/* ===== Global Variables ===== */
:root {
  --primary: #2f61f3;
  --success: #45B7D1;
  --danger: #f44336;
  --warning: #ff9800;
  --ink: #1a1a1a;
  --ink-soft: #666;
  --card: #fff;
  --border: #e0e0e0;
  --radius: 12px;
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.15);
}

/* ===== Base Styles ===== */
* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 0;
  font-family: 'Open Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  color: var(--ink);
  line-height: 1.6;
  position: relative;
  overflow-x: hidden;
  
  /* ===== Rough Paper Texture Background ===== */
  background-color: #e8e8e8;
  background-image:
    /* Paper grain texture - fine noise */
    radial-gradient(circle at 13% 47%, rgba(0, 0, 0, 0.02) 0%, transparent 50%),
    radial-gradient(circle at 67% 13%, rgba(255, 255, 255, 0.03) 0%, transparent 50%),
    radial-gradient(circle at 89% 82%, rgba(0, 0, 0, 0.015) 0%, transparent 50%),
    radial-gradient(circle at 31% 91%, rgba(255, 255, 255, 0.025) 0%, transparent 50%),
    radial-gradient(circle at 52% 24%, rgba(0, 0, 0, 0.018) 0%, transparent 50%),
    radial-gradient(circle at 8% 68%, rgba(255, 255, 255, 0.02) 0%, transparent 50%),
    radial-gradient(circle at 94% 37%, rgba(0, 0, 0, 0.022) 0%, transparent 50%),
    radial-gradient(circle at 43% 56%, rgba(255, 255, 255, 0.028) 0%, transparent 50%),
    radial-gradient(circle at 78% 71%, rgba(0, 0, 0, 0.016) 0%, transparent 50%),
    radial-gradient(circle at 22% 15%, rgba(255, 255, 255, 0.024) 0%, transparent 50%),
    
    /* Medium grain texture */
    radial-gradient(circle at 37% 62%, rgba(0, 0, 0, 0.025) 0%, transparent 40%),
    radial-gradient(circle at 71% 28%, rgba(255, 255, 255, 0.035) 0%, transparent 40%),
    radial-gradient(circle at 18% 84%, rgba(0, 0, 0, 0.02) 0%, transparent 40%),
    radial-gradient(circle at 84% 51%, rgba(255, 255, 255, 0.03) 0%, transparent 40%),
    radial-gradient(circle at 56% 9%, rgba(0, 0, 0, 0.028) 0%, transparent 40%),
    radial-gradient(circle at 4% 33%, rgba(255, 255, 255, 0.022) 0%, transparent 40%),
    radial-gradient(circle at 91% 76%, rgba(0, 0, 0, 0.019) 0%, transparent 40%),
    radial-gradient(circle at 47% 95%, rgba(255, 255, 255, 0.026) 0%, transparent 40%),
    
    /* Larger variations for depth */
    radial-gradient(circle at 63% 44%, rgba(0, 0, 0, 0.012) 0%, transparent 60%),
    radial-gradient(circle at 26% 73%, rgba(255, 255, 255, 0.015) 0%, transparent 60%),
    radial-gradient(circle at 88% 19%, rgba(0, 0, 0, 0.014) 0%, transparent 60%),
    radial-gradient(circle at 11% 58%, rgba(255, 255, 255, 0.018) 0%, transparent 60%),
    radial-gradient(circle at 74% 87%, rgba(0, 0, 0, 0.016) 0%, transparent 60%),
    radial-gradient(circle at 39% 22%, rgba(255, 255, 255, 0.013) 0%, transparent 60%),
    
