:root {
  --primary-color: #4f46e5;
  --secondary-color: #06b6d4;
  --success-color: #10b981;
  --warning-color: #f59e0b;
  --danger-color: #ef4444;
  --dark-color: #1f2937;
  --light-bg: #f8fafc;
  --card-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1),
    0 2px 4px -1px rgba(0, 0, 0, 0.06);
  --card-shadow-hover: 0 10px 15px -3px rgba(0, 0, 0, 0.1),
    0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

* {
  font-family: "Inter", sans-serif;
}

body {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  min-height: 100vh;
}

.main-container {
  background: white;
  border-radius: 20px;
  box-shadow: var(--card-shadow-hover);
  overflow: hidden;
  margin: 20px auto;
  max-width: 1000px;
}

.header-section {
  background: linear-gradient(
    135deg,
    var(--primary-color) 0%,
    var(--secondary-color) 100%
  );
  color: white;
  padding: 30px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.header-section::before {
  content: "";
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grain" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="25" cy="25" r="1" fill="white" opacity="0.1"/><circle cx="75" cy="75" r="1" fill="white" opacity="0.1"/><circle cx="50" cy="10" r="1" fill="white" opacity="0.1"/><circle cx="10" cy="90" r="1" fill="white" opacity="0.1"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>');
  animation: float 20s ease-in-out infinite;
}

@keyframes float {
  0%,
  100% {
    transform: translateY(0px) rotate(0deg);
  }
  50% {
    transform: translateY(-20px) rotate(180deg);
  }
}

.header-content {
  position: relative;
  z-index: 2;
}

.social-section {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
  flex-wrap: wrap;
  gap: 15px;
}

.github-badge {
  transition: transform 0.3s ease;
}

.github-badge:hover {
  transform: scale(1.05);
}

.main-title {
  font-size: 2.5rem;
  font-weight: 700;
  margin: 0;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

@media (max-width: 768px) {
  .main-title {
    display: flex;
    flex-direction: column;
  }

  .bi-mortarboard-fill {
    font-size: 4rem;
  }
}

.subtitle {
  font-size: 1.1rem;
  opacity: 0.9;
  margin-top: 10px;
}

.form-section {
  padding: 40px;
}

.form-card {
  background: var(--light-bg);
  border-radius: 15px;
  padding: 30px;
  box-shadow: var(--card-shadow);
}

.form-label {
  font-weight: 600;
  color: var(--dark-color);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.form-control,
.form-select {
  border: 2px solid #e5e7eb;
  border-radius: 10px;
  padding: 12px 16px;
  font-size: 16px;
  transition: all 0.3s ease;
  background: white;
}

.form-control:focus,
.form-select:focus {
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
  transform: translateY(-1px);
}

.btn-custom {
  padding: 12px 30px;
  border-radius: 10px;
  font-weight: 600;
  font-size: 16px;
  transition: all 0.3s ease;
  border: none;
  position: relative;
  overflow: hidden;
}

.btn-custom::before {
  content: "";
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(255, 255, 255, 0.2),
    transparent
  );
  transition: left 0.5s;
}

.btn-custom:hover::before {
  left: 100%;
}

.btn-primary-custom {
  background: linear-gradient(
    135deg,
    var(--primary-color) 0%,
    var(--secondary-color) 100%
  );
  color: white;
}

.btn-primary-custom:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(79, 70, 229, 0.3);
  color: white;
}

.btn-secondary-custom {
  background: linear-gradient(135deg, #6b7280 0%, #4b5563 100%);
  color: white;
}

.btn-secondary-custom:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(107, 114, 128, 0.3);
  color: white;
}

.captcha-section {
  background: #fff3cd;
  border: 2px solid #ffeaa7;
  border-radius: 10px;
  padding: 20px;
  margin: 20px 0;
}

.captcha-image {
  border: 2px solid #ddd;
  border-radius: 8px;
  margin-right: 10px;
}

.error-message {
  background: #fee2e2;
  border: 2px solid #fecaca;
  color: #dc2626;
  padding: 15px;
  border-radius: 10px;
  margin: 15px 0;
  display: none;
}

.results-section {
  margin-top: 40px;
}

.results-card {
  background: white;
  border-radius: 15px;
  box-shadow: var(--card-shadow);
  overflow: hidden;
  margin-bottom: 30px;
}

.results-card:last-child {
  margin-bottom: 0;
}

.results-header {
  background: linear-gradient(135deg, var(--success-color) 0%, #059669 100%);
  color: white;
  padding: 20px;
  font-weight: 600;
  font-size: 1.2rem;
}

.table-custom {
  margin: 0;
}

.table-custom th {
  background: var(--light-bg);
  font-weight: 600;
  color: var(--dark-color);
  font-size: 13px;
}

.table-custom td {
  vertical-align: middle;
  font-size: 13px;
}

.loading-spinner {
  display: none;
  text-align: center;
  padding: 20px;
}

.feature-highlight {
  background: linear-gradient(135deg, #fef3c7 0%, #fde68a 100%);
  border-radius: 10px;
  padding: 20px;
  margin-bottom: 20px;
  border-left: 4px solid var(--warning-color);
}

@media (max-width: 768px) {
  .main-title {
    font-size: 2rem;
  }

  .form-section {
    padding: 20px;
  }

  .form-card {
    padding: 20px;
  }

  .social-section {
    justify-content: center;
    text-align: center;
  }
}

.animate-fade-in {
  animation: fadeIn 0.6s ease-out;
}

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

footer {
  margin: 40px 0;
  color: var(--black);
}

.footer--copyright,
.footer--fun {
  margin: 0;
}

.footer--copyright {
  font-size: 17px;
  line-height: 22px;
}

#footer--mobile {
  display: none;
  font-weight: 500;
}

.footer--fun {
  font-size: 14px;
  margin-top: 10px;
  padding-bottom: 40px;
  color: #5a5a5a;
}

