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

:root {
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --text-color: #1f2937;
    --text-secondary: #6b7280;
    --bg-color: #ffffff;
    --bg-secondary: #f9fafb;
    --border-color: #e5e7eb;
    --border-radius: 8px;
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--bg-secondary);
    color: var(--text-color);
    line-height: 1.6;
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    background-color: var(--bg-color);
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
    overflow: hidden;
}

header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-hover) 100%);
    color: white;
    padding: 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}

header h1 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 0;
}

.theme-switcher {
    display: flex;
    align-items: center;
    gap: 10px;
}

.theme-switcher label {
    font-weight: 500;
}

#theme-select {
    padding: 8px 12px;
    border: none;
    border-radius: var(--border-radius);
    background-color: rgba(255, 255, 255, 0.9);
    color: var(--text-color);
    font-size: 14px;
    cursor: pointer;
}

main {
    padding: 2rem;
}

.add-task-section {
    margin-bottom: 2rem;
}

.input-group {
    display: flex;
    gap: 12px;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}

#task-input {
    flex: 2;
    min-width: 200px;
    padding: 12px 16px;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 16px;
    transition: border-color 0.2s;
}

#task-input:focus {
    outline: none;
    border-color: var(--primary-color);
}

#task-description {
    flex: 1 1 100%;
    padding: 12px 16px;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 14px;
    font-family: inherit;
    resize: vertical;
    transition: border-color 0.2s;
}

#task-description:focus {
    outline: none;
    border-color: var(--primary-color);
}

#category-select {
    flex: 1;
    padding: 12px 16px;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 16px;
    transition: border-color 0.2s;
    color: var(--text-color);
    background-color: var(--bg-color);
    cursor: pointer;
}

#category-select:focus {
    outline: none;
    border-color: var(--primary-color);
}

#due-date-input {
    flex: 1;
    padding: 12px 16px;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 16px;
    transition: border-color 0.2s;
    color: var(--text-color);
}

#due-date-input:focus {
    outline: none;
    border-color: var(--primary-color);
}

#add-btn {
    padding: 12px 24px;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--border-radius);
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: background-color 0.2s;
}

#add-btn:hover {
    background-color: var(--primary-hover);
}

.filter-section {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
}

.filter-buttons {
    display: flex;
    gap: 8px;
}

.filter-btn {
    padding: 8px 16px;
    border: 2px solid var(--border-color);
    background-color: transparent;
    color: var(--text-secondary);
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: all 0.2s;
    font-size: 14px;
    font-weight: 500;
}

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

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

.task-counter {
    font-size: 14px;
    color: var(--text-secondary);
    font-weight: 500;
}

.task-list {
    list-style: none;
    margin-bottom: 2rem;
}

.task-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px;
    margin-bottom: 8px;
    background-color: var(--bg-color);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    transition: all 0.2s;
}

.task-item:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-1px);
}

.task-item.completed {
    opacity: 0.7;
    background-color: var(--bg-secondary);
}

.task-content {
    display: flex;
    align-items: center;
    gap: 12px;
    flex: 1;
}

.task-checkbox {
    width: 20px;
    height: 20px;
    accent-color: var(--success-color);
    cursor: pointer;
    flex-shrink: 0;
}

.task-details {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 4px;
}

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

.task-text {
    font-size: 16px;
    transition: all 0.2s;
    line-height: 1.4;
}

.task-category {
    display: inline-block;
    padding: 2px 8px;
    font-size: 11px;
    font-weight: 600;
    color: white;
    border-radius: 12px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    white-space: nowrap;
}

.task-description {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.4;
    padding: 4px 0;
    white-space: pre-wrap;
    word-break: break-word;
}

.task-item.completed .task-text {
    text-decoration: line-through;
    color: var(--text-secondary);
}

.task-item.completed .task-description {
    text-decoration: line-through;
    opacity: 0.7;
}

.task-dates {
    display: flex;
    gap: 12px;
    align-items: center;
    flex-wrap: wrap;
}

.task-created-date {
    font-size: 12px;
    color: var(--text-secondary);
    font-weight: 400;
}

