/* المتغيرات الأساسية */
:root {
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --primary-color: #667eea;
    --secondary-color: #764ba2;
    --success-color: #28a745;
    --warning-color: #ffc107;
    --danger-color: #dc3545;
    --urgent-color: #fd7e14;
    --bg-color: #f5f7fa;
    --card-bg: #ffffff;
    --text-primary: #333333;
    --text-secondary: #666666;
    --text-muted: #999999;
    --border-color: #e9ecef;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --shadow-hover: rgba(0, 0, 0, 0.15);
    --input-bg: #ffffff;
    --header-text: #ffffff;
    --transition-speed: 0.3s;
}

/* الوضع الداكن */
body.dark-mode {
    --bg-color: #1a1a2e;
    --card-bg: #16213e;
    --text-primary: #e8e8e8;
    --text-secondary: #b8b8b8;
    --text-muted: #888888;
    --border-color: #2d3a5a;
    --shadow-color: rgba(0, 0, 0, 0.3);
    --shadow-hover: rgba(0, 0, 0, 0.4);
    --input-bg: #0f3460;
    --header-text: #e8e8e8;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: var(--bg-color);
    min-height: 100vh;
    padding: 20px;
    transition: background-color var(--transition-speed), color var(--transition-speed);
}

.container {
    max-width: 800px;
    margin: 0 auto;
    background: var(--card-bg);
    border-radius: 20px;
    box-shadow: 0 20px 60px var(--shadow-color);
    overflow: hidden;
    transition: background-color var(--transition-speed);
}

/* رأس الصفحة */
.header {
    background: var(--primary-gradient);
    color: var(--header-text);
    padding: 25px 30px;
    position: relative;
}

.header-top {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 5px;
}

.header h1 {
    font-size: 2.2rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
}

.subtitle {
    font-size: 0.95rem;
    opacity: 0.9;
}

/* زر الوضع الداكن */
.dark-mode-btn {
    background: rgba(255, 255, 255, 0.2);
    border: none;
    border-radius: 50%;
    width: 45px;
    height: 45px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
    transition: all var(--transition-speed);
}

.dark-mode-btn:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: scale(1.1);
}

.dark-mode .mode-icon::before {
    content: '☀️';
}

/* قسم البحث */
.search-section {
    padding: 15px 20px;
    background: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
}

#searchInput {
    width: 100%;
    padding: 12px 20px;
    border: 2px solid var(--border-color);
    border-radius: 25px;
    font-size: 1rem;
    background: var(--input-bg);
    color: var(--text-primary);
    transition: all var(--transition-speed);
}

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

/* قسم الإدخال */
.input-section {
    padding: 20px;
    background: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
}

.input-row {
    display: flex;
    gap: 10px;
    margin-bottom: 10px;
    flex-wrap: wrap;
}

.input-row:last-child {
    margin-bottom: 0;
}

#taskInput {
    flex: 1;
    min-width: 200px;
    padding: 14px 20px;
    border: 2px solid var(--border-color);
    border-radius: 25px;
    font-size: 1rem;
    background: var(--input-bg);
    color: var(--text-primary);
    transition: all var(--transition-speed);
}

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

#categorySelect, #prioritySelect {
    padding: 14px 18px;
    border: 2px solid var(--border-color);
    border-radius: 25px;
    font-size: 0.95rem;
    background: var(--input-bg);
    color: var(--text-primary);
    cursor: pointer;
    transition: all var(--transition-speed);
}

#categorySelect:focus, #prioritySelect:focus {
    outline: none;
    border-color: var(--primary-color);
}

.date-input {
    padding: 14px 18px;
    border: 2px solid var(--border-color);
    border-radius: 25px;
    font-size: 0.95rem;
    background: var(--input-bg);
    color: var(--text-primary);
    cursor: pointer;
}

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

#addTaskBtn {
    padding: 14px 28px;
    background: var(--primary-gradient);
    color: white;
    border: none;
    border-radius: 25px;
    font-size: 1rem;
    cursor: pointer;
    transition: all var(--transition-speed);
    font-weight: bold;
    white-space: nowrap;
}

#addTaskBtn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 20px rgba(102, 126, 234, 0.4);
}

/* قسم الإحصائيات */
.stats-section {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 12px;
    padding: 20px;
    background: var(--bg-color);
    border-bottom: 1px solid var(--border-color);
}

.stat-card {
    text-align: center;
    padding: 15px;
    background: var(--card-bg);
    border-radius: 15px;
    box-shadow: 0 4px 15px var(--shadow-color);
    transition: all var(--transition-speed);
    position: relative;
}

.stat-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px var(--shadow-hover);
}

