:root {
  --bg-primary: #ffffff;
  --bg-secondary: #f5f5f4;
  --text-primary: #1a1a1a;
  --text-secondary: #6b6b6b;
  --text-tertiary: #9b9b9b;
  --border-tertiary: #dcdcdc;
  --border-secondary: #c2c2c2;
  --border-primary: #8f8f8f;
  --success: #16a34a;
  --warning-bg: #fef3c7;
  --warning-text: #92400e;
  --danger: #e24b4a;
  --radius-md: 8px;
  --radius-xl: 16px;
  --font-mono: ui-monospace, 'Cascadia Code', Consolas, monospace;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg-primary: #1a1a1a;
    --bg-secondary: #0f0f0f;
    --text-primary: #f5f5f5;
    --text-secondary: #a0a0a0;
    --text-tertiary: #707070;
    --border-tertiary: #383838;
    --border-secondary: #525252;
    --border-primary: #757575;
    --warning-bg: #4a3a10;
    --warning-text: #f5d480;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  min-height: 100vh;
  padding: 2rem 1rem;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  background: var(--bg-secondary);
  color: var(--text-primary);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}
.frame {
  width: 100%;
  max-width: 380px;
  background: var(--bg-primary);
  border: 1px solid var(--border-tertiary);
  border-radius: var(--radius-xl);
  overflow: hidden;
}
.hero { text-align: center; padding: 2rem 1.5rem 1rem; }
.hero h1 { margin: 0 0 4px; font-size: 24px; font-weight: 500; }
.hero .tagline { margin: 0; font-size: 13px; color: var(--text-secondary); }
.hero .slogan { margin: 14px 0 0; font-size: 14px; font-style: italic; }
.body { padding: 1rem 1.5rem 1.75rem; }
.body h2 { font-size: 15px; font-weight: 500; margin: 0 0 12px; }
p.lead { font-size: 12.5px; color: var(--text-secondary); line-height: 1.5; margin: 0 0 16px; }
.form-row { margin-bottom: 14px; }
label { display: block; font-size: 10px; text-transform: uppercase; letter-spacing: 0.04em; color: var(--text-secondary); margin-bottom: 4px; font-weight: 500; }
input {
  width: 100%;
  padding: 9px 10px;
  font-size: 13px;
  border: 1px solid var(--border-secondary);
  border-radius: var(--radius-md);
  background: var(--bg-primary);
  color: var(--text-primary);
  font-family: inherit;
}
input:focus { outline: none; border-color: var(--border-primary); }
.handle-row { display: flex; align-items: stretch; }
.handle-row input { border-right: 0; border-radius: var(--radius-md) 0 0 var(--radius-md); }
.handle-suffix {
  background: var(--bg-secondary);
  border: 1px solid var(--border-secondary);
  border-left: 0;
  padding: 9px 10px;
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  font-size: 12.5px;
  color: var(--text-secondary);
  font-family: var(--font-mono);
  display: flex;
  align-items: center;
  white-space: nowrap;
}
.feedback { margin-top: 6px; font-size: 11px; line-height: 1.4; min-height: 14px; }
.feedback.ok { color: var(--success); }
.feedback.warn { color: var(--warning-text); }
.feedback.bad { color: var(--danger); }
.btn {
  width: 100%;
  padding: 11px;
  background: var(--text-primary);
  color: var(--bg-primary);
  border: 0;
  border-radius: var(--radius-md);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  font-family: inherit;
  margin-top: 4px;
}
.btn:hover { opacity: 0.9; }
.btn:disabled { opacity: 0.5; cursor: default; }
.btn-secondary {
  background: var(--bg-secondary);
  color: var(--text-primary);
  border: 1px solid var(--border-secondary);
}
.note { font-size: 10.5px; color: var(--text-tertiary); margin: 14px 0 0; text-align: center; line-height: 1.5; }
.linkbtn { background: none; border: 0; color: var(--text-primary); cursor: pointer; font-family: inherit; font-size: 12px; text-decoration: underline; text-decoration-style: dotted; text-underline-offset: 3px; padding: 0; }
.linkbtn:hover { opacity: 0.7; }
.message { font-size: 12.5px; line-height: 1.5; padding: 10px 12px; border-radius: var(--radius-md); margin-bottom: 14px; }
.message.error { background: rgba(226,75,74,0.1); color: var(--danger); }
.message.success { background: rgba(22,163,74,0.1); color: var(--success); }
.message.info { background: var(--bg-secondary); color: var(--text-secondary); }
.checks { margin-top: 8px; font-size: 10.5px; color: var(--text-secondary); }
.checks div { display: flex; align-items: center; gap: 5px; margin-bottom: 2px; }
.checks div.met { color: var(--success); }
.center { text-align: center; }
.success-icon {
  width: 56px; height: 56px; border-radius: 50%;
  background: var(--success); color: white;
  display: flex; align-items: center; justify-content: center;
  font-size: 30px; margin: 1.5rem auto 1rem;
}