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

:root {
  --bg: #121010;
  --bg-subtle: #1a1614;
  --surface: #1e1a18;
  --surface-hover: #262220;
  --border: #332e2b;
  --border-focus: #5a5350;
  --text: #ede8e4;
  --text-muted: #9e9590;
  --text-dim: #6b6260;
  --accent: #e8a838;
  --accent-hover: #d49530;
  --accent-glow: rgba(232, 168, 56, 0.15);
  --accent-subtle: rgba(232, 168, 56, 0.25);
  --success: #6ee7a0;
  --font-display: 'DM Serif Display', Georgia, serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'SF Mono', Consolas, monospace;
}

html {
  font-size: 16px;
}

body {
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 2rem 1rem;
  -webkit-font-smoothing: antialiased;
}

/* Atmospheric gradient mesh */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 20% 30%, rgba(232, 168, 56, 0.04), transparent),
    radial-gradient(ellipse 60% 80% at 80% 70%, rgba(232, 168, 56, 0.03), transparent);
  pointer-events: none;
  z-index: 0;
}

/* Noise texture */
body::after {
  content: '';
  position: fixed;
  inset: 0;
  opacity: 0.025;
  background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='300' height='300'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.8' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  pointer-events: none;
  z-index: 0;
}

.container {
  width: 100%;
  max-width: 540px;
  position: relative;
  z-index: 1;
}

header {
  text-align: center;
  margin-bottom: 2.5rem;
  animation: entranceUp 0.7s cubic-bezier(0.16, 1, 0.3, 1) both;
}

h1 {
  font-family: var(--font-display);
  font-size: clamp(2.5rem, 5vw, 3.5rem);
  font-weight: 400;
  letter-spacing: -0.01em;
  margin-bottom: 0.75rem;
  color: var(--text);
  position: relative;
  display: inline-block;
}

h1::after {
  content: '';
  display: block;
  width: 60%;
  height: 2px;
  background: var(--accent);
  opacity: 0.5;
  margin: 0.4rem auto 0;
  border-radius: 1px;
}

.subtitle {
  color: var(--text-muted);
  font-size: 1.05rem;
  line-height: 1.6;
  animation: entranceUp 0.7s cubic-bezier(0.16, 1, 0.3, 1) 0.08s both;
}

main {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.input-group {
  animation: entranceUp 0.7s cubic-bezier(0.16, 1, 0.3, 1) 0.16s both;
}

.input-group label {
  display: block;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}

textarea {
  width: 100%;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  color: var(--text);
  font-family: var(--font-body);
  font-size: 1rem;
  padding: 0.85rem 1rem;
  resize: vertical;
  transition: border-color 0.2s, box-shadow 0.2s;
  outline: none;
}

textarea:focus {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px var(--accent-subtle);
}

textarea::placeholder {
  color: var(--text-dim);
}

.ai-options {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1rem 1.15rem;
  animation: entranceUp 0.7s cubic-bezier(0.16, 1, 0.3, 1) 0.24s both;
}

.ai-options-label {
  display: block;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-muted);
  margin-bottom: 0.65rem;
}

.radio-group {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.4rem;
}

.radio-option {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
  padding: 0.45rem 0.6rem;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--surface);
  position: relative;
  transition: background 0.2s, border-color 0.2s, box-shadow 0.2s;
}

.radio-option:hover {
  background: var(--surface-hover);
}

.radio-option:has(input:checked) {
  border-color: var(--accent);
  background: var(--bg-subtle);
  box-shadow: 0 0 16px var(--accent-glow);
}

.radio-option input[type="radio"] {
  position: absolute;
  opacity: 0;
  width: 1px;
  height: 1px;
}

.radio-logo {
  color: var(--text-dim);
  flex-shrink: 0;
  transition: color 0.25s;
}

.radio-option:has(input:checked) .radio-logo {
  color: var(--accent);
}

.radio-name {
  font-weight: 500;
  font-size: 0.88rem;
  flex: 1;
}

/* Tooltip system */
.tooltip-wrap {
  position: relative;
  margin-left: auto;
  display: inline-flex;
  color: var(--text-dim);
}

