Loopcode/14css.html at main · Dharmandra-singh/Loopcode · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
<!DOCTYPE html>
<html lang="en">
<head>
<!-- Google tag (gtag.js) -->
<script async src="https://www.googletagmanager.com/gtag/js?id=G-D0ENCWPZL9"></script>
<script>
  window.dataLayer = window.dataLayer || [];
  function gtag(){dataLayer.push(arguments);}
  gtag('js', new Date());

  gtag('config', 'G-D0ENCWPZL9');
</script>
  <meta charset="UTF-8" />
  <meta name="viewport" content="width=device-width, initial-scale=1" />
  <title>14. CSS Variables (Custom Properties)</title>
  <style>
    * {
      margin: 0;
      padding: 0;
      box-sizing: border-box;
    }
    body {
      font-family: 'Poppins', sans-serif;
      background: #1cc9be;
      color: #222;
    }
    .section {
      background: rgba(255, 255, 255, 0.3);
      padding: 20px;
      margin: 25px auto;
      border-radius: 12px;
      max-width: 1000px;
      box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
    }
    h2, h3 {
      color: #333;
      margin-bottom: 15px;
    }
    p {
      font-size: 18px;
      margin-bottom: 20px;
      line-height: 1.7;
    }
    textarea {
      width: 100%;
      height: 170px;
      font-family: 'Courier New', monospace;
      font-size: 16px;
      padding: 14px;
      background-color: rgba(255, 255, 255, 0.95);
      border: 2px solid #ccc;
      border-radius: 10px;
      margin: 12px 0;
      color: #222;
      transition: all 0.3s ease;
      resize: vertical;
      box-shadow: inset 0 0 6px rgba(0, 0, 0, 0.1);
    }
    textarea:focus {
      outline: none;
      border-color: #00c6ff;
      box-shadow: 0 0 8px rgba(0, 198, 255, 0.5);
    }
    button {
      background: linear-gradient(135deg, #00c6ff, #0072ff);
      color: white;
      padding: 8px 18px;
      font-size: 15px;
      border: none;
      border-radius: 30px;
      cursor: pointer;
      transition: all 0.3s ease;
      box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
    }
    button:hover {
      transform: scale(1.05);
      box-shadow: 0 6px 14px rgba(0, 0, 0, 0.3);
    }
    iframe {
      width: 100%;
      height: 160px;
      border: 2px solid white;
      background: rgba(255, 255, 255, 0.9);
      border-radius: 10px;
      margin-top: 10px;
    }
  </style>
</head>
<body>
  <div class="section">
    <h2>14. CSS Variables (Custom Properties)</h2>

    <h3>I. Defining Variables</h3>
    <p><strong>Explanation:</strong> CSS Variables ko <code>--</code> se define kiya jata hai. Ye variables kisi selector (mostly <code>:root</code>) ke andar declare kiye jaate hain.</p>

    <textarea id="code1">
<style>
  :root {
    --main-color: #ff5733;
    --padding: 20px;
  }

  div {
    background-color: var(--main-color);
    padding: var(--padding);
    color: white;
  }
</style>

<div>This uses CSS Variables</div>
    </textarea>
    <button onclick="runCode('code1', 'output1')">Run Code</button>
    <iframe id="output1"></iframe>

    <h3>II. Using Variables in Styles</h3>
    <p><strong>Explanation:</strong> Variable ka use <code>var(--name)</code> se kiya jata hai. Aap ise background, font-size, padding, kisi bhi property me use kar sakte hain.</p>

    <textarea id="code2">
<style>
  :root {
    --box-size: 100px;
    --box-color: #28a745;
  }

  .box {
    width: var(--box-size);
    height: var(--box-size);
    background-color: var(--box-color);
  }
</style>

<div class="box"></div>
    </textarea>
    <button onclick="runCode('code2', 'output2')">Run Code</button>
    <iframe id="output2"></iframe>

    <h3>III. Global vs Local Scope</h3>
    <p><strong>Explanation:</strong> Agar variable <code>:root</code> me define hai to wo global hota hai, matlab poore document me use ho sakta hai. Agar kisi selector ke andar define hai to wo local variable hai.</p>

    <textarea id="code3">
<style>
  :root {
    --color: teal;
  }

  .global {
    color: var(--color);
  }

  .local {
    --color: red;
    color: var(--color);
  }
</style>

<p class="global">This is using global variable</p>
<p class="local">This is using local variable</p>
    </textarea>
    <button onclick="runCode('code3', 'output3')">Run Code</button>
    <iframe id="output3"></iframe>

    <h3>IV. Theming with Variables</h3>
    <p><strong>Explanation:</strong> CSS Variables ka use themes banane ke liye hota hai. Aap dark mode aur light mode easily toggle kar sakte hain sirf variable values badalkar.</p>

    <textarea id="code4">
<style>
  :root {
    --bg: white;
    --text: black;
  }

  body.dark {
    --bg: #222;
    --text: white;
  }

  .theme-box {
    background: var(--bg);
    color: var(--text);
    padding: 20px;
    border-radius: 10px;
  }
</style>

<div class="theme-box">Theme Example</div>
<script>
  document.body.classList.add("dark");
</script>
    </textarea>
    <button onclick="runCode('code4', 'output4')">Run Code</button>
    <iframe id="output4"></iframe>
  </div>

  <script>
    function runCode(textareaId, iframeId) {
      const code = document.getElementById(textareaId).value;
      const iframe = document.getElementById(iframeId);
      const doc = iframe.contentDocument || iframe.contentWindow.document;
      doc.open();
      doc.write(code);
      doc.close();
    }
  </script>
</body>
</html>