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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: #fafafa;
    color: #37352f;
    line-height: 1.6;
}

.app-container {
    display: flex;
    min-height: 100vh;
}

/* Sidebar Styles */
.sidebar {
    width: 260px;
    background-color: #f7f6f3;
    border-right: 1px solid #e9e9e7;
    display: flex;
    flex-direction: column;
    position: fixed;
    height: 100vh;
    overflow-y: auto;
}

.sidebar-header {
    padding: 20px;
    border-bottom: 1px solid #e9e9e7;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 18px;
    font-weight: 600;
    color: #37352f;
}

.logo i {
    color: #2eaadc;
    font-size: 24px;
}

.sidebar-nav {
    flex: 1;
    padding: 20px 0;
}

.sidebar-nav ul {
    list-style: none;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 8px 20px;
    cursor: pointer;
    transition: background-color 0.2s;
    margin-bottom: 2px;
}

.nav-item:hover {
    background-color: #eeeeec;
}

.nav-item.active {
    background-color: #e9e9e7;
    border-right: 3px solid #2eaadc;
}

.nav-item i {
    width: 20px;
    color: #787774;
}

.nav-item span {
    font-size: 14px;
    color: #37352f;
}

.sidebar-footer {
    padding: 20px;
    border-top: 1px solid #e9e9e7;
}

.user-profile {
    display: flex;
    align-items: center;
    gap: 12px;
}

.avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background-color: #2eaadc;
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    font-weight: 600;
}

/* Main Content Styles */
.main-content {
    flex: 1;
    margin-left: 260px;
    padding: 40px;
    overflow-y: auto;
}

.page {
    display: none;
}

.page.active {
    display: block;
}

.page-header {
    margin-bottom: 32px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.page-header h1 {
    font-size: 32px;
    font-weight: 700;
    color: #37352f;
}

.page-header p {
    color: #787774;
    margin-top: 4px;
}

/* Button Styles */
.btn-primary {
    background-color: #2eaadc;
    color: white;
    border: none;
    padding: 10px 16px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: background-color 0.2s;
}

.btn-primary:hover {
    background-color: #2590c4;
}

.btn-secondary {
    background-color: #e9e9e7;
    color: #37352f;
    border: none;
    padding: 10px 16px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: background-color 0.2s;
}

.btn-secondary:hover {
    background-color: #d9d9d7;
}

/* Dashboard Styles */
.dashboard-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
    margin-bottom: 32px;
}

.card {
    background-color: white;
    border-radius: 8px;
    padding: 24px;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    border: 1px solid #e9e9e7;
}

.card h3 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 16px;
    color: #37352f;
}

.quick-stats {
    grid-column: 1 / -1;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.stat {
    text-align: center;
}

.stat-number {
    font-size: 32px;
    font-weight: 700;
    color: #2eaadc;
    margin-bottom: 4px;
}

.stat-label {
    font-size: 14px;
    color: #787774;
}

/* Task Styles */
.task-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 0;
    border-bottom: 1px solid #f1f1ef;
}

.task-item:last-child {
    border-bottom: none;
}

.task-checkbox {
    width: 18px;
    height: 18px;
    border: 2px solid #d9d9d7;
    border-radius: 4px;
    cursor: pointer;
}

.task-content {
    flex: 1;
}

.task-title {
    font-weight: 500;
    color: #37352f;
    margin-bottom: 2px;
}

.task-meta {
    font-size: 12px;
    color: #787774;
}

.task-item.urgent .task-meta {
    color: #d73502;
    font-weight: 500;
}

/* Task Filters */
.task-filters {
    display: flex;
    gap: 8px;
    margin-bottom: 24px;
}

.filter-btn {
    padding: 8px 16px;
    background-color: #f1f1ef;
    border: none;
    border-radius: 20px;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.2s;
}

.filter-btn.active {
    background-color: #2eaadc;
    color: white;
}

.filter-btn:hover {
    background-color: #e9e9e7;
}

.filter-btn.active:hover {
    background-color: #2590c4;
}

/* Task Cards */
.tasks-container {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.task-card {
    background-color: white;
    border-radius: 8px;
    padding: 20px;
    border: 1px solid #e9e9e7;
    transition: box-shadow 0.2s;
}

.task-card:hover {
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.task-card.completed {
    opacity: 0.6;
}

.task-card.completed .task-header h3 {
    text-decoration: line-through;
}

.task-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 8px;
}

.task-checkbox-input {
    width: 18px;
    height: 18px;
}

.task-header h3 {
    flex: 1;
    font-size: 16px;
    font-weight: 600;
    color: #37352f;
}

.priority-badge {
    padding: 4px 8px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 500;
}

.priority-badge.urgent {
    background-color: #ffe2d9;
    color: #d73502;
}

.priority-badge.high {
    background-color: #fff5cc;
    color: #b7800a;
}

.priority-badge.medium {
    background-color: #e1f5fe;
    color: #0277bd;
}

.task-description {
    color: #787774;
    margin-bottom: 12px;
    font-size: 14px;
}

.task-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 12px;
}

.due-date {
    color: #787774;
}

.subject-tag {
    padding: 4px 8px;
    border-radius: 12px;
    font-weight: 500;
}

.subject-tag.math {
    background-color: #e8f5e8;
    color: #2e7d2e;
}

.subject-tag.physics {
    background-color: #e3f2fd;
    color: #1565c0;
}

.subject-tag.history {
    background-color: #fff3e0;
    color: #ef6c00;
}

/* Calendar Styles */
.calendar-nav {
    display: flex;
    align-items: center;
    gap: 16px;
}

.calendar-nav button {
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    border-radius: 4px;
    color: #37352f;
}

