@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');

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

:root {
  --primary: #0891b2;
  --primary-hover: #0e7490;
  --primary-light: #ecfeff;
  --secondary: #22d3ee;
  --success: #22c55e;
  --success-light: #f0fdf4;
  --error: #ef4444;
  --error-light: #fef2f2;
  --text: #164e63;
  --text-secondary: #64748b;
  --bg: #f8fafc;
  --bg-white: #ffffff;
  --border: #e2e8f0;
  --border-hover: #cbd5e1;
  --radius: 10px;
  --radius-sm: 6px;
  --transition: 180ms ease;
}

html {
  -webkit-text-size-adjust: 100%;
  -ms-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  overscroll-behavior-y: contain;
  -webkit-overflow-scrolling: touch;
}

header {
  background: var(--bg-white);
  border-bottom: 1px solid var(--border);
  padding: 0 20px;
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  max-width: 640px;
  margin: 0 auto;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text);
}

.logo-img {
  width: 28px;
  height: 28px;
  border-radius: var(--radius-sm);
  object-fit: contain;
}

.logo-text {
  font-size: 15px;
  font-weight: 700;
  letter-spacing: -0.3px;
}

.github-link {
  color: var(--text);
  opacity: 0.6;
  transition: opacity var(--transition);
  display: flex;
  align-items: center;
  padding: 6px;
  border-radius: var(--radius-sm);
}

.github-link:hover {
  opacity: 1;
}

main {
  max-width: 640px;
  margin: 0 auto;
  padding: 0 20px 48px;
  width: 100%;
  flex: 1;
}

.hero {
  text-align: center;
  padding: 32px 0 24px;
}

.hero h1 {
  font-size: 24px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 6px;
  letter-spacing: -0.5px;
}

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

.tabs {
  display: flex;
  background: var(--primary-light);
  border-radius: var(--radius);
  padding: 3px;
  margin-bottom: 24px;
}

.tab-btn {
  flex: 1;
  padding: 10px 0;
  border: none;
  background: transparent;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition);
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
}

.tab-btn:active {
  transform: scale(0.98);
}

.tab-btn.active {
  background: var(--bg-white);
  color: var(--primary);
}

.panel {
  display: none;
}

.panel.active {
  display: block;
}

.panel-body {
  padding: 0;
}

.form-group {
  margin-bottom: 20px;
}

.form-label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 6px;
}

.form-hint {
  font-size: 12px;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

.drop-zone {
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 28px 16px;
  text-align: center;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition);
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
}

.drop-zone:active {
  border-color: var(--primary);
  color: var(--primary);
  background: var(--primary-light);
}

@media (hover: hover) {
  .drop-zone:hover {
    border-color: var(--primary);
    color: var(--primary);
    background: var(--primary-light);
  }
}

.drop-zone.dragover {
  border-color: var(--primary);
  color: var(--primary);
  background: var(--primary-light);
  border-style: solid;
}

.drop-zone-icon {
  margin-bottom: 8px;
  opacity: 0.5;
}

.drop-zone-text {
  font-size: 13px;
  font-weight: 500;
}

.drop-zone-hint {
  font-size: 11px;
  margin-top: 3px;
  opacity: 0.6;
}

.file-input {
  display: none;
}

.preview-container {
  margin-top: 12px;
  display: flex;
  align-items: flex-start;
  gap: 12px;
}

.preview-img {
  max-width: 140px;
  max-height: 110px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  object-fit: contain;
}

.preview-info {
  font-size: 12px;
  color: var(--text-secondary);
  padding: 4px 0;
}

.preview-info p {
  margin-bottom: 4px;
}

.textarea {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 16px;
  font-family: inherit;
  line-height: 1.5;
  resize: vertical;
  transition: border-color var(--transition);
  background: var(--bg-white);
  color: var(--text);
  -webkit-appearance: none;
  appearance: none;
}

.textarea:focus {
  outline: none;
  border-color: var(--primary);
}

.textarea::placeholder {
  color: var(--text-secondary);
  opacity: 0.6;
}

.input {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 16px;
  font-family: inherit;
  transition: border-color var(--transition);
  background: var(--bg-white);
  color: var(--text);
  -webkit-appearance: none;
  appearance: none;
}

.input:focus {
  outline: none;
  border-color: var(--primary);
}

.input::placeholder {
  color: var(--text-secondary);
  opacity: 0.6;
}

.btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 24px;
  border: none;
  border-radius: var(--radius);
  font-size: 14px;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  transition: background var(--transition), transform 60ms ease;
  white-space: nowrap;
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
}

.btn:active:not(:disabled) {
  transform: scale(0.98);
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

