:root {
  --bg-gradient: radial-gradient(circle at top, #5f8eff 0%, #1e1f4b 35%, #05050f 100%);
  --card-bg: rgba(255, 255, 255, 0.12);
  --card-border: rgba(255, 255, 255, 0.25);
  --text-primary: #f6f6ff;
  --text-secondary: rgba(246, 246, 255, 0.78);
  --accent: #8dc5ff;
  --accent-strong: #4d9dff;
  --shadow: rgba(11, 16, 42, 0.45);
  --radius-xl: 28px;
  --radius-lg: 18px;
  --radius-md: 12px;
  --radius-pill: 999px;
  --safe-top: env(safe-area-inset-top, 0px);
  --safe-right: env(safe-area-inset-right, 0px);
  --safe-bottom: env(safe-area-inset-bottom, 0px);
  --safe-left: env(safe-area-inset-left, 0px);
  --pad-y: clamp(32px, 9vw, 80px);
  --pad-x: clamp(20px, 7vw, 56px);
  font-family: 'Poppins', 'Helvetica Neue', Helvetica, Arial, sans-serif;
}

* {
  box-sizing: border-box;
  padding: 0;
  margin: 0;
  -webkit-tap-highlight-color: rgba(0, 0, 0, 0);
}

html {
  height: 100%;
}

body {
  min-height: 100vh;
  background: var(--bg-gradient);
  color: var(--text-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0;
  padding: var(--pad-y) var(--pad-x);
  padding-top: calc(var(--pad-y) + var(--safe-top));
  padding-bottom: calc(var(--pad-y) + var(--safe-bottom));
  padding-left: calc(var(--pad-x) + var(--safe-left));
  padding-right: calc(var(--pad-x) + var(--safe-right));
  -webkit-font-smoothing: antialiased;
  font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  touch-action: manipulation;
  overscroll-behavior-y: contain;
  overflow-x: hidden;
}

.hero {
  width: min(880px, calc(100vw - var(--safe-left) - var(--safe-right)));
  margin: 0 auto;
  flex: 1 1 auto;
}

.glass-card {
  background: var(--card-bg);
  -webkit-backdrop-filter: blur(24px) saturate(140%);
  backdrop-filter: blur(24px) saturate(140%);
  border: 1px solid var(--card-border);
  border-radius: var(--radius-xl);
  box-shadow: 0 40px 60px -30px var(--shadow);
  padding: 48px clamp(24px, 4vw, 56px);
  display: grid;
  gap: 36px;
}

.title h1 {
  font-size: clamp(2.4rem, 5vw, 3.4rem);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.title-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
}

.header-links {
  display: flex;
  align-items: center;
  gap: 12px;
}

.icon-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  background: rgba(141, 197, 255, 0.08);
  border: 1px solid rgba(141, 197, 255, 0.2);
  color: var(--text-secondary);
  transition: all 0.3s ease;
  text-decoration: none;
}

.icon-link:hover {
  background: rgba(141, 197, 255, 0.15);
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 8px 16px -8px rgba(141, 197, 255, 0.4);
}

.icon-link:active {
  transform: translateY(0);
  box-shadow: 0 4px 8px -4px rgba(141, 197, 255, 0.3);
}

.icon-link svg {
  transition: transform 0.3s ease;
}

.icon-link:hover svg {
  transform: scale(1.1);
}

/* 兼容旧的类名 */
.download-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  background: rgba(141, 197, 255, 0.08);
  border: 1px solid rgba(141, 197, 255, 0.2);
  color: var(--text-secondary);
  transition: all 0.3s ease;
  text-decoration: none;
}

.download-link:hover {
  background: rgba(141, 197, 255, 0.15);
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 8px 16px -8px rgba(141, 197, 255, 0.4);
}

.download-link:active {
  transform: translateY(0);
  box-shadow: 0 4px 8px -4px rgba(141, 197, 255, 0.3);
}

