Standardize admin panel styling inconsistencies

- Added missing form classes to admin base template
- Standardized button styles across all admin templates
- Added modal styling with consistent spacing and colors
- Added form input, select, and label styling
- Added utility classes for add-source forms
- Removed duplicate CSS classes from individual templates
- Improved button hover states and disabled states

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

templates/_admin_base.html

@@ -84,7 +84,9 @@
         }
 
         /* ===== BUTTONS ===== */
-        .btn {
+        .btn,
+        .btn-primary,
+        .btn-secondary {
             padding: 8px 16px;
             border: none;
             border-radius: 6px;
@@ -94,25 +96,43 @@
             transition: all 0.2s;
             text-decoration: none;
             display: inline-block;
+            text-align: center;
+            border: 1px solid transparent;
         }
 
         .btn-primary {
             background: var(--primary-color);
             color: white;
+            border-color: var(--primary-color);
         }
 
         .btn-primary:hover {
             background: var(--primary-hover);
+            border-color: var(--primary-hover);
+            transform: translateY(-1px);
         }
 
         .btn-secondary {
             background: var(--surface-elevation-1);
             color: var(--text-primary);
-            border: 1px solid var(--divider-color);
+            border-color: var(--divider-color);
         }
 
         .btn-secondary:hover {
             background: var(--surface-elevation-2);
+            border-color: var(--divider-color);
+            transform: translateY(-1px);
+        }
+
+        .btn:disabled {
+            opacity: 0.6;
+            cursor: not-allowed;
+            transform: none !important;
+        }
+
+        .btn:disabled:hover {
+            background: var(--primary-color) !important;
+            border-color: var(--primary-color) !important;
         }
 
         .action-btn {
@@ -331,20 +351,152 @@
             color: var(--text-primary);
         }
 
-        .form-control {
+        .form-control,
+        .form-input {
             width: 100%;
             padding: 8px 12px;
             border: 1px solid var(--divider-color);
             border-radius: 6px;
             font-size: 0.9rem;
+            transition: border-color 0.2s ease;
         }
 
-        .form-control:focus {
+        .form-control:focus,
+        .form-input:focus {
             outline: none;
             border-color: var(--primary-color);
             box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.1);
         }
 
+        .form-select {
+            width: 100%;
+            padding: 8px 12px;
+            border: 1px solid var(--divider-color);
+            border-radius: 6px;
+            font-size: 0.9rem;
+            background-color: var(--surface-color);
+            cursor: pointer;
+            transition: border-color 0.2s ease;
+        }
+
+        .form-select:focus {
+            outline: none;
+            border-color: var(--primary-color);
+            box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.1);
+        }
+
+        .form-label {
+            display: block;
+            margin-bottom: 4px;
+            font-weight: 500;
+            color: var(--text-primary);
+        }
+
+        .help-text {
+            margin-top: 4px;
+            font-size: 0.85rem;
+            color: var(--text-secondary);
+        }
+
+        .add-source-form {
+            background: var(--surface-color);
+            border-radius: 12px;
+            padding: 24px;
+            margin-bottom: 24px;
+            border: 1px solid var(--divider-color);
+        }
+
+        .add-source-form h3 {
+            margin: 0 0 20px 0;
+            color: var(--text-primary);
+            font-size: 1.2rem;
+        }
+
+        /* ===== MODALS ===== */
+        .modal-overlay {
+            display: none;
+            position: fixed;
+            top: 0;
+            left: 0;
+            width: 100%;
+            height: 100%;
+            background: rgba(0, 0, 0, 0.5);
+            z-index: 1000;
+            backdrop-filter: blur(2px);
+        }
+
+        .modal-overlay.active {
+            display: flex;
+            align-items: center;
+            justify-content: center;
+        }
+
+        .modal {
+            background: var(--surface-color);
+            border-radius: 12px;
+            padding: 24px;
+            max-width: 500px;
+            width: 90%;
+            box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
+            border: 1px solid var(--divider-color);
+            max-height: 80vh;
+            overflow-y: auto;
+        }
+
+        .modal-header {
+            display: flex;
+            justify-content: space-between;
+            align-items: center;
+            margin-bottom: 20px;
+            padding-bottom: 16px;
+            border-bottom: 1px solid var(--divider-color);
+        }
+
+        .modal-title {
+            font-size: 1.25rem;
+            font-weight: 600;
+            color: var(--text-primary);
+            margin: 0;
+        }
+
+        .modal-close {
+            background: none;
+            border: none;
+            font-size: 1.5rem;
+            cursor: pointer;
+            color: var(--text-secondary);
+            padding: 4px;
+            border-radius: 4px;
+            transition: all 0.2s ease;
+        }
+
+        .modal-close:hover {
+            background: var(--surface-elevation-1);
+            color: var(--text-primary);
+        }
+
+        .modal-body {
+            margin-bottom: 20px;
+        }
+
+        .modal-footer {
+            display: flex;
+            gap: 12px;
+            justify-content: flex-end;
+            padding-top: 16px;
+            border-top: 1px solid var(--divider-color);
+        }
+
+        .modal-alert {
+            background: #fff3cd;
+            border: 1px solid #ffeaa7;
+            border-radius: 8px;
+            padding: 12px;
+            margin-bottom: 16px;
+            color: #856404;
+            font-size: 0.9rem;
+        }
+
         /* ===== UTILITIES ===== */
         .back-link {
             display: inline-block;