:root{
  --bg:#f6f7fb; --card:#ffffff; --ink:#1c2333; --muted:#667; --brand:#3b6ef6;
  --brand-2:#6c4df6; --line:#e5e8f0; --ok:#16a34a; --danger:#dc2626; --warn:#d97706;
  --radius:16px; --shadow:0 10px 30px rgba(28,35,51,.08);
}
*{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
body{margin:0;background:var(--bg);color:var(--ink);font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",Roboto,Helvetica,Arial,sans-serif;line-height:1.6}
.container{max-width:860px;margin:0 auto;padding:0 16px}
a{color:var(--brand);text-decoration:none}
button{font-family:inherit}

/* header */
.site-header{background:var(--card);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:10}
.header-inner{display:flex;align-items:center;gap:18px;height:60px}
.brand{display:flex;align-items:center;gap:10px;color:var(--ink)}
.brand-logo{width:34px;height:34px;border-radius:9px;background:linear-gradient(135deg,var(--brand),var(--brand-2));color:#fff;display:flex;align-items:center;justify-content:center;font-size:14px;flex:none}
.brand-text{display:flex;flex-direction:column;line-height:1.15}
.brand-name{font-weight:800;font-size:17px}
.brand-tag{font-size:11px;color:var(--muted)}
.site-nav{margin-left:auto;display:flex;gap:4px}
.site-nav a{padding:7px 10px;border-radius:8px;color:var(--ink);font-weight:600;font-size:14px}
.site-nav a:hover{background:#eef2ff}
.site-nav a.active{background:linear-gradient(135deg,var(--brand),var(--brand-2));color:#fff}
.site-nav a.active:hover{background:linear-gradient(135deg,var(--brand),var(--brand-2));color:#fff}
.lang-link{padding:6px 10px;border:1px solid var(--line);border-radius:999px;font-size:13px;color:var(--ink)}
.lang-picker{display:flex;align-items:center;gap:6px;flex:none}
.lang-icon{width:16px;height:16px;flex:none;fill:none;stroke:var(--muted);stroke-width:1.8;stroke-linecap:round;stroke-linejoin:round}
.lang-select{border:1px solid var(--line);border-radius:999px;background:var(--card);color:var(--ink);font:inherit;font-size:13px;padding:6px 8px;cursor:pointer;max-width:126px;font-family:inherit}
.lang-select:focus{outline:none;border-color:var(--brand)}

main{padding:28px 0 8px}
/* hero */
.hero{text-align:center;padding:34px 0 10px}
.hero h1{font-size:clamp(24px,4.6vw,40px);margin:.2em 0;letter-spacing:-.5px}
.subtitle{color:var(--muted);font-size:16px;max-width:560px;margin:6px auto 0}
.platform-hero{text-align:center;padding:20px 0 4px}
.platform-badge{width:54px;height:54px;margin:0 auto 6px;border-radius:14px;display:flex;align-items:center;justify-content:center;color:#fff;font-weight:800;font-size:22px}
.platform-badge[data-platform="bilibili"]{background:#00a1d6}
.platform-badge[data-platform="douyin"]{background:linear-gradient(135deg,#25f4ee 0 47%,#111 47% 53%,#fe2c55 53%)}
.platform-badge[data-platform="vimeo"]{background:#1ab7ea}
.platform-badge[data-platform="pinterest"]{background:#e60023}
.platform-hero h1{font-size:clamp(22px,3.8vw,34px);margin:.1em 0}
.platform-hero .intro{color:var(--muted);max-width:640px;margin:6px auto}
.back-link{display:inline-block;margin:6px 0;font-size:14px}

/* parse box */
.parse-section{max-width:680px;margin:26px auto 0}
.parse-form{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:14px}
.parse-row{display:flex;gap:10px}
.parse-row input{flex:1;min-width:0;border:1px solid var(--line);border-radius:12px;padding:14px 16px;font-size:16px;outline:none}
.parse-row input:focus{border-color:var(--brand);box-shadow:0 0 0 3px rgba(59,110,246,.15)}
.parse-row button{border:none;background:linear-gradient(135deg,var(--brand),var(--brand-2));color:#fff;font-size:16px;font-weight:700;padding:0 26px;border-radius:12px;cursor:pointer}
.parse-row button:disabled{opacity:.6;cursor:not-allowed}
.hint{color:var(--muted);font-size:12px;margin:6px 0 0}
.note{color:var(--muted);font-size:13px;margin:14px auto;max-width:640px}

