body { font-family: sans-serif; background: #f3f3f3; }
.container { width: 100%; max-width: 500px; margin: 100px auto; background: #fff; padding: 20px; border-radius: 8px; box-shadow: 0 0 10px rgba(0,0,0,0.1); box-sizing: border-box;}
.tabs { display: flex; justify-content: space-around; margin-bottom: 20px; }
.tab { padding: 10px 20px; cursor: pointer; border-bottom: 2px solid transparent; }
.tab.active { border-color: #3498db; font-weight: bold; }
.tab-content { display: none; }
.tab-content.active { display: block; }
input { width: 100%; padding: 10px; margin: 8px 0; border: 1px solid #ccc; border-radius: 4px; box-sizing: border-box; outline: none;}
button { width: 100%; padding: 10px; background: #3498db; color: white; border: none; border-radius: 4px; cursor: pointer; }
button:hover { background: #2980b9; }