:root {
  color-scheme: light;
  --color-bg: #f6f5f2;
  --color-surface: #fffefd;
  --color-surface-subtle: #eef0eb;
  --color-border: #d9ddd5;
  --color-border-strong: #858e83;
  --color-text: #252b26;
  --color-text-secondary: #525c53;
  --color-text-muted: #657065;
  --color-primary: #2f5543;
  --color-primary-hover: #244435;
  --color-primary-active: #1c3529;
  --color-primary-soft: #e9efe8;
  --color-on-primary: #ffffff;
  --color-error: #9b342c;
  --color-error-bg: #fff2ef;
  --color-error-border: #e1b9b3;
  --color-success: #2f5543;
  --color-status: #73521f;
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 20px;
  --space-6: 24px;
  --space-8: 32px;
  --space-10: 40px;
  --text-sm: 14px;
  --text-base: 16px;
  --text-lg: 20px;
  --text-xl: 24px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --page-width: 560px;
  --login-width: 420px;
  --textarea-height: 128px;
  --control-height: 48px;
  --touch-height: 44px;
  --icon-size: 20px;
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
html { min-width: 320px; background: var(--color-bg); }
body {
  min-height: 100vh;
  min-height: 100dvh;
  margin: 0;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: var(--text-base);
  line-height: 1.6;
}
h1, h2, p { margin: 0; }
h1 { font-size: var(--text-xl); font-weight: 600; line-height: 1.35; }
h2 { font-size: var(--text-lg); font-weight: 600; line-height: 1.4; }
button, input, textarea { font: inherit; }
button { color: inherit; }
a, button, input, summary { touch-action: manipulation; }
:focus-visible { outline: 2px solid var(--color-primary); outline-offset: 3px; }

.skip-link {
  position: absolute;
  z-index: 1;
  top: var(--space-3);
  left: var(--space-3);
  transform: translateY(-180%);
  padding: var(--space-2) var(--space-3);
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-sm);
  background: var(--color-surface);
  color: var(--color-text);
}
.skip-link:focus { transform: translateY(0); }
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}
.page-shell {
  width: min(100%, var(--page-width));
  margin-inline: auto;
  padding: var(--space-4);
  padding-top: max(var(--space-4), env(safe-area-inset-top));
  padding-bottom: max(var(--space-8), env(safe-area-inset-bottom));
  padding-left: max(var(--space-4), env(safe-area-inset-left));
  padding-right: max(var(--space-4), env(safe-area-inset-right));
}
.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: var(--control-height);
  gap: var(--space-3);
  padding-bottom: var(--space-3);
  border-bottom: 1px solid var(--color-border);
}
.brand { color: var(--color-text); font-size: var(--text-lg); font-weight: 600; text-decoration: none; }
.topbar .brand { display: inline-flex; align-items: center; min-height: var(--touch-height); }
.workspace { display: grid; gap: var(--space-6); padding-top: var(--space-8); }
.page-heading { display: grid; gap: var(--space-2); }
.intro { color: var(--color-text-secondary); font-size: var(--text-sm); }
.panel { border: 1px solid var(--color-border); border-radius: var(--radius-md); background: var(--color-surface); }
.source-panel { padding: var(--space-5); }
/* Older browsers keep the input card visible and retain the same task flow. */
@supports selector(:has(*)) {
  .workspace:has(#result-content:not([hidden])) .source-panel { display: none; }
}
fieldset { min-width: 0; margin: 0; padding: 0; border: 0; }
.mode-switch {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--space-2);
  margin-bottom: var(--space-5);
  border-bottom: 1px solid var(--color-border);
}
.mode-button {
  min-height: var(--control-height);
  padding: var(--space-2);
  border: 0;
  border-bottom: 2px solid transparent;
  background: transparent;
  color: var(--color-text-secondary);
  cursor: pointer;
}
.mode-button[aria-pressed="true"] { border-bottom-color: var(--color-primary); color: var(--color-primary); font-weight: 600; }
.source-content { display: grid; gap: var(--space-2); }
.field-heading { display: flex; align-items: center; justify-content: space-between; gap: var(--space-2); }
