/* ============================================
   StudyForge - Student AI Text Humanizer
   Clean, simple, no live mode
   ============================================ */

:root {
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-card: #1e293b;
  --bg-input: #334155;
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --accent: #38bdf8;
  --accent-hover: #0ea5e9;
  --success: #22c55e;
  --warning: #f59e0b;
  --danger: #ef4444;
  --border: #334155;
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
  --radius: 12px;
  --transition: all 0.3s ease;
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  line-height: 1.6;
}

.app {
  max-width: 1100px;
  margin: 0 auto;
  padding: 40px 20px;
}

/* Header */
.header {
  text-align: center;
  margin-bottom: 48px;
}

.logo {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.logo .highlight {
  color: var(--accent);
}

.tagline {
  color: var(--text-secondary);
  font-size: 1.1rem;
}

/* Layout */
.layout-two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
  align-items: start;
}

@media (max-width: 900px) {
  .layout-two-col {
    grid-template-columns: 1fr;
  }
}

.left-col, .right-col {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

/* Cards */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--shadow);
}

.card-header {
  margin-bottom: 24px;
}

.card-header h2 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.card-header p {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

/* Form Elements */
.form-group {
  margin-bottom: 20px;
}

.form-group.full-width {
  grid-column: 1 / -1;
}

.form-group label {
  display: block;
  font-weight: 600;
  margin-bottom: 8px;
  color: var(--text-primary);
  font-size: 0.9rem;
}

.form-group textarea {
  width: 100%;
  padding: 12px 16px;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-primary);
  font-family: inherit;
  font-size: 0.95rem;
  transition: var(--transition);
  resize: vertical;
  min-height: 100px;
}

.form-group textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.1);
}

/* Buttons */
.form-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border: none;
  border-radius: 8px;
  font-family: inherit;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
}

.btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.btn-primary {
  background: var(--accent);
  color: var(--bg-primary);
}

.btn-primary:hover:not(:disabled) {
  background: var(--accent-hover);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(56,189,248,0.15);
}

.btn-secondary {
  background: var(--bg-input);
  color: var(--text-primary);
  border: 1px solid var(--border);
}

.btn-secondary:hover:not(:disabled) {
  background: var(--border);
}

.btn-icon-only {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--border);
  padding: 8px 16px;
}

.btn-icon-only:hover {
  color: var(--accent);
  border-color: var(--accent);
}

.btn-icon {
  font-size: 1.1rem;
}

/* Spinner */
.spinner {
  display: inline-block;
  width: 16px;
  height: 16px;
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-top-color: white;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* Toggle Switch */
.toggle-switch {
  position: relative;
  width: 44px;
  height: 24px;
  cursor: pointer;
  flex-shrink: 0;
}

.toggle-switch input {
  opacity: 0;
  width: 0;
  height: 0;
}

.toggle-slider {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: #475569;
  border-radius: 24px;
  transition: 0.3s;
}

.toggle-slider::before {
  content: "";
  position: absolute;
  height: 18px;
  width: 18px;
  left: 3px;
  bottom: 3px;
  background: #fff;
  border-radius: 50%;
  transition: 0.3s;
  box-shadow: 0 1px 4px rgba(0,0,0,0.2);
}

.toggle-switch input:checked + .toggle-slider {
  background: var(--accent);
}

.toggle-switch input:checked + .toggle-slider::before {
  transform: translateX(20px);
}

/* Humanization Controls */
.humanization-controls {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px 20px;
}

@media (max-width: 600px) {
  .humanization-controls {
    grid-template-columns: 1fr;
  }
}

.control-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px 14px;
}

.control-item.full-width {
  grid-column: 1 / -1;
  flex-direction: column;
  align-items: stretch;
  gap: 8px;
}

.control-item .toggle-label {
  font-weight: 500;
  font-size: 0.9rem;
}

.control-item .range-label {
  font-weight: 600;
  font-size: 0.95rem;
  margin-bottom: 4px;
}

.range-slider {
  -webkit-appearance: none;
  width: 100%;
  height: 8px;
  border-radius: 4px;
  background: var(--bg-input);
  outline: none;
  margin: 8px 0 4px 0;
}

.range-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
  border: none;
}

.range-slider::-moz-range-thumb {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
  border: none;
}

.range-marks {
  display: flex;
  justify-content: space-between;
  font-size: 0.75rem;
  color: var(--text-secondary);
  margin-top: 2px;
}

/* Output Section */
.output-section {
  display: none;
}

.output-section.active {
  display: block;
}

.output-meta {
  display: flex;
  gap: 16px;
  font-size: 0.85rem;
  color: var(--text-secondary);
  flex-wrap: wrap;
}

.output-box {
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 24px;
  min-height: 200px;
  white-space: pre-wrap;
  font-size: 0.95rem;
  line-height: 1.8;
  color: var(--text-primary);
}

.output-box.placeholder-text {
  color: var(--text-secondary);
  font-style: italic;
}

.output-actions {
  display: flex;
  gap: 12px;
  margin-top: 16px;
  flex-wrap: wrap;
}

/* Tips */
.tips-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}

.tip-card {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 14px;
}

.tip-num {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  min-width: 28px;
  background: var(--accent);
  color: var(--bg-primary);
  border-radius: 50%;
  font-weight: 700;
  font-size: 0.85rem;
}

.tip-card p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.5;
  margin: 0;
}

.tip-card b {
  color: var(--text-primary);
}

/* Toast */
.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--bg-card);
  color: var(--text-primary);
  padding: 12px 24px;
  border-radius: 8px;
  border: 1px solid var(--border);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
  z-index: 1000;
  animation: toastIn 0.3s ease;
  font-weight: 500;
}

@keyframes toastIn {
  from {
    opacity: 0;
    transform: translateX(-50%) translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
  }
}

/* Footer */
.footer {
  text-align: center;
  padding: 48px 0 24px;
  color: var(--text-secondary);
  font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 600px) {
  .app {
    padding: 20px 16px;
  }

  .logo {
    font-size: 2rem;
  }

  .card {
    padding: 24px 16px;
  }

  .humanization-controls {
    grid-template-columns: 1fr;
  }
}