    /* Subtle directional grain */
    linear-gradient(90deg, transparent 0%, rgba(0, 0, 0, 0.005) 50%, transparent 100%),
    linear-gradient(180deg, transparent 0%, rgba(255, 255, 255, 0.008) 50%, transparent 100%),
    linear-gradient(45deg, transparent 0%, rgba(0, 0, 0, 0.004) 50%, transparent 100%),
    linear-gradient(135deg, transparent 0%, rgba(255, 255, 255, 0.006) 50%, transparent 100%);
  
  background-size:
    /* Fine noise patterns */
    3px 3px, 4px 4px, 3.5px 3.5px, 4.2px 4.2px, 3.8px 3.8px,
    4.5px 4.5px, 3.2px 3.2px, 4.8px 4.8px, 3.6px 3.6px, 4.1px 4.1px,
    /* Medium grain */
    8px 8px, 9px 9px, 7.5px 7.5px, 8.5px 8.5px, 9.2px 9.2px,
    7.8px 7.8px, 8.8px 8.8px, 9.5px 9.5px,
    /* Larger variations */
    15px 15px, 16px 16px, 14.5px 14.5px, 15.5px 15.5px, 16.5px 16.5px, 14px 14px,
    /* Directional grain */
    100% 200px, 200px 100%, 100% 150px, 150px 100%;
  
  background-position:
    0 0, 2px 2px, 1px 3px, 3px 1px, 2px 4px,
    4px 2px, 1px 1px, 3px 4px, 4px 3px, 2px 1px,
    0 0, 4px 4px, 2px 5px, 5px 2px, 3px 6px,
    6px 3px, 4px 1px, 5px 5px,
    0 0, 8px 8px, 4px 10px, 10px 4px, 6px 12px, 12px 6px,
    0 0, 0 0, 0 0, 0 0;
  
  background-repeat: repeat;
}

.container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 12px 20px;
  position: relative;
  z-index: 1;
}

/* ===== Typography ===== */
h1, h2, h3, h4, h5, h6 {
  margin: 0 0 16px 0;
  font-weight: 700;
  line-height: 1.2;
}

/* ===== Cards ===== */
.card {
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  padding: 20px;
  margin-bottom: 16px;
  border: 1px solid var(--border);
  max-width: 80%;
  margin-left: auto;
  margin-right: auto;
}

/* ===== Buttons ===== */
.btn {
  display: inline-block;
  padding: 10px 20px;
  font-size: 15px;
  font-weight: 600;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.2s ease;
  text-decoration: none;
  font-family: inherit;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn.primary {
  background: #5cb85c;
  color: #fff;
}

.btn.primary:hover:not(:disabled) {
  background: #4cae4c;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.btn.danger {
  background: var(--danger);
  color: #fff;
}

.btn.danger:hover:not(:disabled) {
  background: #d32f2f;
}

.btn.btn-blue {
  background: var(--success);
  color: #fff;
}

.btn.btn-blue:hover:not(:disabled) {
  background: #3a9fb8;
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

/* ===== Forms ===== */
.field {
  margin-bottom: 20px;
}

.field label {
  display: block;
  margin-bottom: 8px;
  font-weight: 600;
  color: var(--ink);
}

select, input[type="text"], input[type="number"] {
  width: 100%;
  padding: 10px 14px;
  font-size: 16px;
  border: 2px solid var(--border);
  border-radius: 8px;
  font-family: inherit;
  background: #fff;
  transition: all 0.2s ease;
}

select:focus, input[type="text"]:focus, input[type="number"]:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(47, 97, 243, 0.1);
}

/* ===== Segmented Control ===== */
.seg {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.seg-btn {
  flex: 1;
  min-width: 120px;
  padding: 12px 16px;
  border: 2px solid var(--border);
  background: #fff;
  color: var(--ink);
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.2s ease;
  font-weight: 600;
  font-size: 14px;
}

.seg-btn:hover {
  border-color: var(--primary);
  background: rgba(47, 97, 243, 0.05);
}

.seg-btn.active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

/* ===== Actions ===== */
.actions {
  display: flex;
  gap: 12px;
  justify-content: stretch;
  margin-top: 16px;
}

.actions .btn {
  flex: 1;
  text-align: center;
}

/* ===== Quiz Specific Styles ===== */
.title-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
  padding: 12px 0;
  border-bottom: 2px solid var(--border);
  flex-wrap: wrap;
  gap: 12px;
  max-width: 80%;
  margin-left: auto;
  margin-right: auto;
}