.download-link svg {
  transition: transform 0.3s ease;
}

.download-link:hover svg {
  transform: translateY(1px);
}

@media (max-width: 640px) {
  .title-row {
    gap: 12px;
  }
  
  .header-links {
    gap: 10px;
  }
  
  .icon-link,
  .download-link {
    width: 32px;
    height: 32px;
  }
  
  .icon-link svg,
  .download-link svg {
    width: 18px;
    height: 18px;
  }
}

.title p {
  color: var(--text-secondary);
  margin-top: 12px;
  max-width: 520px;
  line-height: 1.6;
}

.upload-box {
  display: block;
  border-radius: var(--radius-xl);
  border: 1px dashed rgba(255, 255, 255, 0.4);
  padding: clamp(34px, 6vw, 54px);
  background: rgba(255, 255, 255, 0.08);
  -webkit-backdrop-filter: blur(22px) saturate(160%);
  backdrop-filter: blur(22px) saturate(160%);
  text-align: center;
  cursor: pointer;
  transition: all 0.35s ease;
  position: relative;
  overflow: hidden;
}

.upload-box::before {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.22), transparent);
  opacity: 0;
  transition: opacity 0.35s ease;
}

.upload-box:hover {
  transform: translateY(-4px);
  box-shadow: 0 26px 40px -32px rgba(0, 0, 0, 0.8);
}

.upload-box:hover::before {
  opacity: 1;
}

.upload-box input {
  display: none;
}

.upload-inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 12px;
  align-items: center;
  justify-items: center;
  color: var(--text-secondary);
}

.upload-inner .icon {
  font-size: 3rem;
  color: var(--text-primary);
  filter: drop-shadow(0 4px 12px rgba(141, 197, 255, 0.3));
}

.upload-inner h2 {
  font-weight: 600;
  letter-spacing: 0.06em;
}

.player {
  display: grid;
  gap: 18px;
  background: rgba(5, 8, 25, 0.35);
  -webkit-backdrop-filter: blur(20px) saturate(160%);
  backdrop-filter: blur(20px) saturate(160%);
  padding: 24px;
  border-radius: var(--radius-lg);
  border: 1px solid rgba(255, 255, 255, 0.16);
}

.track-meta {
  display: flex;
  justify-content: space-between;
  font-weight: 500;
  color: var(--text-secondary);
}

.track-name {
  max-width: 70%;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

audio {
  width: 100%;
  min-height: 48px;
  filter: drop-shadow(0 12px 22px rgba(5, 8, 25, 0.55));
  border-radius: 12px;
  background: rgba(8, 12, 30, 0.6);
  border: 1px solid rgba(255, 255, 255, 0.16);
  -webkit-backdrop-filter: blur(18px) saturate(140%);
  backdrop-filter: blur(18px) saturate(140%);
}

audio::-webkit-media-controls-panel {
  background: transparent;
}

audio::-webkit-media-controls-timeline {
  border-radius: 999px;
}

.range {
  display: grid;
  gap: 18px;
  background: rgba(255, 255, 255, 0.08);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  backdrop-filter: blur(20px) saturate(180%);
  padding: 24px;
  border-radius: var(--radius-lg);
  border: 1px solid rgba(255, 255, 255, 0.18);
}

.range-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  color: var(--text-secondary);
}

.range-header h3 {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0;
}

/* 信息图标样式 */
.info-icon {
  display: inline-flex;
  align-items: center;
  cursor: help;
  color: var(--text-secondary);
  opacity: 0.7;
  transition: opacity 0.2s ease;
}

.info-icon:hover {
  opacity: 1;
  color: var(--accent);
}

/* 提示弹窗样式 */
.info-tooltip {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 1000;
  animation: fadeIn 0.2s ease;
}

.tooltip-content {
  background: rgba(10, 15, 35, 0.98);
  border: 1px solid rgba(141, 197, 255, 0.3);
  border-radius: var(--radius-lg);
  padding: 24px;
  max-width: 380px;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.8);
  backdrop-filter: blur(20px);
}

.tooltip-content h4 {
  margin: 0 0 12px 0;
  color: var(--accent);
  font-size: 1.1rem;
  font-weight: 600;
}

