:root {
    --primary-color: #0f733e;
    --primary-hover: #0c5c32;
    --accent-color: #d4af37;
    --bg-color: #f8fafc;
    --surface-color: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --transition: all 0.3s ease;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: 'Inter', sans-serif; background-color: var(--bg-color); color: var(--text-primary); line-height: 1.5; }

/* Layout */
.app-container { display: flex; min-height: 100vh; position: relative; }
.sidebar { width: 280px; background-color: var(--surface-color); border-right: 1px solid var(--border-color); display: flex; flex-direction: column; box-shadow: var(--shadow-sm); z-index: 20; transition: transform 0.3s ease; }
.sidebar-header { padding: 24px; border-bottom: 1px solid var(--border-color); display: flex; justify-content: center; align-items: center; position: relative; }
.logo { max-height: 70px; width: auto; max-width: 100%; object-fit: contain; mix-blend-mode: multiply; }
.sidebar-nav { flex: 1; padding: 20px 16px; display: flex; flex-direction: column; gap: 4px; overflow-y: auto; }

.nav-section {
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--text-secondary);
    letter-spacing: 0.05em;
    margin-top: 16px;
    margin-bottom: 8px;
    padding-left: 16px;
}

.nav-item { display: flex; align-items: center; gap: 12px; padding: 10px 16px; text-decoration: none; color: var(--text-secondary); font-weight: 500; border-radius: 8px; transition: var(--transition); }
.nav-item i { font-size: 1.1rem; width: 20px; text-align: center; }
.nav-item:hover { background-color: #f1f5f9; color: var(--primary-color); }
.nav-item.active { background-color: var(--primary-color); color: white; box-shadow: var(--shadow-md); }
.sidebar-footer { padding: 16px; text-align: center; color: var(--text-secondary); font-size: 0.875rem; border-top: 1px solid var(--border-color); }

/* Main Content */
.main-content { flex: 1; display: flex; flex-direction: column; overflow-x: hidden; width: 100%; }
.top-header { background-color: var(--surface-color); padding: 20px 32px; display: flex; justify-content: space-between; align-items: center; border-bottom: 1px solid var(--border-color); box-shadow: var(--shadow-sm); }
.header-left { display: flex; align-items: center; gap: 16px; }
.top-header h1 { font-size: 1.5rem; font-weight: 600; color: var(--primary-color); }
.user-profile { display: flex; align-items: center; gap: 12px; }
.avatar { width: 40px; height: 40px; border-radius: 50%; background-color: var(--accent-color); color: white; display: flex; align-items: center; justify-content: center; font-weight: 600; font-size: 1.1rem; }

/* Mobile Menu Controls */
.mobile-menu-toggle { display: none; background: none; border: none; font-size: 1.5rem; color: var(--text-primary); cursor: pointer; }
.mobile-menu-close { display: none; background: none; border: none; font-size: 1.5rem; color: var(--text-primary); cursor: pointer; position: absolute; right: 24px; top: 50%; transform: translateY(-50%); }
.sidebar-overlay { display: none; position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0,0,0,0.5); z-index: 15; opacity: 0; transition: opacity 0.3s ease; }

/* Views Container */
.view-container { padding: 32px; flex: 1; overflow-y: auto; }

/* Dashboard Cards */
.dashboard-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 24px; margin-bottom: 32px; }
.stat-card { background-color: var(--surface-color); padding: 24px; border-radius: 12px; box-shadow: var(--shadow-sm); display: flex; align-items: center; gap: 20px; border-left: 4px solid var(--primary-color); transition: var(--transition); }
.stat-card:hover { box-shadow: var(--shadow-md); transform: translateY(-2px); }
.stat-icon { width: 50px; height: 50px; border-radius: 10px; background-color: #e2f0e9; color: var(--primary-color); display: flex; align-items: center; justify-content: center; font-size: 1.5rem; flex-shrink: 0; }
.stat-content h3 { font-size: 0.875rem; color: var(--text-secondary); font-weight: 500; margin-bottom: 4px; }
.stat-content p { font-size: 1.5rem; font-weight: 700; color: var(--text-primary); }

