:root {
  --bg: #08090b;
  --bg-elev: #101216;
  --bg-elev-2: #16191f;
  --border: #24272e;
  --border-strong: #33373f;
  --text: #eef0f3;
  --text-dim: #9aa0ab;
  --text-faint: #5c6270;
  --accent: #2f6bff;
  --accent-hover: #4a7dff;
  --accent-text: #eaf0ff;
  --danger: #ff4d4d;
  --radius: 10px;
  --radius-lg: 16px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Roboto, Helvetica, Arial, sans-serif;
  --font-mono: "SF Mono", "Cascadia Code", Consolas, monospace;
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
}

* { box-sizing: border-box; }

[hidden] { display: none !important; }

html, body {
  margin: 0;
  padding: 0;
  min-height: 100dvh;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  -webkit-font-smoothing: antialiased;
}

body {
  display: flex;
  flex-direction: column;
  position: relative;
  overflow-x: hidden;
}

.bg-grid {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(255,255,255,0.035) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255,255,255,0.035) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, black 40%, transparent 90%);
}

.site-header, main, .site-footer {
  position: relative;
  z-index: 1;
}

.site-header {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding: 40px 20px 8px;
  text-align: center;
}

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

.brand-icon {
  width: 26px;
  height: 26px;
  color: var(--accent);
}

.brand-name {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.tagline {
  color: var(--text-dim);
  font-size: 14px;
  margin: 0;
}

main {
  flex: 1;
  width: 100%;
  max-width: 640px;
  margin: 0 auto;
  padding: 32px 20px 64px;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.intro {
  text-align: center;
  padding: 8px 4px 4px;
}

.intro h1 {
  font-size: clamp(24px, 5vw, 32px);
  line-height: 1.25;
  letter-spacing: -0.02em;
  margin: 0 0 12px;
}

.intro p {
  color: var(--text-dim);
  font-size: 15px;
  line-height: 1.6;
  margin: 0;
  max-width: 52ch;
  margin-inline: auto;
}

.panel {
  background: var(--bg-elev);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.dropzone {
  border: 1.5px dashed var(--border-strong);
  border-radius: var(--radius);
  padding: 40px 20px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  text-align: center;
  cursor: pointer;
  transition: border-color 180ms var(--ease-out), background-color 180ms var(--ease-out);
}

.dropzone:hover,
.dropzone:focus-visible {
  border-color: var(--accent);
  background: rgba(47, 107, 255, 0.05);
}

.dropzone:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}

.dropzone.drag-active {
  border-color: var(--accent);
  background: rgba(47, 107, 255, 0.08);
  transform: scale(1.005);
}

.dz-icon {
  width: 40px;
  height: 40px;
  color: var(--text-faint);
  margin-bottom: 4px;
}

.dz-title {
  font-size: 16px;
  font-weight: 600;
  margin: 0;
}

.dz-sub {
  font-size: 13px;
  color: var(--text-faint);
  margin: 0;
}

.dz-hint {
  font-size: 12.5px;
  color: var(--text-faint);
  margin: 8px 0 0;
}

.btn {
  font-family: inherit;
  font-size: 14px;
  font-weight: 600;
  border-radius: 8px;
  border: 1px solid transparent;
  padding: 10px 18px;
  cursor: pointer;
  transition: background-color 150ms var(--ease-out), border-color 150ms var(--ease-out), transform 100ms var(--ease-out), opacity 150ms var(--ease-out);
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}

.btn:active {
  transform: scale(0.97);
}

.btn-primary {
  background: var(--bg-elev-2);
  border-color: var(--border-strong);
  color: var(--text);
}

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

.btn-accent {
  background: var(--accent);
  color: var(--accent-text);
  text-decoration: none;
}

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

.btn-accent:disabled {
  background: var(--bg-elev-2);
  color: var(--text-faint);
  cursor: not-allowed;
  opacity: 0.6;
}

.btn-large {
  width: 100%;
  padding: 13px 20px;
  font-size: 15px;
}

.btn-large svg {
  width: 18px;
  height: 18px;
}

.btn-icon {
  background: transparent;
  border: none;
  color: var(--text-faint);
  cursor: pointer;
  width: 32px;
  height: 32px;
  min-width: 44px;
  min-height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  transition: color 150ms, background-color 150ms;
}