.task-due-date {
    font-size: 12px;
    font-weight: 500;
    padding: 2px 6px;
    border-radius: 4px;
    white-space: nowrap;
}

.task-due-date.due-today {
    background-color: var(--warning-color);
    color: white;
}

.task-due-date.due-tomorrow {
    background-color: #f97316;
    color: white;
}

.task-due-date.due-soon {
    background-color: #fb923c;
    color: white;
}

.task-due-date.due-later {
    background-color: var(--bg-secondary);
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
}

.task-due-date.overdue {
    background-color: var(--danger-color);
    color: white;
    animation: pulse 1.5s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.7; }
}

.task-item.overdue {
    border-left: 4px solid var(--danger-color);
}

.task-actions {
    display: flex;
    gap: 8px;
}

.edit-btn, .delete-btn {
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    border-radius: var(--border-radius);
    transition: background-color 0.2s;
    font-size: 16px;
}

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

.delete-btn:hover {
    background-color: rgba(239, 68, 68, 0.1);
}

.edit-input {
    flex: 1;
    padding: 8px;
    border: 2px solid var(--primary-color);
    border-radius: var(--border-radius);
    font-size: 16px;
    background-color: var(--bg-color);
}

.empty-state {
    text-align: center;
    padding: 3rem 1rem;
    color: var(--text-secondary);
}

.empty-state p:first-child {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 8px;
}

.actions-section {
    display: flex;
    gap: 12px;
    justify-content: center;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
}

.secondary-btn {
    padding: 10px 20px;
    background-color: var(--warning-color);
    color: white;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: opacity 0.2s;
}

.secondary-btn:hover {
    opacity: 0.9;
}

.danger-btn {
    padding: 10px 20px;
    background-color: var(--danger-color);
    color: white;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: opacity 0.2s;
}

.danger-btn:hover {
    opacity: 0.9;
}

.notification {
    position: fixed;
    top: 20px;
    right: 20px;
    padding: 12px 20px;
    border-radius: var(--border-radius);
    color: white;
    font-weight: 500;
    transform: translateX(400px);
    transition: transform 0.3s ease;
    z-index: 1000;
    max-width: 300px;
}

.notification.show {
    transform: translateX(0);
}

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

.notification.error {
    background-color: var(--danger-color);
}

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

/* Modal de gestion des catégories */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    align-items: center;
    justify-content: center;
}

.modal-content {
    background-color: var(--bg-color);
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
    max-width: 600px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
}

.modal-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-hover) 100%);
    color: white;
    padding: 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-radius: 12px 12px 0 0;
}

.modal-header h2 {
    margin: 0;
    font-size: 1.5rem;
}

.close-btn {
    background: none;
    border: none;
    color: white;
    font-size: 2rem;
    line-height: 1;
    cursor: pointer;
    padding: 0;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: background-color 0.2s;
}

.close-btn:hover {
    background-color: rgba(255, 255, 255, 0.2);
}

.modal-body {
    padding: 2rem;
}

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

.add-category-form {
    margin-bottom: 2rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid var(--border-color);
}

.form-row {
    display: flex;
    gap: 12px;
    align-items: center;
}

.form-row input[type="text"] {
    flex: 1;
    padding: 10px;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 14px;
}

.form-row input[type="color"] {
    width: 60px;
    height: 42px;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    cursor: pointer;
}

.form-row button {
    padding: 10px 20px;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: background-color 0.2s;
}

.form-row button:hover {
    background-color: var(--primary-hover);
}

.categories-list {
    margin-top: 1.5rem;
}

#categories-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.category-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    margin-bottom: 8px;
    transition: background-color 0.2s;
}

.category-item:hover {
    background-color: var(--bg-secondary);
}

.category-info {
    display: flex;
    align-items: center;
    gap: 12px;
}

.category-badge {
    display: inline-block;
    padding: 4px 12px;
    font-size: 12px;
    font-weight: 600;
    color: white;
    border-radius: 12px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.category-color-code {
    font-family: monospace;
    font-size: 12px;
    color: var(--text-secondary);
}

