*{margin:0;padding:0;box-sizing:border-box}body{font-family:Arial,sans-serif;background-color:#f0f0f0;padding:40px}main{display:flex;justify-content:center;align-items:center;min-height:100vh}.container{background-color:#fff;padding:30px;border-radius:10px;box-shadow:0 4px 12px #0000001a;max-width:500px;width:100%}h2{text-align:center;margin-bottom:20px;color:#333}#datetime-picker{width:100%;padding:10px 15px;font-size:16px;border:1px solid #ccc;border-radius:4px;box-sizing:border-box;margin-bottom:15px}.start-btn{width:100%;padding:12px;font-size:16px;background-color:#007bff;color:#fff;border:none;border-radius:4px;cursor:pointer;transition:background-color .3s}.start-btn:disabled{background-color:#ccc;cursor:not-allowed}.timer{display:flex;justify-content:space-around;margin-top:30px}.field{text-align:center;font-family:Courier New,Courier,monospace}.value{display:block;font-size:48px;color:#333;margin-bottom:5px}.label{font-size:14px;color:#666}.form{max-width:300px;margin:20px auto;padding:20px;border:2px solid #ddd;border-radius:10px;background-color:#fafafa;display:flex;flex-direction:column;gap:15px}label{font-weight:700;display:flex;flex-direction:column;font-size:14px}input[type=number]{padding:8px;font-size:14px;border:1px solid #ccc;border-radius:4px}fieldset.state{display:flex;gap:30px;align-items:center;border:none;padding:0;margin-top:10px}fieldset.state label{display:flex;align-items:center;gap:8px;font-size:14px}legend{font-weight:700;font-size:16px;margin-bottom:8px}label input[type=radio]{margin-right:8px}label span{margin-right:15px}.create-btn{padding:10px;font-size:14px;color:#fff;background-color:#28a745;border:none;border-radius:6px;cursor:pointer;font-weight:700;transition:background-color .3s}.create-btn:hover{background-color:#218838}.create-btn:disabled{background-color:#999;cursor:not-allowed}