@import url('https://fonts.googleapis.com/css2?family=DM+Sans:wght@400;500;600;700;800&display=swap');

:root{font-family:'DM Sans',-apple-system,BlinkMacSystemFont,'PingFang SC','Microsoft YaHei',sans-serif;color:#171d2b;background:#fff;font-synthesis:none}
*{box-sizing:border-box}
body{margin:0}
a{color:inherit;text-decoration:none}
[hidden]{display:none!important}
.visually-hidden{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
.site-header{height:86px;max-width:1180px;margin:auto;padding:0 30px;display:flex;align-items:center;justify-content:space-between}
.brand{display:inline-flex;align-items:center;gap:13px;font-size:18px;font-weight:800;line-height:1.08;letter-spacing:-.035em}
.brand-mark{width:42px;height:42px;display:grid;place-items:center;border-radius:50%;background:#161b20;color:#fff;font-size:22px;font-weight:600}
.brand-name{display:block}
.header-note{font-size:13px;font-weight:600;color:#4e5667}
.hero{max-width:720px;margin:0 auto;padding:95px 24px 122px;text-align:center}
h1{font-size:clamp(42px,5vw,60px);line-height:1.16;letter-spacing:-.055em;margin:0;font-weight:800;color:#171c2b}
.intro{font-size:19px;line-height:1.7;color:#626b79;margin:25px auto 0;max-width:610px}
.input-card{margin:51px auto 0;max-width:650px;padding:36px;background:#fff;border-radius:22px;box-shadow:0 10px 28px rgba(20,28,42,.1);border:1px solid #f5f6f8}
.input-row{display:flex;flex-direction:column;gap:17px}
.input-shell{height:66px;border:1px solid #edf0f4;border-radius:14px;display:flex;align-items:center;gap:13px;padding:0 19px;background:#fff;box-shadow:0 2px 5px rgba(20,28,42,.035)}
.input-shell:focus-within{border-color:#8caafd;box-shadow:0 0 0 3px #e9efff}
.search-icon{width:19px;height:19px;flex:none;border:2px solid #9ba4b4;border-radius:50%;position:relative;transform:scale(.82)}
.search-icon:after{content:'';width:9px;height:2px;background:#9ba4b4;position:absolute;right:-7px;bottom:-3px;transform:rotate(45deg);border-radius:2px}
input{min-width:0;width:100%;height:100%;border:0;outline:0;background:transparent;color:#1d2636;font-family:inherit;font-size:16px;font-weight:500}
input::placeholder{color:#9ba4b4}
button,.download{border:0;border-radius:14px;background:#85a4f4;color:#fff;font-family:inherit;font-size:19px;font-weight:600;cursor:pointer;display:inline-flex;align-items:center;justify-content:center;gap:14px;transition:background .15s,transform .15s}
button{height:68px;width:100%}
button:hover,.download:hover{background:#6f93ef;transform:translateY(-1px)}
button:disabled{opacity:.7;cursor:wait;transform:none}
.button-icon{font-size:23px;line-height:1;font-weight:500}
.disclaimer{font-size:13px;line-height:1.8;color:#626b79;margin:30px auto 0;max-width:610px}
.message{margin:28px auto 0;max-width:650px;padding:15px 18px;text-align:left;background:#fff4f1;border:1px solid #f0d9d3;border-radius:12px;color:#9a4a3a;font-size:14px}
.result{margin:34px auto 0;max-width:650px;padding:24px;background:#fff;border:1px solid #e9ecf3;border-radius:20px;box-shadow:0 10px 28px rgba(20,28,42,.06);text-align:left}
.result-head{display:flex;justify-content:space-between;align-items:flex-end;gap:15px}
.result-kicker,.section-label{font-size:11px;font-weight:800;letter-spacing:.16em;color:#7f99da}
