:root {
  --primary: #6366f1;
  --primary-gradient: linear-gradient(135deg, #6366f1, #8b5cf6);
  --success: #10b981;
  --error: #ef4444;
  --warning: #f59e0b;
}

/* Default = Dark Mode */
body {
  --text: #f1f5f9;
  --text-light: #cbd5e1;
  --bg: #0f172a;
  --card-bg: #1e293b;
  --card-border: #334155;
  --shadow: 0 12px 32px rgba(0, 0, 0, 0.5);
  --border: #334155;
  --input-bg: #334155;
  --input-border: #475569;
  --input-text: #f1f5f9;
  --placeholder: #94a3b8;
  --table-bg: #1e293b;
  --table-header-bg: #334155;
  --table-border: #475569;
  --pagination-bg: #334155;
  --pagination-hover: #475569;

  font-family: 'Inter', 'Noto Sans Khmer', sans-serif;
  background: var(--bg);
  color: var(--text);
  margin: 0;
  padding: 20px;
  min-height: 100vh;
  transition: all 0.6s ease;
  box-sizing: border-box;
}

/* Light Mode */
body.light {
  --text: #1e293b;
  --text-light: #64748b;
  --bg: #f8fafc;
  --card-bg: #ffffff;
  --card-border: #cbd5e1;
  --shadow: 0 12px 32px rgba(0, 0, 0, 0.15);
  --border: #cbd5e1;
  --input-bg: #ffffff;
  --input-border: #94a3b8;
  --input-text: #1e293b;
  --placeholder: #94a3b8;
  --table-bg: #ffffff;
  --table-header-bg: #e0e7ff;
  --table-border: #cbd5e1;
  --pagination-bg: #e0e7ff;
  --pagination-hover: #c7d2fe;
}

/* Base Styles */
h1, h2, h3 { 
  color: var(--primary); 
  text-align: center; 
  margin: 0 0 8px 0; 
  line-height: 1.3;
}

h1 {
  font-size: clamp(1.8rem, 4vw, 2.5rem);
  margin-bottom: 12px;
}

h2 {
  font-size: clamp(1.5rem, 3vw, 2rem);
  margin-bottom: 20px;
}

h3 {
  font-size: clamp(1.2rem, 2.5vw, 1.5rem);
  margin: 25px 0 15px 0;
}

.container { 
  max-width: 1200px; 
  margin: 0 auto; 
  position: relative;
  padding: 10px;
}

.header { 
  text-align: center; 
  margin-bottom: 40px; 
  padding: 20px 0;
}

.header p {
  font-size: clamp(1rem, 2vw, 1.2rem);
  color: var(--text-light);
  max-width: 600px;
  margin: 0 auto;
  line-height: 1.6;
}

/* Dark Mode Toggle */
.dark-toggle {
  position: fixed;
  top: 20px;
  right: 20px;
  background: var(--card-bg);
  border: 3px solid var(--card-border);
  padding: 12px;
  border-radius: 50px;
  cursor: pointer;
  box-shadow: var(--shadow);
  font-size: 26px;
  width: 56px;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.3s ease;
  z-index: 1000;
}
.dark-toggle:hover { transform: scale(1.1); }

/* Cards */
.card {
  background: var(--card-bg);
  padding: clamp(20px, 4vw, 32px);
  border-radius: 24px;
  box-shadow: var(--shadow);
  margin-bottom: 40px;
  border: 2px solid var(--card-border);
  transition: all 0.6s ease;
  width: 100%;
  box-sizing: border-box;
}

/* Textarea */
textarea {
  width: 100%;
  min-height: 150px;
  padding: 20px;
  border: 2px solid var(--input-border);
  border-radius: 20px;
  font-size: clamp(16px, 2vw, 17px);
  background: var(--input-bg);
  color: var(--input-text);
  resize: vertical;
  font-family: inherit;
  transition: all 0.6s ease;
  box-sizing: border-box;
  min-height: 150px;
  max-height: 400px;
}
textarea::placeholder { 
  color: var(--placeholder); 
  opacity: 0.8; 
  font-size: clamp(14px, 2vw, 16px);
}
textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 4px rgba(99, 102, 241, 0.3);
}

