:root {
  --bg-color: #f6f8fa;
  --card-bg: #fff;
  --text-color: #333;
  --title-color: #0066cc;
  --border-color: #e1e4e8;
  --stats-bg: #f8f9fa;
  --table-header-bg: #edf2f7;
  --tab-active-bg: #fff;
  --tab-inactive-bg: #edf2f7;
  --primary-btn-bg: #0066cc;
  --primary-btn-hover: #0052a3;
  --success-btn-bg: #28a745;
  --success-btn-hover: #218838;
  --shadow-color: rgba(0,0,0,0.08);
  --toggle-inactive: #cbd5e0;
  --toggle-active: #0066cc;
  --accent-color: #ff6b6b;
  --highlight-row: #f0f7ff;
}

[data-theme="dark"] {
  --bg-color: #1a202c;
  --card-bg: #2d3748;
  --text-color: #e2e8f0;
  --title-color: #63b3ed;
  --border-color: #4a5568;
  --stats-bg: #2c3344;
  --table-header-bg: #3a4556;
  --tab-active-bg: #2d3748;
  --tab-inactive-bg: #3a4556;
  --primary-btn-bg: #4299e1;
  --primary-btn-hover: #3182ce;
  --success-btn-bg: #38a169;
  --success-btn-hover: #2f855a;
  --shadow-color: rgba(0,0,0,0.3);
  --toggle-inactive: #4a5568;
  --toggle-active: #4299e1;
  --accent-color: #fc8181;
  --highlight-row: #2a4365;
}

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

body { 
  display: flex; 
  flex-direction: column;
  align-items: center; 
  justify-content: center; 
  min-height: 100vh; 
  background: var(--bg-color); 
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--text-color);
  padding: 1.5rem 1rem;
  transition: background-color 0.3s ease;
  line-height: 1.6;
}

.card {
  background: var(--card-bg);
  border-radius: 16px;
  box-shadow: 0 8px 30px var(--shadow-color);
  padding: 2.5rem;
  width: 100%;
  max-width: 950px;
  text-align: center;
  transition: all 0.3s ease;
  border: 1px solid var(--border-color);
}

.logo {
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.5rem;
}

.logo-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  background: var(--primary-btn-bg);
  color: white;
  font-weight: bold;
  border-radius: 8px;
  margin-right: 10px;
  font-size: 18px;
  box-shadow: 0 4px 12px rgba(0, 102, 204, 0.2);
}

h1 {
  font-size: 1.8rem;
  margin-bottom: 1.2rem;
  color: var(--title-color);
  transition: color 0.3s ease;
  font-weight: 600;
}

p { 
  margin-bottom: 1.8rem; 
  line-height: 1.6;
  font-size: 1.05rem;
  max-width: 650px;
  margin-left: auto;
  margin-right: auto;
  color: var(--text-color);
  opacity: 0.9;
}

.file-input {
  position: relative;
  display: inline-block;
  margin-bottom: 2rem;
}

.file-input input[type="file"] {
  display: none;
}

.file-input label {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.8rem 1.8rem;
  background: var(--primary-btn-bg);
  color: #fff;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.3s ease;
  font-weight: 500;
  font-size: 1.05rem;
  box-shadow: 0 4px 12px rgba(0, 102, 204, 0.15);
  min-width: 180px;
}

.file-input label:hover {
  background: var(--primary-btn-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(0, 102, 204, 0.2);
}

.file-input label:active {
  transform: translateY(0);
}

.file-input label::before {
  content: "📁";
  margin-right: 8px;
  font-size: 1.2rem;
}

#stats {
  margin: 1.5rem auto;
  text-align: left;
  background: var(--stats-bg);
  padding: 1.2rem 1.5rem;
  border-radius: 12px;
  transition: all 0.3s ease;
  border-left: 4px solid var(--primary-btn-bg);
  max-width: 650px;
  box-shadow: 0 4px 12px var(--shadow-color);
}

