/* Reset and Base Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  /* GitHub Soft Dark Theme Colors */
  /* Background colors */
  --color-background: #0d1117;
  --color-surface: #161b22;
  --color-surface-elevated: #21262d;
  --color-border: #30363d;
  --color-border-hover: #484f58;

  /* Primary brand colors - subtle blues and purples from GitHub */
  --color-primary: #58a6ff;
  --color-primary-hover: #79c0ff;
  --color-primary-light: rgba(88, 166, 255, 0.1);

  --color-accent: #bc8cff;
  --color-accent-hover: #d2a8ff;

  --color-secondary: #56d364;
  --color-secondary-hover: #46c653;

  /* Text colors */
  --color-text-primary: #e6edf3;
  --color-text-secondary: #8d96a0;
  --color-text-muted: #7d8590;

  --color-success: #3fb950;
  --color-warning: #d29922;

  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 0.75rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;

  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;

  /* Typography */
  --font-sans:
    -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue",
    Arial, sans-serif;
  --font-mono:
    "SF Mono", Monaco, "Cascadia Code", "Roboto Mono", Consolas, "Courier New",
    monospace;
}

body {
  font-family: var(--font-sans);
  background: var(--color-background);
  color: var(--color-text-primary);
  line-height: 1.6;
  min-height: 100vh;
  padding: var(--spacing-xl) var(--spacing-md);
  /* Removed gradients for flat GitHub style */
}

.container {
  max-width: 1200px;
  margin: 0 auto;
}

/* Header */
.header {
  text-align: center;
  margin-bottom: var(--spacing-2xl);
  padding-bottom: var(--spacing-xl);
  border-bottom: 1px solid var(--color-border);
}

.logo {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-sm);
}

.logo-icon {
  width: 88px;
  height: 88px;
}

.header h1 {
  font-size: 2.5rem;
  font-weight: 700;
  /* Simple text color instead of gradient */
  color: var(--color-text-primary);
  letter-spacing: -0.025em;
}

.tagline {
  color: var(--color-text-secondary);
  font-size: 1.125rem;
  margin-top: var(--spacing-xs);
}

/* Form Sections */
.form-section {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--spacing-xl);
  margin-bottom: var(--spacing-xl);
  transition: border-color 0.2s ease;
}

.form-section:hover {
  border-color: var(--color-border-hover);
}

.section-header {
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-xl);
}

.step-badge {
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  /* Flat color instead of gradient */
  background: var(--color-surface-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  /* Removed shadow */
}

.step-number {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--color-primary);
  letter-spacing: 0.05em;
}

.section-title-group {
  flex: 1;
}

.section-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-xs);
  letter-spacing: -0.025em;
}

.section-description {
  color: var(--color-text-secondary);
  font-size: 0.9375rem;
}

/* Dual Input Grid */
.dual-input-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-lg);
}

/* Input Cards */
.input-card {
  background: var(--color-surface-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--spacing-lg);
  transition: all 0.2s ease;
}

.input-card:hover {
  border-color: var(--color-border-hover);
  /* Removed translateY transform for GitHub style */
}

.input-card.single {
  max-width: 100%;
}

.card-header {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-lg);
  padding-bottom: var(--spacing-md);
  border-bottom: 1px solid var(--color-border);
}

.card-header .icon {
  width: 20px;
  height: 20px;
  color: var(--color-text-secondary);
  flex-shrink: 0;
}

.card-header h3 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-text-primary);
}

/* File Upload */
.file-upload-wrapper {
  margin-bottom: var(--spacing-lg);
}

.file-upload-button {
  display: block;
  position: relative;
  cursor: pointer;
}

.file-upload-button input[type="file"] {
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
}

.file-upload-button .upload-text {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  padding: var(--spacing-md);
  background: var(--color-surface-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text-secondary);
  font-weight: 500;
  font-size: 0.9375rem;
  transition: all 0.2s ease;
}

.file-upload-button:hover .upload-text {
  background: var(--color-surface);
  border-color: var(--color-primary);
  color: var(--color-primary);
  /* Removed translateY transform */
}

.file-upload-button.secondary .upload-text {
  background: transparent;
  border-style: solid;
  color: var(--color-text-secondary);
  font-size: 0.875rem;
  padding: var(--spacing-sm) var(--spacing-md);
}

/* Divider */
.divider {
  display: flex;
  align-items: center;
  text-align: center;
  margin: var(--spacing-lg) 0;
  color: var(--color-text-muted);
  font-size: 0.875rem;
  font-weight: 500;
}

.divider::before,
.divider::after {
  content: "";
  flex: 1;
  border-bottom: 1px solid var(--color-border);
}

.divider span {
  padding: 0 var(--spacing-md);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* Textarea */
.textarea-wrapper {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.textarea-label {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text-secondary);
}

textarea {
  width: 100%;
  padding: var(--spacing-md);
  background: var(--color-background);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text-primary);
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  line-height: 1.5;
  resize: vertical;
  transition: all 0.3s ease;
}

textarea::placeholder {
  color: var(--color-text-muted);
  opacity: 0.6;
}

textarea:focus {
  outline: none;
  border-color: var(--color-primary);
  /* Removed box-shadow for cleaner GitHub style */
}

/* Text Input */
.input-label {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-sm);
}