.btn-icon:hover {
  color: var(--text);
  background: var(--bg-elev-2);
}

.btn-icon svg {
  width: 18px;
  height: 18px;
}

.file-info {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 14px;
  background: var(--bg-elev-2);
}

.file-info-row {
  display: flex;
  align-items: center;
  gap: 12px;
}

.file-icon {
  width: 28px;
  height: 28px;
  color: var(--accent);
  flex-shrink: 0;
}

.file-name {
  font-size: 14px;
  font-weight: 600;
  margin: 0;
  word-break: break-all;
}

.file-size {
  font-size: 12.5px;
  color: var(--text-dim);
  margin: 2px 0 0;
  font-variant-numeric: tabular-nums;
}

.file-info-row > div {
  flex: 1;
  min-width: 0;
}

.advanced {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.advanced summary {
  padding: 12px 14px;
  font-size: 13.5px;
  font-weight: 600;
  cursor: pointer;
  color: var(--text-dim);
  list-style: none;
  display: flex;
  align-items: center;
  user-select: none;
}

.advanced summary::before {
  content: "▸";
  display: inline-block;
  margin-right: 8px;
  transition: transform 150ms var(--ease-out);
  color: var(--text-faint);
}

.advanced[open] summary::before {
  transform: rotate(90deg);
}

.advanced summary::-webkit-details-marker { display: none; }

.advanced-body {
  padding: 4px 14px 16px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  border-top: 1px solid var(--border);
  padding-top: 14px;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.field label {
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
}

.field-hint {
  font-size: 12px;
  color: var(--text-faint);
  margin: 0;
}

input[type="range"] {
  width: 100%;
  accent-color: var(--accent);
  height: 36px;
}

select {
  font-family: inherit;
  font-size: 14px;
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border-strong);
  border-radius: 8px;
  padding: 10px 12px;
  min-height: 44px;
}

select:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.progress-wrap {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.progress-track {
  height: 8px;
  border-radius: 999px;
  background: var(--bg-elev-2);
  overflow: hidden;
  border: 1px solid var(--border);
}

.progress-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--accent), var(--accent-hover));
  border-radius: 999px;
  transition: width 220ms var(--ease-out);
}

.progress-meta {
  display: flex;
  justify-content: space-between;
  font-size: 12.5px;
  color: var(--text-dim);
  font-variant-numeric: tabular-nums;
}

.result-panel {
  align-items: stretch;
}

.result-panel h2 {
  margin: 0;
  font-size: 18px;
}

.result-video {
  width: 100%;
  border-radius: var(--radius);
  background: #000;
  max-height: 480px;
  display: block;
  border: 1px solid var(--border);
}

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

.compare-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  min-width: 100px;
}

.compare-label {
  font-size: 12px;
  color: var(--text-faint);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.compare-value {
  font-size: 16px;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.compare-value.accent {
  color: var(--accent-hover);
}

.compare-arrow {
  width: 20px;
  height: 20px;
  color: var(--text-faint);
  flex-shrink: 0;
}

.size-warning {
  margin: 0;
  padding: 10px 12px;
  border: 1px solid rgba(255, 77, 77, 0.3);
  background: rgba(255, 77, 77, 0.06);
  border-radius: 8px;
  color: #ffb3b3;
  font-size: 13px;
  text-align: center;
}

.error-panel {
  flex-direction: row;
  align-items: flex-start;
  gap: 12px;
  border-color: rgba(255, 77, 77, 0.35);
  background: rgba(255, 77, 77, 0.06);
}

.error-panel svg {
  width: 20px;
  height: 20px;
  color: var(--danger);
  flex-shrink: 0;
  margin-top: 1px;
}

.error-panel p {
  margin: 0;
  font-size: 14px;
  color: #ffb3b3;
  line-height: 1.5;
}

.site-footer {
  text-align: center;
  padding: 20px;
  color: var(--text-faint);
  font-size: 12.5px;
}

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

@media (max-width: 420px) {
  .compare {
    gap: 10px;
  }
  .compare-item {
    min-width: 84px;
  }
}