*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: #f0f2f5;
  color: #1a1a2e;
  min-height: 100vh;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding: 2rem 1rem;
}

.container {
  background: #ffffff;
  border-radius: 12px;
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.08);
  padding: 2rem;
  width: 100%;
  max-width: 600px;
}

h1 {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 1.5rem;
  color: #1a1a2e;
}

h2 {
  font-size: 1rem;
  font-weight: 600;
  color: #4a4a6a;
  margin-bottom: 0.75rem;
}

/* Input Section */
.input-section {
  margin-bottom: 1.5rem;
}

.input-section label {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 0.5rem;
  color: #4a4a6a;
}

.input-wrapper {
  position: relative;
  display: flex;
  align-items: center;
}

#password-input {
  width: 100%;
  padding: 0.75rem 3rem 0.75rem 1rem;
  font-size: 1rem;
  border: 2px solid #d1d5db;
  border-radius: 8px;
  outline: none;
  transition: border-color 0.2s, box-shadow 0.2s;
  background: #fafafa;
  font-family: monospace;
}

#password-input:focus {
  border-color: #6366f1;
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.15);
  background: #fff;
}

#password-input.valid {
  border-color: #22c55e;
  box-shadow: 0 0 0 3px rgba(34, 197, 94, 0.15);
  background: #f0fdf4;
}

#toggle-visibility {
  position: absolute;
  right: 0.75rem;
  background: none;
  border: none;
  cursor: pointer;
  font-size: 1.1rem;
  padding: 0.25rem;
  display: flex;
  align-items: center;
  opacity: 0.6;
  transition: opacity 0.2s;
}

#toggle-visibility:hover {
  opacity: 1;
}

/* Check List */
.result-section {
  margin-bottom: 1.5rem;
}

.check-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.check-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.6rem 0.75rem;
  border-radius: 6px;
  background: #f8f9fa;
  font-size: 0.875rem;
  transition: background 0.2s;
}

.check-icon {
  font-size: 1rem;
  font-weight: 700;
  width: 1.25rem;
  text-align: center;
  color: #ef4444;
  transition: color 0.2s;
}

.check-label {
  color: #374151;
}

.check-item.pass {
  background: #f0fdf4;
}

.check-item.pass .check-icon {
  color: #22c55e;
}

.check-item.pass .check-label {
  color: #166534;
}

/* Responsive */
@media (max-width: 480px) {
  .container {
    padding: 1.25rem;
  }

  h1 {
    font-size: 1.25rem;
  }

}