.icon-small {
  width: 16px;
  height: 16px;
  color: var(--color-text-secondary);
  flex-shrink: 0;
}

.icon-big {
  width: 32px;
  height: 32px;
  color: var(--color-primary);
  flex-shrink: 0;
}

.text-input {
  width: 100%;
  padding: var(--spacing-md);
  background: var(--color-background);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text-primary);
  font-size: 0.9375rem;
  transition: all 0.3s ease;
}

.text-input::placeholder {
  color: var(--color-text-muted);
  opacity: 0.6;
}

.text-input:hover {
  border-color: var(--color-border-hover);
}

.text-input:focus {
  outline: none;
  border-color: var(--color-primary);
  /* Removed box-shadow */
}

.input-hint {
  margin-top: var(--spacing-sm);
  font-size: 0.8125rem;
  color: var(--color-text-muted);
}

/* Parameters Grid */
.parameters-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-lg);
}

.select-card {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.select-card.optional {
  grid-column: span 2;
}

.select-label {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--color-text-primary);
}

.optional-badge {
  margin-left: auto;
  padding: 0.25rem 0.625rem;
  background: rgba(245, 158, 11, 0.15);
  color: var(--color-warning);
  border-radius: 9999px;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.select-input {
  width: 100%;
  padding: var(--spacing-md);
  background: var(--color-background);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text-primary);
  font-size: 0.9375rem;
  cursor: pointer;
  transition: all 0.3s ease;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%2394a3b8' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right var(--spacing-md) center;
  padding-right: calc(var(--spacing-md) * 3);
}

.select-input:hover {
  border-color: var(--color-border-hover);
}

.select-input:focus {
  outline: none;
  border-color: var(--color-primary);
  /* Removed box-shadow */
}

.select-input option {
  background: var(--color-surface);
  color: var(--color-text-primary);
  padding: var(--spacing-sm);
}

/* Submit Section */
.submit-section {
  display: flex;
  justify-content: center;
  margin-top: var(--spacing-2xl);
  margin-bottom: var(--spacing-2xl);
}

.submit-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-xl);
  /* GitHub-style primary button */
  background: var(--color-primary);
  color: #0d1117;
  font-size: 0.875rem;
  font-weight: 600;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all 0.2s ease;
  /* Removed box-shadow and uppercase */
}

.submit-button:hover {
  background: var(--color-primary-hover);
  /* Removed translateY and box-shadow */
}

.submit-button:active {
  transform: scale(0.98);
}

.button-icon {
  width: 18px;
  height: 18px;
}

/* Output Container */
.output-container {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--spacing-xl);
  margin-top: var(--spacing-2xl);
  margin-bottom: var(--spacing-2xl);
}

.output-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--spacing-xl);
  padding-bottom: var(--spacing-lg);
  border-bottom: 1px solid var(--color-border);
}

.output-title-group {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.output-title-group .icon {
  width: 28px;
  height: 28px;
  color: var(--color-success);
}

.output-title-group h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-text-primary);
}

.download-form {
  display: flex;
}

.download-button {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-lg);
  background: var(--color-surface-elevated);
  color: var(--color-text-primary);
  font-size: 0.9375rem;
  font-weight: 600;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all 0.3s ease;
}

.download-button:hover {
  background: var(--color-surface-elevated);
  border-color: var(--color-primary);
  color: var(--color-primary);
  /* Removed translateY and box-shadow */
}

.download-button .button-icon {
  width: 18px;
  height: 18px;
}

/* Preview Container */
.preview-container {
  background: var(--color-background);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-sm);
}

.preview-label {
  padding: var(--spacing-sm) var(--spacing-md);
  color: var(--color-text-muted);
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  border-bottom: 1px solid var(--color-border);
  margin-bottom: var(--spacing-sm);
}

iframe {
  width: 100%;
  height: 600px;
  border: none;
  border-radius: var(--radius-md);
  background: white;
}

/* Footer */
.footer {
  text-align: center;
  padding: var(--spacing-xl) 0;
  margin-top: var(--spacing-2xl);
  border-top: 1px solid var(--color-border);
  color: var(--color-text-muted);
  font-size: 0.875rem;
}

/* Responsive Design */
@media (max-width: 768px) {
  body {
    padding: var(--spacing-md) var(--spacing-sm);
  }

  .header h1 {
    font-size: 1.875rem;
  }

  .tagline {
    font-size: 1rem;
  }

  .dual-input-grid,
  .parameters-grid {
    grid-template-columns: 1fr;
  }

  .section-header {
    flex-direction: column;
    gap: var(--spacing-md);
  }

  .step-badge {
    width: 48px;
    height: 48px;
  }

  .step-number {
    font-size: 1.125rem;
  }

  .section-title {
    font-size: 1.25rem;
  }

  .form-section {
    padding: var(--spacing-lg);
  }

  .output-header {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--spacing-md);
  }

  .submit-button {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-lg);
    font-size: 1rem;
  }

  .select-card.optional {
    grid-column: span 1;
  }

  iframe {
    height: 400px;
  }
}

@media (max-width: 480px) {
  .header h1 {
    font-size: 1.5rem;
  }

  .logo {
    flex-direction: column;
    gap: var(--spacing-sm);
  }

  .input-card {
    padding: var(--spacing-md);
  }
}