refactor(app): make a bit more neat structure

src/app/@theme/components/search-input/_search-input.component.theme.scss

@@ -0,0 +1,7 @@
+@mixin search-input-theme() {
+  /deep/ search-input {
+    input {
+      background: transparent;
+    }
+  }
+}

src/app/@theme/components/search-input/search-input.component.scss

@@ -0,0 +1,27 @@
+:host {
+  display: flex;
+  align-items: center;
+
+  i.control-icon {
+    &:before {
+      font-size: 2.3rem;
+    }
+
+    &:hover {
+      cursor: pointer;
+    }
+  }
+
+  input {
+    border: none;
+    outline: none;
+    margin-left: 1rem;
+    width: 15rem;
+    transition: width 0.2s ease;
+
+    &.hidden {
+      width: 0;
+      margin: 0;
+    }
+  }
+}

src/app/@theme/components/search-input/search-input.component.ts

@@ -0,0 +1,35 @@
+import { Component, ElementRef, EventEmitter, Output, ViewChild } from '@angular/core';
+
+@Component({
+  selector: 'search-input',
+  styleUrls: ['./search-input.component.scss'],
+  template: `
+    <i class="control-icon ion ion-ios-search"
+       (click)="showInput()"></i>
+    <input placeholder="Type your search request here..."
+           #input
+           [class.hidden]="!isInputShown"
+           (blur)="hideInput()"
+           (input)="onInput($event)">
+  `,
+})
+export class SearchInputComponent {
+  @ViewChild('input') input: ElementRef;
+
+  @Output() search: EventEmitter<string> = new EventEmitter<string>();
+
+  isInputShown: boolean = false;
+
+  showInput() {
+    this.isInputShown = true;
+    this.input.nativeElement.focus();
+  }
+
+  hideInput() {
+    this.isInputShown = false;
+  }
+
+  onInput(val: string) {
+    this.search.emit(val);
+  }
+}