.category-actions {
    display: flex;
    gap: 8px;
}

.edit-category-btn,
.delete-category-btn {
    background: none;
    border: none;
    cursor: pointer;
    padding: 6px;
    font-size: 16px;
    border-radius: var(--border-radius);
    transition: background-color 0.2s;
}

.edit-category-btn:hover {
    background-color: rgba(37, 99, 235, 0.1);
}

.delete-category-btn:hover {
    background-color: rgba(239, 68, 68, 0.1);
}

.edit-category-form {
    display: flex;
    gap: 8px;
    align-items: center;
    flex: 1;
}

.edit-category-name {
    flex: 1;
    padding: 8px;
    border: 2px solid var(--primary-color);
    border-radius: var(--border-radius);
    font-size: 14px;
}

.edit-category-color {
    width: 50px;
    height: 36px;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    cursor: pointer;
}

.save-category-btn,
.cancel-category-btn {
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px 12px;
    font-size: 18px;
    border-radius: var(--border-radius);
    transition: background-color 0.2s;
}

.save-category-btn {
    color: var(--success-color);
}

.save-category-btn:hover {
    background-color: rgba(16, 185, 129, 0.1);
}

.cancel-category-btn {
    color: var(--danger-color);
}

.cancel-category-btn:hover {
    background-color: rgba(239, 68, 68, 0.1);
}

.no-categories {
    text-align: center;
    padding: 2rem;
    color: var(--text-secondary);
}

.category-selector-wrapper {
    display: flex;
    gap: 4px;
    align-items: center;
}

#manage-categories-btn {
    padding: 10px 12px;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 16px;
    transition: background-color 0.2s;
}

#manage-categories-btn:hover {
    background-color: var(--border-color);
}

/* Sélecteur de vue (Liste/Calendrier) */
.view-selector {
    display: flex;
    gap: 8px;
    margin-bottom: 1.5rem;
    justify-content: center;
}

.view-btn {
    padding: 10px 24px;
    background-color: var(--bg-secondary);
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    color: var(--text-color);
    transition: all 0.2s;
}

.view-btn:hover {
    border-color: var(--primary-color);
    background-color: var(--bg-color);
}

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

/* Vue Calendrier */
#calendar-view {
    margin-top: 2rem;
}

.calendar-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    padding: 1rem;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-hover) 100%);
    border-radius: var(--border-radius);
    color: white;
}

.calendar-header h2 {
    margin: 0;
    font-size: 1.5rem;
}

.calendar-nav-btn {
    background: rgba(255, 255, 255, 0.2);
    border: none;
    color: white;
    font-size: 24px;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    cursor: pointer;
    transition: background-color 0.2s;
}

.calendar-nav-btn:hover {
    background: rgba(255, 255, 255, 0.3);
}

.calendar-grid {
    background-color: var(--bg-color);
    border-radius: var(--border-radius);
    padding: 1rem;
    box-shadow: var(--shadow);
}

.calendar-weekdays {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 8px;
    margin-bottom: 8px;
}

.weekday {
    text-align: center;
    font-weight: 600;
    color: var(--text-secondary);
    padding: 8px;
    font-size: 14px;
}

.calendar-days {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 8px;
}

.calendar-day {
    min-height: 100px;
    padding: 8px;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: all 0.2s;
    background-color: var(--bg-color);
}

.calendar-day:hover {
    border-color: var(--primary-color);
    box-shadow: var(--shadow);
    transform: translateY(-2px);
}

.calendar-day.empty {
    background-color: var(--bg-secondary);
    cursor: default;
}

.calendar-day.empty:hover {
    border-color: var(--border-color);
    box-shadow: none;
    transform: none;
}

.calendar-day.today {
    border-color: var(--primary-color);
    border-width: 2px;
}

.calendar-day.selected {
    background-color: rgba(37, 99, 235, 0.1);
    border-color: var(--primary-color);
}

.day-number {
    font-weight: 600;
    margin-bottom: 4px;
    color: var(--text-color);
}

.task-indicators {
    display: flex;
    flex-direction: column;
    gap: 2px;
    margin-top: 4px;
}