#stats p {
  margin: 0.5rem 0;
  font-size: 1.05rem;
  display: flex;
  justify-content: space-between;
  max-width: 100%;
}

#stats p strong {
  font-weight: 600;
  color: var(--title-color);
}

.btn {
  display: inline-block;
  margin: 1.5rem 0.5rem;
  padding: 0.8rem 1.8rem;
  border-radius: 8px;
  transition: all 0.3s ease;
  font-weight: 500;
  font-size: 1rem;
  cursor: pointer;
  border: none;
  text-decoration: none;
  text-align: center;
}

.btn-primary {
  background: var(--primary-btn-bg);
  color: #fff;
  box-shadow: 0 4px 12px rgba(0, 102, 204, 0.15);
}

.btn-primary:hover {
  background: var(--primary-btn-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(0, 102, 204, 0.2);
}

.btn-success {
  background: var(--success-btn-bg);
  color: #fff;
  box-shadow: 0 4px 12px rgba(40, 167, 69, 0.15);
}

.btn-success:hover {
  background: var(--success-btn-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(40, 167, 69, 0.2);
}

.action-buttons {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 1rem;
  margin-top: 1rem;
}

table {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  margin-top: 0.5rem;
  font-size: 0.95rem;
}

table th, table td {
  border: 1px solid var(--border-color);
  padding: 12px 15px;
  text-align: left;
  transition: all 0.3s ease;
}

table th {
  background-color: var(--table-header-bg);
  font-weight: 600;
  position: sticky;
  top: 0;
  z-index: 10;
  box-shadow: 0 1px 2px var(--shadow-color);
}

table th:first-child {
  border-top-left-radius: 8px;
}

table th:last-child {
  border-top-right-radius: 8px;
}

table tr:nth-child(even) {
  background-color: var(--stats-bg);
}

table tr:hover {
  background-color: var(--highlight-row);
}

.table-container {
  margin-top: 1rem;
  max-height: 400px;
  overflow-y: auto;
  border-radius: 12px;
  border: 1px solid var(--border-color);
  transition: all 0.3s ease;
  box-shadow: 0 4px 12px var(--shadow-color);
  scrollbar-width: thin;
  scrollbar-color: var(--border-color) transparent;
}

.table-container::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

.table-container::-webkit-scrollbar-track {
  background: transparent;
}

.table-container::-webkit-scrollbar-thumb {
  background-color: var(--border-color);
  border-radius: 10px;
}

.tabs {
  display: flex;
  margin: 2rem 0 1rem;
  border-bottom: 2px solid var(--border-color);
  transition: all 0.3s ease;
  overflow-x: auto;
  scrollbar-width: none;
  padding-bottom: 2px;
}

.tabs::-webkit-scrollbar {
  display: none;
}

.tab-button {
  padding: 0.8rem 1.5rem;
  background: var(--tab-inactive-bg);
  border: none;
  border-bottom: 3px solid transparent;
  cursor: pointer;
  margin-right: 5px;
  font-size: 1rem;
  transition: all 0.3s ease;
  color: var(--text-color);
  opacity: 0.7;
  font-weight: 500;
  border-radius: 8px 8px 0 0;
}

.tab-button:hover {
  opacity: 1;
  background: var(--tab-active-bg);
}

.tab-button.active {
  background: var(--tab-active-bg);
  border-bottom: 3px solid var(--primary-btn-bg);
  opacity: 1;
  font-weight: 600;
  color: var(--title-color);
}

.tab-content {
  display: none;
  padding: 1.5rem 0;
}

.tab-content.active {
  display: block;
  animation: fadeIn 0.4s ease;
}

.settings-panel {
  position: fixed;
  top: 20px;
  right: 20px;
  display: flex;
  align-items: center;
  gap: 15px;
  background: var(--card-bg);
  padding: 12px 20px;
  border-radius: 30px;
  box-shadow: 0 4px 15px var(--shadow-color);
  z-index: 1000;
  transition: all 0.3s ease;
  border: 1px solid var(--border-color);
}

