:root {
  --background-gradient: linear-gradient(135deg, #0f2027, #203a43, #2c5364);
  --glow-color-1: #24c8db;
  --glow-color-2: #1dd1a1;
  --glow-color-3: #3b82f6;
  --text-color: #fff;
  --tile-background: rgba(31, 31, 31, 0.8);
  --tile-border: #2c5364;
  --hover-glow: rgba(36, 200, 219, 0.3);
  --button-background: #1a2b3c;
  --input-background: #1a2b3c;
  --table-header-bg: #16202a;
  --table-row-bg: #23283a;
  --table-row-alt-bg: #293447;
  font-family: Inter, Avenir, Helvetica, Arial, sans-serif;
  font-size: 16px;
  line-height: 24px;
  font-weight: 400;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  -webkit-text-size-adjust: 100%;
}

/* Base styles */
* {
  box-sizing: border-box;
}

html, body {
  height: 100%;
  margin: 0;
  padding: 0;
}

body {
  min-height: calc(100vh - 24px - 89px);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  font-family: inherit;
  background: var(--background-gradient);
  background-position: fixed;
  background-repeat: no-repeat;
  background-attachment: fixed;
  background-size: cover;
  color: var(--text-color);
  padding: 0px 10px;
  overflow-x: hidden;
}

main {
  flex: 1 0 auto;
  display: flex;
  flex-direction: column;
  margin-top: 70px;
  width: 100%;
  max-width: 1200px;
}

/* Header styling */
.header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: rgba(31, 31, 31, 0.8);
  padding: 1rem 2rem;
  border-bottom: 1px solid var(--tile-border);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(10px);
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
}

.header-left h1 {
  margin: 0;
  font-size: 1.5rem;
  color: var(--text-color);
}

.header-right a {
  margin-left: 1.5rem;
  font-size: 1rem;
  color: var(--glow-color-1);
  text-decoration: none;
  transition: color 0.3s ease, text-shadow 0.3s ease;
}

.header-right a:hover {
  color: var(--glow-color-2);
  text-shadow: 0 0 5px var(--hover-glow);
}

/* Container - main tile styling */
.container {
  background: var(--tile-background);
  max-width: 1200px;
  padding: 2em 2.5em 2.5em 2.5em;
  border-radius: 18px;
  box-shadow: 0 4px 32px var(--hover-glow), 0 1.5px 0 var(--tile-border);
  border: 1.5px solid var(--tile-border);
  width: 100%;
  margin: 20px auto;
  transition: transform 0.2s, box-shadow 0.2s, border 0.2s;
}

.container:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 40px var(--hover-glow), 0 2px 0 var(--tile-border), 0 0 15px var(--glow-color-1);
  border: 1.5px solid var(--glow-color-2);
}

/* Typography */
h1, h2 {
  text-align: center;
  color: var(--text-color);
  margin-bottom: 1.5em;
}

h2 {
  margin-bottom: 1em;
  font-size: 1.5rem;
}

/* Form elements */
.form-group {
  margin-bottom: 1.5rem;
}

/* Set generation options layout */
.set-options-row {
  display: flex;
  gap: 20px;
  align-items: flex-end;
  flex-wrap: wrap;
  justify-content: center;
}

.set-options-row .form-group {
  margin-bottom: 0;
  flex: 1;
  min-width: 200px;
  max-width: 300px;
}

.set-options-row .form-group:last-child {
  flex: none;
  min-width: auto;
  display: flex;
  flex-direction: column;
  align-items: center;
}

/* Generate button centering */
.generate-section {
  text-align: center;
}

.generate-section button {
  margin: 0 auto;
  display: inline-block;
  min-width: 250px;
  padding: 1em 2em;
  font-size: 1.1em;
}

.generate-section #generateStatus {
  margin-top: 1em;
  text-align: center;
}

label {
  display: block;
  font-weight: bold;
  margin-bottom: 8px;
  color: var(--text-color);
  letter-spacing: 0.5px;
}

/* Upload section styling */
.upload-section {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  flex-wrap: wrap;
  margin-bottom: 15px;
  min-height: 50px;
}

.upload-option {
  display: flex;
  flex-direction: column;
  gap: 8px;
  align-items: center;
  min-height: 50px;
  justify-content: flex-start;
}

.upload-option select,
.upload-option button {
  height: 44px;
  min-width: 200px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 8px 12px;
  box-sizing: border-box;
  font-size: 1em;
}

.upload-option select {
  padding-right: 30px; /* Space for dropdown arrow */
}

.upload-divider {
  font-weight: bold;
  color: var(--glow-color-1);
  padding: 0 15px;
  font-size: 1.1em;
  line-height: 44px;
  height: 44px;
  display: flex;
  align-items: center;
}

#selectedFileName {
  font-size: 0.9em;
  color: var(--glow-color-2);
  margin-top: 5px;
  font-style: italic;
}