.category-header-right {
  display: flex;
  align-items: center;
  gap: 12px;
}

.category-icon-large {
  font-size: 26px;
}

.title-bar h1 {
  margin: 0;
  font-size: clamp(20px, 2.5vw, 26px);
}

.resume-container {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 8px;
}

.resume-container.hidden {
  display: none;
}

.remaining-count {
  font-size: 14px;
  color: var(--ink-soft);
  font-weight: 600;
}

/* Question */
.question {
  font-size: 18px;
  font-weight: 700;
  color: var(--ink);
  margin-bottom: 16px;
  line-height: 1.4;
}

/* Options */
.options {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-bottom: 16px;
}

.opt {
  position: relative;
  cursor: pointer;
}

.opt input {
  position: absolute;
  opacity: 0;
  cursor: pointer;
}

.opt label {
  display: flex;
  align-items: center;
  padding: 12px 16px;
  background: #fff;
  border: 2px solid var(--border);
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.2s ease;
  font-size: 15px;
}

/* Default hover - green */
.opt label:hover {
  border-color: #4caf50;
  background: rgba(76, 175, 80, 0.08);
  transform: translateX(4px);
}

/* Selected state - green */
.opt input:checked + label {
  background: rgba(76, 175, 80, 0.15);
  border-color: #4caf50;
}

.opt input:disabled + label {
  cursor: not-allowed;
  opacity: 0.7;
}

.opt input:disabled + label:hover {
  transform: none;
  border-color: var(--border);
  background: #fff;
}

/* Correct answer highlight after submission */
.opt.correct-answer label {
  background: rgba(76, 175, 80, 0.2) !important;
  border-color: #4caf50 !important;
  opacity: 1 !important;
}

.opt.correct-answer label .k {
  background: #4caf50 !important;
}

/* Wrong answer highlight after submission */
.opt.wrong-answer label {
  background: rgba(244, 67, 54, 0.15) !important;
  border-color: #f44336 !important;
  opacity: 1 !important;
}

.opt.wrong-answer label .k {
  background: #f44336 !important;
}

.opt .k {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 28px;
  height: 28px;
  background: var(--primary);
  color: #fff;
  border-radius: 6px;
  font-weight: 700;
  margin-right: 10px;
  font-size: 13px;
}

/* Selected key badge - green */
.opt input:checked + label .k {
  background: #4caf50;
}

.opt .ans {
  flex: 1;
  font-weight: 500;
}

/* Single-select: Remove hover from unselected options once something is selected */
.options.has-selection .opt label:not(:has(input:checked)):hover {
  border-color: var(--border);
  background: #fff;
  transform: none;
}

/* Multi-select: Keep green hover on all unselected options */
.options.is-multi-select .opt label:not(:has(input:checked)):hover {
  border-color: #4caf50;
  background: rgba(76, 175, 80, 0.08);
  transform: translateX(4px);
}

/* Feedback */
.feedback {
  padding: 16px 20px;
  border-radius: 8px;
  font-weight: 700;
  font-size: 18px;
  margin-bottom: 16px;
  text-align: center;
}

.feedback.hidden {
  display: none;
}

.feedback.ok {
  background: rgba(76, 175, 80, 0.1);
  color: #2e7d32;
  border: 2px solid #4caf50;
}

.feedback.bad {
  background: rgba(244, 67, 54, 0.1);
  color: #c62828;
  border: 2px solid #f44336;
}

.answer-line {
  padding: 16px 20px;
  background: rgba(47, 97, 243, 0.05);
  border-left: 4px solid var(--primary);
  border-radius: 4px;
  margin-bottom: 16px;
  font-size: 15px;
  line-height: 1.8;
}

.answer-line.hidden {
  display: none;
}

.rationale {
  padding: 16px 20px;
  background: rgba(69, 183, 209, 0.05);
  border-left: 4px solid var(--success);
  border-radius: 4px;
  margin-bottom: 16px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-soft);
}

