.grading-system {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem 1rem;
}

.hero-section {
  text-align: center;
  margin-bottom: 3rem;
  padding: 6rem 2rem;
  background: linear-gradient(135deg, #2c3e50, #3498db),
              url('https://www.transparenttextures.com/patterns/cubes.png');
  background-blend-mode: overlay;
  border-radius: 30px;
  color: white;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
  position: relative;
  overflow: hidden;
}

.hero-section::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(circle at center, transparent 0%, rgba(0,0,0,0.3) 100%);
}

.hero-section h1 {
  font-size: 3.5rem;
  margin-bottom: 1.5rem;
  font-weight: 800;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
  position: relative;
  background: linear-gradient(to right, #fff, #e3f2fd);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  animation: fadeInUp 0.8s ease-out;
}

.hero-description {
  font-size: 1.3rem;
  opacity: 0.95;
  max-width: 700px;
  margin: 0 auto;
  line-height: 1.8;
  position: relative;
  animation: fadeInUp 0.8s ease-out 0.2s backwards;
}

.upload-section {
  background-color: white;
  padding: 3.5rem;
  border-radius: 30px;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
  position: relative;
  overflow: hidden;
}

.upload-section::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 6px;
  background: linear-gradient(to right, #3498db, #2ecc71);
}

.section-header {
  text-align: center;
  margin-bottom: 4rem;
  position: relative;
}

.icon-container {
  width: 100px;
  height: 100px;
  margin: 0 auto 2rem;
  background: linear-gradient(135deg, #3498db, #2980b9);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 10px 20px rgba(52, 152, 219, 0.2);
  animation: pulse 2s infinite;
}

.icon-container i {
  font-size: 2.5rem;
  color: white;
  animation: bounce 2s infinite;
}

.section-header h2 {
  color: #2c3e50;
  font-size: 2.4rem;
  margin-bottom: 1rem;
  font-weight: 700;
}

.section-description {
  color: #7f8c8d;
  font-size: 1.2rem;
  max-width: 600px;
  margin: 0 auto;
  line-height: 1.8;
}

.upload-containers {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3.5rem;
  margin: 3rem 0;
}

.upload-container {
  background: #f8f9fa;
  padding: 2.5rem;
  border-radius: 20px;
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.05);
  transition: all 0.4s cubic-bezier(0.165, 0.84, 0.44, 1);
  position: relative;
}

.upload-container::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  border-radius: 20px;
  box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1);
  opacity: 0;
  transition: all 0.4s cubic-bezier(0.165, 0.84, 0.44, 1);
}

.upload-container:hover {
  transform: translateY(-8px);
}

.upload-container:hover::after {
  opacity: 1;
}

.container-header {
  display: flex;
  align-items: center;
  margin-bottom: 2rem;
  padding-bottom: 1.2rem;
  border-bottom: 2px solid #e1e8ed;
}

.container-header i {
  font-size: 1.8rem;
  color: #3498db;
  margin-right: 1.2rem;
  transition: all 0.3s ease;
}

.upload-container:hover .container-header i {
  transform: scale(1.1);
  color: #2980b9;
}

.container-header h3 {
  color: #2c3e50;
  font-size: 1.6rem;
  margin: 0;
  font-weight: 600;
}

.submissions-preview {
  max-height: 300px;
  overflow-y: auto;
  margin-top: 1rem;
  padding-right: 0.5rem;
}

.submissions-preview::-webkit-scrollbar {
  width: 8px;
}

.submissions-preview::-webkit-scrollbar-track {
  background: #f1f1f1;
  border-radius: 4px;
}

.submissions-preview::-webkit-scrollbar-thumb {
  background: #c1c1c1;
  border-radius: 4px;
}

.action-section {
  text-align: center;
  margin-top: 4rem;
  padding-top: 2rem;
  border-top: 2px solid #f0f2f5;
}

.submit-button {
  background: linear-gradient(to right, #3498db, #2980b9);
  color: white;
  border: none;
  padding: 1.4rem 5rem;
  border-radius: 50px;
  cursor: pointer;
  font-size: 1.3rem;
  font-weight: 600;
  transition: all 0.4s cubic-bezier(0.165, 0.84, 0.44, 1);
  text-transform: uppercase;
  letter-spacing: 2px;
  display: inline-flex;
  align-items: center;
  gap: 1.2rem;
  position: relative;
  overflow: hidden;
}

.submit-button::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(to right, #2ecc71, #27ae60);
  opacity: 0;
  transition: opacity 0.4s ease;
}

.submit-button:hover:not(:disabled)::after {
  opacity: 1;
}

.submit-button:hover:not(:disabled) {
  transform: translateY(-3px);
  box-shadow: 0 15px 30px rgba(52, 152, 219, 0.3);
}