/* Input styling with hover effects */
input[type="text"], 
input[type="number"], 
input[type="file"], 
select, 
textarea {
  width: 100%;
  padding: 0.5em 0.8em;
  border: 1.5px solid var(--tile-border);
  border-radius: 7px;
  font-size: 1em;
  margin-bottom: 0.5em;
  background: var(--input-background);
  color: var(--text-color);
  transition: border 0.2s, background 0.2s, box-shadow 0.2s, transform 0.2s;
  box-shadow: 0 0 0 0 var(--glow-color-1);
}

input[type="text"]:hover, 
input[type="number"]:hover, 
input[type="file"]:hover, 
select:hover, 
textarea:hover,
input[type="text"]:focus, 
input[type="number"]:focus, 
input[type="file"]:focus, 
select:focus, 
textarea:focus {
  border: 1.5px solid var(--glow-color-2);
  outline: none;
  background: #22344a;
  box-shadow: 0 0 8px var(--hover-glow), 0 0 12px var(--glow-color-1);
  transform: translateY(-1px);
}

/* Specific input sizing */
#setNamePrefix, #csvFile {
  max-width: 300px;
}

input[type="number"] {
  max-width: 100px;
}

/* Checkbox styling */
input[type="checkbox"] {
  appearance: none;
  -webkit-appearance: none;
  -moz-appearance: none;
  width: 18px;
  height: 18px;
  border: 2px solid var(--tile-border);
  border-radius: 4px;
  background: var(--input-background);
  cursor: pointer;
  position: relative;
  transition: border 0.2s, box-shadow 0.2s, transform 0.2s;
  margin-right: 8px;
  vertical-align: middle;
}

input[type="checkbox"]:hover {
  border: 2px solid var(--glow-color-2);
  box-shadow: 0 0 8px var(--hover-glow), 0 0 12px var(--glow-color-1);
  transform: scale(1.1);
}

input[type="checkbox"]:checked {
  border: 2px solid var(--glow-color-1);
  background: var(--glow-color-1);
}

input[type="checkbox"]:checked::after {
  content: "✓";
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  color: white;
  font-size: 12px;
  font-weight: bold;
}



/* Button styling */
button {
  background: var(--button-background);
  color: var(--text-color);
  border: 1px solid transparent;
  border-radius: 8px;
  padding: 0.6em 1.2em;
  font-size: 1em;
  font-weight: 500;
  font-family: inherit;
  letter-spacing: 1px;
  box-shadow: 0 0 3px var(--hover-glow), 0 0 5px var(--glow-color-1);
  margin: 0.5rem 0.5rem 0.5rem 0;
  cursor: pointer;
  transition: box-shadow 0.3s ease, transform 0.3s ease, background 0.2s, color 0.2s, border 0.2s;
}

button:hover {
  box-shadow: 0 0 6px var(--hover-glow), 0 0 10px var(--glow-color-1);
  color: #fff;
  border: 1px solid var(--glow-color-2);
  transform: translateY(-2px);
}

button:disabled {
  background: #2c3e50;
  cursor: not-allowed;
  opacity: 0.6;
  box-shadow: none;
  transform: none;
}

button:disabled:hover {
  transform: none;
  box-shadow: none;
  border: 1px solid transparent;
}

/* Book selection grid */
.book-selection {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
  margin-top: 20px;
}

.book-item {
  background: var(--input-background);
  padding: 20px;
  border-radius: 12px;
  border: 1.5px solid var(--tile-border);
  transition: transform 0.2s, box-shadow 0.2s, border 0.2s;
}

.book-item:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 16px var(--hover-glow), 0 0 8px var(--glow-color-1);
  border: 1.5px solid var(--glow-color-2);
}

.book-item label {
  display: flex;
  align-items: center;
  margin-bottom: 15px;
  cursor: pointer;
}

.book-item strong {
  color: var(--glow-color-1);
}

.book-item small {
  color: #aaa;
  font-size: 0.9em;
  margin-top: 10px;
  display: block;
}

/* Chapter range styling */
.chapter-range {
  display: flex;
  gap: 15px;
  align-items: center;
  margin-top: 15px;
  flex-wrap: wrap;
}

.chapter-range label {
  margin: 0;
  white-space: nowrap;
  font-size: 0.9em;
}

.chapter-range input {
  width: 70px;
  margin: 0;
}

/* Status messages */
.info {
  color: var(--text-color);
  background: var(--tile-background);
  padding: 15px;
  border-radius: 8px;
  margin-bottom: 15px;
  box-shadow: 0 2px 4px var(--hover-glow), 0 0 8px var(--glow-color-1);
  border: 1px solid var(--tile-border);
}

.success {
  color: #2e7d32;
  background: rgba(76, 175, 80, 0.1);
  border: 1px solid #4caf50;
  padding: 15px;
  border-radius: 8px;
  margin-bottom: 15px;
}

.error {
  color: #d32f2f;
  background: rgba(244, 67, 54, 0.1);
  border: 1px solid #f44336;
  padding: 15px;
  border-radius: 8px;
  margin-bottom: 15px;
}

