* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: Arial, sans-serif;
  background: linear-gradient(135deg, #0f172a, #1e293b);
  color: #f8fafc;
}

.container {
  width: min(100%, 900px);
  margin: 0 auto;
  padding: 40px 20px 60px;
}

.hero {
  text-align: center;
  margin-bottom: 32px;
}

.brand {
  margin: 0 0 10px;
  color: #22c55e;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 1.5px;
  text-transform: uppercase;
}

.hero h1 {
  margin: 0 0 12px;
  font-size: clamp(32px, 5vw, 52px);
  line-height: 1.15;
}

.subtitle {
  max-width: 700px;
  margin: 0 auto 12px;
  color: #cbd5e1;
  font-size: 18px;
  line-height: 1.6;
}

.trust-note {
  display: inline-block;
  margin: 0;
  padding: 8px 14px;
  border: 1px solid rgba(34, 197, 94, 0.35);
  border-radius: 999px;
  background: rgba(34, 197, 94, 0.08);
  color: #bbf7d0;
  font-size: 14px;
}

.card {
  margin-bottom: 24px;
  padding: 24px;
  border: 1px solid rgba(148, 163, 184, 0.2);
  border-radius: 18px;
  background: rgba(15, 23, 42, 0.65);
  backdrop-filter: blur(8px);
}

.card h2 {
  margin-top: 0;
  margin-bottom: 10px;
  font-size: 28px;
}

.card h3 {
  margin-top: 24px;
  margin-bottom: 12px;
  font-size: 18px;
  color: #e2e8f0;
}

.section-text {
  margin-top: 0;
  margin-bottom: 20px;
  color: #cbd5e1;
  line-height: 1.6;
}

.options-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 12px;
  margin-bottom: 20px;
}

.option-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px 14px;
  border-radius: 12px;
  background: rgba(148, 163, 184, 0.08);
  cursor: pointer;
  font-size: 16px;
}

input[type="checkbox"] {
  margin: 0;
  cursor: pointer;
}

.length-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px;
  margin-bottom: 20px;
}

.length-row label {
  font-size: 16px;
  font-weight: 600;
}

input[type="number"] {
  width: 100px;
  padding: 10px 12px;
  border: none;
  border-radius: 10px;
  font-size: 16px;
  background: #e2e8f0;
  color: #0f172a;
}

.button-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 18px;
}

button {
  padding: 12px 18px;
  border: none;
  border-radius: 12px;
  background: #22c55e;
  color: #0f172a;
  font-size: 16px;
  font-weight: 700;
  cursor: pointer;
  transition: transform 0.15s ease, background 0.15s ease;
}

button:hover {
  background: #16a34a;
  transform: translateY(-1px);
}

.secondary-btn {
  background: #e2e8f0;
  color: #0f172a;
}

.secondary-btn:hover {
  background: #cbd5e1;
}

.output-box {
  min-height: 58px;
  margin: 0;
  padding: 14px 16px;
  border-radius: 12px;
  background: #e2e8f0;
  color: #0f172a;
  font-weight: 700;
  word-break: break-word;
  line-height: 1.5;
}

.strength-wrapper {
  margin-top: 14px;
  margin-bottom: 8px;
}

.strength-label {
  margin: 0 0 8px;
  font-size: 15px;
  color: #cbd5e1;
}

.strength-bar {
  width: 100%;
  height: 12px;
  border-radius: 999px;
  background: rgba(148, 163, 184, 0.2);
  overflow: hidden;
}

#strength-fill {
  height: 100%;
  width: 0%;
  border-radius: 999px;
  background: #22c55e;
  transition: width 0.25s ease;
}

.status-text {
  min-height: 24px;
  margin: 10px 0 0;
  color: #bbf7d0;
  font-size: 14px;
}

.status-text.success {
  color: #86efac;
}

.status-text.error {
  color: #fca5a5;
}

.tips-list {
  margin: 0;
  padding-left: 20px;
  color: #cbd5e1;
  line-height: 1.8;
}

.footer {
  margin-top: 10px;
  text-align: center;
  color: #94a3b8;
  font-size: 14px;
}

.footer p {
  margin: 6px 0;
}

.footer-note {
  color: #64748b;
}

.footer a {
  color: #cbd5e1;
  text-decoration: none;
}

.footer a:hover {
  text-decoration: underline;
}

@media (max-width: 640px) {
  .container {
    padding: 24px 16px 40px;
  }

  .card {
    padding: 20px;
  }

  .button-row button {
    width: 100%;
  }

  .length-row {
    flex-direction: column;
    align-items: flex-start;
  }
}

.logo-container {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  margin-bottom: 10px;
}

.logo {
  width: 40px;
  height: 40px;
  border-radius: 10px;
}