:root {
  color-scheme: light;
  --ink: #17202a;
  --muted: #5f6b7a;
  --line: #d9e1e8;
  --soft: #f4f8fb;
  --blue: #2f78b7;
  --green: #2e8b57;
  --red: #d94a45;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  background: #f7fbff;
  color: var(--ink);
  font-family: "Microsoft YaHei", "Hiragino Sans GB", Arial, sans-serif;
}

.plus-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 14px clamp(18px, 5vw, 72px);
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.96);
}

.brand, .plus-header nav { display: flex; align-items: center; gap: 14px; }
.brand { color: inherit; font-size: 20px; font-weight: 800; text-decoration: none; }
.brand img { border-radius: 8px; }
.plus-header nav a { color: var(--muted); font-size: 14px; text-decoration: none; }
.plus-header nav a[aria-current="page"] { color: var(--ink); font-weight: 800; }

.plus-shell {
  width: min(1080px, calc(100vw - 36px));
  margin: 0 auto;
  padding: clamp(34px, 7vw, 72px) 0 48px;
}

.plus-hero { max-width: 780px; margin-bottom: 26px; }
.eyebrow { margin: 0 0 12px; color: var(--green); font-size: 13px; font-weight: 800; letter-spacing: 0; }
h1 { margin: 0; font-size: clamp(38px, 7vw, 72px); line-height: 0.98; letter-spacing: 0; }
.intro { margin: 20px 0 0; color: var(--muted); font-size: 17px; line-height: 1.75; }

.redeem-panel {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  padding: clamp(18px, 4vw, 30px);
  box-shadow: 0 18px 50px rgba(22, 34, 48, 0.1);
}

.field { display: grid; gap: 8px; color: var(--muted); font-size: 13px; font-weight: 800; }
.field input {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #fff;
  color: var(--ink);
  padding: 13px 14px;
  font: inherit;
  font-size: 16px;
}
.field input:focus { outline: none; border-color: var(--blue); box-shadow: 0 0 0 3px rgba(47, 120, 183, 0.14); }

.formats { display: flex; align-items: center; flex-wrap: wrap; gap: 12px; margin-top: 18px; }
.formats > span { color: var(--muted); font-size: 13px; font-weight: 800; margin-right: 2px; }
.formats label {
  min-height: 42px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--soft);
  color: var(--ink);
  padding: 9px 13px;
  font-size: 14px;
  font-weight: 700;
}
.formats input { width: 16px; height: 16px; accent-color: var(--blue); }

.actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 24px; }
button {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 6px;
  padding: 11px 18px;
  font: inherit;
  font-weight: 800;
  cursor: pointer;
}
button.primary { border: 1px solid var(--blue); background: var(--blue); color: #fff; }
button.secondary { border: 1px solid var(--line); background: #fff; color: var(--ink); }
button:hover:not(:disabled) { transform: translateY(-1px); box-shadow: 0 8px 18px rgba(22, 34, 48, 0.12); }
button:disabled { opacity: 0.48; cursor: not-allowed; }

.status {
  margin-top: 26px;
  border: 1px dashed var(--line);
  border-radius: 8px;
  background: var(--soft);
  color: var(--muted);
  min-height: 72px;
  padding: 14px 16px;
  white-space: pre-wrap;
  line-height: 1.7;
}
.status.ok { border-color: rgba(46, 139, 87, 0.45); background: #f1faf5; color: var(--green); }
.status.err { border-color: rgba(217, 74, 69, 0.45); background: #fff5f5; color: var(--red); }
.downloads { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 14px; }
.downloads button { border-color: var(--green); background: #fff; color: var(--green); }
.downloads button:hover { background: var(--green); color: #fff; }

@media (max-width: 720px) {
  .plus-header { align-items: flex-start; flex-direction: column; }
  .plus-header nav { flex-wrap: wrap; }
  .formats { align-items: stretch; flex-direction: column; }
  .formats label, .actions button { width: 100%; }
}