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

:root {
  --bg: #0a0a1a;
  --bg-card: rgba(255, 255, 255, 0.04);
  --border: rgba(255, 255, 255, 0.08);
  --text: #e0e0f0;
  --text-dim: #7a7a9a;
  --accent: #00d4ff;
  --accent2: #b44aff;
  --accent-glow: rgba(0, 212, 255, 0.3);
  --danger: #ff4a8a;
}

body {
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
}

/* Header */
header {
  text-align: center;
  padding: 2rem 1rem 0.5rem;
}

.logo {
  font-size: 2rem;
  font-weight: 300;
  letter-spacing: 0.05em;
  color: var(--text);
}

.logo span {
  font-weight: 700;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.tagline {
  color: var(--text-dim);
  font-size: 0.85rem;
  margin-top: 0.25rem;
  letter-spacing: 0.03em;
}

/* Main */
main {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 1rem;
  max-width: 600px;
  width: 100%;
  overflow: visible;
}

/* Server Info */
.server-info {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.5rem 1.5rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1rem 1.5rem;
  width: 100%;
  margin-bottom: 1rem;
  backdrop-filter: blur(10px);
  transition: opacity 0.4s, transform 0.4s;
}

.server-info.hidden {
  opacity: 0;
  transform: translateY(-10px);
  pointer-events: none;
}

.server-info:not(.hidden) {
  opacity: 1;
  transform: translateY(0);
}

.info-item {
  display: flex;
  flex-direction: column;
}

.info-label {
  font-size: 0.7rem;
  text-transform: uppercase;
  color: var(--text-dim);
  letter-spacing: 0.08em;
}

.info-value {
  font-size: 0.9rem;
  color: var(--text);
}

/* Progress Bar */
.progress-container {
  width: 100%;
  margin-bottom: 0.75rem;
  transition: opacity 0.3s;
}

.progress-container.hidden {
  opacity: 0;
  height: 0;
  overflow: hidden;
  margin: 0;
}

.progress-bar {
  width: 100%;
  height: 6px;
  background: rgba(255, 255, 255, 0.06);
  border-radius: 3px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  width: 0%;
  border-radius: 3px;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  transition: width 0.3s ease-out;
  box-shadow: 0 0 8px var(--accent-glow);
}

.progress-info {
  display: flex;
  justify-content: space-between;
  margin-top: 0.35rem;
  font-size: 0.75rem;
}

.progress-label {
  color: var(--text-dim);
}

.progress-percent {
  color: var(--text);
  font-variant-numeric: tabular-nums;
  font-weight: 600;
}

.progress-eta {
  text-align: center;
  margin-top: 0.25rem;
  font-size: 0.8rem;
}

#progress-eta-label {
  color: var(--text-dim);
}

#progress-eta-value {
  color: var(--text);
  font-weight: 600;
  font-variant-numeric: tabular-nums;
  margin-left: 0.3rem;
}

/* File Size Selector */
.size-selector {
  margin-bottom: 1rem;
  text-align: center;
  transition: opacity 0.3s;
}

.size-selector.disabled {
  opacity: 0.3;
  pointer-events: none;
}

.size-label {
  display: block;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-dim);
  margin-bottom: 0.5rem;
}

.size-buttons {
  display: flex;
  gap: 0.35rem;
  flex-wrap: wrap;
  justify-content: center;
}

.size-btn {
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-dim);
  padding: 0.4rem 0.8rem;
  border-radius: 8px;
  font-size: 0.8rem;
  cursor: pointer;
  transition: all 0.2s;
}

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

.size-btn.active {
  background: linear-gradient(135deg, rgba(0, 212, 255, 0.15), rgba(180, 74, 255, 0.15));
  border-color: var(--accent);
  color: var(--accent);
  font-weight: 600;
}

/* Gauge */
.gauge-container {
  position: relative;
  width: 100%;
  max-width: 400px;
  aspect-ratio: 1;
  margin: 0 auto;
}

#gauge {
  width: 100%;
  height: 100%;
}

.speed-display {
  text-align: center;
  margin: -1rem 0 0.5rem;
  position: relative;
  z-index: 1;
}

.speed-value {
  display: block;
  font-size: 3.5rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  line-height: 1;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.speed-unit {
  display: block;
  font-size: 1.1rem;
  color: var(--text-dim);
  margin-top: 0.2rem;
}

.status-text {
  text-align: center;
  font-size: 0.85rem;
  color: var(--text-dim);
  white-space: nowrap;
  transition: opacity 0.3s;
  margin-top: 0.25rem;
  margin-bottom: 0.25rem;
}

/* GO Button */
.go-btn {
  width: 100px;
  height: 100px;
  border-radius: 50%;
  border: 3px solid var(--accent);
  background: transparent;
  color: var(--accent);
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  cursor: pointer;
  margin: 0.5rem 0 1.5rem;
  transition: all 0.3s;
  position: relative;
}

