:root {
  --primary: #10b981;
  --primary-dark: #059669;
  --primary-light: #34d399;
  --secondary: #6366f1;
  --secondary-dark: #4f46e5;
  --accent: #f59e0b;
  --success: #10b981;
  --warning: #f59e0b;
  --error: #ef4444;
  --bg-primary: #ffffff;
  --bg-secondary: #f9fafb;
  --bg-tertiary: #f3f4f6;
  --text-primary: #111827;
  --text-secondary: #6b7280;
  --text-tertiary: #9ca3af;
  --border: #e5e7eb;
  --border-light: #f3f4f6;
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  background-attachment: fixed;
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1rem;
}

/* Header */
.header {
  text-align: center;
  padding: 2.5rem 1rem;
  animation: fadeInDown 0.6s ease-out;
}

.header-content {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-radius: var(--radius-xl);
  padding: 2rem;
  box-shadow: var(--shadow-xl);
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.logo {
  width: 70px;
  height: 70px;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1rem;
  box-shadow: 0 8px 16px rgba(16, 185, 129, 0.3);
  animation: float 3s ease-in-out infinite;
}

.logo i {
  font-size: 2rem;
  color: white;
}

.header h1 {
  font-size: clamp(1.75rem, 5vw, 2.5rem);
  font-weight: 800;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 0.5rem;
}

.subtitle {
  font-size: clamp(0.95rem, 2.5vw, 1.125rem);
  color: var(--text-secondary);
  font-weight: 500;
}

/* Quick Guide */
.quick-guide {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 1rem;
  margin-bottom: 2rem;
  padding: 1rem;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  flex-wrap: wrap;
  animation: slideIn 0.6s ease-out 0.2s both;
}

.guide-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.75rem 1rem;
  background: var(--bg-tertiary);
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-primary);
  transition: all 0.3s ease;
}

.guide-item:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

.guide-number {
  width: 28px;
  height: 28px;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.875rem;
  font-weight: 700;
}

.guide-arrow {
  color: var(--text-tertiary);
  display: flex;
  align-items: center;
}

/* Main Content */
.main-content {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

/* Selection Section */
.selection-section {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1rem;
  animation: slideIn 0.6s ease-out 0.3s both;
}

.selection-card {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  padding: 1.5rem;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  border: 1px solid rgba(255, 255, 255, 0.2);
  transition: all 0.3s ease;
}

.selection-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.selection-card label {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.75rem;
  font-size: 0.95rem;
}

.selection-card label i {
  color: var(--primary);
  font-size: 1.125rem;
}

.modern-select {
  width: 100%;
  padding: 0.875rem 1rem;
  font-size: 1rem;
  border: 2px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--bg-primary);
  color: var(--text-primary);
  cursor: pointer;
  transition: all 0.3s ease;
  font-family: inherit;
  font-weight: 500;
}

.modern-select:hover {
  border-color: var(--primary-light);
}

.modern-select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.1);
}

/* Subjects Section */
.subjects-section {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  padding: 1.5rem;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  border: 1px solid rgba(255, 255, 255, 0.2);
  animation: slideIn 0.6s ease-out 0.4s both;
}

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 2px solid var(--border-light);
  flex-wrap: wrap;
  gap: 1rem;
}

.section-header h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.section-header h2 i {
  color: var(--primary);
}

.header-actions {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}

/* Buttons */
.btn-primary,
.btn-secondary {
  padding: 0.75rem 1.25rem;
  border: none;
  border-radius: var(--radius-md);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  transition: all 0.3s ease;
  font-family: inherit;
  white-space: nowrap;
}

.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  color: white;
  box-shadow: 0 4px 12px rgba(16, 185, 129, 0.3);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(16, 185, 129, 0.4);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-secondary {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  border: 2px solid var(--border);
}

.btn-secondary:hover {
  background: var(--bg-secondary);
  border-color: var(--primary);
  color: var(--primary);
}

