arregla el logo y la imagen de fondo para todos los tamaños de pantalla, es lo mas parecido que me quedó al original

public/style/style.css

@@ -97,37 +97,19 @@ hr.separador{
 { margin-left: auto;
   margin-right: auto;}
 
-#main
-{ /*padding-bottom: 40px;*/}
+.jumbotron{background:transparent;margin-bottom:0;}
 
-#header
-{ /*background: transparent url(logo.jpg) no-repeat;*/
-  /*background-color: #FC9C04;*/
-}
-.jumbotron{
-  margin-bottom: 0px;
-  background:transparent;
-
-}
-
-#logo
-{ 
+.logopic{
+  width:700px; 
+  display:block;
+  margin:auto;
+ 
   
-  /*height: 600px;*/
-  
-  padding:10px 0px;
-  background:transparent;
+}
 
-}
-#logo_text{
-  margin-top:20px;
-  margin-bottom:20px;
-  /*text-shadow: #444 0 1px 1px;*/
-}
-#logo_text h1.title{
-  text-shadow: #ccc 1px 1px 10px;
-}
+.logo-container{margin-top:70px;}
 h2.subtitle{
+  margin-top:180px;
   text-shadow: #333 2px 2px 1px;
   color:white;
   font-weight: normal;
@@ -135,10 +117,17 @@ h2.subtitle{
   border-bottom: 0;
   text-transform: none;
   font-size:2em;
-  margin: 0;
+ 
+
 
 }
 
+@media screen and (max-width: 480px){
+  
+  .logopic{width:320px;}
+  .logo-container{margin:0}
+  h2.subtitle{font-size:14px;margin-top:70px}
+}
 /*h2#when{margin-top:10px!important;}
 
 h2#where{

templates/header.html

@@ -2,23 +2,13 @@
   <!--<div class="bg"></div>-->
   
   <div id="logo" class="jumbotron" data-parallax="scroll" data-position="center" data-natural-height="1000" data-natural-width="1920" data-image-src="img/headerpic2.jpg">
-    <div style="height:450px;"></div>
-    <!--<div id="logo_text">
-
+    <div  class="logo-container">
+      <img class="logopic" src="img/logo-clam.png">
       
-      <h1 class="title"><a href="/"><span class="logo_colour"> CLAM 2020</span></a></h1>
-
-      <h2 class="subtitle">
-        <strong>VI Congreso Latinoamericano de Matemáticos</strong><br>
-      </h2>-->
-
-      <h2 id="when" class="subtitle">
-        20 al 24 de julio de 2020 <span style="color:#00b1d7">/</span> Montevideo, Uruguay
-      </h2>
-      <!--<h2 id="where" class="subtitle">
-        <strong>Montevideo, Uruguay</strong>
-      </h2>
-    </div>-->
+    </div>
+    <h2 id="when" class="subtitle">
+      20 al 24 de julio de 2020 <span style="color:#00b1d7">/</span> Montevideo, Uruguay
+    </h2>
   </div>
   <nav class="navbar navbar-inverse " id="menubar">
     <div class="container-fluid">