:root {
  --bg-1: #0f1226;
  --bg-2: #121735;
  --accent: #6ee7f9;
  --accent-2: #a78bfa;
  --text: #e6e6f0;
  --muted: #9aa0b6;
  --card: rgba(255, 255, 255, 0.06);
  --card-border: rgba(255, 255, 255, 0.12);
  --shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
  --success: #10b981;
  --warn: #f59e0b;
  --danger: #ef4444;
}

* {
  box-sizing: border-box;
}

html, body {
  height: 100%;
}

body {
  margin: 0;
  font-family: 'Inter', system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, 'Apple Color Emoji', 'Segoe UI Emoji';
  color: var(--text);
  background: radial-gradient(1200px 800px at 20% 10%, #1b1f4a 0%, transparent 60%),
              radial-gradient(1000px 800px at 80% 80%, #43136d 0%, transparent 55%),
              linear-gradient(120deg, var(--bg-1), var(--bg-2));
  background-size: 200% 200%;
  animation: bgShift 16s ease-in-out infinite;
}

@keyframes bgShift {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

.app {
  min-height: 100dvh;
  max-width: 720px;
  margin: 0 auto;
  padding: 32px 20px 40px;
  display: grid;
  gap: 20px;
  align-content: center;
}

.app__header {
  text-align: center;
}

.app__title {
  margin: 0 0 6px;
  font-size: 28px;
  font-weight: 700;
  letter-spacing: 0.2px;
}

.app__subtitle {
  margin: 0;
  color: var(--muted);
}

.output {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 10px;
  align-items: center;
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: 16px;
  padding: 14px;
  box-shadow: var(--shadow);
  backdrop-filter: blur(8px) saturate(110%);
}

.output__field {
  width: 100%;
  height: 48px;
  border: 0;
  outline: none;
  color: var(--text);
  background: rgba(255,255,255,0.04);
  border: 1px solid rgba(255,255,255,0.12);
  border-radius: 12px;
  padding: 0 14px;
  font-size: 18px;
  font-weight: 600;
  letter-spacing: 0.6px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, 'Liberation Mono', 'Courier New', monospace;
}

.output__actions {
  display: flex;
  gap: 8px;
}

.icon-btn {
  height: 48px;
  min-width: 48px;
  padding: 0 12px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  color: var(--text);
  background: rgba(255,255,255,0.05);
  border: 1px solid rgba(255,255,255,0.14);
  border-radius: 12px;
  cursor: pointer;
  transition: transform 0.1s ease, filter 0.2s ease, background 0.2s ease;
}

.icon-btn:hover { filter: brightness(1.1); }
.icon-btn:active { transform: translateY(1px) scale(0.99); }

.icon-btn.primary {
  background: linear-gradient(135deg, rgba(110,231,249,0.25), rgba(167,139,250,0.25));
  border-color: rgba(167,139,250,0.45);
}

.icon {
  width: 22px;
  height: 22px;
}

.strength {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 12px;
  align-items: center;
}

.strength__label { color: var(--muted); }

.strength__meter {
  height: 10px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 6px;
}

.strength__meter span {
  display: block;
  background: rgba(255,255,255,0.16);
  border-radius: 999px;
  border: 1px solid rgba(255,255,255,0.12);
  transition: background 0.25s ease, border-color 0.25s ease;
}

.strength__meter.score-0 span:nth-child(-n+0) { background: rgba(255,255,255,0.16); }
.strength__meter.score-1 span:nth-child(-n+1) { background: var(--danger); border-color: rgba(239,68,68,0.6); }
.strength__meter.score-2 span:nth-child(-n+2) { background: var(--warn); border-color: rgba(245,158,11,0.6); }
.strength__meter.score-3 span:nth-child(-n+3) { background: #22c55e; border-color: rgba(34,197,94,0.6); }
.strength__meter.score-4 span:nth-child(-n+4) { background: #06b6d4; border-color: rgba(6,182,212,0.6); }

.strength__text { color: var(--muted); }

.controls {
  display: grid;
  gap: 16px;
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: 16px;
  padding: 18px;
  box-shadow: var(--shadow);
  backdrop-filter: blur(8px) saturate(110%);
}

.control__label-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 8px;
}

.control__label {
  font-weight: 600;
}

.control__value {
  font-variant-numeric: tabular-nums;
  color: var(--accent);
  font-weight: 700;
}

.range { width: 100%; }

/* Range styling */
.range { -webkit-appearance: none; appearance: none; height: 6px; border-radius: 999px; background: rgba(255,255,255,0.16); outline: none; }
.range::-webkit-slider-thumb { -webkit-appearance: none; appearance: none; width: 20px; height: 20px; border-radius: 50%; background: linear-gradient(135deg, var(--accent), var(--accent-2)); border: 2px solid rgba(255,255,255,0.7); box-shadow: 0 2px 6px rgba(0,0,0,0.35); cursor: pointer; }
.range::-moz-range-thumb { width: 20px; height: 20px; border-radius: 50%; background: linear-gradient(135deg, var(--accent), var(--accent-2)); border: 2px solid rgba(255,255,255,0.7); box-shadow: 0 2px 6px rgba(0,0,0,0.35); cursor: pointer; }
.range::-moz-range-track { height: 6px; border-radius: 999px; background: rgba(255,255,255,0.16); }

.grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px 14px;
}

.check {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  border: 1px solid rgba(255,255,255,0.12);
  border-radius: 12px;
  background: rgba(255,255,255,0.04);
}

.check input[type="checkbox"] {
  width: 18px;
  height: 18px;
  margin: 0;
  accent-color: #7dd3fc;
}

.actions {
  display: flex;
  justify-content: center;
}

.btn {
  height: 48px;
  padding: 0 18px;
  font-weight: 700;
  letter-spacing: 0.3px;
  color: #0b1020;
  background: linear-gradient(135deg, #7dd3fc, #c4b5fd);
  border: 0;
  border-radius: 12px;
  cursor: pointer;
  box-shadow: 0 8px 20px rgba(125, 211, 252, 0.25);
  transition: transform 0.08s ease, filter 0.2s ease;
}

.btn:hover { filter: brightness(1.05); }
.btn:active { transform: translateY(1px) scale(0.99); }

.app__footer { text-align: center; color: var(--muted); }

.toast {
  position: fixed;
  left: 50%;
  bottom: 22px;
  transform: translateX(-50%) translateY(20px);
  opacity: 0;
  pointer-events: none;
  background: rgba(15, 23, 42, 0.9);
  color: #e6e6f0;
  padding: 10px 14px;
  border-radius: 999px;
  border: 1px solid rgba(255,255,255,0.12);
  box-shadow: var(--shadow);
  transition: opacity 0.25s ease, transform 0.25s ease;
  font-size: 14px;
}

.toast--show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

@media (max-width: 560px) {
  .app { padding: 24px 14px 30px; }
  .output { grid-template-columns: 1fr; }
  .output__actions { justify-content: stretch; }
  .icon-btn { flex: 1; }
  .grid { grid-template-columns: 1fr; }
}