:root{
  --bg:#0e1320; --card:#fff; --line:#e7eaf0; --grad:linear-gradient(135deg,#6d5efc,#9e6bff);
  --text:#1f2733; --muted:#7a869a;
}
*{box-sizing:border-box;margin:0;padding:0}
body.install-page{font-family:-apple-system,"Segoe UI",Roboto,"PingFang SC","Microsoft YaHei",sans-serif;
  background:radial-gradient(1200px 600px at 50% -10%,#1b2540,#0e1320);min-height:100vh;color:var(--text);
  display:flex;align-items:center;justify-content:center;padding:24px}
.install-shell{width:100%;max-width:520px}
.install-head{text-align:center;margin-bottom:22px}
.logo-mark{width:54px;height:54px;border-radius:14px;background:var(--grad);color:#fff;font-weight:800;
  font-size:24px;display:grid;place-items:center;margin:0 auto 14px;box-shadow:0 10px 30px rgba(110,94,252,.35)}
.install-head h1{color:#fff;font-size:24px;margin-bottom:6px}
.install-head p{color:#aeb9d0;font-size:14px}
.install-card{background:var(--card);border-radius:16px;padding:26px;box-shadow:0 20px 60px rgba(0,0,0,.35)}
.step{display:flex;gap:14px;padding:14px 0;border-bottom:1px dashed var(--line)}
.step:last-of-type{border-bottom:none}
.step-no{width:26px;height:26px;flex:none;border-radius:50%;background:var(--grad);color:#fff;font-weight:700;
  display:grid;place-items:center;font-size:13px}
.step-body{flex:1}
.step-body h3{font-size:15px;margin-bottom:10px}
.step-body label{display:block;font-size:13px;color:var(--muted);margin:12px 0 6px}
.step-body input,.step-body select{width:100%;padding:10px 12px;border:1px solid var(--line);border-radius:9px;
  font-size:14px;outline:none}
.step-body input:focus,.step-body select:focus{border-color:#6d5efc}
.hint{font-size:12px;color:var(--muted);margin-top:6px;line-height:1.5}
.hint code{background:#f3f4f8;padding:2px 6px;border-radius:5px;color:#d6336c}
.form-msg.bad{color:#dc3645;font-size:13px;margin:12px 0 0}
.btn-primary.submit{width:100%;margin-top:18px;padding:13px;border:none;border-radius:10px;background:var(--grad);
  color:#fff;font-size:15px;font-weight:600;cursor:pointer}
.btn-primary.submit:hover{opacity:.92}
.install-foot{text-align:center;color:#8b97b3;font-size:12px;margin-top:18px}