Glass Sheet

'use client';

import { useRef, useState } from 'react';


// Glass only reads against something behind it — place this over an image,
// a gradient or busy content; on a plain white background it will look
// nearly invisible. The material (backdrop-filter, a mask-composite rim,
// the pointer-driven highlight) is outside what Tailwind can express, so it
// lives in the embedded style element below.
const css = `
/* ---------- the glass sheet ---------- */
.glass-sheet-demo { position: absolute; inset: 0; }
.glass-sheet__scrim {
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(180deg, rgba(9, 5, 28, 0) 22%, rgba(9, 5, 28, 0.45) 100%);
  transition: opacity 420ms ease;
}
.glass-sheet-demo:not(.is-open) .glass-sheet__scrim { opacity: 0; }
.glass-sheet {
  position: absolute;
  isolation: isolate;
  box-sizing: border-box;
  left: 14px;
  right: 14px;
  bottom: 14px;
  padding: 11px 17px 15px;
  border-radius: 30px;
  background: linear-gradient(152deg, rgba(255, 255, 255, 0.3) 0%, rgba(255, 255, 255, 0.09) 46%, rgba(255, 255, 255, 0.2) 100%);
  -webkit-backdrop-filter: blur(15px) saturate(205%) brightness(1.1);
  backdrop-filter: blur(15px) saturate(205%) brightness(1.1);
  box-shadow:
    inset 0 1px 1px rgba(255, 255, 255, 0.66),
    inset 0 -1px 1px rgba(255, 255, 255, 0.24),
    /* the lens lip: light gathering just inside the whole perimeter */
    inset 0 0 26px -8px rgba(255, 255, 255, 0.42),
    0 -2px 8px rgba(8, 6, 32, 0.2),
    0 -14px 34px -14px rgba(8, 6, 32, 0.42),
    0 24px 48px -24px rgba(8, 6, 32, 0.55);
  translate: 0 0;
  transition: translate 560ms cubic-bezier(0.32, 1.3, 0.5, 1);
}
.glass-sheet-demo:not(.is-open) .glass-sheet { translate: 0 calc(100% + 26px); }
/* specular rim: bright where the light lands, gone along the shaded arc */
.glass-sheet::before {
  content: "";
  position: absolute;
  inset: 0;
  padding: 1.5px;
  border-radius: inherit;
  pointer-events: none;
  z-index: 3;
  background: linear-gradient(
    152deg,
    rgba(255, 255, 255, 1) 0%,
    rgba(255, 255, 255, 0.52) 16%,
    rgba(255, 255, 255, 0.06) 42%,
    rgba(255, 255, 255, 0.06) 62%,
    rgba(255, 255, 255, 0.8) 100%
  );
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
}
/* one specular sweep as it arrives */
.glass-sheet::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  pointer-events: none;
  z-index: 2;
  opacity: 0;
  background: linear-gradient(104deg, transparent 36%, rgba(255, 255, 255, 0.4) 50%, transparent 64%);
  background-size: 240% 100%;
  background-position: 150% 0;
}
.glass-sheet-demo.is-open .glass-sheet::after {
  animation: glass-sheet-sweep 1100ms cubic-bezier(0.4, 0, 0.2, 1) 160ms;
}
@keyframes glass-sheet-sweep {
  0%   { opacity: 0; background-position: 150% 0; }
  20%  { opacity: 1; }
  100% { opacity: 0; background-position: -60% 0; }
}
.glass-sheet__grip {
  display: block;
  width: 40px;
  height: 5px;
  margin: 0 auto 10px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.55);
  box-shadow: inset 0 1px 1px rgba(255, 255, 255, 0.9);
}
.glass-sheet__head {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.glass-sheet__title {
  font-size: 16px;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: #fff;
  text-shadow: 0 1px 2px rgba(8, 6, 32, 0.34);
}
.glass-sheet__text {
  position: relative;
  margin-top: 4px;
  font-size: 12.5px;
  line-height: 1.5;
  color: rgba(255, 255, 255, 0.86);
  text-shadow: 0 1px 2px rgba(8, 6, 32, 0.34);
}
.glass-sheet__row {
  position: relative;
  display: flex;
  gap: 10px;
  margin-top: 12px;
}
.glass-sheet__btn {
  flex: 1;
  height: 34px;
  border: 0;
  border-radius: 999px;
  font: inherit;
  font-size: 13px;
  font-weight: 600;
  color: #fff;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
  background: linear-gradient(150deg, rgba(255, 255, 255, 0.3) 0%, rgba(255, 255, 255, 0.11) 100%);
  box-shadow:
    inset 0 1px 1px rgba(255, 255, 255, 0.6),
    inset 0 -1px 1px rgba(255, 255, 255, 0.2),
    0 2px 6px rgba(8, 6, 32, 0.22);
  transition: transform 180ms cubic-bezier(0.34, 1.4, 0.5, 1), box-shadow 200ms ease;
}
.glass-sheet__btn--primary {
  color: #2a1046;
  text-shadow: none;
  background: linear-gradient(150deg, rgba(255, 255, 255, 0.94) 0%, rgba(255, 255, 255, 0.7) 100%);
  box-shadow:
    inset 0 1px 1px rgba(255, 255, 255, 1),
    inset 0 -2px 3px rgba(255, 255, 255, 0.7),
    0 3px 9px rgba(8, 6, 32, 0.3);
}
.glass-sheet__btn:hover { transform: translateY(-1px); }
.glass-sheet__btn:active { transform: translateY(0) scale(0.975); }
.glass-sheet__close {
  display: grid;
  place-items: center;
  flex: none;
  width: 28px;
  height: 28px;
  border: 0;
  border-radius: 999px;
  color: #fff;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
  background: linear-gradient(150deg, rgba(255, 255, 255, 0.32) 0%, rgba(255, 255, 255, 0.12) 100%);
  box-shadow: inset 0 1px 1px rgba(255, 255, 255, 0.65), 0 1px 3px rgba(8, 6, 32, 0.24);
}
.glass-sheet__close svg { width: 13px; height: 13px; display: block; }
/* the affordance that brings it back */
.glass-sheet__open {
  position: absolute;
  left: 50%;
  bottom: 20%;
  translate: -50% 0;
  padding: 11px 22px;
  border: 0;
  border-radius: 999px;
  font: inherit;
  font-size: 14px;
  font-weight: 600;
  color: #fff;
  text-shadow: 0 1px 2px rgba(8, 6, 32, 0.4);
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
  background: linear-gradient(150deg, rgba(255, 255, 255, 0.3) 0%, rgba(255, 255, 255, 0.1) 100%);
  -webkit-backdrop-filter: blur(14px) saturate(190%) brightness(1.1);
  backdrop-filter: blur(14px) saturate(190%) brightness(1.1);
  box-shadow:
    inset 0 1px 1px rgba(255, 255, 255, 0.7),
    inset 0 -1px 1px rgba(255, 255, 255, 0.26),
    0 3px 10px rgba(8, 6, 32, 0.3);
  transition: opacity 300ms ease, translate 300ms ease;
}
.glass-sheet-demo.is-open .glass-sheet__open {
  opacity: 0;
  translate: -50% 10px;
  pointer-events: none;
}
.glass-sheet :focus-visible,
.glass-sheet__open:focus-visible {
  outline: 2px solid rgba(255, 255, 255, 0.95);
  outline-offset: 2px;
}
`;

