/* ==========================================================================
   1. المتغيرات والإعدادات العامة
   ========================================================================== */
:root {
    --primary-color: #3f51b5;
    --secondary-color: #ff9800;
    --accent-color: #4caf50;
    --background-color: #e8eaf6;
    --surface-color: #ffffff;
    --text-color-dark: #212121;
    --text-color-light: #ffffff;
    --border-color: #e0e0e0;
    --shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    
    --sidebar-width-expanded: 280px;
    --sidebar-width-collapsed: 80px;
    --header-height: 80px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Cairo', sans-serif;
}

body {
    direction: rtl;
    background-color: var(--background-color);
    color: var(--text-color-dark);
    display: flex;
    min-height: 100vh;
    overflow-x: hidden; /* منع الارتجاج الأفقي */
}

/* ==========================================================================
   2. الهيكل الرئيسي (Header & Fixed Sidebar & Main)
   ========================================================================== */

header {
    background: var(--primary-color);
    color: var(--text-color-light);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 40px;
    box-shadow: var(--shadow);
    z-index: 1100;
    position: fixed;
    top: 0; left: 0; right: 0;
    height: var(--header-height);
}

/* القائمة الجانبية - Sidebar (حل مشكلة الارتجاج) */
aside {
    background-color: var(--surface-color);
    width: var(--sidebar-width-collapsed);
    padding: 20px 10px;
    box-shadow: 2px 0 10px rgba(0, 0, 0, 0.1);
    position: fixed;
    top: var(--header-height);
    right: 0;
    height: calc(100vh - var(--header-height));
    overflow-x: hidden;
    overflow-y: auto;
    z-index: 1000;
    transition: width 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

aside:hover {
    width: var(--sidebar-width-expanded);
}

aside ul { list-style: none; padding: 0; }

aside ul li a {
    display: flex; align-items: center; gap: 15px;
    padding: 15px 12px; color: var(--text-color-dark);
    text-decoration: none; border-radius: 8px;
    white-space: nowrap; transition: background-color 0.3s;
}

aside ul li a span {
    opacity: 0; visibility: hidden;
    transition: opacity 0.2s ease;
}

aside:hover ul li a span {
    opacity: 1; visibility: visible;
    transition-delay: 0.15s;
}

aside ul li a i { font-size: 1.2rem; color: var(--primary-color); min-width: 30px; text-align: center; }

aside ul li a:hover, aside ul li a.active {
    background-color: var(--primary-color); color: var(--text-color-light);
}
aside ul li a:hover i, aside ul li a.active i { color: var(--text-color-light); }

/* المحتوى الرئيسي - Main (ثبات تام) */
main {
    margin-top: var(--header-height);
    margin-right: var(--sidebar-width-collapsed); /* هامش ثابت لمنع الارتجاج */
    padding: 30px;
    flex-grow: 1;
    width: calc(100% - var(--sidebar-width-collapsed));
    transition: none; /* إلغاء حركة المحتوى مع الماوس */
}

/* ==========================================================================
   3. علامات التبويب (Tabs & Subtabs)
   ========================================================================== */

.tabs-container { margin-bottom: 20px; border-bottom: 2px solid var(--border-color); }
.tabs { display: flex; gap: 10px; }
.tab-button {
    background: none; border: none; padding: 10px 15px; cursor: pointer;
    font-size: 1rem; font-weight: 600; color: #666; border-bottom: 3px solid transparent;
    transition: all 0.3s; display: flex; align-items: center; gap: 8px;
}
.tab-button.active { color: var(--primary-color); border-bottom-color: var(--primary-color); }

.tab-content { display: none; }
.tab-content.active { display: block; }

/* التبويبات الفرعية */
.subtabs { display: flex; gap: 10px; border-bottom: 1px solid var(--border-color); margin-bottom: 15px; }
.subtab-button {
    background-color: #f5f5f5; border: 1px solid #ddd; border-bottom: none;
    padding: 8px 15px; border-radius: 6px 6px 0 0; cursor: pointer; font-size: 0.9rem;
}
.subtab-button.active {
    background-color: var(--surface-color); color: var(--primary-color);
    border-color: var(--primary-color); border-bottom: 2px solid var(--surface-color);
    transform: translateY(1px); font-weight: bold;
}