/* Subjects Table */
.subjects-table-wrapper {
  overflow-x: auto;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  background: var(--bg-primary);
}

.subjects-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 600px;
}

.subjects-table thead {
  background: linear-gradient(135deg, var(--bg-secondary), var(--bg-tertiary));
}

.subjects-table th {
  padding: 1rem 0.75rem;
  text-align: left;
  font-weight: 600;
  font-size: 0.8125rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  border-bottom: 2px solid var(--border);
}

.subjects-table td {
  padding: 1rem 0.75rem;
  border-bottom: 1px solid var(--border-light);
  color: var(--text-primary);
  font-size: 0.95rem;
}

.subjects-table tbody tr {
  transition: background-color 0.2s ease;
}

.subjects-table tbody tr:hover {
  background: var(--bg-secondary);
}

.subjects-table tbody tr:last-child td {
  border-bottom: none;
}

.credit-col,
.marks-col,
.grade-col {
  text-align: center;
}

.action-col {
  text-align: center;
  width: 80px;
}

/* Subject Row Input */
.subject-input {
  width: 100%;
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 0.95rem;
  transition: all 0.2s ease;
  font-family: inherit;
}

.subject-input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 2px rgba(16, 185, 129, 0.1);
}

.subject-select {
  width: 100%;
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  cursor: pointer;
  font-family: inherit;
  background: var(--bg-primary);
}

.subject-type-badge {
  display: inline-block;
  padding: 0.25rem 0.625rem;
  border-radius: 12px;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
}

.badge-theory {
  background: #dbeafe;
  color: #1e40af;
}

.badge-practical {
  background: #d1fae5;
  color: #065f46;
}

/* Grade Badges */
.grade-badge {
  display: inline-block;
  padding: 0.375rem 0.875rem;
  border-radius: 16px;
  font-size: 0.875rem;
  font-weight: 700;
  letter-spacing: 0.025em;
}

.grade-A {
  background: linear-gradient(135deg, #10b981, #34d399);
  color: white;
  box-shadow: 0 2px 8px rgba(16, 185, 129, 0.3);
}

.grade-A- {
  background: linear-gradient(135deg, #34d399, #6ee7b7);
  color: #065f46;
}

.grade-B\+ {
  background: linear-gradient(135deg, #3b82f6, #60a5fa);
  color: white;
}

.grade-B {
  background: linear-gradient(135deg, #60a5fa, #93c5fd);
  color: #1e40af;
}

.grade-B- {
  background: linear-gradient(135deg, #fbbf24, #fcd34d);
  color: #78350f;
}

.grade-C\+ {
  background: linear-gradient(135deg, #f59e0b, #fbbf24);
  color: white;
}

.grade-C {
  background: linear-gradient(135deg, #fb923c, #fdba74);
  color: #7c2d12;
}

.grade-F {
  background: linear-gradient(135deg, #ef4444, #f87171);
  color: white;
  box-shadow: 0 2px 8px rgba(239, 68, 68, 0.3);
}

/* Delete Button */
.btn-delete {
  padding: 0.5rem 0.75rem;
  background: transparent;
  border: 1px solid var(--error);
  color: var(--error);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.2s ease;
  font-size: 0.875rem;
}

.btn-delete:hover {
  background: var(--error);
  color: white;
  transform: scale(1.05);
}

/* Empty State */
.empty-state {
  text-align: center;
  padding: 4rem 2rem;
  color: var(--text-tertiary);
}

.empty-state i {
  font-size: 4rem;
  margin-bottom: 1rem;
  color: var(--border);
  opacity: 0.5;
}

.empty-state h3 {
  font-size: 1.25rem;
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
  font-weight: 600;
}

.empty-state p {
  font-size: 0.95rem;
  max-width: 400px;
  margin: 0 auto;
  line-height: 1.5;
}

/* Results Section */
.results-section {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  padding: 1.5rem;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  border: 1px solid rgba(255, 255, 255, 0.2);
  animation: slideIn 0.6s ease-out 0.5s both;
}