.calendar-nav button:hover {
    background-color: #f1f1ef;
}

#currentMonth {
    font-size: 18px;
    font-weight: 600;
    min-width: 150px;
    text-align: center;
}

.calendar-container {
    background-color: white;
    border-radius: 8px;
    border: 1px solid #e9e9e7;
    overflow: hidden;
}

.calendar-grid {
    display: grid;
}

.calendar-header {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    background-color: #f7f6f3;
}

.day-header {
    padding: 16px;
    text-align: center;
    font-weight: 600;
    font-size: 14px;
    color: #787774;
    border-right: 1px solid #e9e9e7;
}

.day-header:last-child {
    border-right: none;
}

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

.calendar-day {
    min-height: 100px;
    padding: 8px;
    border-right: 1px solid #e9e9e7;
    border-bottom: 1px solid #e9e9e7;
    cursor: pointer;
}

.calendar-day:nth-child(7n) {
    border-right: none;
}

.calendar-day:hover {
    background-color: #f9f9f9;
}

.calendar-day.other-month {
    color: #c4c4c2;
    background-color: #fafafa;
}

.calendar-day.today {
    background-color: #e8f4fd;
}

.day-number {
    font-weight: 600;
    margin-bottom: 4px;
}

/* Notes Styles */
.notes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
}

.note-card {
    background-color: white;
    border-radius: 8px;
    padding: 20px;
    border: 1px solid #e9e9e7;
    cursor: pointer;
    transition: box-shadow 0.2s;
}

.note-card:hover {
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.note-card h3 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 8px;
    color: #37352f;
}

.note-preview {
    color: #787774;
    font-size: 14px;
    margin-bottom: 12px;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    line-clamp: 3; /* Standard property for modern browsers */
    -webkit-box-orient: vertical;
    overflow: hidden;
    
    /* Fallback for browsers that don't support line-clamp */
    max-height: 4.2em; /* Approximate height for 3 lines */
    line-height: 1.4em;
}

/* Fallback for older browsers that don't support line-clamp */
@supports not (-webkit-line-clamp: 3) {
    .note-preview {
        display: block;
        max-height: 4.2em;
        overflow: hidden;
        position: relative;
    }
    
    .note-preview::after {
        content: '...';
        position: absolute;
        bottom: 0;
        right: 0;
        background: white;
        padding-left: 5px;
    }
}

.note-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 12px;
}

.note-date {
    color: #787774;
}

.notes-list .note-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 0;
    border-bottom: 1px solid #f1f1ef;
    cursor: pointer;
}

.notes-list .note-item:last-child {
    border-bottom: none;
}

.notes-list .note-item:hover {
    background-color: #f9f9f9;
    margin: 0 -12px;
    padding-left: 12px;
    padding-right: 12px;
    border-radius: 4px;
}

.notes-list .note-title {
    font-weight: 500;
    color: #37352f;
}

.notes-list .note-date {
    color: #787774;
    font-size: 12px;
}

/* Subjects Styles */
.subjects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
}

.subject-card {
    background-color: white;
    border-radius: 8px;
    padding: 24px;
    border: 1px solid #e9e9e7;
    cursor: pointer;
    transition: box-shadow 0.2s;
}

.subject-card:hover {
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.subject-card.math {
    border-left: 4px solid #2e7d2e;
}

.subject-card.physics {
    border-left: 4px solid #1565c0;
}

.subject-card.history {
    border-left: 4px solid #ef6c00;
}

.subject-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
}

.subject-header h3 {
    font-size: 18px;
    font-weight: 600;
    color: #37352f;
}

.grade {
    font-size: 20px;
    font-weight: 700;
    color: #2eaadc;
}

.subject-stats {
    display: flex;
    gap: 24px;
}

.subject-stats .stat {
    text-align: left;
}

.subject-stats .stat-label {
    display: block;
    font-size: 12px;
    color: #787774;
    margin-bottom: 4px;
}

.subject-stats .stat-value {
    font-size: 18px;
    font-weight: 600;
    color: #37352f;
}

/* Modal Styles */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 1000;
}

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

.modal-content {
    background-color: white;
    border-radius: 8px;
    width: 90%;
    max-width: 500px;
    max-height: 90vh;
    overflow-y: auto;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 24px 24px 0;
    margin-bottom: 20px;
}

.modal-header h2 {
    font-size: 20px;
    font-weight: 600;
    color: #37352f;
}

.modal-close {
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: #787774;
    padding: 4px;
}

.modal-close:hover {
    color: #37352f;
}

.form-group {
    margin-bottom: 20px;
    padding: 0 24px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: #37352f;
    font-size: 14px;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 12px;
    border: 1px solid #e9e9e7;
    border-radius: 6px;
    font-size: 14px;
    font-family: inherit;
    background-color: white;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: #2eaadc;
    box-shadow: 0 0 0 3px rgba(46, 170, 220, 0.1);
}

.form-group textarea {
    min-height: 80px;
    resize: vertical;
}

.modal-actions {
    display: flex;
    gap: 12px;
    justify-content: flex-end;
    padding: 20px 24px 24px;
}

/* Responsive Design */
@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
        transition: transform 0.3s;
    }
    
    .main-content {
        margin-left: 0;
        padding: 20px;
    }
    
    .dashboard-grid {
        grid-template-columns: 1fr;
    }
    
    .page-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 16px;
    }
    
    .calendar-nav {
        flex-direction: column;
        gap: 8px;
    }
    
    .notes-grid,
    .subjects-grid {
        grid-template-columns: 1fr;
    }
    
    .task-footer {
        flex-direction: column;
        align-items: flex-start;
        gap: 8px;
    }
}

@media (max-width: 480px) {
    .main-content {
        padding: 16px;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }
    
    .modal-content {
        width: 95%;
        margin: 20px;
    }
}