:root {
    --bg-base: #f8fafc;
    --bg-panel: #ffffff;
    --bg-card: #f1f5f9;
    
    --accent-primary: #2563eb;
    --accent-glow: rgba(37, 99, 235, 0.2);
    --accent-danger: #dc2626;
    --accent-success: #059669;
    
    --border-glass: #e2e8f0;
    --border-hl: rgba(37, 99, 235, 0.3);
    
    --text-primary: #0f172a;
    --text-muted: #64748b;
    
    --font-tajawal: 'Tajawal', sans-serif;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: var(--font-tajawal);
}

body {
    background-color: var(--bg-base);
    color: var(--text-primary);
    min-height: 100vh;
    overflow-x: hidden;
    /* Ambient backgrounds */
    background-image: 
        radial-gradient(circle at 15% 50%, rgba(37, 99, 235, 0.05), transparent 30%),
        radial-gradient(circle at 85% 30%, rgba(5, 150, 105, 0.05), transparent 30%);
    background-attachment: fixed;
}

.glass-panel {
    background: var(--bg-panel);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--border-glass);
    border-radius: 16px;
}

/* Navbar */
header.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.25rem 3rem;
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom-left-radius: 0;
    border-bottom-right-radius: 0;
}

.logo {
    font-size: 1.5rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-success));
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: 1px;
}

.nav-links {
    display: flex;
    gap: 1rem;
}

.nav-btn {
    background: transparent;
    border: none;
    color: var(--text-muted);
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    padding: 0.5rem 1.5rem;
    border-radius: 50px;
    transition: all 0.3s ease;
}

.nav-btn:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
}

.nav-btn.active {
    color: var(--text-primary);
    background: var(--bg-card);
    border: 1px solid var(--border-hl);
    box-shadow: 0 0 15px rgba(59, 130, 246, 0.2);
}

/* Main Layout */
.app-container {
    padding: 2rem 3rem;
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.view-section {
    display: none;
    animation: fadeIn 0.4s ease forwards;
}

.view-section.active {
    display: flex;
}

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

/* Auto Gen View */
#auto-gen-view {
    flex-direction: row;
    gap: 2rem;
    align-items: flex-start;
}

.sidebar {
    width: 320px;
    height: 80vh;
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    overflow-y: auto;
}

.filters-group {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    border-bottom: 1px solid var(--border-glass);
    padding-bottom: 1.5rem;
}

.filter-title {
    font-size: 0.9rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.toggle-pills {
    display: flex;
    background: rgba(0,0,0,0.3);
    border-radius: 50px;
    padding: 0.25rem;
    border: 1px solid var(--border-glass);
}
.pill {
    flex: 1;
    border: none;
    background: transparent;
    color: var(--text-muted);
    padding: 0.6rem;
    border-radius: 50px;
    cursor: pointer;
    font-weight: 600;
    transition: 0.3s;
}
.pill.active {
    background: var(--accent-primary);
    color: white;
    box-shadow: 0 4px 15px var(--accent-glow);
}

.schedule-list {
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
}

.sch-item {
    background: var(--bg-card);
    border: 1px solid var(--border-glass);
    padding: 1rem;
    border-radius: 12px;
    cursor: pointer;
    transition: 0.3s;
}
.sch-item:hover {
    border-color: var(--accent-primary);
    transform: translateX(-5px);
}
.sch-item.active {
    border-color: var(--accent-success);
    background: rgba(59, 130, 246, 0.1);
}
.sch-item h3 { font-size: 1.1rem; margin-bottom: 0.3rem; }
.sch-item p { font-size: 0.85rem; color: var(--text-muted); }

.main-board {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

/* Schedule Table */
.schedule-table-wrapper {
    width: 100%;
    overflow-x: auto;
    border-radius: 16px;
    border: 1px solid var(--border-glass);
    background: var(--bg-panel);
}

table.schedule-grid {
    width: 100%;
    border-collapse: collapse;
}

table.schedule-grid th, table.schedule-grid td {
    border: 1px solid var(--border-glass);
    padding: 1rem;
    text-align: center;
}

table.schedule-grid th {
    background: #f1f5f9;
    font-weight: 700;
}
.th-time { display: block; font-size: 0.75rem; color: var(--accent-primary); margin-top: 0.3rem; font-weight: normal; }

table.schedule-grid .day-cell {
    background: rgba(37, 99, 235, 0.1);
    color: var(--accent-primary);
    font-weight: 800;
    font-size: 1.2rem;
    width: 120px;
}

