:root {
  --primary: #3b82f6;
  --primary-dark: #2563eb;
  --background: #ffffff;
  --text: #1f2937;
  --text-light: #6b7280;
  --border: #e5e7eb;
  --success: #10b981;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
}

body {
  background-color: var(--background);
  color: var(--text);
  min-height: 100vh;
  line-height: 1.5;
}

.container {
  max-width: 640px;
  margin: 0 auto;
  padding: 1rem;
}

header {
  text-align: center;
  margin: 2rem 0 3rem;
}

.logo {
  font-size: 2rem;
  font-weight: 800;
  color: var(--primary);
  margin-bottom: 0.5rem;
  letter-spacing: -0.5px;
}

.tagline {
  color: var(--text-light);
  font-size: 1.125rem;
}

.main-box {
  background: white;
  border-radius: 12px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
  border: 1px solid var(--border);
  overflow: hidden;
}

.input-container {
  padding: 1.5rem;
  border-bottom: 1px solid var(--border);
}

.input-group {
  display: flex;
  gap: 0.5rem;
}

#url {
  flex: 1;
  padding: 0.75rem 1rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  font-size: 0.9375rem;
  transition: all 0.2s;
}

#url:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15);
}

#downloadBtn {
  background-color: var(--primary);
  color: white;
  border: none;
  border-radius: 8px;
  padding: 0 1.5rem;
  font-size: 0.9375rem;
  font-weight: 500;
  cursor: pointer;
  transition: background-color 0.2s;
  white-space: nowrap;
}

#downloadBtn:hover {
  background-color: var(--primary-dark);
}

.info-text {
  font-size: 0.8125rem;
  color: var(--text-light);
  margin-top: 1rem;
  text-align: center;
}

.result-container {
  display: none;
  padding: 1.5rem;
}

.loading-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 2rem 0;
}

.spinner {
  width: 2.5rem;
  height: 2.5rem;
  border: 3px solid rgba(59, 130, 246, 0.1);
  border-radius: 50%;
  border-top-color: var(--primary);
  animation: spin 1s linear infinite;
  margin-bottom: 1rem;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.video-info {
  margin-bottom: 1.5rem;
  display: none;
}

.video-title {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.video-thumbnail {
  width: 100%;
  border-radius: 8px;
  margin: 1rem 0;
  border: 1px solid var(--border);
  display: none;
}

.options-title {
  font-size: 0.9375rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: var(--text-light);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  display: none;
}

.download-options {
  margin-top: 1.5rem;
}

.option {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.75rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  margin-bottom: 0.75rem;
  transition: all 0.2s;
}

.option:hover {
  border-color: var(--primary);
}

.option-info {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.option-icon {
  color: var(--text-light);
  font-size: 1.25rem;
}

.option-details {
  display: flex;
  flex-direction: column;
}

.option-format {
  font-weight: 500;
  font-size: 0.9375rem;
}

.option-meta {
  font-size: 0.8125rem;
  color: var(--text-light);
}

.option-btn {
  background-color: var(--primary);
  color: white;
  border: none;
  border-radius: 6px;
  padding: 0.375rem 0.75rem;
  font-size: 0.8125rem;
  font-weight: 500;
  cursor: pointer;
  transition: background-color 0.2s;
}

.option-btn:hover {
  background-color: var(--primary-dark);
}

footer {
  text-align: center;
  margin-top: 3rem;
  color: var(--text-light);
  font-size: 0.8125rem;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin-top: 0.5rem;
}

.footer-link {
  color: var(--text-light);
  text-decoration: none;
  transition: color 0.2s;
}

.footer-link:hover {
  color: var(--primary);
}

@media (max-width: 640px) {
  .container {
    padding: 1rem;
  }
  
  .input-group {
    flex-direction: column;
  }
  
  #downloadBtn {
    padding: 0.75rem;
    width: 100%;
  }
  
  header {
    margin: 1rem 0 2rem;
  }
}