.result-head h2{font-size:24px;letter-spacing:-.04em;margin:5px 0 0}
.result-head a{font-size:12px;font-weight:700;color:#6d8fe8;white-space:nowrap}
.post-text{font-size:13px;line-height:1.7;color:#697284;margin:17px 0;white-space:pre-wrap;overflow-wrap:anywhere}
.video-list{display:grid;gap:11px}
.video-card{display:flex;align-items:center;gap:14px;padding:12px;background:#fafbff;border:1px solid #e8ecf5;border-radius:12px}
.video-card img{width:104px;height:70px;object-fit:cover;background:#eff2f8;border-radius:7px}
.video-info{flex:1;min-width:0}
.video-info strong{display:block;font-size:14px}
.video-info small{display:block;margin-top:4px;color:#8790a0;font-size:12px}
.download{height:42px;padding:0 17px;font-size:13px;border-radius:9px;white-space:nowrap}
.video-actions{display:flex;gap:8px;align-items:center}
.archive-button{width:auto;height:42px;padding:0 14px;font-size:13px;border-radius:9px;background:#eef2fd;color:#536fb3;white-space:nowrap}
.archive-button:hover{background:#dfe8fd}
.save-tip{max-width:650px;margin:28px auto 0;color:#7d8797;text-align:left;font-size:13px;line-height:1.8}
.save-tip summary{cursor:pointer;width:max-content;max-width:100%;margin:auto;color:#667288;text-decoration:underline;text-underline-offset:4px}
.save-tip p{max-width:590px;margin:12px auto 0;background:#f7f9fd;padding:14px 16px;border-radius:10px}
.how{border-top:1px solid #f0f2f6;padding:70px max(5vw,24px) 85px;display:grid;grid-template-columns:1fr 2fr;gap:50px;max-width:1200px;margin:auto}
.how h2{font-size:35px;letter-spacing:-.055em;margin:12px 0}
.steps{display:grid;grid-template-columns:repeat(3,1fr);gap:25px}
.steps article{border-top:1px solid #dae2f3;padding-top:14px}
.steps b{font-size:12px;color:#8ba8ee}
.steps h3{font-size:16px;margin:24px 0 8px}
.steps p{font-size:13px;line-height:1.8;color:#818a98;margin:0}
footer{padding:28px max(5vw,24px);border-top:1px solid #f0f2f6;display:flex;justify-content:space-between;gap:20px;color:#87909e;font-size:12px}
footer>span:first-child{font-weight:500;color:#87909e}
@media(max-width:720px){
  .site-header{height:74px;padding:0 21px}
  .brand{font-size:16px}
  .brand-mark{width:39px;height:39px;font-size:20px}
  .hero{padding:98px 20px 100px}
  h1{font-size:clamp(38px,10.7vw,47px);line-height:1.18}
  .intro{font-size:17px;line-height:1.65;margin-top:24px}
  .input-card{margin-top:47px;padding:27px 25px;border-radius:20px}
  .input-shell{height:57px;padding:0 15px}
  input{font-size:16px}
  button{height:59px;font-size:18px}
  .disclaimer{font-size:12px;line-height:1.7;margin-top:27px;padding:0 8px}
  .result{padding:19px}
  .video-card{flex-wrap:wrap;gap:10px}
  .video-card img{width:86px;height:64px}
  .video-actions{width:100%}
  .download,.archive-button{height:42px;flex:1;padding:0 8px}
  .save-tip{margin-top:23px}
  .how{display:block;padding:58px 23px}
  .how h2{font-size:30px}
  .steps{display:grid;grid-template-columns:1fr;gap:25px;margin-top:32px}
  .steps h3{margin:12px 0 5px}
  footer{padding:25px 22px;flex-direction:column;gap:8px}
}
@media(max-width:370px){
  .site-header{padding:0 17px}
  .hero{padding-left:16px;padding-right:16px}
  h1{font-size:38px}
  .input-card{padding:23px 18px}
  .header-note{font-size:12px}
}