:root {
  --color-primary: #e60124;
  --color-primary-hover: #cc0120;
  --color-text: #000000;
  --color-text-secondary: #767676;
  --color-input-bg: #e5e5e1;
  --color-bg: #ffffff;
  --color-success: #00a400;
  --color-error: #ff0000;
  --color-border: #d9d9d9;
  --color-shadow: rgba(0, 0, 0, 0.1);

  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --border-radius: 24px;
  --border-radius-sm: 12px;
  --transition: all 0.2s ease;
}

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

body {
  font-family: var(--font-family);
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Header */
.header {
  padding: 16px 0;
  border-bottom: 1px solid var(--color-border);
}

.header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  text-decoration: none;
  color: var(--color-text);
  font-weight: 700;
  font-size: 20px;
}

.logo img {
  width: 32px;
  height: 32px;
}

.nav {
  display: flex;
  gap: 24px;
}

.nav a {
  color: var(--color-text-secondary);
  text-decoration: none;
  font-size: 14px;
  transition: var(--transition);
}

.nav a:hover {
  color: var(--color-text);
}

/* Hero */
.hero {
  padding: 60px 0;
  text-align: center;
}

.hero h1 {
  font-size: 48px;
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 16px;
}

.hero .subtitle {
  font-size: 20px;
  color: var(--color-text-secondary);
  margin-bottom: 40px;
}

/* Download Form */
.download-form {
  max-width: 640px;
  margin: 0 auto;
}

.input-group {
  display: flex;
  gap: 12px;
  background: var(--color-input-bg);
  padding: 8px;
  border-radius: var(--border-radius);
}

.url-input {
  flex: 1;
  padding: 12px 20px;
  border: none;
  background: transparent;
  font-size: 16px;
  font-family: inherit;
  outline: none;
}

.url-input::placeholder {
  color: var(--color-text-secondary);
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 32px;
  background: var(--color-primary);
  color: white;
  border: none;
  border-radius: var(--border-radius);
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  min-width: 120px;
}

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

.btn-primary:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.spinner {
  animation: spin 1s linear infinite;
}

@keyframes spin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

.input-hint {
  margin-top: 12px;
  font-size: 14px;
  color: var(--color-text-secondary);
  min-height: 20px;
}

.input-hint.error {
  color: var(--color-error);
}

.input-hint.success {
  color: var(--color-success);
}

.tip {
  margin-top: 24px;
  font-size: 14px;
  color: var(--color-text-secondary);
}

.tip code {
  background: var(--color-input-bg);
  padding: 2px 8px;
  border-radius: 4px;
  font-family: monospace;
}

/* Result Section */
.result {
  padding: 40px 0;
}

.result .container {
  text-align: center;
}

/* Queue Status */
.queue-status {
  max-width: 400px;
  margin: 0 auto;
  text-align: center;
  padding: 16px 0;
}

.spinner {
  width: 48px;
  height: 48px;
  border: 4px solid var(--color-input-bg);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: spin 0.9s linear infinite;
  margin: 0 auto 16px;
}

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

.processing-label {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
}

.elapsed-time {
  font-size: 14px;
  color: var(--color-text-secondary);
}

/* Download Ready */
.download-ready {
  max-width: 400px;
  margin: 0 auto;
}

.video-thumbnail {
  width: 100%;
  max-width: 300px;
  border-radius: var(--border-radius-sm);
  margin-bottom: 16px;
}

.video-title {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 8px;
  overflow: hidden;
  text-overflow: ellipsis;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
}

.video-info {
  font-size: 14px;
  color: var(--color-text-secondary);
  margin-bottom: 24px;
}

.btn-download {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 16px 40px;
  background: var(--color-success);
  color: white;
  border: none;
  border-radius: var(--border-radius);
  font-size: 18px;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: var(--transition);
  margin-bottom: 16px;
}

.btn-download:hover {
  background: #009000;
}

.btn-secondary {
  display: inline-block;
  padding: 12px 24px;
  background: transparent;
  color: var(--color-text-secondary);
  border: 1px solid var(--color-border);
  border-radius: var(--border-radius);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
}

