website: optimize logo size

fixes #110

website/Makefile

@@ -2,7 +2,9 @@ all: clean
 	node install.js
 	python3 filter.py
 	cp ../assets/cover-2nd.png ./src/modern-cpp/assets/cover-2nd.png
+	cp ../assets/cover-2nd-logo.png ./src/modern-cpp/assets/cover-2nd-logo.png
 	cp ../assets/cover-2nd-en.png ./src/modern-cpp/assets/cover-2nd-en.png
+	cp ../assets/cover-2nd-en-logo.png ./src/modern-cpp/assets/cover-2nd-en-logo.png
 	cp ../assets/alipay.jpg ./src/modern-cpp/assets/alipay.jpg
 	cp ../assets/wechat.jpg ./src/modern-cpp/assets/wechat.jpg
 	cp ../assets/donate.md ./src/modern-cpp/about/
@@ -16,6 +18,9 @@ s: all
 	node_modules/serve/bin/serve.js ./public
 clean:
 	rm -rf ./src/modern-cpp/assets/cover-2nd.png \
+		./src/modern-cpp/assets/cover-2nd-en.png \
+		./src/modern-cpp/assets/cover-2nd-logo.png \
+		./src/modern-cpp/assets/cover-2nd-en-logo.png \
 		./src/modern-cpp/assets/figures \
 		./src/modern-cpp/assets/alipay.jpg \
 		./src/modern-cpp/assets/wechat.jpg \

website/themes/moderncpp/layout/partials/header.ejs

@@ -1,10 +1,10 @@
 <div id="header">
   <a id="logo" href="<%- url_for("/modern-cpp/") %>">
     <% if (page.type == 'book-en-us') { %>
-      <img src="<%- url_for("/modern-cpp/assets/cover-2nd-en.png") %>">
+      <img src="<%- url_for("/modern-cpp/assets/cover-2nd-en-logo.png") %>">
       <span>Modern C++ Tutorial: C++ 11/14/17/20 On the Fly</span>
     <% } else {%>
-      <img src="<%- url_for("/modern-cpp/assets/cover-2nd.png") %>">
+      <img src="<%- url_for("/modern-cpp/assets/cover-2nd-logo.png") %>">
       <span>现代 C++ 教程：高速上手 C++ 11/14/17/20</span>
     <% } %>
   </a>

website/themes/moderncpp/source/modern-cpp/css/_header.styl

@@ -138,7 +138,7 @@ body.docs
     position: absolute
     width: 25px
     height: 30px
-    background: url(../assets/cover-2nd-en.png) center center no-repeat
+    background: url(../assets/cover-2nd-en-logo.png) center center no-repeat
     background-size: auto 100%
     top: 12px
     right: 12px