.rationale.hidden {
  display: none;
}

/* Counters */
.counters {
  margin-bottom: 20px;
}

.count-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  font-size: 16px;
  font-weight: 600;
  color: var(--ink);
}

/* Progress Bar */
.pbar-wrap {
  position: relative;
  margin-top: 16px;
}

.pbar {
  width: 100%;
  height: 20px;
  background: #e0e0e0;
  border-radius: 10px;
  overflow: hidden;
  position: relative;
}

.pbar-fill {
  height: 100%;
  background: var(--primary);
  transition: width 0.5s ease, background-color 0.5s ease;
  border-radius: 10px;
}

.pbar-label {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-weight: 700;
  font-size: 11px;
  color: var(--ink);
  text-shadow: 0 0 4px #fff;
  pointer-events: none;
}

/* Summary */
.first-try {
  padding: 20px;
  background: rgba(69, 183, 209, 0.1);
  border-radius: 8px;
  margin-bottom: 24px;
  font-size: 16px;
}

.review-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.rev-item {
  padding: 20px;
  border-radius: 8px;
  border: 2px solid var(--border);
  background: #fff;
}

.rev-item.ok {
  border-color: #4caf50;
  background: rgba(76, 175, 80, 0.05);
}

.rev-item.bad {
  border-color: #f44336;
  background: rgba(244, 67, 54, 0.05);
}

.rev-q {
  font-weight: 700;
  margin-bottom: 12px;
  font-size: 16px;
  color: var(--ink);
}

.rev-wrong-count {
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 12px;
  padding: 6px 12px;
  border-radius: 6px;
  display: inline-block;
  background: rgba(0, 0, 0, 0.05);
  color: var(--ink-soft);
}

.rev-wrong-count.yellow {
  background: rgba(255, 193, 7, 0.2);
  color: #f57c00;
}

.rev-wrong-count.orange {
  background: rgba(255, 152, 0, 0.2);
  color: #e65100;
}

.rev-wrong-count.red {
  background: rgba(244, 67, 54, 0.2);
  color: #c62828;
}

.rev-ans {
  margin-bottom: 12px;
  padding: 12px;
  background: rgba(47, 97, 243, 0.05);
  border-radius: 6px;
  font-size: 14px;
  line-height: 1.8;
}

.rev-rationale {
  padding: 12px;
  background: rgba(69, 183, 209, 0.05);
  border-radius: 6px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--ink-soft);
}

/* Help Section */
.help {
  margin-top: 32px;
  padding: 24px;
  background: rgba(69, 183, 209, 0.05);
  border-radius: 8px;
  border-left: 4px solid var(--success);
}

.help h3 {
  color: var(--ink);
  margin-bottom: 16px;
  font-size: 20px;
}

.help ul {
  margin: 0;
  padding-left: 24px;
}

.help li {
  margin-bottom: 12px;
  line-height: 1.6;
  color: var(--ink-soft);
}

/* Hidden utility */
.hidden {
  display: none !important;
}

/* Responsive */
@media (max-width: 768px) {
  .container {
    padding: 12px;
  }

  .card {
    padding: 16px;
    max-width: 100%;
  }

  .title-bar {
    flex-direction: column;
    align-items: flex-start;
    max-width: 100%;
  }

  .category-header-right {
    width: 100%;
  }

  .resume-container {
    width: 100%;
    align-items: flex-start;
  }

  .question {
    font-size: 16px;
  }

  .opt label {
    padding: 10px 12px;
    font-size: 14px;
  }

  .seg {
    flex-direction: column;
  }

  .seg-btn {
    width: 100%;
    min-width: 0;
  }

  .count-row {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 480px) {
  .question {
    font-size: 15px;
  }

  .opt label {
    padding: 10px 12px;
    font-size: 13px;
  }

  .opt .k {
    min-width: 24px;
    height: 24px;
    font-size: 12px;
  }

  .btn {
    padding: 10px 16px;
    font-size: 14px;
  }
}