-bottom: 2rem;
}

.filter-form .form-row {
    align-items: end;
}

/* Пустое состояние */
.empty-state {
    text-align: center;
    padding: 3rem;
    color: var(--text-light);
}

.empty-state a {
    color: var(--primary-color);
    text-decoration: none;
}

/* Группы дат */
.date-group {
    margin-bottom: 2rem;
}

.date-group h3 {
    margin-bottom: 1rem;
    color: var(--text-color);
    font-size: 1.1rem;
}

.lesson-time {
    font-weight: 600;
    color: var(--primary-color);
    min-width: 60px;
}

/* Футер */
.footer {
    background-color: var(--bg-light);
    border-top: 1px solid var(--border-color);
    padding: 2rem 0;
    margin-top: 4rem;
    text-align: center;
    color: var(--text-light);
}

/* Адаптивность */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 60px;
        left: -100%;
        flex-direction: column;
        background: var(--bg-color);
        width: 100%;
        padding: 2rem;
        box-shadow: var(--shadow);
        transition: left 0.3s;
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-toggle {
        display: flex;
    }

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

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

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

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

    .calendar-day {
        min-height: 60px;
        font-size: 0.875rem;
    }

    .calendar-lesson {
        font-size: 0.65rem;
        padding: 0.15rem;
    }

    .table-responsive {
        font-size: 0.875rem;
    }

    .lesson-card,
    .task-card {
        flex-direction: column;
        align-items: flex-start;
    }
}

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

    .container {
        padding: 0 15px;
    }

    .card {
        padding: 1rem;
    }
}