@media only screen and (max-width: 960px) {
  #footer--desktop {
    display: none;
  }

  #footer--mobile {
    display: block;
  }

  .footer--fun {
    font-size: 8px;
  }
}

.section-header {
  background: linear-gradient(135deg, #6f42c1 0%, #e83e8c 100%);
  color: white;
  border-radius: 15px 15px 0 0;
}
.avatar {
  width: 45px;
  height: 45px;
  border-radius: 50%;
  background: linear-gradient(135deg, #6f42c1 0%, #e83e8c 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: bold;
  font-size: 16px;
}
.comment-card {
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.comment-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.reply-section {
  border-left: 3px solid #6f42c1;
  margin-left: 1.5rem;
}
.reply-section > div {
  border-top-left-radius: 0;
  border-bottom-left-radius: 0;
}

/* Add styling for level 3 nested replies */
.nested-replies {
  border-left: 3px solid #6f42c1;
  margin-left: 1rem;
}
.nested-replies > div {
  border-top-left-radius: 0;
  border-bottom-left-radius: 0;
}

.subject-badge {
  font-size: 0.75rem;
}

.lookup-card {
  background: white;
  border: 2px solid #e3f2fd;
  border-radius: 15px;
  transition: all 0.3s ease;
  margin-bottom: 15px;
}

.lookup-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(66, 133, 244, 0.15);
  border-color: #4285f4;
}

.student-name {
  font-weight: 600;
  color: #1976d2;
  font-size: 16px;
}

.info-text {
  color: #666;
  font-size: 14px;
}

.location-badge {
  background: linear-gradient(135deg, #4285f4 0%, #1976d2 100%);
  color: white;
  font-size: 12px;
  font-weight: 500;
}

.status-updating {
  color: #ff9800;
  font-weight: 500;
}

.recent-lookups-container {
  background: white;
  border-radius: 15px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
  overflow: hidden;
}

.auto-refresh {
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% {
    opacity: 1;
  }
  50% {
    opacity: 0.7;
  }
  100% {
    opacity: 1;
  }
}

.new-lookup {
  animation: slideInRight 0.5s ease-out;
}

@keyframes slideInRight {
  from {
    transform: translateX(100%);
    opacity: 0;
  }
  to {
    transform: translateX(0);
    opacity: 1;
  }
}

#fb-like {
  filter: invert(1) hue-rotate(180deg);
  mix-blend-mode: difference; /* tuỳ chọn nếu muốn blending hài hòa hơn */
}

/* Loading Skeleton Styles */
.skeleton-container {
  padding: 20px;
}

.skeleton-card {
  background: #f0f0f0;
  border-radius: 15px;
  height: 70px;
  margin-bottom: 15px;
  position: relative;
  overflow: hidden;
}

.skeleton-card::before {
  content: "";
  display: block;
  position: absolute;
  left: -150px;
  top: 0;
  height: 100%;
  width: 150px;
  background: linear-gradient(
    to right,
    transparent 0%,
    rgba(255, 255, 255, 0.6) 50%,
    transparent 100%
  );
  animation: shimmer 1.5s cubic-bezier(0.4, 0, 0.2, 1) infinite;
}

@keyframes shimmer {
  0% {
    left: -150px;
  }
  100% {
    left: 100%;
  }
}

.skeleton-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
}

.skeleton-text {
  height: 15px;
  background: #e0e0e0;
  border-radius: 4px;
  margin-bottom: 10px;
}

.skeleton-text.sm {
  width: 30%;
}

.skeleton-text.md {
  width: 50%;
}

.skeleton-text.lg {
  width: 80%;
}

.skeleton-badge {
  height: 20px;
  width: 100px;
  background: #e0e0e0;
  border-radius: 20px;
}

.skeleton-stats {
  display: flex;
  justify-content: space-between;
  margin-top: 30px;
  padding-top: 20px;
  border-top: 1px solid #eee;
}

.skeleton-stat {
  width: 22%;
  text-align: center;
}

.skeleton-stat-number {
  height: 30px;
  width: 60%;
  background: #e0e0e0;
  border-radius: 4px;
  margin: 0 auto 10px;
}

.skeleton-stat-label {
  height: 15px;
  width: 80%;
  background: #e0e0e0;
  border-radius: 4px;
  margin: 0 auto;
}

.fade-in {
  animation: fadeIn 0.5s ease-in-out;
}

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

.fade-out {
  animation: fadeOut 0.5s ease-in-out forwards;
}

@keyframes fadeOut {
  from {
    opacity: 1;
  }
  to {
    opacity: 0;
  }
}

.comment-text {
  position: relative;
  margin-bottom: 10px;
  /* keep break line */
  white-space: pre-wrap;
  word-break: break-word;
}

.comment-text-content {
  margin: 0;
  white-space: pre-wrap;
  word-break: break-word;
}

.comment-text.truncated .comment-text-content {
  max-height: 10em;
  overflow: hidden;
}

.comment-text.truncated.overflowing .comment-text-content::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 50px;
  background: linear-gradient(180deg, transparent, white 90%);
  pointer-events: none;
}

.show-more-btn {
  color: #4f46e5;
  background: none;
  border: none;
  padding: 0;
  font: inherit;
  cursor: pointer;
  outline: inherit;
  font-size: 0.9em;
  margin-top: 5px;
}

.show-more-btn:hover {
  text-decoration: underline;
}