.field-label { min-width: 0; font-size: var(--text-sm); font-weight: 600; }
.text-control, .file-control {
  width: 100%;
  min-width: 0;
  min-height: var(--control-height);
  padding: var(--space-3);
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-sm);
  background: var(--color-surface);
  color: var(--color-text);
  font-size: var(--text-base);
}
.text-control::placeholder { color: var(--color-text-muted); opacity: 1; }
textarea.text-control { min-height: var(--textarea-height); resize: vertical; }
.file-control { padding: var(--space-2); }
.file-control::file-selector-button {
  min-height: var(--touch-height);
  margin-right: var(--space-2);
  padding-inline: var(--space-3);
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-sm);
  background: var(--color-surface-subtle);
  color: var(--color-text);
  cursor: pointer;
}
.field-help, .file-details { color: var(--color-text-muted); font-size: var(--text-sm); overflow-wrap: anywhere; }
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: var(--control-height);
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  font-size: var(--text-base);
  font-weight: 500;
  line-height: 1.5;
  text-align: center;
  text-decoration: none;
  cursor: pointer;
  transition: transform 120ms ease-out;
}
.button--primary { background: var(--color-primary); color: var(--color-on-primary); }
.button--quiet { border-color: var(--color-border-strong); background: var(--color-surface); color: var(--color-text-secondary); }
.button--text { min-height: var(--touch-height); padding-inline: var(--space-2); background: transparent; color: var(--color-text-secondary); font-size: var(--text-sm); }
.button--small { flex-shrink: 0; }
.button--full { width: 100%; }
.button--primary:active { background: var(--color-primary-active); }
.button--quiet:active, .button--text:active, .mode-button:active { background: var(--color-primary-soft); }
.button:active { transform: translateY(1px); }
button:disabled, fieldset:disabled .mode-button { cursor: default; }
button:disabled.button--primary { background: var(--color-surface-subtle); color: var(--color-text-muted); }
button:disabled.button--quiet { border-color: var(--color-border); background: var(--color-surface-subtle); color: var(--color-text-muted); }
fieldset:disabled .text-control, fieldset:disabled .file-control { background: var(--color-surface-subtle); }
button:disabled.button--text, fieldset:disabled .mode-button { color: var(--color-text-muted); }
.start-button { margin-top: var(--space-6); }
.availability { display: flex; align-items: baseline; gap: var(--space-2); margin-top: var(--space-4); color: var(--color-status); font-size: var(--text-sm); }
.availability--ready { color: var(--color-text-muted); }
.status-dot { width: var(--space-2); height: var(--space-2); flex-shrink: 0; border-radius: 50%; background: var(--color-status); }
.availability--ready .status-dot { background: var(--color-success); }
.usage-details { margin-top: var(--space-3); border-top: 1px solid var(--color-border); }
summary { min-height: var(--touch-height); padding-block: var(--space-2); color: var(--color-text-secondary); font-size: var(--text-sm); cursor: pointer; }
details > p { margin-bottom: var(--space-3); color: var(--color-text-secondary); font-size: var(--text-sm); }
.form-feedback, .retry-capabilities { margin-top: var(--space-3); }
.notice { padding: var(--space-3); border-radius: var(--radius-sm); font-size: var(--text-sm); overflow-wrap: anywhere; }
.notice--error { border: 1px solid var(--color-error-border); background: var(--color-error-bg); color: var(--color-error); }
.privacy-note { color: var(--color-text-muted); font-size: var(--text-sm); }
.task-panel { display: grid; gap: var(--space-4); padding: var(--space-5); }
.eyebrow { color: var(--color-text-muted); font-size: var(--text-sm); }
.task-panel h2, .task-message, .result-meta { overflow-wrap: anywhere; }
.task-message, .result-meta, .expiry-note { color: var(--color-text-secondary); font-size: var(--text-sm); }
