Neon Border Button

---
/**
 * NeonBorderButton — Futuristic button wrapped in an animated rotating neon conic-gradient border.
 * 
 * @param {string} color - Primary neon hue (e.g. '#fbbf24', '#38bdf8', '#a855f7'). Default is '#d4a017'.
 * @param {'sm' | 'md' | 'lg'} size - Button size variant. Default is 'md'.
 * @param {string} href - Optional link destination.
 * @param {boolean} disabled - Whether the button is disabled.
 * @param {string} className - Additional CSS class names.
 */
interface Props {
  color?: string;
  size?: 'sm' | 'md' | 'lg';
  href?: string;
  disabled?: boolean;
  className?: string;
}

const {
  color = '#d4a017',
  size = 'md',
  href,
  disabled = false,
  className = '',
} = Astro.props;

const Tag = href ? 'a' : 'button';
---

<Tag
  href={href}
  disabled={!href && disabled ? true : undefined}
  aria-disabled={disabled ? 'true' : undefined}
  class:list={['neon-border-btn', `neon-border-btn--${size}`, className]}
  style={`--neon-accent: ${color};`}
>
  <span class="neon-border-btn__glow" aria-hidden="true"></span>
  <span class="neon-border-btn__border" aria-hidden="true"></span>
  <span class="neon-border-btn__content">
    <slot />
  </span>
</Tag>

<style>
  .neon-border-btn {
    --neon-speed: 4s;
    position: relative;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    border: none;
    background: transparent;
    border-radius: var(--r-md, 12px);
    cursor: pointer;
    user-select: none;
    transition: transform 0.25s ease;
  }

  .neon-border-btn:hover {
    transform: translateY(-2px);
  }

  .neon-border-btn:focus-visible {
    outline: 2px solid var(--neon-accent);
    outline-offset: 4px;
  }

  .neon-border-btn[disabled],
  .neon-border-btn[aria-disabled="true"] {
    opacity: 0.45;
    cursor: not-allowed;
    pointer-events: none;
  }

  /* Sizes */
  .neon-border-btn--sm .neon-border-btn__content {
    padding: 0.45rem 1rem;
    font-size: 0.8rem;
  }
  .neon-border-btn--md .neon-border-btn__content {
    padding: 0.75rem 1.6rem;
    font-size: 0.92rem;
  }
  .neon-border-btn--lg .neon-border-btn__content {
    padding: 1rem 2.2rem;
    font-size: 1.05rem;
  }

  /* Border track & animated beam */
  .neon-border-btn__border {
    position: absolute;
    inset: 0;
    border-radius: inherit;
    padding: 1.5px;
    background: conic-gradient(
      from 0deg,
      transparent 0deg,
      transparent 90deg,
      var(--neon-accent) 180deg,
      transparent 270deg,
      transparent 360deg
    );
    mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    -webkit-mask: linear-gradient(#fff 0 0) content-box, linear-gradient(#fff 0 0);
    mask-composite: exclude;
    -webkit-mask-composite: xor;
    animation: neon-spin var(--neon-speed) linear infinite;
    pointer-events: none;
  }

  .neon-border-btn__glow {
    position: absolute;
    inset: -3px;
    border-radius: inherit;
    background: radial-gradient(circle, var(--neon-accent), transparent 70%);
    opacity: 0;
    filter: blur(14px);
    transition: opacity 0.3s ease;
    pointer-events: none;
  }

  .neon-border-btn:hover .neon-border-btn__glow {
    opacity: 0.5;
  }

  .neon-border-btn__content {
    position: relative;
    z-index: 2;
    display: inline-flex;
    align-items: center;
    gap: var(--sp-2, 0.5rem);
    width: 100%;
    height: 100%;
    background: rgba(10, 10, 12, 0.95);
    border-radius: inherit;
    color: var(--c-text-1, #ffffff);
    font-family: var(--font-sans, system-ui, sans-serif);
    font-weight: 700;
    letter-spacing: 0.03em;
    backdrop-filter: blur(16px);
    transition: background 0.2s ease, color 0.2s ease;
  }

  .neon-border-btn:hover .neon-border-btn__content {
    background: rgba(16, 16, 20, 0.98);
    color: var(--neon-accent);
  }

  @keyframes neon-spin {
    to {
      transform: rotate(360deg);
    }
  }

  @media (prefers-reduced-motion: reduce) {
    .neon-border-btn__border {
      animation: none;
      background: var(--neon-accent);
    }
  }
</style>