.submit-button i {
  font-size: 1.4rem;
  position: relative;
  z-index: 1;
}

.submit-button span {
  position: relative;
  z-index: 1;
}

@keyframes pulse {
  0% { transform: scale(1); }
  50% { transform: scale(1.05); }
  100% { transform: scale(1); }
}

@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-5px); }
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Responsive design */
@media (max-width: 768px) {
  .upload-containers {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .hero-section {
    padding: 4rem 1.5rem;
  }

  .hero-section h1 {
    font-size: 2.5rem;
  }

  .hero-description {
    font-size: 1.1rem;
  }

  .submit-button {
    padding: 1.2rem 3rem;
    font-size: 1.1rem;
  }
}

.progress-container {
  margin-top: 2rem;
}

.progress-bar {
  width: 100%;
  height: 25px;
  background-color: #e9ecef;
  border-radius: 15px;
  margin-top: 1.5rem;
  position: relative;
  overflow: hidden;
  box-shadow: inset 0 2px 5px rgba(0, 0, 0, 0.1);
}

.progress-fill {
  height: 100%;
  background: linear-gradient(to right, #3498db, #2980b9);
  transition: width 0.3s ease;
  border-radius: 15px;
}

.progress-text {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  color: white;
  font-size: 0.9rem;
  font-weight: 600;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.2);
}

.progress-status {
  color: #7f8c8d;
  margin-top: 1rem;
  font-size: 1rem;
}

.error-message {
  color: #dc3545;
  font-size: 0.9rem;
  margin-top: 0.5rem;
}

.drag-active {
  border-color: #3498db;
  background-color: #e3f2fd;
}

.welcome-screen {
  max-width: 1200px;
  margin: 2rem auto;
  padding: 4rem 2rem;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(10px);
  border-radius: 24px;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.05);
  text-align: center;
  position: relative;
  overflow: hidden;
  border: 1px solid rgba(0, 0, 0, 0.05);
}

.welcome-screen::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 6px;
  background: linear-gradient(to right, #3b82f6, #60a5fa);
}

.welcome-content {
  max-width: 800px;
  margin: 0 auto;
}

.welcome-icon {
  width: 120px;
  height: 120px;
  margin: 0 auto 2rem;
  background: linear-gradient(135deg, var(--accent-primary), var(--accent-hover));
  border-radius: 60px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 15px 30px rgba(0, 102, 255, 0.2);
}

.welcome-icon i {
  font-size: 3.5rem;
  color: white;
}

.welcome-screen h1 {
  font-size: 3.5rem;
  color: var(--text-primary);
  margin-bottom: 1.5rem;
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.2;
}

.welcome-description {
  font-size: 1.25rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto 3rem;
  line-height: 1.6;
}

.create-rubric-btn {
  background: linear-gradient(to right, #3b82f6, #60a5fa);
  color: white;
  border: none;
  padding: 1.2rem 3rem;
  border-radius: 50px;
  font-size: 1.2rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  display: inline-flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 4rem;
  box-shadow: 0 10px 20px rgba(59, 130, 246, 0.2);
}

.create-rubric-btn span,
.create-rubric-btn i {
  color: white;
}

.create-rubric-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 15px 30px rgba(59, 130, 246, 0.3);
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2.5rem;
  margin: 2rem auto;
  max-width: 1000px;
  padding: 0 2rem;
}

.feature-item {
  padding: 2.5rem;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(5px);
  border-radius: 16px;
  border: 1px solid rgba(0, 0, 0, 0.05);
  transition: all 0.3s ease;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.02);
  text-align: left;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.feature-item:hover {
  transform: translateY(-5px);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.08);
}

.feature-item i {
  font-size: 2.5rem;
  color: var(--accent-primary);
  margin-bottom: 1.5rem;
}

.feature-item h3 {
  font-size: 1.4rem;
  color: var(--text-primary);
  margin-bottom: 1rem;
  font-weight: 600;
}

.feature-item p {
  font-size: 1.1rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

@media (max-width: 768px) {
  .feature-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
    padding: 0 1rem;
  }

  .feature-item {
    padding: 2rem;
  }
}

@media (max-width: 1024px) {
  .feature-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .welcome-screen {
    padding: 3rem 1.5rem;
  }

  .welcome-screen h1 {
    font-size: 2.5rem;
  }

  .welcome-description {
    font-size: 1.1rem;
  }

  .feature-grid {
    grid-template-columns: 1fr;
  }

  .create-rubric-btn {
    padding: 1rem 2rem;
    font-size: 1.1rem;
  }
}

/* Main layout after rubric creation */
.grading-layout {
  display: grid;
  grid-template-columns: 47% 47%;
  gap: 6%;
  min-height: calc(100vh - 80px);
  padding: 1rem 4%;
  margin: 0;
  width: 92%;
  max-width: none;
  position: relative;
}