.tooltip-content p {
  margin: 0 0 20px 0;
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
}

.tooltip-close {
  width: 100%;
  padding: 10px;
  background: rgba(141, 197, 255, 0.15);
  border: 1px solid rgba(141, 197, 255, 0.3);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s ease;
}

.tooltip-close:hover {
  background: rgba(141, 197, 255, 0.25);
  border-color: var(--accent);
  transform: translateY(-1px);
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translate(-50%, -50%) scale(0.95);
  }
  to {
    opacity: 1;
    transform: translate(-50%, -50%) scale(1);
  }
}

.range-slider {
  position: relative;
  height: 32px;
}

.range-slider input[type='range'] {
  position: absolute;
  width: 100%;
  pointer-events: none;
  -webkit-appearance: none;
  appearance: none;
  background: transparent;
  height: 32px;
  margin: 0;
  padding: 0;
  touch-action: pan-y;
}

.range-slider input[type='range']:first-of-type {
  z-index: 2;
}

.range-slider input[type='range']:last-of-type {
  z-index: 3;
}

.range-slider input[type='range']::-webkit-slider-thumb {
  pointer-events: auto;
  -webkit-appearance: none;
  width: 22px;
  height: 22px;
  margin-top: -8px;
  border-radius: 50%;
  background: linear-gradient(180deg, #eef6ff, #8dd7ff);
  border: 2px solid rgba(9, 22, 58, 0.45);
  box-shadow: 0 10px 20px -8px rgba(79, 154, 255, 0.7);
}

.range-slider input[type='range']::-moz-range-thumb {
  pointer-events: auto;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: linear-gradient(180deg, #eef6ff, #8dd7ff);
  border: 2px solid rgba(9, 22, 58, 0.45);
  box-shadow: 0 10px 20px -8px rgba(79, 154, 255, 0.7);
}

.range-slider input[type='range']::-webkit-slider-runnable-track {
  height: 6px;
  background: linear-gradient(90deg, rgba(255, 255, 255, 0.25), rgba(77, 157, 255, 0.55));
  border-radius: 999px;
}

.range-slider input[type='range']::-moz-range-track {
  height: 6px;
  background: linear-gradient(90deg, rgba(255, 255, 255, 0.25), rgba(77, 157, 255, 0.55));
  border-radius: 999px;
}

.range-info {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  text-align: center;
  color: var(--text-secondary);
}

.range-info strong {
  display: block;
  margin-top: 6px;
  color: var(--text-primary);
  font-size: 1.1rem;
}

.range-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

button {
  -webkit-appearance: none;
  appearance: none;
  border: none;
  padding: 14px 22px;
  min-height: 44px;
  border-radius: var(--radius-pill);
  font-size: 0.96rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease, opacity 0.2s ease;
  touch-action: manipulation;
}

button.primary {
  background: linear-gradient(135deg, var(--accent), var(--accent-strong));
  color: #041021;
  box-shadow: 0 18px 28px -16px rgba(77, 157, 255, 0.85);
}

button.primary:disabled {
  opacity: 0.45;
  cursor: wait;
  box-shadow: none;
}

button.ghost {
  background: rgba(255, 255, 255, 0.1);
  color: var(--text-primary);
  border: 1px solid rgba(255, 255, 255, 0.2);
}

button:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: 0 18px 30px -20px rgba(141, 197, 255, 0.7);
}

button:active:not(:disabled) {
  transform: translateY(0);
  box-shadow: 0 12px 22px -18px rgba(141, 197, 255, 0.6);
}

button:focus-visible {
  outline: 2px solid rgba(141, 197, 255, 0.65);
  outline-offset: 2px;
}

.status {
  min-height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 12px 18px;
  border-radius: var(--radius-pill);
  border: 1px solid rgba(255, 255, 255, 0.18);
  background: rgba(6, 14, 36, 0.45);
  -webkit-backdrop-filter: blur(18px) saturate(150%);
  backdrop-filter: blur(18px) saturate(150%);
  color: var(--text-secondary);
  font-size: 0.92rem;
}

