body {
                background: #f7fbff;
                margin: 0;
                font-family: "Segoe UI", Arial, sans-serif;
                color: #234;
                display: flex;
                flex-direction: column;
                align-items: center;
                min-height: 100vh;
            }
            .container {
                margin: 42px auto 0 auto;
                max-width: 480px;
                background: #fff;
                border-radius: 18px;
                box-shadow: 0 4px 22px #13d2b033;
                padding: 28px 15px 18px 15px;
                width: 95vw;
                min-width: 270px;
            }
            .logo {
                font-size: 1.22em;
                font-weight: bold;
                text-align: center;
                color: #1763a8;
                margin-bottom: 9px;
                letter-spacing: 0.01em;
            }
            .desc {
                text-align: center;
                color: #2172a2;
                margin-bottom: 17px;
                font-size: 1.04em;
            }
            textarea {
                width: 100%;
                min-height: 90px;
                border-radius: 8px;
                border: 1.2px solid #bde0fc;
                padding: 11px;
                font-size: 1.07em;
                background: #fafdff;
                color: #234;
                resize: vertical;
                margin-bottom: 10px;
                box-sizing: border-box;
            }
            .options {
                display: flex;
                gap: 10px;
                margin-bottom: 13px;
                align-items: center;
                flex-wrap: wrap;
            }
            .options label {
                font-size: 1em;
                color: #206589;
                background: #eef8fd;
                border-radius: 6px;
                padding: 5px 13px 5px 8px;
                cursor: pointer;
                display: flex;
                align-items: center;
                font-weight: 500;
                border: 1px solid #bde0fc;
                transition:
                    background 0.13s,
                    border 0.13s;
            }
            .options input[type="radio"] {
                margin-right: 6px;
                accent-color: #1763a8;
            }
            .result-block {
                background: #f4f7fd;
                border: 1.2px solid #bfe1fa;
                border-radius: 9px;
                padding: 15px 10px 11px 10px;
                margin-bottom: 8px;
                color: #185490;
                font-size: 1.11em;
                min-height: 44px;
                word-break: break-all;
                position: relative;
            }
            .copy-btn {
                position: absolute;
                top: 8px;
                right: 14px;
                background: #19b16e;
                color: #fff;
                border: none;
                border-radius: 6px;
                padding: 6px 13px;
                cursor: pointer;
                font-size: 0.97em;
                font-weight: bold;
                box-shadow: 0 2px 8px #14b26e11;
                transition: background 0.13s;
            }
            .copy-btn:active {
                background: #116847;
            }
            .footer {
                color: #789;
                text-align: center;
                font-size: 0.93em;
                margin-top: 19px;
            }
            #backBtn {
                position: fixed;
                left: 50%;
                bottom: 32px;
                transform: translateX(-50%);
                background: #1763a8;
                color: #fff;
                font-weight: 700;
                border: none;
                border-radius: 2rem;
                padding: 0.58em 1.5em;
                box-shadow: 0 4px 16px #13d2b066;
                font-size: 1.09em;
                text-decoration: none;
                cursor: pointer;
                letter-spacing: 0.01em;
                transition:
                    background 0.15s,
                    transform 0.12s;
                z-index: 2000;
            }
            #backBtn:hover {
                background: #0f3e66;
                transform: translateX(-50%) scale(1.04);
            }
            @media (max-width: 600px) {
                .container {
                    padding: 11px 2vw 11px 2vw;
                }
                .logo {
                    font-size: 1.08em;
                }
                #backBtn {
                    bottom: 18px;
                    font-size: 0.98em;
                    padding: 0.48em 1em;
                }
                .result-block {
                    font-size: 0.99em;
                }
                .options label {
                    font-size: 0.98em;
                }
            }