:root {
  --bg: #0f1115; --surface: #1a1d24; --border: #2a2f3a;
  --text: #e8eaed; --muted: #9aa0a6; --accent: #5b8def; --success: #34c759;
  --radius: 12px; --font: system-ui, -apple-system, sans-serif;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: var(--font); background: var(--bg); color: var(--text); min-height: 100vh; padding: 24px 16px; }
.container { max-width: 480px; margin: 0 auto; }
header { text-align: center; margin-bottom: 24px; }
h1 { font-size: 1.6rem; margin-bottom: 6px; }
.subtitle { color: var(--muted); font-size: 0.9rem; }
.output-box { display: flex; gap: 8px; margin-bottom: 12px; }
.output-box input {
  flex: 1; background: var(--surface); border: 1px solid var(--border); color: var(--text);
  padding: 14px; border-radius: 8px; font-family: ui-monospace, monospace; font-size: 1.1rem;
}
.output-box button {
  background: var(--accent); color: #fff; border: none; padding: 0 18px; border-radius: 8px;
  font-weight: 600; cursor: pointer;
}
.strength { height: 6px; border-radius: 3px; background: var(--border); margin-bottom: 20px; overflow: hidden; }
.strength::after { content: ''; display: block; height: 100%; width: 0; transition: width 0.2s, background 0.2s; }
.controls { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; }
.form-group { margin-bottom: 16px; }
label { font-size: 0.9rem; color: var(--muted); }
input[type="range"] { width: 100%; margin-top: 8px; }
.check { display: block; margin: 10px 0; color: var(--text); cursor: pointer; }
.check input { margin-right: 8px; }
.calc-btn {
  width: 100%; background: var(--accent); color: #fff; border: none; padding: 14px;
  border-radius: 8px; font-weight: 600; cursor: pointer; margin-top: 16px;
}
footer { text-align: center; margin-top: 28px; color: var(--muted); font-size: 0.8rem; }