:root {
  --primary-color: #667eea;
  --secondary-color: #764ba2;
  --text-color: #2d3748;
  --text-secondary: #4a5568;
  --background-white: rgba(255, 255, 255, 0.95);
  --background-white-fallback: rgba(255, 255, 255, 0.98);
  --background-light: #f7fafc;
  --background-lighter: #edf2f7;
  --border-color: #e2e8f0;
  --border-color-hover: #cbd5e0;
  --error-color: #e53e3e;
  --error-bg: #fed7d7;
  --warning-color: #ed8936;
  
  --border-radius-sm: 12px;
  --border-radius-md: 16px;
  --border-radius-lg: 24px;
  --border-radius-xl: 25px;
  
  --spacing-xs: 0.5em;
  --spacing-sm: 0.8em;
  --spacing-md: 1em;
  --spacing-lg: 1.2em;
  --spacing-xl: 1.5em;
  --spacing-2xl: 2em;
  --spacing-3xl: 2.5em;
  
  --shadow-sm: 0 4px 12px rgba(0,0,0,0.1);
  --shadow-md: 0 4px 20px rgba(0,0,0,0.05);
  --shadow-lg: 0 8px 25px rgba(0,0,0,0.2);
  --shadow-primary: 0 8px 25px rgba(102, 126, 234, 0.3);
  --shadow-primary-hover: 0 12px 35px rgba(102, 126, 234, 0.4);
  --shadow-container: 0 20px 50px rgba(0,0,0,0.1), 0 0 0 1px rgba(255,255,255,0.05);
  
  --font-size-sm: 0.85em;
  --font-size-base: 1em;
  --font-size-md: 1.05em;
  --font-size-lg: 1.1em;
  --font-size-xl: 1.8em;
  --font-size-2xl: 2.5em;
  
  --transition: all 0.3s ease;
}

* {
  box-sizing: border-box;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

body {
  font-family: 'Poppins', sans-serif;
  margin: 0;
  padding: var(--spacing-md);
  background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
  min-height: 100vh;
  color: var(--text-color);
}

@media (min-width: 480px) {
  body {
    padding: var(--spacing-xl);
  }
}

@media (min-width: 768px) {
  body {
    padding: var(--spacing-2xl);
  }
}

@media (min-width: 1024px) {
  .container {
    max-width: 800px;
  }
}

h3.title {
  text-align: center;
  margin-bottom: var(--spacing-md);
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: #fff;
  text-shadow: 0 4px 20px rgba(0,0,0,0.3);
  letter-spacing: -0.5px;
}

@media (min-width: 768px) {
  h3.title {
    font-size: var(--font-size-2xl);
    margin-bottom: var(--spacing-lg);
  }
}

.container {
  max-width: 680px;
  margin: 0 auto;
  padding: var(--spacing-xl);
  background: var(--background-white-fallback);
  background: var(--background-white);
  backdrop-filter: blur(10px);
  border-radius: var(--border-radius-md);
  box-shadow: var(--shadow-container);
  border: 1px solid rgba(255,255,255,0.2);
}

@supports not (backdrop-filter: blur(10px)) {
  .container {
    background: var(--background-white-fallback);
  }
}

@media (min-width: 768px) {
  .container {
    padding: var(--spacing-3xl);
    border-radius: var(--border-radius-lg);
  }
}

.error {
  color: var(--error-color);
  background: var(--error-bg);
  padding: var(--spacing-md);
  border-radius: var(--border-radius-sm);
  margin-bottom: var(--spacing-xl);
  display: none;
  border-left: 4px solid var(--error-color);
  font-weight: 500;
}

.inputs {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-2xl);
}

@media (min-width: 480px) {
  .inputs {
    gap: var(--spacing-lg);
  }
}

@media (min-width: 768px) {
  .inputs {
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
  }
}

.input-group {
  display: flex;
  flex-direction: column;
}

label {
  margin-bottom: var(--spacing-xs);
  font-weight: 600;
  color: var(--text-secondary);
  font-size: 0.9em;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

input[type="text"], select {
  padding: var(--spacing-sm);
  font-size: var(--font-size-base);
  border: 2px solid var(--border-color);
  border-radius: var(--border-radius-sm);
  background: #fff;
  transition: var(--transition);
  font-family: inherit;
  min-height: 44px;
}

@media (min-width: 768px) {
  input[type="text"], select {
    padding: var(--spacing-md);
  }
}

input[type="text"]:focus, select:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
  transform: translateY(-1px);
}

input[type="text"]:hover, select:hover {
  border-color: var(--border-color-hover);
}

