@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@500;600;700;800&family=Inter:wght@400;500;600;700&display=swap');

:root {
  --primary: #4F46E5;
  --primary-hover: #4338CA;
  --primary-light: #EEF2FF;
  --primary-glow: rgba(79, 70, 229, 0.25);
  --secondary: #7C3AED;
  --accent: #06B6D4;
  --success: #10B981;
  --success-light: #DEF7EC;
  --danger: #EF4444;
  --danger-light: #FDE8E8;
  --warning: #F59E0B;
  --warning-light: #FEF3C7;
  
  --bg-gradient: linear-gradient(135deg, #F8FAFC 0%, #F1F5F9 50%, #EEF2FF 100%);
  --surface: #FFFFFF;
  --surface-translucent: rgba(255, 255, 255, 0.85);
  --text-main: #0F172A;
  --text-muted: #64748B;
  --text-subtle: #94A3B8;
  --border-color: #E2E8F0;
  --border-focus: #818CF8;

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.04);
  --shadow-glow: 0 10px 25px -5px rgba(79, 70, 229, 0.35);

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-full: 9999px;
  --transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg-gradient);
  min-height: 100vh;
  color: var(--text-main);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.container {
  max-width: 1140px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem;
}

/* Typography */
h1, h2, h3, h4, h5 {
  font-family: 'Plus Jakarta Sans', sans-serif;
  color: var(--text-main);
  margin-top: 0;
  letter-spacing: -0.02em;
}

h1 {
  font-size: 2rem;
  font-weight: 800;
  line-height: 1.2;
}

h2 {
  font-size: 1.4rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

h3 {
  font-size: 1.15rem;
  font-weight: 600;
}

p {
  margin-top: 0;
}

/* Header & Navigation */
header.app-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 2.5rem;
  background: var(--surface-translucent);
  backdrop-filter: blur(12px);
  padding: 1.25rem 2rem;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-sm);
}

.brand-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: linear-gradient(135deg, rgba(79, 70, 229, 0.1) 0%, rgba(124, 58, 237, 0.1) 100%);
  color: var(--primary);
  padding: 4px 12px;
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 6px;
}

.brand-logo-wrap {
  display: flex;
  align-items: center;
  gap: 14px;
}

.brand-icon {
  width: 44px;
  height: 44px;
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.3rem;
  box-shadow: var(--shadow-glow);
}

/* Cards & Containers */
.card {
  background: var(--surface);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-md);
  padding: 1.75rem;
  margin-bottom: 1.75rem;
  transition: var(--transition);
}

.card:hover {
  box-shadow: var(--shadow-lg);
}

.card-header-styled {
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 1rem;
  margin-bottom: 1.5rem;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 0.65rem 1.25rem;
  border-radius: var(--radius-md);
  font-family: 'Plus Jakarta Sans', sans-serif;
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  text-decoration: none;
  transition: var(--transition);
  border: 1px solid transparent;
  line-height: 1.2;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary) 0%, #4338CA 100%);
  color: white;
  box-shadow: 0 4px 12px var(--primary-glow);
}

.btn-primary:hover {
  background: linear-gradient(135deg, #4338CA 0%, #3730A3 100%);
  transform: translateY(-1px);
  box-shadow: var(--shadow-glow);
}

.btn-secondary {
  background: white;
  color: var(--text-main);
  border-color: var(--border-color);
  box-shadow: var(--shadow-sm);
}

.btn-secondary:hover {
  background: #F8FAFC;
  border-color: var(--text-subtle);
  transform: translateY(-1px);
}

.btn-success {
  background: linear-gradient(135deg, var(--success) 0%, #059669 100%);
  color: white;
  box-shadow: 0 4px 12px rgba(16, 185, 129, 0.25);
}

.btn-success:hover {
  background: linear-gradient(135deg, #059669 0%, #047857 100%);
  transform: translateY(-1px);
}

.btn-sm {
  padding: 0.45rem 0.85rem;
  font-size: 0.85rem;
  border-radius: var(--radius-sm);
}

