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

:root {
  --primary: #6c3fc5;
  --primary-dark: #5530a8;
  --primary-light: #f0ebff;
  --accent: #f5a623;
  --bg: #0f0f13;
  --bg-card: #1a1a24;
  --bg-card2: #22222f;
  --text: #e8e8f0;
  --text-muted: #888899;
  --border: #2e2e40;
  --success: #4caf82;
  --error: #e05555;
  --radius: 16px;
  --radius-sm: 8px;
}

html, body {
  height: 100%;
}

body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Header */
header {
  background: linear-gradient(135deg, #1a0a3e 0%, #0f0f1f 100%);
  border-bottom: 1px solid var(--border);
  padding: 24px 0;
}

.header-inner {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  gap: 20px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo-icon {
  font-size: 2.4rem;
  color: var(--accent);
  line-height: 1;
}

.logo-text {
  font-size: 1.8rem;
  font-weight: 700;
  background: linear-gradient(135deg, #c8a0ff, #7b4fe8);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.tagline {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-left: auto;
}

/* Main */
main {
  flex: 1;
  max-width: 900px;
  margin: 0 auto;
  padding: 40px 24px;
  width: 100%;
}

.section {
  margin-bottom: 32px;
}

.hidden {
  display: none !important;
}

/* Drop Zone */
.drop-zone {
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  background: var(--bg-card);
  padding: 60px 24px;
  text-align: center;
  cursor: pointer;
  transition: all 0.25s ease;
}

.drop-zone:hover,
.drop-zone.drag-over {
  border-color: var(--primary);
  background: #1c1030;
  box-shadow: 0 0 40px rgba(108, 63, 197, 0.15);
}

.drop-icon {
  font-size: 4rem;
  margin-bottom: 16px;
}

.drop-content h2 {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.drop-desc {
  color: var(--text-muted);
  margin-bottom: 6px;
}

.drop-formats {
  color: var(--text-muted);
  font-size: 0.85rem;
  margin-bottom: 28px;
  letter-spacing: 0.05em;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: 999px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: all 0.2s ease;
  text-decoration: none;
}

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

.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
  box-shadow: 0 8px 24px rgba(108, 63, 197, 0.4);
}

.btn-convert {
  background: linear-gradient(135deg, #7b4fe8, #a855f7);
  color: #fff;
  font-size: 1.05rem;
  padding: 16px 36px;
  box-shadow: 0 4px 20px rgba(108, 63, 197, 0.4);
}

.btn-convert:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 32px rgba(108, 63, 197, 0.55);
}

.btn-download {
  background: var(--success);
  color: #fff;
}

.btn-download:hover {
  background: #3d9e6f;
  transform: translateY(-1px);
}

.btn-ghost {
  background: transparent;
  color: var(--text-muted);
  border: 1px solid var(--border);
}

.btn-ghost:hover {
  background: var(--bg-card2);
  color: var(--text);
}

.btn-icon {
  font-size: 1.1em;
}

/* Preview / Two-column */
.two-col {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 32px;
  align-items: center;
}

.col-title {
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  margin-bottom: 12px;
}

.image-preview-box {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  max-height: 400px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.image-preview-box img {
  max-width: 100%;
  max-height: 400px;
  object-fit: contain;
  display: block;
}

.file-name {
  margin-top: 8px;
  font-size: 0.85rem;
  color: var(--text-muted);
  text-align: center;
}

.center-col {
  display: flex;
  justify-content: center;
}

.arrow-area {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
}

.arrow {
  font-size: 2rem;
  color: var(--primary);
  animation: pulse 1.5s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 0.5; transform: translateX(0); }
  50% { opacity: 1; transform: translateX(4px); }
}

/* Loading */
.loading-box {
  text-align: center;
  padding: 60px 24px;
  background: var(--bg-card);
  border-radius: var(--radius);
  border: 1px solid var(--border);
}

.music-notes-animation {
  font-size: 2.5rem;
  margin-bottom: 24px;
  display: flex;
  justify-content: center;
  gap: 12px;
}

.music-notes-animation span {
  display: inline-block;
  animation: bounce 1.2s ease-in-out infinite;
  color: var(--primary);
}

.music-notes-animation span:nth-child(1) { animation-delay: 0s; }
.music-notes-animation span:nth-child(2) { animation-delay: 0.15s; }
.music-notes-animation span:nth-child(3) { animation-delay: 0.3s; }
.music-notes-animation span:nth-child(4) { animation-delay: 0.45s; }

@keyframes bounce {
  0%, 100% { transform: translateY(0); opacity: 0.5; }
  50% { transform: translateY(-12px); opacity: 1; }
}

.loading-box h2 {
  font-size: 1.4rem;
  margin-bottom: 8px;
}

.loading-desc {
  color: var(--text-muted);
  margin-bottom: 32px;
}

.progress-bar {
  height: 4px;
  background: var(--border);
  border-radius: 999px;
  overflow: hidden;
  max-width: 400px;
  margin: 0 auto;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--primary), #a855f7);
  border-radius: 999px;
  animation: progress 3s ease-in-out infinite;
}

@keyframes progress {
  0% { width: 0%; }
  60% { width: 80%; }
  100% { width: 95%; }
}

/* Result */
.result-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 24px;
  flex-wrap: wrap;
  gap: 16px;
}

.result-title-area h2 {
  font-size: 1.5rem;
}

.result-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.score-wrapper {
  background: #fff;
  border-radius: var(--radius);
  padding: 32px;
  min-height: 200px;
  overflow-x: auto;
}

#scoreContainer {
  min-height: 150px;
}

.xml-details {
  margin-top: 16px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 16px;
}

.xml-details summary {
  cursor: pointer;
  font-size: 0.85rem;
  color: var(--text-muted);
  user-select: none;
}

.xml-details summary:hover {
  color: var(--text);
}

#xmlPreview {
  margin-top: 12px;
  font-size: 0.78rem;
  color: #a0a0b8;
  white-space: pre-wrap;
  word-break: break-all;
  max-height: 300px;
  overflow-y: auto;
  line-height: 1.6;
}

/* Error */
.error-box {
  text-align: center;
  padding: 48px 24px;
  background: #1e0f0f;
  border: 1px solid #4a1f1f;
  border-radius: var(--radius);
}

.error-icon {
  font-size: 3rem;
  margin-bottom: 16px;
}

.error-box h3 {
  font-size: 1.3rem;
  margin-bottom: 8px;
  color: #f88;
}

.error-box p {
  color: var(--text-muted);
  margin-bottom: 24px;
}

/* Footer */
footer {
  text-align: center;
  padding: 24px;
  border-top: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 0.85rem;
}

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

footer a:hover {
  text-decoration: underline;
}

/* Responsive */
@media (max-width: 640px) {
  .two-col {
    grid-template-columns: 1fr;
  }
  .arrow { display: none; }
  .header-inner { flex-direction: column; align-items: flex-start; gap: 8px; }
  .tagline { margin-left: 0; }
  .result-header { flex-direction: column; align-items: flex-start; }
}