table.schedule-grid .course-block {
    background: var(--bg-panel);
    border: 1px solid var(--accent-primary);
    color: var(--text-primary);
    border-radius: 8px;
    transition: 0.3s;
}
table.schedule-grid .course-block:hover {
    background: rgba(59, 130, 246, 0.3);
    transform: scale(1.02);
}
.c-name { font-weight: bold; margin-bottom: 0.3rem; }
.c-type { font-size: 0.75rem; color: var(--accent-success); }
.c-doc { font-size: 0.8rem; color: var(--text-muted); margin-top: 0.3rem; display: block; }
.c-del { color: var(--accent-danger); cursor: pointer; display: none; font-size: 0.8rem; margin-top:0.3rem; font-weight: bold;}
.course-block:hover .c-del { display: block; }

/* Builder View */
#builder-view {
    flex-direction: row;
    gap: 2rem;
}

.subjects-pool {
    width: 350px;
    height: 80vh;
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
    overflow-y: auto;
}

.cat-section {
    margin-bottom: 1rem;
}
.cat-title {
    font-size: 1.1rem;
    color: var(--accent-primary);
    margin-bottom: 0.8rem;
    border-bottom: 1px solid var(--border-glass);
    padding-bottom: 0.5rem;
}

.pool-course {
    background: var(--bg-card);
    border: 1px solid var(--border-glass);
    padding: 0.8rem;
    border-radius: 8px;
    margin-bottom: 0.5rem;
    cursor: pointer;
    transition: 0.2s;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.pool-course:hover {
    border-color: var(--accent-primary);
    background: rgba(59, 130, 246, 0.1);
}
.pool-course.added {
    opacity: 0.5;
    pointer-events: none;
    border-color: var(--accent-success);
}
.pool-info h4 { font-size: 0.95rem; }
.pool-info span { font-size: 0.75rem; color: var(--text-muted); }

.builder-board {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.builder-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.stats {
    display: flex;
    gap: 1.5rem;
}
.stat-box {
    background: var(--bg-card);
    padding: 0.6rem 1.2rem;
    border-radius: 8px;
    border: 1px solid var(--border-glass);
}
.stat-box span { color: var(--accent-success); font-weight: bold; }

/* Notifications */
#toast-container {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    z-index: 9999;
}
.toast {
    background: rgba(30, 41, 59, 0.9);
    backdrop-filter: blur(8px);
    border-right: 4px solid var(--accent-danger);
    padding: 1rem 1.5rem;
    border-radius: 8px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.5);
    color: white;
    font-weight: 600;
    animation: slideIn 0.3s ease forwards, fadeOut 0.3s ease 3s forwards;
}
@keyframes slideIn { from {transform: translateX(100%);} to {transform: translateX(0);} }
@keyframes fadeOut { from {opacity: 1;} to {opacity: 0; visibility: hidden;} }

/* Action Buttons */
.action-btn {
    background: var(--accent-primary);
    border: none;
    color: #ffffff;
    padding: 0.75rem 2rem;
    border-radius: 50px;
    font-weight: bold;
    cursor: pointer;
    transition: 0.3s;
    box-shadow: 0 4px 15px rgba(37, 99, 235, 0.3);
}
.action-btn:hover {
    box-shadow: 0 4px 20px rgba(37, 99, 235, 0.5);
    transform: translateY(-2px);
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
    header.navbar {
        flex-direction: column;
        padding: 1rem;
        gap: 1rem;
        text-align: center;
    }
    .logo {
        font-size: 1.1rem;
    }
    .logo span:last-child {
        font-size: 0.85rem !important;
    }
    .nav-links {
        width: 100%;
        justify-content: center;
        flex-wrap: wrap;
    }
    .nav-btn {
        padding: 0.4rem 1rem;
        font-size: 0.95rem;
    }
    .app-container {
        padding: 1rem;
    }
    
    #builder-view, #auto-gen-view {
        flex-direction: column;
    }
    
    .sidebar, .subjects-pool {
        width: 100%;
        height: auto;
        max-height: 350px;
        padding: 1rem;
    }
    
    .builder-board, .main-board {
        width: 100%;
        overflow: hidden;
    }
    
    .builder-header {
        flex-direction: column;
        gap: 1rem;
        align-items: stretch;
    }
    .stats {
        justify-content: space-between;
    }
    
    table.schedule-grid th, table.schedule-grid td {
        padding: 0.5rem;
    }
    table.schedule-grid .day-cell {
        font-size: 1rem;
        width: 70px;
    }
    .th-time {
        font-size: 0.65rem;
    }
    .c-name {
        font-size: 0.85rem;
    }
    .c-doc {
        font-size: 0.7rem;
    }
}