.go-btn::before {
  content: '';
  position: absolute;
  inset: -6px;
  border-radius: 50%;
  border: 2px solid transparent;
  background: linear-gradient(135deg, var(--accent), var(--accent2)) border-box;
  -webkit-mask: linear-gradient(#fff 0 0) padding-box, linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  opacity: 0;
  transition: opacity 0.3s;
}

.go-btn:hover::before {
  opacity: 1;
}

.go-btn:hover {
  box-shadow: 0 0 30px var(--accent-glow);
  text-shadow: 0 0 10px var(--accent-glow);
}

.go-btn.running {
  animation: pulse 1.5s ease-in-out infinite;
  border-color: var(--danger);
  color: var(--danger);
  cursor: pointer;
}

.go-btn.hidden {
  display: none;
}

@keyframes pulse {
  0%, 100% { box-shadow: 0 0 15px var(--accent-glow); }
  50% { box-shadow: 0 0 40px var(--accent-glow), 0 0 60px rgba(180, 74, 255, 0.2); }
}

/* Results Panel */
.results-panel {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.75rem;
  width: 100%;
  margin-bottom: 1rem;
  transition: opacity 0.5s, transform 0.5s;
}

.results-panel.hidden {
  opacity: 0;
  transform: translateY(20px);
  pointer-events: none;
  height: 0;
  overflow: hidden;
  margin: 0;
}

.result-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1rem 0.5rem;
  text-align: center;
  backdrop-filter: blur(10px);
}

.result-card.download {
  border-color: rgba(0, 212, 255, 0.3);
}

.result-card.upload {
  border-color: rgba(180, 74, 255, 0.3);
}

.result-icon {
  font-size: 1.2rem;
  margin-bottom: 0.25rem;
}

.result-label {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-dim);
}

.result-value {
  font-size: 1.8rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  margin: 0.15rem 0;
}

.result-card.download .result-value {
  color: var(--accent);
}

.result-card.upload .result-value {
  color: var(--accent2);
}

.result-unit {
  font-size: 0.75rem;
  color: var(--text-dim);
}

/* Actions */
.actions {
  display: flex;
  gap: 0.75rem;
  margin-bottom: 2rem;
  transition: opacity 0.4s;
}

.actions.hidden {
  opacity: 0;
  pointer-events: none;
  height: 0;
  overflow: hidden;
  margin: 0;
}

.action-btn {
  padding: 0.6rem 1.5rem;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text);
  font-size: 0.85rem;
  cursor: pointer;
  transition: all 0.2s;
}

.action-btn:hover {
  border-color: var(--accent);
  background: rgba(0, 212, 255, 0.08);
}

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

/* Share Modal */
.share-modal {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  backdrop-filter: blur(4px);
}

.share-modal-content {
  background: #14142a;
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.25rem;
  width: 90%;
  max-width: 400px;
}

.share-modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.75rem;
  font-size: 0.9rem;
  color: var(--text);
}

.share-modal-close {
  background: none;
  border: none;
  color: var(--text-dim);
  font-size: 1.4rem;
  cursor: pointer;
  line-height: 1;
}

.share-modal-close:hover {
  color: var(--text);
}

.share-modal-text {
  width: 100%;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  font-family: inherit;
  font-size: 0.85rem;
  padding: 0.75rem;
  resize: none;
  outline: none;
}

.share-modal-text:focus {
  border-color: var(--accent);
}

/* Scale Visualization */
.scale-panel {
  width: 100%;
  margin-bottom: 1.5rem;
  transition: opacity 0.6s, transform 0.6s;
}

.scale-panel.hidden {
  opacity: 0;
  transform: translateY(20px);
  pointer-events: none;
  height: 0;
  overflow: hidden;
  margin: 0;
}

.scale-header {
  text-align: center;
  margin-bottom: 1rem;
}

.scale-headline {
  font-size: 1.15rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.4;
}

.scale-subline {
  font-size: 0.85rem;
  color: var(--text-dim);
  margin-top: 0.25rem;
}

.scale-canvas-wrap {
  width: 100%;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1rem;
  backdrop-filter: blur(10px);
  overflow: hidden;
}

#scale-canvas {
  width: 100%;
  height: 420px;
  display: block;
}

/* Footer */
footer {
  text-align: center;
  padding: 1.5rem 1rem;
  color: var(--text-dim);
  font-size: 0.75rem;
}

/* Mobile */
@media (max-width: 480px) {
  .logo { font-size: 1.5rem; }
  .speed-value { font-size: 2.5rem; }
  .gauge-container { max-width: 300px; }
  .result-value { font-size: 1.4rem; }
  .size-btn { padding: 0.35rem 0.6rem; font-size: 0.75rem; }
}