.subtab-content { display: none; }
.subtab-content.active { display: block; }

/* ==========================================================================
   4. البطاقات والجداول والإحصائيات
   ========================================================================== */

.card { background-color: var(--surface-color); border-radius: 12px; padding: 25px; margin-bottom: 25px; box-shadow: var(--shadow); }

.stats-grid { display: flex; flex-wrap: wrap; gap: 20px; margin-bottom: 30px; }
.stat-box { flex: 1; min-width: 150px; padding: 20px; border-radius: 10px; text-align: center; box-shadow: 0 2px 5px rgba(0,0,0,0.05); }
.stat-box.fee { background-color: #f8f9fa; }
.stat-box.paid { background-color: #d4edda; color: #155724; }
.stat-box.remaining { background-color: #f8d7da; color: #721c24; }

.table-responsive { width: 100%; overflow-x: auto; border: 1px solid var(--border-color); border-radius: 8px; }
.data-table, .table { width: 100%; border-collapse: collapse; min-width: 800px; }
.data-table th, .table thead th { background-color: #f8f9fa; padding: 12px; border: 1px solid var(--border-color); white-space: nowrap; }
.data-table td, .table td { padding: 10px; border: 1px solid var(--border-color); text-align: center; }

/* ==========================================================================
   5. الأزرار والنماذج والتنبيهات
   ========================================================================== */

.btn { padding: 10px 20px; border: none; border-radius: 8px; cursor: pointer; font-weight: 600; display: inline-flex; align-items: center; gap: 8px; transition: 0.3s; }
.btn-primary { background-color: var(--primary-color); color: white; }
.btn-success { background-color: var(--accent-color); color: white; }
.btn-danger { background-color: #f44336; color: white; }

input, select, textarea { width: 100%; padding: 10px; border: 1px solid var(--border-color); border-radius: 6px; margin-top: 5px; }

.alert-info { background-color: #fff3cd; color: #856404; padding: 12px; border-radius: 8px; margin-bottom: 15px; display: flex; align-items: center; gap: 10px; }

/* الاستجابة */
@media (max-width: 992px) {
    header { padding: 0 20px; }
    aside { width: 60px; }
    aside:hover { width: 200px; }
    main { margin-right: 60px; width: calc(100% - 60px); padding: 15px; }
}

/* Loading Overlay */
.loading-overlay { position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(255,255,255,0.8); display: flex; justify-content: center; align-items: center; z-index: 2000; }
/* --- تحسين نتائج البحث (البطاقات) --- */
.results-header {
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--background-color);
}

.student-search-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 15px;
}

.student-result-card {
    background: white;
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 15px;
    display: flex;
    align-items: center;
    gap: 15px;
    cursor: pointer;
    transition: all 0.2s ease;
    position: relative;
    overflow: hidden;
}

.student-result-card:hover {
    transform: translateY(-3px);
    border-color: var(--primary-color);
    box-shadow: 0 6px 15px rgba(63, 81, 181, 0.15);
    background-color: #fcfdff;
}

.card-avatar {
    width: 50px;
    height: 50px;
    background: var(--background-color);
    color: var(--primary-color);
    border-radius: 10px;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.4rem;
}

.student-result-card:hover .card-avatar {
    background: var(--primary-color);
    color: white;
}

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

.student-name {
    font-weight: 700;
    font-size: 1.05rem;
    color: var(--text-color-dark);
}

.student-meta {
    font-size: 0.85rem;
    color: #666;
    display: flex;
    align-items: center;
    gap: 6px;
}

.card-action {
    display: flex;
    align-items: center;
}

.btn-select-mini {
    background: #f0f2ff;
    color: var(--primary-color);
    border: none;
    padding: 8px 12px;
    border-radius: 8px;
    font-size: 0.85rem;
    font-weight: 600;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    transition: all 0.2s;
}

.student-result-card:hover .btn-select-mini {
    background: var(--accent-color);
    color: white;
}

/* التجاوب مع الشاشات الصغيرة */
@media (max-width: 480px) {
    .student-search-grid {
        grid-template-columns: 1fr;
    }
}