.task-indicator {
    height: 4px;
    border-radius: 2px;
    font-size: 10px;
}

.task-indicator.completed {
    opacity: 0.5;
}

.task-indicator.more {
    height: auto;
    padding: 2px 4px;
    font-size: 9px;
    text-align: center;
    background-color: var(--text-secondary);
    color: white;
}

.selected-day-tasks {
    margin-top: 2rem;
    padding: 1.5rem;
    background-color: var(--bg-color);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
}

.selected-day-tasks h3 {
    margin: 0 0 1rem 0;
    color: var(--text-color);
}

#selected-day-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.calendar-task-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px;
    margin-bottom: 8px;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    background-color: var(--bg-secondary);
    transition: background-color 0.2s;
}

.calendar-task-item:hover {
    background-color: var(--bg-color);
}

.calendar-task-item.completed {
    opacity: 0.7;
}

.calendar-task-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.calendar-task-item .task-text {
    font-size: 14px;
}

.calendar-task-item .task-description {
    font-size: 12px;
    color: var(--text-secondary);
}

.calendar-task-item.completed .task-text {
    text-decoration: line-through;
}

.no-tasks {
    text-align: center;
    padding: 2rem;
    color: var(--text-secondary);
}

@media (max-width: 768px) {
    body {
        padding: 10px;
    }

    header {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }

    header h1 {
        font-size: 1.5rem;
    }

    main {
        padding: 1rem;
    }

    .input-group {
        flex-direction: column;
    }

    .filter-section {
        flex-direction: column;
        gap: 1rem;
        align-items: stretch;
    }

    .filter-buttons {
        justify-content: center;
    }

    .task-content {
        align-items: flex-start;
    }

    .task-dates {
        margin-left: 32px;
        flex-direction: column;
        align-items: flex-start;
        gap: 4px;
    }

    .actions-section {
        flex-direction: column;
        align-items: center;
    }

    .modal-content {
        width: 95%;
        max-height: 90vh;
    }

    .modal-body {
        padding: 1rem;
    }

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

    .form-row input[type="color"] {
        width: 100%;
    }

    .calendar-day {
        min-height: 80px;
    }

    .view-selector {
        flex-direction: column;
    }

    .view-btn {
        width: 100%;
    }
}
/* === Login === */
.login-overlay {
    position: fixed;
    inset: 0;
    background: var(--bg-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}

.login-box {
    background: var(--bg-color);
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
    padding: 2.5rem;
    width: 100%;
    max-width: 380px;
}

.login-box h1 {
    font-size: 1.4rem;
    color: var(--primary-color);
    margin-bottom: 0.25rem;
    text-align: center;
}

.login-box h2 {
    font-size: 1.1rem;
    color: var(--text-secondary);
    font-weight: 400;
    margin-bottom: 1.5rem;
    text-align: center;
}

.login-field {
    margin-bottom: 1rem;
}

.login-field label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-color);
    margin-bottom: 0.35rem;
}

.login-field input {
    width: 100%;
    padding: 0.6rem 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 1rem;
    color: var(--text-color);
    background: var(--bg-color);
    outline: none;
    transition: border-color 0.2s;
}

.login-field input:focus {
    border-color: var(--primary-color);
}

.login-error {
    color: var(--danger-color);
    font-size: 0.875rem;
    margin-bottom: 0.75rem;
    text-align: center;
}

#login-btn {
    width: 100%;
    padding: 0.7rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    margin-top: 0.5rem;
    transition: background 0.2s;
}

#login-btn:hover:not(:disabled) { background: var(--primary-hover); }
#login-btn:disabled { opacity: 0.6; cursor: not-allowed; }

/* Header right */
.header-right {
    display: flex;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.logout-btn {
    background: rgba(255,255,255,0.15);
    color: white;
    border: 1px solid rgba(255,255,255,0.4);
    padding: 0.35rem 0.85rem;
    border-radius: var(--border-radius);
    font-size: 0.875rem;
    cursor: pointer;
    transition: background 0.2s;
}

.logout-btn:hover { background: rgba(255,255,255,0.25); }