body{font-family:Arial,sans-serif;background-color:#fff;color:#2e2f42;padding:40px;display:flex;flex-direction:column;align-items:center}.container{text-align:center;margin-bottom:20px}.main-title{font-size:36px;font-weight:700;margin-bottom:12px}.back-link{display:inline-block;text-decoration:none;color:#4e75ff;font-size:16px;font-weight:500}input#datetime-picker{width:220px;padding:10px 14px;font-size:16px;border:1px solid #4e75ff;border-radius:4px;margin-right:10px;margin-top:44px}button[data-start]{padding:10px 20px;font-size:16px;font-weight:500;background-color:#4e75ff;color:#fff;border:none;border-radius:4px;cursor:pointer;transition:background-color .3s ease}button[data-start]:hover:not(:disabled){background-color:#6c8cff}button[data-start]:disabled{background-color:#cfcfcf;cursor:not-allowed}.timer{display:flex;gap:24px;margin-top:30px;justify-content:center}.field{display:flex;flex-direction:column;align-items:center;min-width:60px}.value{font-size:40px;font-weight:600;line-height:1.2;color:#2e2f42}.label{font-size:14px;font-weight:500;color:#2e2f42;text-transform:uppercase;margin-top:6px}