/* Kanban Board (Leads) */
.kanban-board { display: flex; gap: 24px; overflow-x: auto; padding-bottom: 16px; snap-type: x mandatory; }
.kanban-col { background-color: #f1f5f9; border-radius: 12px; min-width: 300px; padding: 16px; display: flex; flex-direction: column; gap: 16px; scroll-snap-align: start; }
.kanban-col h3 { font-size: 1rem; color: var(--text-primary); border-bottom: 2px solid var(--border-color); padding-bottom: 12px; margin-bottom: 4px; display: flex; justify-content: space-between; }
.kanban-card { background-color: var(--surface-color); padding: 16px; border-radius: 8px; box-shadow: var(--shadow-sm); border: 1px solid var(--border-color); }
.kanban-card h4 { margin-bottom: 8px; color: var(--primary-color); }
.kanban-card p { font-size: 0.875rem; color: var(--text-secondary); margin-bottom: 12px; }
.kanban-actions { display: flex; gap: 8px; }

/* Courses Grid */
.courses-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 24px; }
.course-card { background-color: var(--surface-color); border-radius: 12px; box-shadow: var(--shadow-md); overflow: hidden; transition: var(--transition); border: 1px solid var(--border-color); }
.course-card:hover { transform: translateY(-5px); box-shadow: var(--shadow-lg); }
.course-header { background-color: var(--primary-color); color: white; padding: 16px 20px; }
.course-body { padding: 20px; }
.course-detail { display: flex; justify-content: space-between; margin-bottom: 12px; font-size: 0.95rem; }
.course-price { margin-top: 16px; padding-top: 16px; border-top: 1px dashed var(--border-color); font-size: 1.25rem; font-weight: 700; color: var(--primary-color); text-align: right; }

/* Tables */
.data-table-container { background-color: var(--surface-color); border-radius: 12px; box-shadow: var(--shadow-md); overflow-x: auto; margin-bottom: 32px; }
.table-header-actions { padding: 20px; display: flex; justify-content: space-between; align-items: center; border-bottom: 1px solid var(--border-color); flex-wrap: wrap; gap: 12px; }
.btn { padding: 10px 20px; border-radius: 6px; font-weight: 500; cursor: pointer; border: none; transition: var(--transition); display: inline-flex; align-items: center; justify-content: center; gap: 8px; font-size: 0.95rem; }
.btn-primary { background-color: var(--primary-color); color: white; }
.btn-primary:hover { background-color: var(--primary-hover); }
.btn-sm { padding: 6px 12px; font-size: 0.85rem; }
.btn-danger { background-color: #ef4444; color: white; }
.btn-success { background-color: #10b981; color: white; }
table { width: 100%; border-collapse: collapse; min-width: 600px; }
th, td { padding: 16px 20px; text-align: left; border-bottom: 1px solid var(--border-color); }
th { background-color: #f8fafc; color: var(--text-secondary); font-weight: 600; text-transform: uppercase; font-size: 0.75rem; }
tr:hover td { background-color: #f1f5f9; }

/* Badge */
.badge { padding: 4px 8px; border-radius: 12px; font-size: 0.75rem; font-weight: 600; }
.badge-income { background-color: #d1fae5; color: #047857; }
.badge-expense { background-color: #fee2e2; color: #b91c1c; }

/* Modals */
.modal { display: none; position: fixed; z-index: 100; left: 0; top: 0; width: 100%; height: 100%; background-color: rgba(0,0,0,0.5); backdrop-filter: blur(4px); align-items: center; justify-content: center; padding: 16px; }
.modal.active { display: flex; }
.modal-content { background-color: var(--surface-color); padding: 32px; border-radius: 12px; width: 100%; max-width: 500px; position: relative; box-shadow: var(--shadow-lg); animation: modalSlideIn 0.3s ease-out; }
@keyframes modalSlideIn { from { transform: translateY(-20px); opacity: 0; } to { transform: translateY(0); opacity: 1; } }
.close-btn { position: absolute; top: 20px; right: 24px; font-size: 1.5rem; font-weight: bold; color: var(--text-secondary); cursor: pointer; }
.form-group { margin-bottom: 20px; }
.form-group label { display: block; margin-bottom: 8px; font-weight: 500; color: var(--text-primary); }
.form-group input, .form-group select { width: 100%; padding: 12px; border: 1px solid var(--border-color); border-radius: 6px; font-family: 'Inter', sans-serif; }
.empty-state { text-align: center; padding: 40px; color: var(--text-secondary); }

/* Responsive Media Queries */
@media (max-width: 768px) {
    .sidebar { position: fixed; height: 100vh; transform: translateX(-100%); }
    .sidebar.open { transform: translateX(0); }
    .sidebar-overlay.active { display: block; opacity: 1; }
    .mobile-menu-toggle { display: block; }
    .mobile-menu-close { display: block; }
    .desktop-only { display: none; }
    .view-container { padding: 16px; }
    .top-header { padding: 16px; }
    .table-header-actions { flex-direction: column; align-items: flex-start; }
    .btn { width: 100%; }
}