/* Controls */
.controls {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  margin-top: 20px;
  gap: 15px;
}

.button-container { 
  flex-shrink: 0; 
}

button {
  flex: 1 1 auto;
  max-width: 250px;
  width: 100%;
  background: var(--primary-gradient);
  color: white;
  border: none;
  padding: clamp(12px, 3vw, 16px) clamp(24px, 4vw, 40px);
  border-radius: 50px;
  cursor: pointer;
  font-size: clamp(16px, 2vw, 18px);
  font-weight: 600;
  transition: all 0.3s ease;
  box-shadow: 0 8px 25px rgba(99, 102, 241, 0.4);
  white-space: nowrap;
}
button:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 35px rgba(99, 102, 241, 0.5);
}
button:active {
  transform: translateY(-1px);
}

.word-count {
  font-size: clamp(14px, 2vw, 15px);
  color: var(--text-light);
  font-weight: 500;
  white-space: nowrap;
}
.word-limit-warning { 
  color: var(--error); 
  font-weight: 700; 
  animation: pulse 2s infinite;
}
@keyframes pulse {
  0% { opacity: 1; }
  50% { opacity: 0.7; }
  100% { opacity: 1; }
}

/* Result Section */
.result {
  margin-top: 30px;
  padding: clamp(20px, 4vw, 28px);
  background: rgba(99, 102, 241, 0.15);
  border-radius: 20px;
  border-left: 8px solid var(--primary);
  border: 1px solid var(--border);
  animation: fadeIn 0.6s ease;
  width: 100%;
  box-sizing: border-box;
  word-wrap: break-word;
}
@keyframes fadeIn { 
  from { opacity: 0; transform: translateY(20px); } 
  to { opacity: 1; transform: translateY(0); } 
}

/* Feedback Buttons */
.feedback-buttons { 
  text-align: center; 
  margin: 30px 0;
  display: flex;
  justify-content: center;
  gap: 20px;
  flex-wrap: wrap;
}
.feedback-btn {
  font-size: clamp(40px, 8vw, 52px);
  cursor: pointer;
  padding: clamp(12px, 3vw, 16px);
  border-radius: 20px;
  display: inline-block;
  transition: all 0.3s ease;
  margin: 0 clamp(10px, 3vw, 30px);
}
.feedback-btn.liked { 
  background: rgba(16, 185, 129, 0.25); 
  transform: scale(1.2); 
}
.feedback-btn.disliked { 
  background: rgba(239, 68, 68, 0.25); 
  transform: scale(1.2); 
}
.feedback-btn:hover { transform: scale(1.1); }

/* Probability Table */
#prob-table {
  width: 100%;
  margin-top: 15px;
  border-collapse: collapse;
}
#prob-table th, 
#prob-table td {
  padding: 12px 15px;
  text-align: left;
  border-bottom: 1px solid var(--border);
}
#prob-table th {
  font-weight: 600;
  color: var(--primary);
  background: transparent;
}
#prob-table td {
  color: var(--text);
}

/* Pagination Controls */
.pagination-controls {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 15px;
  margin-bottom: 20px;
  padding: 15px;
  background-color: var(--pagination-bg);
  border-radius: 12px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.page-info-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  min-width: 150px;
}

#page-info {
  font-weight: 600;
  color: var(--text);
  font-size: clamp(14px, 2vw, 16px);
}

.page-jump {
  display: flex;
  gap: 8px;
  align-items: center;
}

.page-input {
  width: 60px;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--input-bg);
  color: var(--input-text);
  text-align: center;
  font-size: 14px;
}

.pagination-btn {
  padding: 10px 20px;
  border: none;
  border-radius: 8px;
  background-color: var(--primary);
  color: white;
  cursor: pointer;
  font-weight: 500;
  transition: all 0.2s;
  font-size: clamp(14px, 2vw, 16px);
}
.pagination-btn.small {
  padding: 8px 15px;
  font-size: 14px;
}
.pagination-btn:hover:not(:disabled) {
  background-color: var(--primary);
  opacity: 0.9;
  transform: translateY(-2px);
}
.pagination-btn:disabled {
  background-color: var(--border);
  cursor: not-allowed;
  opacity: 0.5;
}