.warning {
  color: #f57c00;
  background: rgba(255, 152, 0, 0.1);
  border: 1px solid #ff9800;
  padding: 15px;
  border-radius: 8px;
  margin-bottom: 15px;
}

.warning span {
  color: #f57c00;
  font-weight: bold;
}

/* File info styling */
.file-info {
  background: var(--table-row-bg);
  border: 1px solid var(--tile-border);
  padding: 15px;
  border-radius: 8px;
  margin-top: 15px;
  font-size: 0.9em;
  line-height: 1.5;
}

/* Results section */
.set-info {
  background: var(--input-background);
  padding: 15px;
  border-radius: 8px;
  margin-bottom: 15px;
  border: 1px solid var(--tile-border);
  transition: transform 0.2s, box-shadow 0.2s;
}

.set-info:hover {
  transform: translateY(-1px);
  box-shadow: 0 2px 8px var(--hover-glow);
}

/* Download buttons */
.download-buttons {
  display: flex;
  gap: 15px;
  flex-wrap: wrap;
  justify-content: center;
  margin-top: 20px;
}

.download-buttons button {
  min-width: 200px;
}

/* Radio button styling from example.css */
input[type="radio"] {
  appearance: none;
  -webkit-appearance: none;
  -moz-appearance: none;
  width: 20px;
  height: 20px;
  border: 2px solid var(--tile-border);
  border-radius: 50%;
  background: var(--input-background);
  cursor: pointer;
  position: relative;
  transition: border 0.2s, box-shadow 0.2s, transform 0.2s;
  flex-shrink: 0;
  flex-grow: 0;
  flex-basis: auto;
  margin: 0;
  padding: 0;
  margin-right: 8px;
  vertical-align: middle;
}

input[type="radio"]:hover {
  border: 2px solid var(--glow-color-2);
  box-shadow: 0 0 8px var(--hover-glow), 0 0 12px var(--glow-color-1);
  transform: scale(1.1);
}

input[type="radio"]:checked {
  border: 2px solid var(--glow-color-1);
  background: var(--glow-color-1);
}

input[type="radio"]:checked::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: white;
}

.radio-container {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  justify-content: flex-start;
  gap: 8px;
  margin-top: 5px;
}

.radio-option {
  display: flex;
  align-items: center;
  cursor: pointer;
  color: var(--text-color);
  font-size: 1em;
  transition: color 0.2s;
}

.radio-option:hover {
  color: var(--glow-color-2);
}

.radio-label {
  margin-left: 5px;
  user-select: none;
}

.radio-group-label {
  font-weight: 500;
  color: var(--text-color);
  margin-bottom: 5px;
}

/* Footer styling */
.footer {
  background: rgba(31, 31, 31, 0.8);
  color: var(--text-color);
  text-align: center;
  padding: 1rem;
  border-top: 1px solid var(--tile-border);
  box-shadow: 0 -2px 4px rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(10px);
  width: 100vw;
  position: static;
  left: 0;
  bottom: 0;
  margin-top: auto;
  margin-left: -10px;
  margin-right: -10px;
}

.footer a {
  color: var(--glow-color-1);
  text-decoration: none;
  transition: color 0.3s ease;
}

.footer a:hover {
  color: var(--glow-color-2);
}

/* Responsive design */
@media (max-width: 768px) {
  .header {
    padding: 1rem;
    width: 100%;
  }
  
  .header-right {
    display: none;
  }
  
  .container {
    padding: 1.5em;
    margin: 10px auto;
  }
  
  .book-selection {
    grid-template-columns: 1fr;
  }
  
  .chapter-range {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
  }
  
  .chapter-range input {
    width: 100px;
  }
  
  .download-buttons {
    flex-direction: column;
  }
  
  .download-buttons button {
    width: 100%;
    min-width: auto;
  }
  
  body {
    padding: 0px 5px;
  }
  
  .footer {
    margin-left: -5px;
    margin-right: -5px;
  }
  
  .upload-section {
    flex-direction: column;
    align-items: center;
    gap: 15px;
  }
  
  .upload-option {
    width: 100%;
    max-width: 300px;
  }
  
  .upload-option select,
  .upload-option button {
    width: 100%;
    min-width: auto;
  }
  
  .upload-divider {
    padding: 10px 0;
    order: 1;
  }
  
  .upload-option:first-child {
    order: 0;
  }
  
  .upload-option:last-child {
    order: 2;
  }
  
  .set-options-row {
    flex-direction: column;
    gap: 15px;
    align-items: center;
  }
  
  .set-options-row .form-group {
    width: 100%;
    max-width: 300px;
    min-width: auto;
  }
  
  .generate-section button {
    min-width: auto;
    width: 100%;
    max-width: 300px;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 1em;
  }
  
  h1 {
    font-size: 1.5rem;
  }
  
  h2 {
    font-size: 1.3rem;
  }
  
  .chapter-range {
    gap: 8px;
  }
  
  .chapter-range input {
    width: 80px;
  }
}