/* result */
.result{margin-top:20px;text-align:left}
.result .status-line{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:14px 16px;display:flex;align-items:center;gap:12px;box-shadow:var(--shadow)}
.spinner{width:18px;height:18px;border:3px solid #dfe5f5;border-top-color:var(--brand);border-radius:50%;animation:spin .8s linear infinite;flex:none}
@keyframes spin{to{transform:rotate(360deg)}}
.result .error{background:#fef2f2;border:1px solid #fecaca;color:var(--danger);border-radius:12px;padding:14px 16px}
.result .error small{display:block;color:var(--muted);margin-top:6px;word-break:break-all}

.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);overflow:hidden;display:flex;flex-direction:column}
.card-cover{background:#000}
.card-cover img{width:100%;max-height:340px;object-fit:cover;display:block;aspect-ratio:16/9}
.card-main{padding:18px}
.video-title{font-size:19px;margin:0 0 8px;line-height:1.4}
.video-meta{display:flex;flex-wrap:wrap;gap:6px;color:var(--muted);font-size:13px;margin-bottom:14px}
.chip{background:#eef2ff;color:#3b4dbd;border-radius:999px;padding:2px 10px}
.field-title{font-weight:700;font-size:14px;margin:4px 0 8px}
.group-title{font-weight:700;font-size:13px;color:var(--muted);margin:16px 0 2px}
.fmt-row{display:flex;justify-content:space-between;align-items:center;gap:12px;flex-wrap:wrap;border:1px solid var(--line);border-radius:12px;padding:10px 12px;margin-top:8px}
.fmt-info{display:flex;align-items:baseline;gap:8px;min-width:120px;flex-wrap:wrap}
.fmt-info strong{font-size:15px;display:flex;align-items:center;gap:6px}
.fmt-actions{display:flex;align-items:center;gap:8px;flex-wrap:wrap}
.muted{color:var(--muted);font-size:13px}
.split-note{color:var(--warn);font-size:12px}
.badge-reco{background:#ecfdf5;color:var(--ok);border:1px solid #bbf7d0;border-radius:999px;font-size:11px;padding:1px 8px;font-weight:600}
.btn-sm{padding:7px 13px;font-size:13px;border-radius:9px}
.actions{display:flex;flex-wrap:wrap;gap:10px;margin-top:16px}
.btn{border:none;border-radius:12px;padding:12px 22px;font-size:15px;font-weight:700;cursor:pointer;display:inline-flex;align-items:center;gap:8px}
.btn-primary{background:linear-gradient(135deg,var(--brand),var(--brand-2));color:#fff}
.btn-primary:disabled{opacity:.6;cursor:not-allowed}
.btn-ghost{background:#fff;border:1px solid var(--line);color:var(--ink)}
.btn-success{background:var(--ok);color:#fff}

/* task progress */
.task-panel{margin-top:18px;background:var(--card);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:18px}
.task-head{display:flex;justify-content:space-between;align-items:center;gap:12px;font-weight:600;flex-wrap:wrap}
.progress-track{height:10px;background:#e8ebf4;border-radius:999px;overflow:hidden;margin-top:12px}
.progress-bar{height:100%;width:0%;background:linear-gradient(90deg,var(--brand),var(--brand-2));transition:width .4s ease;border-radius:999px}
.task-file{margin-top:14px;display:flex;align-items:center;gap:12px;flex-wrap:wrap}

/* advertising */
.native-ad{max-width:728px;margin:26px auto 0;text-align:center;overflow:hidden}
.native-ad > div{max-width:100%}