.info-icon {
  transition: color 0.2s;
}

.tooltip-wrap:hover .info-icon {
  color: var(--text-muted);
}

.tooltip {
  position: absolute;
  bottom: calc(100% + 10px);
  left: 50%;
  transform: translateX(-50%) translateY(6px) scale(0.94);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  background: rgba(38, 34, 32, 0.85);
  border: 1px solid var(--border-focus);
  border-radius: 8px;
  padding: 0.4rem 0.65rem;
  font-size: 0.72rem;
  font-weight: 400;
  letter-spacing: 0.01em;
  white-space: nowrap;
  color: var(--text);
  opacity: 0;
  pointer-events: none;
  transition: opacity 220ms ease-out, transform 220ms ease-out;
  z-index: 10;
}

.tooltip::after {
  content: '';
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  border: 5px solid transparent;
  border-top-color: var(--border-focus);
}

.tooltip-wrap:hover .tooltip {
  opacity: 1;
  transform: translateX(-50%) translateY(0) scale(1);
}

/* Right-column tooltip overflow fix */
.radio-option:nth-child(even) .tooltip {
  left: auto;
  right: 0;
  transform: translateY(6px) scale(0.94);
}

.radio-option:nth-child(even) .tooltip::after {
  left: auto;
  right: 8px;
  transform: none;
}

.radio-option:nth-child(even) .tooltip-wrap:hover .tooltip {
  transform: translateY(0) scale(1);
}

.btn-generate {
  width: 100%;
  padding: 0.85rem;
  background: var(--accent);
  color: var(--bg);
  font-family: var(--font-body);
  font-size: 1rem;
  font-weight: 600;
  border: none;
  border-radius: 12px;
  cursor: pointer;
  transition: background 0.2s, box-shadow 0.2s;
  animation: entranceUp 0.7s cubic-bezier(0.16, 1, 0.3, 1) 0.32s both;
}

.btn-generate:hover {
  background: var(--accent-hover);
  box-shadow: 0 0 24px var(--accent-glow);
}

.btn-generate:active {
  transform: scale(0.99);
}

.result {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1rem 1.15rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
  animation: slideUp 0.3s ease;
}

.result.hidden {
  display: none;
}

.result-url {
  flex: 1;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--accent);
  word-break: break-all;
  min-width: 0;
}

.btn-copy {
  width: 36px;
  height: 36px;
  padding: 0;
  background: transparent;
  color: var(--text);
  font-family: var(--font-body);
  border: 1px solid var(--border);
  border-radius: 10px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: border-color 0.2s, background 0.2s, color 0.2s;
}

.btn-copy:hover {
  border-color: var(--accent);
  background: var(--surface-hover);
  color: var(--accent);
}

.btn-copy.copied {
  border-color: var(--success);
  color: var(--success);
  animation: copyPulse 0.35s ease-out;
}

@keyframes copyPulse {
  0% { transform: scale(0.9); }
  50% { transform: scale(1.08); }
  100% { transform: scale(1); }
}

.copy-feedback {
  font-size: 0.8rem;
  color: var(--success);
  opacity: 0;
  transition: opacity 0.3s;
  width: 100%;
  text-align: center;
}

.copy-feedback.visible {
  opacity: 1;
}

@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes entranceUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

footer {
  text-align: center;
  margin-top: 3rem;
  color: var(--text-dim);
  font-size: 0.8rem;
  animation: entranceUp 0.7s cubic-bezier(0.16, 1, 0.3, 1) 0.4s both;
}

footer a {
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.2s;
}

footer a:hover {
  color: var(--accent);
  text-decoration: underline;
}

@media (max-width: 480px) {
  h1 {
    font-size: 2rem;
  }

  .subtitle {
    font-size: 0.95rem;
  }

  .radio-group {
    grid-template-columns: 1fr;
  }

  .result {
    flex-direction: column;
    align-items: stretch;
  }

  .btn-copy {
    text-align: center;
  }

  /* Center-align all tooltips in single column */
  .radio-option:nth-child(even) .tooltip {
    left: 50%;
    right: auto;
    transform: translateX(-50%) translateY(6px) scale(0.94);
  }

  .radio-option:nth-child(even) .tooltip::after {
    left: 50%;
    right: auto;
    transform: translateX(-50%);
  }

  .radio-option:nth-child(even) .tooltip-wrap:hover .tooltip {
    transform: translateX(-50%) translateY(0) scale(1);
  }
}