.options {
  margin-bottom: 1em;
  padding: 1em;
  background-color: #f8f9fa;
  border-radius: 4px;
  border: 1px solid #dee2e6;
}

.options .input-group {
  margin-bottom: 0.8em;
}

.options .input-group:last-child {
  margin-bottom: 0;
}

input[type="checkbox"] {
  margin-right: var(--spacing-sm);
  width: 20px;
  height: 20px;
  min-width: 20px;
  min-height: 20px;
  accent-color: var(--primary-color);
  cursor: pointer;
}

.button-group {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
  margin-top: var(--spacing-md);
}

@media (min-width: 480px) {
  .button-group {
    flex-direction: row;
    gap: var(--spacing-md);
  }
}

.sub-button {
  padding: var(--spacing-sm) var(--spacing-xl);
  font-size: 0.9em;
  font-weight: 500;
  cursor: pointer;
  border-radius: var(--border-radius-xl);
  background: var(--background-light);
  color: var(--text-secondary);
  border: 2px solid var(--border-color);
  transition: var(--transition);
  font-family: inherit;
  min-height: 44px;
  flex: 1;
}

.sub-button:hover {
  background: var(--background-lighter);
  border-color: var(--border-color-hover);
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

.main-button {
  padding: var(--spacing-lg) var(--spacing-2xl);
  font-size: var(--font-size-lg);
  font-weight: 600;
  cursor: pointer;
  margin-bottom: var(--spacing-2xl);
  border-radius: var(--border-radius-md);
  background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
  color: white;
  border: none;
  transition: var(--transition);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  box-shadow: var(--shadow-primary);
  font-family: inherit;
  width: 100%;
  min-height: 48px;
}

.main-button:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-primary-hover);
}

.main-button:active {
  transform: translateY(0);
}

.result {
  padding: 1.5em;
  border: 2px solid #e2e8f0;
  background: linear-gradient(135deg, #f7fafc 0%, #edf2f7 100%);
  border-radius: 16px;
  white-space: pre-wrap;
  font-family: inherit;
  font-size: 1em;
  line-height: 1.6;
  box-shadow: 0 4px 20px rgba(0,0,0,0.05);
  margin-bottom: 1em;
}

@media (min-width: 768px) {
  .result {
    padding: 2em;
    border-radius: 20px;
    font-size: 1.05em;
  }
}

details {
  margin-bottom: 2em;
  border: 2px solid #e2e8f0;
  border-radius: 16px;
  overflow: hidden;
  background: #fff;
}

summary {
  padding: var(--spacing-md) var(--spacing-xl);
  background: linear-gradient(135deg, var(--background-light) 0%, var(--background-lighter) 100%);
  cursor: pointer;
  font-size: 0.95em;
  font-weight: 600;
  color: var(--text-secondary);
  border-bottom: 2px solid var(--border-color);
  transition: var(--transition);
  user-select: none;
  outline: none;
}

summary:focus {
  box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
  background: linear-gradient(135deg, var(--background-lighter) 0%, var(--border-color) 100%);
}

summary:hover {
  background: linear-gradient(135deg, var(--background-lighter) 0%, var(--border-color) 100%);
}

.details-content {
  padding: 1.5em;
  background: #fff;
}

.warning-icon {
  color: #ed8936;
  margin-right: 0.5em;
  font-size: 1.1em;
}

.tooltip {
  position: relative;
  display: inline-block;
  cursor: help;
}

.tooltip .tooltiptext {
  visibility: hidden;
  width: 280px;
  background: linear-gradient(135deg, #2d3748 0%, #4a5568 100%);
  color: #fff;
  text-align: center;
  border-radius: 12px;
  padding: 12px 16px;
  position: absolute;
  z-index: 1000;
  bottom: 150%;
  left: 50%;
  margin-left: -140px;
  opacity: 0;
  transition: all 0.3s ease;
  font-size: 0.85em;
  line-height: 1.4;
  box-shadow: 0 8px 25px rgba(0,0,0,0.2);
  font-weight: 500;
}

@media (min-width: 768px) {
  .tooltip .tooltiptext {
    width: 320px;
    margin-left: -160px;
  }
}

.tooltip .tooltiptext::after {
  content: "";
  position: absolute;
  top: 100%;
  left: 50%;
  margin-left: -6px;
  border-width: 6px;
  border-style: solid;
  border-color: #2d3748 transparent transparent transparent;
}

.tooltip:hover .tooltiptext,
.tooltip:focus .tooltiptext {
  visibility: visible;
  opacity: 1;
  transform: translateY(-4px);
}

.tooltip:focus {
  outline: 2px solid var(--primary-color);
  outline-offset: 2px;
  border-radius: 4px;
}