.stat-card.completed {
    border-right: 4px solid var(--success-color);
}

.stat-card.pending {
    border-right: 4px solid var(--warning-color);
}

.stat-card.productivity {
    border-right: 4px solid var(--primary-color);
}

.stat-icon {
    display: block;
    font-size: 1.5rem;
    margin-bottom: 5px;
}

.stat-number {
    display: block;
    font-size: 1.8rem;
    font-weight: bold;
    color: var(--text-primary);
}

.stat-label {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

/* قسم التصفية */
.filter-section {
    padding: 15px 20px;
    background: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
}

.filter-group {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 10px;
}

.filter-group:last-child {
    margin-bottom: 0;
}

.filter-group.category-filter {
    padding-top: 10px;
    border-top: 1px dashed var(--border-color);
}

.filter-btn {
    padding: 8px 18px;
    border: 2px solid var(--border-color);
    background: var(--card-bg);
    border-radius: 20px;
    cursor: pointer;
    transition: all var(--transition-speed);
    font-size: 0.85rem;
    color: var(--text-secondary);
}

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

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

/* الإجراءات الجماعية */
.bulk-actions {
    display: none;
    align-items: center;
    gap: 10px;
    padding: 12px 20px;
    background: linear-gradient(135deg, #e8f4ff 0%, #d4e8ff 100%);
    border-bottom: 1px solid var(--border-color);
    animation: slideDown 0.3s ease;
}

.bulk-actions.visible {
    display: flex;
    flex-wrap: wrap;
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.bulk-info {
    font-weight: bold;
    color: var(--primary-color);
}

.bulk-btn {
    padding: 8px 16px;
    border: none;
    border-radius: 15px;
    cursor: pointer;
    font-size: 0.85rem;
    transition: all var(--transition-speed);
}

.bulk-btn.complete-selected {
    background: var(--success-color);
    color: white;
}

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

.bulk-btn:hover {
    transform: scale(1.05);
}

/* قائمة المهام */
.task-list {
    list-style: none;
    padding: 20px;
    max-height: 450px;
    overflow-y: auto;
}

.task-item {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    padding: 15px 18px;
    background: var(--card-bg);
    border-radius: 12px;
    margin-bottom: 10px;
    box-shadow: 0 3px 10px var(--shadow-color);
    transition: all var(--transition-speed);
    animation: slideIn 0.3s ease;
    cursor: pointer;
    border-right: 4px solid var(--border-color);
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.task-item:hover {
    box-shadow: 0 6px 20px var(--shadow-hover);
}

.task-item.selected {
    background: linear-gradient(135deg, #e8f4ff 0%, #d4e8ff 100%);
    border-color: var(--primary-color);
}

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

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

/* الأولويات */
.task-item.priority-low {
    border-right-color: #20c997;
}

.task-item.priority-normal {
    border-right-color: var(--primary-color);
}

.task-item.priority-high {
    border-right-color: var(--urgent-color);
}

.task-item.priority-urgent {
    border-right-color: var(--danger-color);
}

/* التصنيفات */
.task-item.category-work::before {
    content: '💼';
    margin-left: 10px;
}

.task-item.category-personal::before {
    content: '🏠';
    margin-left: 10px;
}

.task-item.category-study::before {
    content: '📚';
    margin-left: 10px;
}

.task-item.category-health::before {
    content: '🏃';
    margin-left: 10px;
}

.task-item.category-other::before {
    content: '📁';
    margin-left: 10px;
}

/* تاريخ الاستحقاق */
.due-date {
    font-size: 0.75rem;
    padding: 3px 8px;
    border-radius: 10px;
    margin-right: 10px;
    background: var(--bg-color);
    color: var(--text-secondary);
}

.due-date.overdue {
    background: #ffe3e3;
    color: var(--danger-color);
}

.due-date.soon {
    background: #fff3cd;
    color: var(--urgent-color);
}

/* مربع الاختيار */
.task-checkbox {
    width: 24px;
    height: 24px;
    border: 2px solid var(--primary-color);
    border-radius: 50%;
    margin-left: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-speed);
    flex-shrink: 0;
    cursor: pointer;
}

.task-checkbox:hover {
    background: rgba(102, 126, 234, 0.1);
}

.task-checkbox.checked {
    background: var(--primary-color);
    border-color: var(--primary-color);
}

.task-checkbox.checked::after {
    content: '✓';
    color: white;
    font-size: 14px;
}

/* مربع الاختيار متعدد */
.task-select {
    width: 22px;
    height: 22px;
    border: 2px solid var(--border-color);
    border-radius: 6px;
    margin-left: 10px;
    cursor: pointer;
    transition: all var(--transition-speed);
    flex-shrink: 0;
}

.task-select:hover {
    border-color: var(--primary-color);
}

.task-select.selected {
    background: var(--primary-color);
    border-color: var(--primary-color);
}