/* Refresh Button */
.refresh-container {
  display: flex;
  justify-content: flex-end;
  margin-bottom: 15px;
}
.refresh-btn {
  background: var(--pagination-bg);
  color: var(--text);
  padding: 10px 20px;
  border-radius: 8px;
  border: 1px solid var(--border);
  font-size: 14px;
}
.refresh-btn:hover {
  background: var(--pagination-hover);
}

/* History Table Container */
.table-container {
  overflow-x: auto;
  margin: 20px 0;
  border-radius: 12px;
  border: 1px solid var(--border);
}

/* History Table */
#history-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 600px;
}
#history-table th, 
#history-table td {
  padding: 15px;
  text-align: left;
  border-bottom: 1px solid var(--border);
  background: var(--table-bg);
}
#history-table th {
  font-weight: 600;
  color: var(--primary);
  background: var(--table-header-bg);
  font-size: clamp(14px, 2vw, 16px);
  position: sticky;
  top: 0;
}
#history-table tbody tr:hover {
  background: rgba(99, 102, 241, 0.1);
}

/* Table Column Sizes */
.time-col { width: 180px; min-width: 150px; }
.text-col { width: 40%; min-width: 200px; }
.topic-col { width: 120px; min-width: 100px; }
.acc-col { width: 100px; min-width: 80px; }
.feedback-col { width: 80px; min-width: 60px; text-align: center; }

/* Loader */
.loader {
  display: none;
  text-align: center;
  margin: 40px;
  font-size: clamp(18px, 3vw, 20px);
  color: var(--primary);
}
.loader::after {
  content: '';
  display: inline-block;
  width: 32px;
  height: 32px;
  border: 4px solid var(--primary);
  border-top-color: transparent;
  border-radius: 50%;
  animation: spin 1s linear infinite;
  margin-left: 16px;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* No History Message */
#no-history {
  text-align: center;
  color: var(--text-light);
  font-style: italic;
  padding: 40px;
  display: none;
}

/* Responsive Design */
@media (max-width: 768px) {
  body {
    padding: 10px;
  }
  
  .container {
    padding: 5px;
  }
  
  .card {
    padding: 20px;
    border-radius: 20px;
    margin-bottom: 30px;
  }
  
  .dark-toggle {
    top: 10px;
    right: 10px;
    width: 48px;
    height: 48px;
    font-size: 22px;
  }
  
  .controls {
    flex-direction: column;
    align-items: stretch;
    gap: 15px;
  }
  
  .button-container {
    width: 100%;
  }
  
  button {
    width: 100%;
  }
  
  .word-count {
    text-align: center;
    width: 100%;
  }
  
  .pagination-controls {
    flex-direction: column;
    gap: 12px;
  }
  
  .page-info-container {
    order: 2;
  }
  
  #prev-page {
    order: 1;
    width: 100%;
  }
  
  #next-page {
    order: 3;
    width: 100%;
  }
  
  .page-jump {
    width: 100%;
    justify-content: center;
  }
  
  .page-input {
    flex-grow: 1;
    max-width: 80px;
  }
  
  .refresh-container {
    justify-content: center;
  }
  
  .feedback-buttons {
    gap: 10px;
  }
  
  .feedback-btn {
    margin: 0;
  }
  
  #history-table th,
  #history-table td {
    padding: 12px 8px;
    font-size: 14px;
  }
  
  .time-col { width: 140px; }
  .text-col { min-width: 180px; }
  .topic-col { width: 100px; }
  .acc-col { width: 80px; }
  .feedback-col { width: 60px; }
}

@media (max-width: 480px) {
  h1 {
    font-size: 1.6rem;
  }
  
  h2 {
    font-size: 1.3rem;
  }
  
  textarea {
    height: 150px;
    padding: 15px;
    font-size: 15px;
  }
  
  .result {
    padding: 15px;
  }
  
  .feedback-btn {
    font-size: 36px;
    padding: 10px;
  }
  
  #history-table th,
  #history-table td {
    padding: 10px 6px;
    font-size: 13px;
  }
  
  .time-col { width: 120px; }
  .text-col { min-width: 150px; }
}