Добовил страницу ошибки

static/css/components/error.css

@@ -0,0 +1,29 @@
+.error {
+    display: flex;
+    align-items: center;
+    justify-content: space-between;
+}
+.not_found {
+    color: #f9b43b;
+    font-family: 'Gagalin';
+    padding-left: 100px;
+}
+.not_found-title {
+    font-size: 220px;
+    font-weight: 400;
+    line-height: 1.42;
+    margin: 0;
+}
+.not_found-text {
+    font-size: 79px;
+    font-weight: 400;
+    line-height: 1.42;
+    margin: 0;
+
+}
+.not_found-img {
+    height: 571px;
+}
+.img404 {
+    height: 100%;
+}

static/css/layout/fonts.css

@@ -35,4 +35,10 @@
     src: url('../../fonts/Roboto-Bold.woff') format('woff');
     font-weight: bold;
     font-style: normal;
+  }
+  @font-face {
+    font-family: 'Gagalin';
+    src: url('../../fonts/gagalin-regular-webfont.woff2') format('woff2');
+    font-weight: normal;
+    font-style: normal;
   }

static/css/main.css

@@ -3,6 +3,7 @@
 @import "layout/normalize.css";
 @import "components/footer.css";
 @import "components/header.css";
+@import "components/error.css";
 
 /* главная-- */