diff --git a/src/AudioWidget.js b/src/AudioWidget.js
deleted file mode 100644
index a1b8937..0000000
--- a/src/AudioWidget.js
+++ /dev/null
@@ -1,92 +0,0 @@
-import React, { Component } from 'react';
-import load from 'load-script';
-
-window.audio_cache = {};
-
-function load_amrnb() {
-  return new Promise((resolve, reject) => {
-    if (window.AMR) resolve();
-    else
-      load('static/amr_all.min.js', (err) => {
-        if (err) reject(err);
-        else resolve();
-      });
-  });
-}
-
-export class AudioWidget extends Component {
-  constructor(props) {
-    super(props);
-    this.state = {
-      url: this.props.src,
-      state: 'waiting',
-      data: null,
-    };
-  }
-
-  load() {
-    if (window.audio_cache[this.state.url]) {
-      this.setState({
-        state: 'loaded',
-        data: window.audio_cache[this.state.url],
-      });
-      return;
-    }
-
-    console.log('fetching audio', this.state.url);
-    this.setState({
-      state: 'loading',
-    });
-    Promise.all([fetch(this.state.url), load_amrnb()]).then((res) => {
-      res[0].blob().then((blob) => {
-        const reader = new FileReader();
-        reader.onload = (event) => {
-          const raw = new window.AMR().decode(event.target.result);
-          if (!raw) {
-            alert('audio decoding failed');
-            return;
-          }
-          const wave = window.PCMData.encode({
-            sampleRate: 8000,
-            channelCount: 1,
-            bytesPerSample: 2,
-            data: raw,
-          });
-          const binary_wave = new Uint8Array(wave.length);
-          for (let i = 0; i < wave.length; i++)
-            binary_wave[i] = wave.charCodeAt(i);
-
-          const objurl = URL.createObjectURL(
-            new Blob([binary_wave], { type: 'audio/wav' }),
-          );
-          window.audio_cache[this.state.url] = objurl;
-          this.setState({
-            state: 'loaded',
-            data: objurl,
-          });
-        };
-        reader.readAsBinaryString(blob);
-      });
-      this.setState({
-        state: 'decoding',
-      });
-    });
-  }
-
-  render() {
-    if (this.state.state === 'waiting')
-      return (
-        <p>
-          <a onClick={this.load.bind(this)}>加载音频</a>
-        </p>
-      );
-    if (this.state.state === 'loading') return <p>正在下载……</p>;
-    else if (this.state.state === 'decoding') return <p>正在解码……</p>;
-    else if (this.state.state === 'loaded')
-      return (
-        <p>
-          <audio src={this.state.data} controls />
-        </p>
-      );
-  }
-}
diff --git a/src/infrastructure/appicon/course_survey.png b/src/infrastructure/appicon/course_survey.png
deleted file mode 100644
index a2ea2e3..0000000
Binary files a/src/infrastructure/appicon/course_survey.png and /dev/null differ
diff --git a/src/infrastructure/appicon/dropdown.png b/src/infrastructure/appicon/dropdown.png
deleted file mode 100644
index 0ac094a..0000000
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diff --git a/src/infrastructure/appicon/dropdown_rev.png b/src/infrastructure/appicon/dropdown_rev.png
deleted file mode 100644
index ad14288..0000000
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diff --git a/src/infrastructure/appicon/hole.png b/src/infrastructure/appicon/hole.png
deleted file mode 100644
index 3089e7b..0000000
Binary files a/src/infrastructure/appicon/hole.png and /dev/null differ
diff --git a/src/infrastructure/appicon/homepage.png b/src/infrastructure/appicon/homepage.png
deleted file mode 100644
index c5cd092..0000000
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diff --git a/src/infrastructure/appicon/imasugu.png b/src/infrastructure/appicon/imasugu.png
deleted file mode 100644
index 43c0bd7..0000000
Binary files a/src/infrastructure/appicon/imasugu.png and /dev/null differ
diff --git a/src/infrastructure/appicon/imasugu_rev.png b/src/infrastructure/appicon/imasugu_rev.png
deleted file mode 100644
index dc2e505..0000000
Binary files a/src/infrastructure/appicon/imasugu_rev.png and /dev/null differ
diff --git a/src/infrastructure/appicon/score.png b/src/infrastructure/appicon/score.png
deleted file mode 100644
index 105a4c1..0000000
Binary files a/src/infrastructure/appicon/score.png and /dev/null differ
diff --git a/src/infrastructure/appicon/syllabus.png b/src/infrastructure/appicon/syllabus.png
deleted file mode 100644
index 4ea1557..0000000
Binary files a/src/infrastructure/appicon/syllabus.png and /dev/null differ
diff --git a/src/infrastructure/elevator.js b/src/infrastructure/elevator.js
deleted file mode 100644
index 0ee93a4..0000000
--- a/src/infrastructure/elevator.js
+++ /dev/null
@@ -1,47 +0,0 @@
-const DUMP_VER='dump_v1';
-
-function dump() {
-    return JSON.stringify({
-        _dump_ver: DUMP_VER,
-        token: localStorage['TOKEN']||null,
-        hole_config: localStorage['hole_config']||null,
-    });
-}
-function load(s) {
-    console.log('elevator: loading',s);
-    let obj=JSON.parse(s);
-    if(obj._dump_ver!==DUMP_VER) {
-        console.error('elevator: loading version mismatch, current',DUMP_VER,'param',obj._dump_ver);
-        return;
-    }
-    if(localStorage['TOKEN']===undefined && obj.token) {
-        console.log('replace token');
-        localStorage['TOKEN']=obj.token;
-    }
-    if(localStorage['hole_config']===undefined && obj.hole_config) {
-        console.log('replace hole config');
-        localStorage['hole_config']=obj.hole_config;
-    }
-}
-
-export function elevate() {
-    // load
-    // '?foo=fo&bar=ba' -> [["foo","fo"],["bar","ba"]]
-    let params=window.location.search.substr(1).split('&').map((kv)=>kv.split('='));
-    params.forEach((kv)=>{
-        if(kv.length===2 && kv[0]==='_elevator_data') {
-            load(decodeURIComponent(kv[1]));
-            let url=new URL(window.location.href);
-            url.search='';
-            window.history.replaceState('','',url.href);
-        }
-    });
-
-    // dump
-    if(window.location.protocol==='http:' && window.location.hostname==='pkuhelper.pku.edu.cn') {
-        let url=new URL(window.location.href);
-        url.protocol='https:';
-        url.search='?_elevator_data='+encodeURIComponent(dump());
-        window.location.replace(url.href);
-    }
-}
\ No newline at end of file
diff --git a/src/infrastructure/widgets.js b/src/infrastructure/widgets.js
index c73385b..0cc1960 100644
--- a/src/infrastructure/widgets.js
+++ b/src/infrastructure/widgets.js
@@ -8,15 +8,6 @@ import buildFormatter from 'react-timeago/lib/formatters/buildFormatter';
 import './global.css';
 import './widgets.css';
 
-import appicon_hole from './appicon/hole.png';
-import appicon_imasugu from './appicon/imasugu.png';
-import appicon_imasugu_rev from './appicon/imasugu_rev.png';
-import appicon_syllabus from './appicon/syllabus.png';
-import appicon_score from './appicon/score.png';
-import appicon_course_survey from './appicon/course_survey.png';
-import appicon_dropdown from './appicon/dropdown.png';
-import appicon_dropdown_rev from './appicon/dropdown_rev.png';
-import appicon_homepage from './appicon/homepage.png';
 import {get_json, API_VERSION_PARAM} from './functions';
 
 function pad2(x) {