/* sections */
.section-title{font-size:22px;margin:40px 0 4px;text-align:center}
.section-desc{text-align:center;color:var(--muted);margin:0 0 18px}
.howto-tabs{display:flex;justify-content:center;flex-wrap:wrap;gap:8px;margin:16px 0 4px}
.howto-tab{border:1px solid var(--line);background:var(--card);color:var(--muted);font:inherit;font-size:14px;font-weight:600;padding:8px 22px;border-radius:999px;cursor:pointer;transition:background .15s ease,color .15s ease,border-color .15s ease}
.howto-tab:hover{color:var(--brand);border-color:var(--brand)}
.howto-tab.is-active{background:linear-gradient(135deg,var(--brand),var(--brand-2));border-color:transparent;color:#fff}
.howto-panel{display:none}
.howto-panel.is-active{display:block;animation:fadeIn .18s ease}
@keyframes fadeIn{from{opacity:0;transform:translateY(4px)}to{opacity:1;transform:none}}
.steps{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:16px;margin-top:18px}
.step{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;position:relative;display:flex;flex-direction:column;padding:0 0 18px;min-width:0}
.step-img{display:block;width:100%;max-width:100%;height:auto;aspect-ratio:4/3;background:#eef1f7}
.step img{max-width:100%}
.step-num{position:absolute;top:12px;left:12px;width:28px;height:28px;border-radius:50%;background:linear-gradient(135deg,var(--brand),var(--brand-2));color:#fff;display:flex;align-items:center;justify-content:center;font-size:14px;font-weight:700;box-shadow:0 2px 8px rgba(28,35,51,.22)}
.step-body{padding:16px 18px 0}
.step h3{margin:0 0 4px;font-size:16px}
.step p{margin:0;color:var(--muted);font-size:14px}
.platform-cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:14px;margin-top:10px}
.platform-card{display:flex;align-items:center;gap:14px;background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:18px;color:var(--ink);transition:transform .12s ease,box-shadow .12s ease}
.platform-card:hover{transform:translateY(-2px);box-shadow:var(--shadow)}
.platform-icon{width:46px;height:46px;border-radius:12px;display:flex;align-items:center;justify-content:center;color:#fff;font-weight:800;font-size:20px;flex:none}
.platform-icon.bili{background:#00a1d6}
.platform-icon.douyin{background:linear-gradient(135deg,#25f4ee 0 47%,#111 47% 53%,#fe2c55 53%)}
.platform-icon.vimeo{background:#1ab7ea}
.platform-info{display:flex;flex-direction:column;min-width:0}
.platform-info strong{font-size:16px}
.platform-info small{color:var(--muted);font-size:13px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}

/* platform content */
.seo-content{max-width:760px;margin:0 auto}
.seo-intro{color:var(--muted);text-align:center;margin:0 auto 18px;font-size:15px}
.seo-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:14px}
.seo-card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:18px 20px;box-shadow:var(--shadow)}
.seo-card h3{margin:0 0 8px;font-size:17px}
.seo-card p{margin:0;color:var(--muted);font-size:14px}

/* faq */
.faq details{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:14px 18px;margin-top:10px}
.faq summary{cursor:pointer;font-weight:600}
.faq p{margin:10px 0 0;color:var(--muted);font-size:14px}

/* footer */
.site-footer{margin-top:44px;background:var(--card);border-top:1px solid var(--line);padding:26px 0}
.disclaimer{color:var(--muted);font-size:13px;max-width:760px;margin:0 auto 8px;text-align:center}
.copyright{color:var(--muted);font-size:12px;text-align:center;margin:0}

@media (max-width:600px){
  .header-inner{height:auto;min-height:60px;flex-wrap:wrap;padding-top:8px;padding-bottom:8px;gap:4px 18px}
  .brand{order:1}
  .lang-picker{order:2;margin-left:auto}
  .site-nav{order:3;width:100%;margin-left:0;justify-content:center}
  .parse-row{flex-direction:column}
  .parse-row button{padding:13px}
  .site-nav a{padding:6px 8px;font-size:13px}
  .brand-tag{display:none}
  .card-main{padding:14px}
}