.results-header {
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 2px solid var(--border-light);
}

.results-header h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.results-header h2 i {
  color: var(--primary);
}

/* Score Cards */
.score-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
  margin-bottom: 2rem;
}

.score-card {
  background: white;
  border: 2px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  display: flex;
  align-items: center;
  gap: 1rem;
  transition: all 0.3s ease;
}

.score-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--primary-light);
}

.score-card.highlight {
  background: linear-gradient(135deg, rgba(16, 185, 129, 0.1), rgba(52, 211, 153, 0.1));
  border-color: var(--primary);
  border-width: 3px;
}

.score-icon {
  width: 50px;
  height: 50px;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.score-icon i {
  font-size: 1.5rem;
  color: white;
}

.score-content {
  flex: 1;
}

.score-label {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.25rem;
}

.score-value {
  font-size: clamp(1.5rem, 4vw, 2rem);
  font-weight: 800;
  color: var(--text-primary);
  line-height: 1;
}

.score-value.large {
  font-size: clamp(2rem, 5vw, 2.5rem);
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.score-grade {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--primary);
  margin-top: 0.25rem;
}

/* Grade Distribution */
.grade-distribution {
  background: white;
  border-radius: var(--radius-md);
  padding: 1.5rem;
  border: 1px solid var(--border);
}

.grade-distribution h3 {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 1rem;
}

.distribution-bars {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.distribution-bar {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.bar-label {
  min-width: 40px;
  font-weight: 600;
  font-size: 0.875rem;
}

.bar-track {
  flex: 1;
  height: 28px;
  background: var(--bg-secondary);
  border-radius: 14px;
  overflow: hidden;
  position: relative;
}

.bar-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--primary), var(--primary-light));
  border-radius: 14px;
  transition: width 0.6s ease;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  padding-right: 0.75rem;
}

.bar-count {
  color: white;
  font-size: 0.75rem;
  font-weight: 700;
}

/* Modal */
.modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
  overflow-y: auto;
}

.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(4px);
  animation: fadeIn 0.3s ease;
}

.modal-content {
  position: relative;
  background: white;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
  max-width: 600px;
  width: 100%;
  max-height: 90vh;
  overflow-y: auto;
  animation: scaleIn 0.3s ease;
  margin: auto;
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.5rem;
  border-bottom: 2px solid var(--border-light);
}

.modal-header h3 {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
}

.modal-close {
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: none;
  border-radius: 50%;
  cursor: pointer;
  color: var(--text-secondary);
  transition: all 0.2s ease;
  font-size: 1.25rem;
}

.modal-close:hover {
  background: var(--bg-secondary);
  color: var(--text-primary);
}

.modal-body {
  padding: 1.5rem;
}

/* Form */
.form-group {
  margin-bottom: 1.25rem;
}

.form-group label {
  display: block;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
  font-size: 0.9375rem;
}

.required {
  color: var(--error);
}

.form-group input,
.form-group select {
  width: 100%;
  padding: 0.875rem 1rem;
  border: 2px solid var(--border);
  border-radius: var(--radius-md);
  font-size: 1rem;
  transition: all 0.3s ease;
  font-family: inherit;
  background: var(--bg-primary);
}

.form-group input:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.1);
}

.form-group small {
  font-weight: 400;
  color: var(--text-tertiary);
  margin-left: 0.25rem;
}

.form-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1rem;
}

.input-hint {
  font-size: 0.75rem;
  color: var(--text-tertiary);
  margin-top: 0.25rem;
}

.marks-section {
  margin-top: 1.5rem;
  padding-top: 1.5rem;
  border-top: 2px solid var(--border-light);
}

.marks-section h4 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 1rem;
}

/* Live Preview */
.live-preview {
  margin-top: 1rem;
  padding: 1rem;
  background: linear-gradient(135deg, rgba(16, 185, 129, 0.05), rgba(99, 102, 241, 0.05));
  border-radius: var(--radius-md);
  border: 2px dashed var(--border);
}