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

@media (hover: hover) {
  .btn-primary:hover:not(:disabled) {
    background: var(--primary-hover);
  }
}

.btn-secondary {
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
}

@media (hover: hover) {
  .btn-secondary:hover:not(:disabled) {
    background: var(--border);
  }
}

.btn-block {
  width: 100%;
}

.spinner {
  width: 16px;
  height: 16px;
  border: 2px solid rgba(255,255,255,0.3);
  border-top-color: white;
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
  display: none;
}

.btn.loading .spinner {
  display: block;
}

.btn.loading .btn-text {
  display: none;
}

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

.alert {
  padding: 10px 12px;
  border-radius: var(--radius);
  font-size: 13px;
  display: none;
  align-items: flex-start;
  gap: 8px;
  margin-top: 14px;
}

.alert.show {
  display: flex;
}

.alert-success {
  background: var(--success-light);
  color: #15803d;
  border: 1px solid #bbf7d0;
}

.alert-error {
  background: var(--error-light);
  color: var(--error);
  border: 1px solid #fecaca;
}

.alert-icon {
  flex-shrink: 0;
  margin-top: 1px;
  display: flex;
}

.alert-content {
  flex: 1;
  word-break: break-all;
}

.alert-content .secret-text {
  display: block;
  margin-top: 8px;
  padding: 10px 12px;
  background: rgba(0,0,0,0.04);
  border-radius: var(--radius-sm);
  font-family: "SF Mono", "Fira Code", monospace;
  font-size: 13px;
  line-height: 1.5;
  color: var(--text);
  user-select: all;
  -webkit-user-select: all;
}

.alert-content .secret-actions {
  margin-top: 10px;
}

.result-image-wrapper {
  margin-top: 16px;
  text-align: center;
}

.result-image {
  max-width: 100%;
  max-height: 360px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  cursor: pointer;
  transition: transform var(--transition);
}

.result-image:active {
  transform: scale(0.98);
}

.result-hint {
  font-size: 12px;
  color: var(--text-secondary);
  margin-top: 6px;
}

.capacity-bar {
  margin-top: 6px;
  height: 3px;
  background: var(--border);
  border-radius: 2px;
  overflow: hidden;
}

.capacity-bar-fill {
  height: 100%;
  background: var(--primary);
  border-radius: 2px;
  transition: width 0.3s ease;
}

.capacity-text {
  font-size: 11px;
  color: var(--text-secondary);
  margin-top: 3px;
}

.label-tag {
  display: inline-block;
  padding: 1px 7px;
  border-radius: 8px;
  font-size: 10px;
  font-weight: 600;
  background: var(--border);
  color: var(--text-secondary);
  vertical-align: middle;
  margin-left: 4px;
  transition: all var(--transition);
}

.label-tag.active {
  background: var(--primary-light);
  color: var(--primary);
}

.toggle-row {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 10px;
}

.toggle-switch {
  position: relative;
  display: inline-block;
  width: 40px;
  height: 22px;
  cursor: pointer;
  flex-shrink: 0;
  -webkit-tap-highlight-color: transparent;
}

.toggle-switch input {
  opacity: 0;
  width: 0;
  height: 0;
  position: absolute;
}

.toggle-slider {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--border);
  border-radius: 22px;
  transition: background var(--transition);
}

.toggle-slider::before {
  content: "";
  position: absolute;
  height: 16px;
  width: 16px;
  left: 3px;
  bottom: 3px;
  background: white;
  border-radius: 50%;
  transition: transform var(--transition);
}

.toggle-switch input:checked + .toggle-slider {
  background: var(--primary);
}

.toggle-switch input:checked + .toggle-slider::before {
  transform: translateX(18px);
}

.toggle-label {
  font-size: 13px;
  color: var(--text-secondary);
  user-select: none;
  -webkit-user-select: none;
}

footer {
  text-align: center;
  padding: 20px;
  color: var(--text-secondary);
  font-size: 12px;
  border-top: 1px solid var(--border);
  background: var(--bg-white);
}

footer a {
  color: var(--primary);
  text-decoration: none;
}

@media (max-width: 640px) {
  .header-inner {
    height: 48px;
  }

  .logo-text {
    font-size: 14px;
  }

  .hero {
    padding: 24px 0 20px;
  }

  .hero h1 {
    font-size: 20px;
  }

  .hero p {
    font-size: 13px;
  }

  .tabs {
    margin-bottom: 20px;
  }

  .tab-btn {
    padding: 9px 0;
    font-size: 13px;
  }

  .drop-zone {
    padding: 22px 12px;
  }

  .preview-container {
    flex-direction: column;
  }

  .preview-img {
    max-width: 100%;
  }

  .btn {
    padding: 14px 24px;
    font-size: 15px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}