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

.download-pill {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 14px 28px;
  min-height: 48px;
  border-radius: var(--radius-pill);
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.82), rgba(143, 205, 255, 0.9));
  color: #041021;
  text-decoration: none;
  font-weight: 600;
  letter-spacing: 0.05em;
  box-shadow: 0 24px 40px -30px rgba(255, 255, 255, 0.6);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  white-space: nowrap;
  touch-action: manipulation;
}

.download-pill:hover {
  transform: translateY(-3px);
  box-shadow: 0 30px 48px -32px rgba(255, 255, 255, 0.75);
}

@media (max-width: 640px) {
  body {
    align-items: flex-start;
  }

  .hero {
    width: 100%;
  }

  .glass-card {
    padding: 32px 20px;
    gap: 28px;
  }

  .range-info {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 12px;
  }

  button {
    flex: 1 1 100%;
    text-align: center;
  }
}

.upload.drag-hover .upload-box {
  border-style: solid;
  border-color: rgba(141, 197, 255, 0.85);
  background: rgba(77, 157, 255, 0.2);
  -webkit-backdrop-filter: blur(24px) saturate(180%);
  backdrop-filter: blur(24px) saturate(180%);
}

@supports (height: 100dvh) {
  body {
    min-height: calc(100dvh + var(--safe-top) + var(--safe-bottom));
  }
}

/* 淡入淡出控制样式 */
.fade-controls {
  display: flex;
  flex-direction: column;
  gap: 16px;
  padding: 16px 0;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.fade-toggle {
  display: flex;
  align-items: center;
}

.toggle-label {
  display: flex;
  align-items: center;
  gap: 12px;
  cursor: pointer;
  color: var(--text-secondary);
  font-size: 0.95rem;
  font-weight: 500;
}

.toggle-label input[type="checkbox"] {
  display: none;
}

.toggle-slider {
  position: relative;
  width: 48px;
  height: 26px;
  background: rgba(255, 255, 255, 0.15);
  border-radius: 13px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  transition: all 0.3s ease;
}

.toggle-slider::before {
  content: '';
  position: absolute;
  top: 2px;
  left: 2px;
  width: 20px;
  height: 20px;
  background: linear-gradient(135deg, #eef6ff, #8dd7ff);
  border-radius: 50%;
  transition: all 0.3s ease;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.3);
}

.toggle-label input[type="checkbox"]:checked + .toggle-slider {
  background: linear-gradient(135deg, var(--accent), var(--accent-strong));
  border-color: var(--accent);
}

.toggle-label input[type="checkbox"]:checked + .toggle-slider::before {
  transform: translateX(22px);
  background: #fff;
}

.fade-duration {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.fade-duration label {
  font-weight: 500;
  min-width: 90px;
}

.fade-duration select {
  -webkit-appearance: none;
  appearance: none;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: var(--radius-md);
  padding: 8px 32px 8px 12px;
  color: var(--text-primary);
  font-size: 0.9rem;
  cursor: pointer;
  transition: all 0.2s ease;
  background-image: url("data:image/svg+xml;charset=utf-8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16'%3E%3Cpath fill='%238dc5ff' d='M4.427 6.573L8 10.146l3.573-3.573a.4.4 0 01.566.566l-3.856 3.856a.4.4 0 01-.566 0L3.86 7.139a.4.4 0 01.566-.566z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: calc(100% - 8px) center;
  background-size: 16px;
}

.fade-duration select:hover {
  background-color: rgba(255, 255, 255, 0.15);
  border-color: var(--accent);
}

.fade-duration select:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 2px rgba(141, 197, 255, 0.3);
}

@media (max-width: 640px) {
  .fade-controls {
    gap: 14px;
    padding: 14px 0;
  }
  
  .fade-duration {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }
  
  .fade-duration label {
    min-width: auto;
  }
  
  .fade-duration select {
    width: 100%;
  }
}