:root {
  --bg: #0c0f14;
  --surface: #161c26;
  --border: #2a3545;
  --text: #e8ecf1;
  --muted: #8a96a8;
  --accent: #6a9bc4;
  --accent-dim: #4a7aa3;
  --danger: #d97882;
  --radius: 10px;
  --font-sans: "SF Pro Text", "Segoe UI", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "SimSun", serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-sans);
  background: radial-gradient(ellipse 100% 80% at 50% -20%, rgba(45, 65, 95, 0.35) 0%, transparent 55%),
    radial-gradient(ellipse 80% 50% at 100% 0%, rgba(55, 40, 70, 0.2) 0%, transparent 45%), var(--bg);
  color: var(--text);
}

.page {
  max-width: 640px;
  margin: 0 auto;
  padding: 2.75rem 1.35rem 3.25rem;
}

.header h1 {
  margin: 0 0 0.85rem;
  font-family: var(--font-serif);
  font-size: 1.75rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  line-height: 1.35;
}

.sub {
  margin: 0;
  color: var(--muted);
  font-size: 0.94rem;
  line-height: 1.75;
  text-align: justify;
  text-justify: inter-ideograph;
}

.example-link {
  margin-left: 0.35em;
  color: var(--accent);
  text-decoration: none;
  white-space: nowrap;
}

.example-link:hover {
  text-decoration: underline;
}

.section-heading {
  margin: 0 0 0.5rem;
  font-family: var(--font-serif);
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text);
}

.section-heading--spaced {
  margin-top: 1.75rem;
}

.section-lead {
  margin: 0 0 1.25rem;
  font-size: 0.82rem;
  line-height: 1.65;
  color: var(--muted);
}

.card {
  margin-top: 2rem;
  padding: 1.5rem 1.4rem 1.45rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.28);
}

.row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-bottom: 1rem;
}

.row--single {
  grid-template-columns: 1fr;
}

.api-block {
  margin-top: 0.25rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
}

.switch-row {
  display: flex;
  align-items: flex-start;
  gap: 0.65rem;
  cursor: pointer;
  font-size: 0.9rem;
  line-height: 1.45;
  color: var(--text);
}

.switch-row input[type="checkbox"] {
  margin-top: 0.2rem;
  width: 1rem;
  height: 1rem;
  flex-shrink: 0;
  cursor: pointer;
  accent-color: var(--accent);
}

.switch-label {
  user-select: none;
}

.api-fields {
  margin-top: 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.api-fields.is-hidden {
  display: none;
}

.api-field {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.api-field .label {
  font-size: 0.78rem;
}

.api-field input[type="text"],
.api-field input[type="password"] {
  width: 100%;
  padding: 0.5rem 0.65rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  font-size: 0.9rem;
}

.api-field input:focus {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.label {
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text);
  letter-spacing: 0.04em;
}

select {
  appearance: none;
  padding: 0.55rem 0.75rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  font-size: 0.95rem;
  cursor: pointer;
}

select:focus {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}

select:disabled {
  opacity: 0.55;
  cursor: not-allowed;
  background: rgba(0, 0, 0, 0.22);
  color: var(--muted);
  border-color: var(--border);
}

.field--locked .label {
  color: var(--muted);
}

.dropzone {
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 1.75rem 1rem;
  text-align: center;
  cursor: pointer;
  transition: border-color 0.15s, background 0.15s;
}

.dropzone:hover,
.dropzone:focus {
  border-color: var(--accent-dim);
  background: rgba(91, 159, 212, 0.06);
  outline: none;
}

.dropzone.dragover {
  border-color: var(--accent);
  background: rgba(91, 159, 212, 0.12);
}

.drop-title {
  margin: 0 0 0.4rem;
  font-family: var(--font-serif);
  font-weight: 600;
  font-size: 0.98rem;
}

.drop-hint {
  margin: 0;
  font-size: 0.82rem;
  line-height: 1.55;
  color: var(--muted);
}

.file-name {
  margin: 0.85rem 0 0;
  font-size: 0.9rem;
  color: var(--accent);
  word-break: break-all;
}

.actions {
  margin-top: 1.25rem;
}

.btn {
  width: 100%;
  padding: 0.75rem 1rem;
  border: none;
  border-radius: 10px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: opacity 0.15s, transform 0.1s;
}

.btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.btn.primary {
  background: linear-gradient(180deg, var(--accent) 0%, var(--accent-dim) 100%);
  color: #f8fafc;
  font-family: var(--font-sans);
  letter-spacing: 0.02em;
}

.btn.primary:not(:disabled):hover {
  filter: brightness(1.06);
}

.btn.primary:not(:disabled):active {
  transform: scale(0.99);
}

.status {
  margin: 1rem 0 0;
  min-height: 1.25rem;
  font-size: 0.9rem;
  color: var(--muted);
}

.generation-warning {
  margin: 0.55rem 0 0;
  padding: 0.7rem 0.8rem;
  border-radius: 8px;
  border: 1px solid rgba(217, 120, 130, 0.35);
  background: rgba(217, 120, 130, 0.08);
  color: #f0c2c8;
  font-size: 0.86rem;
  line-height: 1.6;
}

.error {
  margin: 0.5rem 0 0;
  font-size: 0.9rem;
  color: var(--danger);
}

.support-footer {
  margin-top: 2rem;
  padding: 1.25rem 1.1rem 1.35rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.support-heading {
  margin: 0 0 0.75rem;
  font-family: var(--font-serif);
  font-size: 1rem;
  font-weight: 600;
  color: var(--text);
}

.support-text {
  margin: 0 0 0.85rem;
  font-size: 0.82rem;
  line-height: 1.65;
  color: var(--muted);
  text-align: justify;
  text-justify: inter-ideograph;
}

.support-qq {
  margin: 0 0 1rem;
  font-size: 0.88rem;
  color: var(--text);
}

.support-label {
  color: var(--muted);
}

.support-value {
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--accent);
  user-select: all;
}

.support-qr-wrap {
  text-align: center;
}

.support-qr-caption {
  margin: 0 0 0.5rem;
  font-size: 0.78rem;
  color: var(--muted);
}

.support-qr {
  display: inline-block;
  max-width: min(200px, 70vw);
  height: auto;
  border-radius: 8px;
  border: 1px solid var(--border);
  vertical-align: top;
}

@media (max-width: 520px) {
  .row {
    grid-template-columns: 1fr;
  }

  .header h1 {
    font-size: 1.5rem;
  }
}