.btn-lg {
  padding: 0.85rem 1.75rem;
  font-size: 1.05rem;
}

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

.form-group label {
  display: block;
  margin-bottom: 0.5rem;
  font-family: 'Plus Jakarta Sans', sans-serif;
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--text-main);
}

.form-control {
  width: 100%;
  padding: 0.85rem 1rem;
  border: 1.5px solid var(--border-color);
  border-radius: var(--radius-md);
  font-family: 'Inter', sans-serif;
  font-size: 0.95rem;
  background-color: #FFFFFF;
  color: var(--text-main);
  transition: var(--transition);
}

.form-control:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 4px var(--primary-glow);
}

.form-control::placeholder {
  color: var(--text-subtle);
}

/* Paper Grid (Dashboard) */
.paper-list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1.5rem;
}

.paper-item {
  position: relative;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  border-top: 4px solid var(--primary);
}

.paper-item:hover {
  transform: translateY(-4px);
  border-color: var(--secondary);
}

.paper-item h3 {
  font-size: 1.25rem;
  margin-bottom: 0.4rem;
}

.paper-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--text-muted);
  font-size: 0.88rem;
  margin-bottom: 1.5rem;
}

.paper-meta-badge {
  background: var(--primary-light);
  color: var(--primary);
  padding: 3px 10px;
  border-radius: var(--radius-full);
  font-weight: 600;
  font-size: 0.8rem;
}

.paper-actions {
  display: flex;
  gap: 8px;
  margin-top: auto;
}

/* File Upload Dropzone */
.dropzone {
  border: 2px dashed #CBD5E1;
  border-radius: var(--radius-lg);
  padding: 2.25rem 1.5rem;
  text-align: center;
  background: #F8FAFC;
  cursor: pointer;
  transition: var(--transition);
  position: relative;
}

.dropzone:hover, .dropzone.dragover {
  border-color: var(--primary);
  background: var(--primary-light);
}

.dropzone-icon {
  width: 52px;
  height: 52px;
  margin: 0 auto 1rem;
  background: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-sm);
  color: var(--primary);
  font-size: 1.5rem;
}

/* Answer Key Matrix */
.answer-key-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(75px, 1fr));
  gap: 10px;
  max-height: 480px;
  overflow-y: auto;
  padding: 4px;
}

.answer-input-group {
  display: flex;
  flex-direction: column;
  align-items: center;
  background: #F8FAFC;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 6px 4px;
  transition: var(--transition);
}

.answer-input-group:hover, .answer-input-group.filled {
  background: white;
  border-color: var(--primary);
  box-shadow: var(--shadow-sm);
}

.answer-input-group label {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--text-muted);
  margin-bottom: 4px;
}

.answer-input-group select {
  width: 100%;
  padding: 4px 6px;
  border: 1px solid var(--border-color);
  border-radius: 6px;
  font-weight: 600;
  text-align: center;
  background: white;
  cursor: pointer;
}

.answer-input-group select:focus {
  outline: none;
  border-color: var(--primary);
}

/* Badges & Pills */
.pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border-radius: var(--radius-full);
  font-size: 0.8rem;
  font-weight: 600;
}

.pill-success { background: var(--success-light); color: #065F46; }
.pill-danger { background: var(--danger-light); color: #991B1B; }
.pill-warning { background: var(--warning-light); color: #92400E; }
.pill-primary { background: var(--primary-light); color: var(--primary); }

/* Quick Presets for Question Counts */
.preset-pills {
  display: flex;
  gap: 8px;
  margin-top: 8px;
  flex-wrap: wrap;
}

.preset-btn {
  background: white;
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  border-radius: var(--radius-full);
  padding: 4px 14px;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
}

.preset-btn:hover {
  background: var(--primary-light);
  border-color: var(--primary);
  color: var(--primary);
}

/* Clean Empty State */
.empty-state {
  text-align: center;
  padding: 4rem 2rem;
  background: white;
  border-radius: var(--radius-lg);
  border: 2px dashed var(--border-color);
}

.empty-state-icon {
  font-size: 3rem;
  margin-bottom: 1rem;
}