export function GlassSheet({
  title = 'Share this view',
  children = 'Anyone with the link can open it.',
  defaultOpen = true,
}: {
  title?: string;
  children?: React.ReactNode;
  defaultOpen?: boolean;
}) {
  const [open, setOpen] = useState(defaultOpen);
  const openerRef = useRef<HTMLButtonElement>(null);
  const closerRef = useRef<HTMLButtonElement>(null);

  // The panel stays mounted and slides out of frame, so the element to focus
  // already exists when the state flips.
  const toggle = (next: boolean) => {
    setOpen(next);
    (next ? closerRef : openerRef).current?.focus({ preventScroll: true });
  };

  return (
    <>
      <style>{css}</style>

      <div className={open ? 'glass-sheet-demo is-open' : 'glass-sheet-demo'}>
        <span className="glass-sheet__scrim" aria-hidden="true" />
        <button
          ref={openerRef}
          type="button"
          className="glass-sheet__open"
          aria-expanded={open}
          aria-controls="glass-sheet-panel"
          onClick={() => toggle(true)}
        >
          Show sheet
        </button>

        <section
          className="glass-sheet"
          id="glass-sheet-panel"
          role="dialog"
          aria-label={title}
        >
          <span className="glass-sheet__grip" aria-hidden="true" />
          <div className="glass-sheet__head">
            <h3 className="glass-sheet__title">{title}</h3>
            <button
              ref={closerRef}
              type="button"
              className="glass-sheet__close"
              aria-label="Close sheet"
              onClick={() => toggle(false)}
            >
              <svg
                viewBox="0 0 24 24"
                fill="none"
                stroke="currentColor"
                strokeWidth="2.4"
                strokeLinecap="round"
                aria-hidden="true"
              >
                <path d="M6 6l12 12M18 6L6 18" />
              </svg>
            </button>
          </div>
          <p className="glass-sheet__text">{children}</p>
          <div className="glass-sheet__row">
            <button className="glass-sheet__btn" type="button">
              Copy link
            </button>
            <button className="glass-sheet__btn glass-sheet__btn--primary" type="button">
              Share
            </button>
          </div>
        </section>
      </div>
    </>
  );
}