.upload-progress { display: grid; gap: var(--space-2); }
progress { width: 100%; height: var(--space-2); border: 0; border-radius: var(--radius-sm); background: var(--color-surface-subtle); accent-color: var(--color-primary); }
progress::-webkit-progress-bar { border-radius: var(--radius-sm); background: var(--color-surface-subtle); }
progress::-webkit-progress-value { border-radius: var(--radius-sm); background: var(--color-primary); }
progress::-moz-progress-bar { border-radius: var(--radius-sm); background: var(--color-primary); }
.process-steps { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: var(--space-2); margin: 0; padding: 0; list-style: none; }
.process-steps li { padding-top: var(--space-2); border-top: 2px solid var(--color-border); color: var(--color-text-muted); font-size: var(--text-sm); text-align: center; }
.process-steps li.is-current { border-color: var(--color-primary); color: var(--color-primary); font-weight: 600; }
.process-steps li.is-complete { border-color: var(--color-success); }
.result-content { display: grid; min-width: 0; gap: var(--space-4); }
audio { display: block; width: 100%; min-width: 0; }
.share-actions { display: grid; justify-items: start; gap: var(--space-2); }
.share-actions .button { padding-inline: 0; color: var(--color-primary); }
#share-feedback:empty, #video-feedback:empty { display: none; }
.expiry-note { font-variant-numeric: tabular-nums; }
.save-guide { border-top: 1px solid var(--color-border); }
.task-actions { display: grid; gap: var(--space-2); }
.page-shell--centered {
  display: grid;
  align-items: center;
  min-height: 100vh;
  min-height: 100dvh;
  max-width: var(--login-width);
  padding-top: max(var(--space-10), env(safe-area-inset-top));
  padding-bottom: max(var(--space-10), env(safe-area-inset-bottom));
}
.login-panel { display: grid; gap: var(--space-6); padding: var(--space-6); border: 0; background: transparent; }
.login-heading { display: grid; justify-items: center; gap: var(--space-2); text-align: center; }
.login-heading .brand { display: inline-flex; align-items: center; min-height: var(--touch-height); font-size: var(--text-xl); }
.login-heading h1 { font-size: var(--text-lg); font-weight: 500; color: var(--color-text-secondary); }
.form-stack { display: grid; gap: var(--space-3); }
.form-stack .button { margin-top: var(--space-2); }
.password-control { position: relative; }
.password-control .text-control { padding-right: calc(var(--touch-height) + var(--space-3)); }
.form-stack .password-toggle {
  position: absolute;
  top: 50%;
  right: var(--space-1);
  width: var(--touch-height);
  height: var(--touch-height);
  min-height: var(--touch-height);
  margin: 0;
  padding: var(--space-2);
  transform: translateY(-50%);
}
.password-icon { width: var(--icon-size); height: var(--icon-size); }
.password-icon--hide, .password-toggle[aria-pressed="true"] .password-icon--show { display: none; }
.password-toggle[aria-pressed="true"] .password-icon--hide { display: block; }

@media (hover: hover) {
  .brand:hover, summary:hover { color: var(--color-primary); }
  .button--primary:hover:not(:disabled) { background: var(--color-primary-hover); }
  .button--quiet:hover:not(:disabled), .button--text:hover:not(:disabled), .mode-button:hover:not(:disabled) { background: var(--color-surface-subtle); }
  .file-control::file-selector-button:hover { background: var(--color-primary-soft); }
}
@media (min-width: 480px) {
  .page-shell {
    padding-left: max(var(--space-6), env(safe-area-inset-left));
    padding-right: max(var(--space-6), env(safe-area-inset-right));
    padding-top: max(var(--space-6), env(safe-area-inset-top));
  }
  .source-panel, .task-panel { padding: var(--space-6); }
  .workspace { padding-top: var(--space-10); }
}
@media (min-width: 768px) {
  .page-shell { padding-top: max(var(--space-10), env(safe-area-inset-top)); }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; transition-duration: 0.01ms !important; }
}