body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: #f4f6fb;
  color: #1c2333;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  padding: 20px;
}
.box {
  background: white;
  border-radius: 12px;
  box-shadow: 0 10px 30px rgba(20,30,60,0.08);
  padding: 32px;
  max-width: 460px;
  width: 100%;
}
h1 { font-size: 20px; margin: 0 0 8px; }
p.sub { color: #6b7385; font-size: 14px; margin-top: 0; }
label { display: block; font-size: 13px; color: #4a5266; margin: 14px 0 4px; }
input[type=text], input[type=email] {
  width: 100%; padding: 10px 12px; border-radius: 8px; border: 1px solid #dde1ea; font-size: 14px;
}
.btn {
  display: inline-block; background: #4c6fff; color: white; border: none;
  padding: 11px 18px; border-radius: 8px; cursor: pointer; font-size: 14px; margin-top: 18px; width: 100%;
}
.btn.danger { background: #e85d5d; }
.btn.secondary { background: white; color: #4c6fff; border: 1px solid #4c6fff; }
.error { background: #fdeaea; color: #b23a3a; padding: 10px 14px; border-radius: 8px; margin-bottom: 14px; font-size: 13px; }

.pref-item { display: flex; align-items: center; justify-content: space-between; gap: 14px; padding: 14px 0; border-bottom: 1px solid #eef0f5; }
.pref-item-main { flex: 1; min-width: 0; }
.pref-item .label { font-weight: 600; font-size: 14px; }
.pref-item .desc { font-size: 12.5px; color: #6b7385; margin-top: 3px; line-height: 1.4; }

.yn-toggle { display: inline-flex; border-radius: 999px; border: 1px solid #dde1ea; overflow: hidden; flex-shrink: 0; }
.yn-toggle input { position: absolute; opacity: 0; pointer-events: none; width: 0; height: 0; margin: 0; }
.yn-toggle label { margin: 0; padding: 7px 16px; font-size: 13px; font-weight: 600; color: #6b7385; cursor: pointer; user-select: none; }
.yn-toggle input:checked + label { background: #4c6fff; color: white; }
.yn-toggle input:focus-visible + label { outline: 2px solid #4c6fff; outline-offset: -2px; }

.pref-actions { display: flex; flex-direction: column; gap: 10px; }
.pref-actions .btn { margin-top: 0; }

.pref-footer { margin-top: 22px; padding-top: 16px; border-top: 1px solid #eef0f5; font-size: 12px; color: #8890a3; line-height: 1.5; }
.pref-footer p { margin: 6px 0; }
.pref-footer a { color: #4c6fff; }

.success { background: #eafbf1; color: #1f8a54; padding: 10px 14px; border-radius: 8px; margin-bottom: 14px; font-size: 13px; }