.preview-label {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.5rem;
}

.preview-grade {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.preview-marks {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
}

/* Modal Actions */
.modal-actions {
  display: flex;
  gap: 1rem;
  margin-top: 2rem;
  padding-top: 1.5rem;
  border-top: 2px solid var(--border-light);
}

.btn-cancel {
  flex: 1;
  padding: 0.875rem 1.5rem;
  background: transparent;
  border: 2px solid var(--border);
  color: var(--text-primary);
  border-radius: var(--radius-md);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  font-family: inherit;
}

.btn-cancel:hover {
  background: var(--bg-secondary);
  border-color: var(--text-secondary);
}

.btn-submit {
  flex: 1;
  padding: 0.875rem 1.5rem;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  border: none;
  color: white;
  border-radius: var(--radius-md);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  font-family: inherit;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  box-shadow: 0 4px 12px rgba(16, 185, 129, 0.3);
}

.btn-submit:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(16, 185, 129, 0.4);
}

.btn-submit:active {
  transform: translateY(0);
}

/* Footer */
.footer {
  text-align: center;
  padding: 2rem 1rem;
  margin-top: 3rem;
  color: white;
}

.footer p {
  font-size: 0.95rem;
  margin-bottom: 0.5rem;
}

.footer a {
  color: rgb(213, 216, 224);
  text-decoration: none;
  font-weight: 700;
  transition: all 0.2s ease;
  border-bottom: 2px solid transparent;
}

.footer a:hover {
  border-bottom-color: white;
}

.footer i.fa-heart {
  color: #ef4444;
  animation: heartbeat 1.5s ease-in-out infinite;
}

.footer-note {
  font-size: 0.875rem;
  opacity: 0.9;
  font-weight: 500;
}

/* Animations */
@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

@keyframes fadeInDown {
  from {
    opacity: 0;
    transform: translateY(-30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateX(-20px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes scaleIn {
  from {
    opacity: 0;
    transform: scale(0.9);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

@keyframes float {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-10px);
  }
}

@keyframes heartbeat {
  0%, 100% {
    transform: scale(1);
  }
  25% {
    transform: scale(1.1);
  }
  50% {
    transform: scale(1);
  }
  75% {
    transform: scale(1.15);
  }
}

/* Responsive */
@media (max-width: 768px) {
  .container {
    padding: 0.75rem;
  }

  .header-content {
    padding: 1.5rem;
  }

  .quick-guide {
    flex-direction: column;
    gap: 0.5rem;
  }

  .guide-arrow {
    transform: rotate(90deg);
  }

  .guide-item {
    width: 100%;
    justify-content: center;
  }

  .section-header {
    flex-direction: column;
    align-items: flex-start;
  }

  .header-actions {
    width: 100%;
  }

  .header-actions button {
    flex: 1;
    justify-content: center;
  }

  .btn-primary span,
  .btn-secondary span {
    display: none;
  }

  .subjects-section,
  .results-section {
    padding: 1rem;
  }

  .score-cards {
    grid-template-columns: 1fr;
  }

  .form-row {
    grid-template-columns: 1fr;
  }

  .modal-actions {
    flex-direction: column;
  }

  .modal-content {
    margin: 0;
  }
}

@media (min-width: 769px) and (max-width: 1024px) {
  .score-cards {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* Touch Devices */
@media (hover: none) {
  .btn-primary,
  .btn-secondary,
  .btn-delete,
  .modal-close {
    min-height: 44px;
    min-width: 44px;
  }
}

/* Print Styles */
@media print {
  body {
    background: white;
  }

  .header-actions,
  .btn-delete,
  .modal,
  .footer {
    display: none !important;
  }

  .subjects-section,
  .results-section {
    box-shadow: none;
    border: 1px solid #000;
  }
}