/* نص المهمة */
.task-text {
    flex: 1;
    font-size: 1rem;
    color: var(--text-primary);
    min-width: 150px;
    word-break: break-word;
}

/* قسم الأزرار */
.task-actions {
    display: flex;
    gap: 6px;
    margin-right: 15px;
}

.task-btn {
    width: 32px;
    height: 32px;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    transition: all var(--transition-speed);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.9rem;
}

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

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

.delete-btn {
    background: #ffe3e3;
    color: var(--danger-color);
}

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

/* رسالة فارغة */
.empty-message {
    text-align: center;
    padding: 40px 20px;
    color: var(--text-muted);
}

.empty-icon {
    font-size: 3.5rem;
    display: block;
    margin-bottom: 15px;
}

.empty-message p {
    font-size: 1.1rem;
}

.empty-hint {
    font-size: 0.9rem !important;
    margin-top: 5px;
}

/* شريط التقدم */
.progress-section {
    padding: 15px 20px;
    background: var(--bg-color);
    border-top: 1px solid var(--border-color);
}

.progress-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 8px;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.progress-bar {
    height: 10px;
    background: var(--border-color);
    border-radius: 10px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: var(--primary-gradient);
    border-radius: 10px;
    transition: width 0.5s ease;
    width: 0%;
}

/* قسم الإجراءات */
.actions-section {
    display: flex;
    justify-content: center;
    gap: 10px;
    padding: 15px;
    background: var(--bg-color);
    border-top: 1px solid var(--border-color);
    flex-wrap: wrap;
}

.action-btn {
    padding: 10px 18px;
    border: 2px solid var(--border-color);
    background: var(--card-bg);
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.85rem;
    color: var(--text-secondary);
    transition: all var(--transition-speed);
}

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

.action-btn.danger {
    border-color: #ffe3e3;
    color: var(--danger-color);
}

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

/* إشعار التراجع عن الحذف */
.undo-toast {
    position: fixed;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--card-bg);
    padding: 15px 25px;
    border-radius: 12px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
    display: flex;
    align-items: center;
    gap: 15px;
    z-index: 1000;
    opacity: 0;
    transition: all 0.4s ease;
}

.undo-toast.visible {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

.undo-toast span {
    color: var(--text-primary);
}

.undo-toast button {
    padding: 8px 16px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-weight: bold;
}

.undo-toast button:hover {
    background: var(--secondary-color);
}

/* قائمة التنقل المخصصة */
select {
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%23666' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: left 15px center;
    padding-left: 40px !important;
}

body.dark-mode select {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%23b8b8b8' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
}

/* شريط التمرير المخصص */
.task-list::-webkit-scrollbar {
    width: 8px;
}

.task-list::-webkit-scrollbar-track {
    background: var(--bg-color);
    border-radius: 10px;
}

.task-list::-webkit-scrollbar-thumb {
    background: var(--primary-color);
    border-radius: 10px;
}

.task-list::-webkit-scrollbar-thumb:hover {
    background: var(--secondary-color);
}

/* التجاوب */
@media (max-width: 600px) {
    .header h1 {
        font-size: 1.8rem;
    }
    
    .input-row {
        flex-direction: column;
    }
    
    #taskInput, #categorySelect, #prioritySelect, .date-input, #addTaskBtn {
        width: 100%;
        border-radius: 12px;
    }
    
    select {
        background-position: left 15px center;
        padding-left: 40px !important;
    }
    
    .stats-section {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .task-item {
        padding: 12px 15px;
    }
    
    .task-actions {
        width: 100%;
        justify-content: flex-end;
        margin-top: 10px;
        margin-right: 0;
        padding-top: 10px;
        border-top: 1px dashed var(--border-color);
    }
    
    .due-date {
        order: -1;
        width: 100%;
        margin-bottom: 10px;
        margin-right: 0;
    }
    
    .task-checkbox {
        margin-left: 8px;
    }
    
    .bulk-actions {
        flex-direction: column;
        align-items: stretch;
    }
    
    .bulk-actions .bulk-btn {
        width: 100%;
        padding: 12px;
    }
}

/* تأثيرات إضافية */
.task-item.deleting {
    animation: slideOut 0.3s ease forwards;
}

@keyframes slideOut {
    to {
        opacity: 0;
        transform: translateX(-30px);
    }
}

/* تلميحات الأدوات */
[data-tooltip] {
    position: relative;
}

[data-tooltip]::after {
    content: attr(data-tooltip);
    position: absolute;
    bottom: 100%;
    left: 50%;
    transform: translateX(-50%);
    padding: 5px 10px;
    background: #333;
    color: white;
    font-size: 0.75rem;
    border-radius: 5px;
    white-space: nowrap;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s;
}

[data-tooltip]:hover::after {
    opacity: 1;
}