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

/* Ad Block */
.ad-block {
  padding: 40px 0;
}

.ad-placeholder {
  background: var(--color-input-bg);
  padding: 40px;
  text-align: center;
  border-radius: var(--border-radius-sm);
  color: var(--color-text-secondary);
}

/* How To Section */
.how-to {
  padding: 60px 0;
  background: #f9f9f9;
}

.how-to h2 {
  text-align: center;
  font-size: 32px;
  margin-bottom: 40px;
}

.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
  margin-bottom: 48px;
}

.step {
  text-align: center;
  padding: 24px;
}

.step-number {
  width: 48px;
  height: 48px;
  background: var(--color-primary);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  font-weight: 700;
  margin: 0 auto 16px;
}

.step h3 {
  font-size: 18px;
  margin-bottom: 8px;
}

.step p {
  font-size: 14px;
  color: var(--color-text-secondary);
}

.quick-tip {
  background: white;
  padding: 32px;
  border-radius: var(--border-radius-sm);
  text-align: center;
  max-width: 600px;
  margin: 0 auto;
}

.quick-tip h3 {
  font-size: 20px;
  margin-bottom: 12px;
}

.quick-tip p {
  color: var(--color-text-secondary);
  margin-bottom: 16px;
}

.example {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}

.example code {
  background: var(--color-input-bg);
  padding: 8px 16px;
  border-radius: 8px;
  font-family: monospace;
  font-size: 14px;
}

.arrow {
  color: var(--color-primary);
  font-weight: bold;
}

/* Footer */
.footer {
  margin-top: auto;
  padding: 32px 0;
  background: #f9f9f9;
  border-top: 1px solid var(--color-border);
}

.footer-content {
  text-align: center;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 24px;
  margin-bottom: 16px;
  flex-wrap: wrap;
}

.footer-links a {
  color: var(--color-text-secondary);
  text-decoration: none;
  font-size: 14px;
  transition: var(--transition);
}

.footer-links a:hover {
  color: var(--color-text);
}

.copyright {
  font-size: 14px;
  color: var(--color-text-secondary);
  margin-bottom: 8px;
}

.disclaimer {
  font-size: 12px;
  color: var(--color-text-secondary);
  max-width: 500px;
  margin: 0 auto;
}

/* Modal */
.modal {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  padding: 20px;
}

.modal-content {
  background: white;
  padding: 32px;
  border-radius: var(--border-radius-sm);
  max-width: 440px;
  width: 100%;
  text-align: center;
}

.modal-icon {
  font-size: 48px;
  margin-bottom: 16px;
  color: var(--color-error);
}

.modal-content h3 {
  font-size: 24px;
  margin-bottom: 12px;
}

.modal-content > p {
  color: var(--color-text-secondary);
  margin-bottom: 24px;
}

.error-code {
  background: var(--color-input-bg);
  padding: 12px;
  border-radius: 8px;
  margin-bottom: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}

.error-code span {
  font-size: 14px;
  color: var(--color-text-secondary);
}

.error-code code {
  font-family: monospace;
  font-weight: 600;
}

.btn-copy {
  padding: 6px 12px;
  background: white;
  border: 1px solid var(--color-border);
  border-radius: 6px;
  font-size: 12px;
  cursor: pointer;
  transition: var(--transition);
}

.btn-copy:hover {
  border-color: var(--color-text);
}

.modal-actions {
  display: flex;
  gap: 12px;
  justify-content: center;
}

/* Mobile Responsive */
@media (max-width: 767px) {
  .hero h1 {
    font-size: 32px;
  }

  .hero .subtitle {
    font-size: 16px;
  }

  .input-group {
    flex-direction: column;
    padding: 12px;
  }

  .url-input {
    padding: 16px;
    text-align: center;
  }

  .btn-primary {
    width: 100%;
    padding: 16px;
  }

  .steps {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .nav {
    display: none;
  }

  .footer-links {
    flex-direction: column;
    gap: 12px;
  }

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

  .modal-actions button {
    width: 100%;
  }

  .example {
    flex-direction: column;
    gap: 8px;
  }
}

/* Tablet */
@media (min-width: 768px) and (max-width: 1023px) {
  .hero h1 {
    font-size: 40px;
  }

  .steps {
    gap: 24px;
  }
}