/* Left side - Rubric display */
.rubric-sidebar {
  width: 100%;
  min-width: 600px;
  background: white;
  padding: 2.5rem;
  border-radius: 12px;
  border: 1px solid #e5e9f2;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
  height: calc(100vh - 100px);
  position: sticky;
  top: 2rem;
  overflow-y: auto;
}

.rubric-sidebar h2 {
  font-size: 1.8rem;
  margin-bottom: 2rem;
  padding-bottom: 1rem;
  border-bottom: 2px solid #f1f5f9;
}

/* Right side - Submissions section */
.submissions-section {
  width: 100%;
  min-width: 600px;
  background: white;
  padding: 2.5rem;
  border-radius: 12px;
  border: 1px solid #e5e9f2;
  box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
  height: calc(100vh - 100px);
  overflow-y: auto;
}

.submissions-header {
  margin-bottom: 2rem;
  padding-bottom: 1rem;
  border-bottom: 2px solid #f1f5f9;
}

.submissions-header h2 {
  font-size: 1.8rem;
  margin-bottom: 1rem;
}

/* Upload area */
.upload-area {
  background: #f8fafc;
  padding: 2rem;
  border-radius: 8px;
  border: 2px dashed #e2e8f0;
  margin-bottom: 2rem;
}

/* Submissions list */
.submissions-list {
  max-height: calc(100vh - 300px);
  overflow-y: auto;
  padding-right: 1rem;
}

.submission-item {
  background: white;
  padding: 1rem 1.5rem;
  border-radius: 8px;
  border: 1px solid #e5e9f2;
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.submission-info {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  flex-grow: 1;
}

.pennid-input {
  width: 150px;
  padding: 0.8rem 1rem;
  border: 1px solid #e5e9f2;
  border-radius: 6px;
  font-size: 1rem;
}

/* Grade button */
.grade-btn {
  width: 100%;
  padding: 1rem;
  margin-top: 2rem;
  background: #2563eb;
  color: white;
  border: none;
  border-radius: 8px;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.75rem;
  transition: all 0.2s ease;
}

.grade-btn:hover:not(:disabled) {
  background: #1d4ed8;
  transform: translateY(-1px);
}

/* Responsive design */
@media (max-width: 1200px) {
  .grading-layout {
    grid-template-columns: 100%;
    gap: 2rem;
  }

  .rubric-sidebar,
  .submissions-section {
    height: auto;
    position: static;
  }
}

.completed-rubric-view {
  max-width: 1000px;
  margin: 2rem auto;
  padding: 3rem;
  background: white;
  border-radius: 20px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

.completed-rubric-view h2 {
  font-size: 2.4rem;
  color: #1a1a1a;
  margin-bottom: 2rem;
  text-align: center;
  font-weight: 700;
}

.rubric-content {
  margin-bottom: 3rem;
}

.rubric-question {
  background: #f8fafc;
  border-radius: 12px;
  padding: 2rem;
  margin-bottom: 2rem;
  border: 1px solid #e2e8f0;
}

.rubric-question .question-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1.5rem;
  padding-bottom: 1rem;
  border-bottom: 2px solid #e2e8f0;
}

.rubric-question h3 {
  font-size: 1.4rem;
  color: #1a1a1a;
  font-weight: 600;
}

.rubric-question .points {
  background: #3b82f6;
  color: white;
  padding: 0.5rem 1.2rem;
  border-radius: 20px;
  font-weight: 500;
}

.question-text {
  font-size: 1.1rem;
  color: #334155;
  margin-bottom: 1.5rem;
  line-height: 1.6;
}

.criteria-list {
  display: grid;
  gap: 1rem;
}

.criterion-item {
  display: flex;
  align-items: flex-start;
  gap: 1.5rem;
  background: white;
  padding: 1rem 1.5rem;
  border-radius: 8px;
  border: 1px solid #e2e8f0;
}

.points-positive,
.points-negative {
  font-weight: 600;
  padding: 0.5rem 1rem;
  border-radius: 20px;
  font-size: 0.95rem;
  min-width: 90px;
  text-align: center;
  flex-shrink: 0;
}

.points-positive {
  color: #059669;
  background: #ecfdf5;
}

.points-negative {
  color: #dc2626;
  background: #fef2f2;
}

.grade-submissions-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  background: #3b82f6;
  color: white;
  border: none;
  padding: 1.2rem 3rem;
  border-radius: 12px;
  font-size: 1.2rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
  margin: 0 auto;
  box-shadow: 0 4px 12px rgba(59, 130, 246, 0.2);
}

.grade-submissions-btn:hover {
  background: #2563eb;
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(59, 130, 246, 0.3);
}

.grade-submissions-btn i {
  font-size: 1.3rem;
}