.language-select {
  padding: 8px 12px;
  border-radius: 20px;
  border: 1px solid var(--border-color);
  background: var(--card-bg);
  color: var(--text-color);
  font-size: 0.9rem;
  cursor: pointer;
  outline: none;
  transition: all 0.3s ease;
  -webkit-appearance: none;
  background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='currentColor' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6 9 12 15 18 9'%3e%3c/polyline%3e%3c/svg%3e");
  background-repeat: no-repeat;
  background-position: right 8px center;
  background-size: 12px;
  padding-right: 30px;
}

.language-select:hover {
  border-color: var(--primary-btn-bg);
}

.theme-switch {
  position: relative;
  display: inline-block;
  width: 52px;
  height: 26px;
}

.theme-switch input {
  opacity: 0;
  width: 0;
  height: 0;
}

.slider {
  position: absolute;
  cursor: pointer;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: var(--toggle-inactive);
  transition: .4s;
  border-radius: 26px;
}

.slider:before {
  position: absolute;
  content: "";
  height: 20px;
  width: 20px;
  left: 3px;
  bottom: 3px;
  background-color: white;
  transition: .4s;
  border-radius: 50%;
  box-shadow: 0 2px 5px rgba(0,0,0,0.2);
}

input:checked + .slider {
  background-color: var(--toggle-active);
}

input:checked + .slider:before {
  transform: translateX(26px);
}

.theme-icon {
  display: inline-block;
  margin: 0 5px;
  font-size: 1rem;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes slideIn {
  from { transform: translateY(-15px); opacity: 0; }
  to { transform: translateY(0); opacity: 1; }
}

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

.notice {
  margin-top: 2rem;
  padding: 1rem 1.5rem;
  background: var(--stats-bg);
  border-radius: 12px;
  font-size: 0.9rem;
  text-align: center;
  animation: slideIn 0.5s ease;
  max-width: 650px;
  margin-left: auto;
  margin-right: auto;
  border-left: 4px solid var(--accent-color);
  box-shadow: 0 4px 12px var(--shadow-color);
}

.loading {
  display: none;
  margin: 2rem auto;
  width: 50px;
  height: 50px;
  border: 5px solid var(--stats-bg);
  border-radius: 50%;
  border-top: 5px solid var(--primary-btn-bg);
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

.table-summary {
  text-align: right;
  padding: 0.8rem;
  font-size: 0.9rem;
  color: var(--text-color);
  opacity: 0.8;
  font-style: italic;
}

@media (max-width: 768px) {
  .card {
    padding: 1.8rem 1.2rem;
    border-radius: 12px;
  }
  
  h1 {
    font-size: 1.5rem;
  }
  
  table {
    font-size: 0.85rem;
  }
  
  table th, table td {
    padding: 10px 8px;
  }
  
  .settings-panel {
    position: relative;
    top: 0;
    right: 0;
    margin: 0 auto 20px;
    width: fit-content;
    flex-wrap: wrap;
    justify-content: center;
  }
  
  .tabs {
    flex-wrap: nowrap;
    overflow-x: auto;
  }
  
  .tab-button {
    padding: 0.6rem 1rem;
    white-space: nowrap;
  }
  
  #stats p {
    flex-direction: column;
    align-items: flex-start;
  }
  
  .action-buttons {
    flex-direction: column;
    align-items: center;
  }
  
  .btn {
    width: 100%;
    margin: 0.5rem 0;
  }
}

@media (max-width: 480px) {
  .card {
    padding: 1.5rem 1rem;
  }
  
  .file-input label {
    padding: 0.7rem 1.4rem;
    font-size: 0.95rem;
  }
  
  h1 {
    font-size: 1.3rem;
  }
  
  p {
    font-size: 0.95rem;
  }
  
  .tabs {
    margin-top: 1.5rem;
  }
  
  .tab-button {
    padding: 0.5rem 0.8rem;
    font-size: 0.9rem;
  }
}