:root {
  --green: #0f6b45;
  --green-dark: #0a4f33;
  --green-soft: #eaf4ef;
  --green-line: #cfe4d9;
  --red: #f42a41;
  --amber: #b26a00;
  --page-bg-from: #eef6f1;
  --page-bg-to: #e4eee8;
  --bg: #f4f6f5;
  --panel: #ffffff;
  --text: #1c2521;
  --muted: #5f6f68;
  --line: #e2e7e4;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
}

* { box-sizing: border-box; }

/*
 * position: fixed, not just overflow: hidden -- on iOS Safari, focusing an
 * input auto-scrolls the *page* to keep it above the keyboard, and that
 * scroll happens at the visual-viewport level, bypassing normal overflow
 * rules. Pinning html/body removes any document-level scroll surface for
 * it to act on; syncAppHeight() below also snaps window scroll back to
 * (0, 0) as a second line of defense.
 */
html, body { height: 100%; overflow: hidden; position: fixed; width: 100%; }

body {
  margin: 0;
  font-family: "Segoe UI", "Noto Sans Bengali", system-ui, sans-serif;
  /* Faint শাপলা (water lily, the national flower) watermark, tiled behind the chat card. */
  background-image:
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='150' height='150' viewBox='0 0 150 150'%3E%3Cg fill='%230f6b45' fill-opacity='0.05'%3E%3Cg transform='translate(38 38)'%3E%3Cellipse cx='0' cy='-19' rx='8.5' ry='19'/%3E%3Cellipse cx='0' cy='-19' rx='8.5' ry='19' transform='rotate(72)'/%3E%3Cellipse cx='0' cy='-19' rx='8.5' ry='19' transform='rotate(144)'/%3E%3Cellipse cx='0' cy='-19' rx='8.5' ry='19' transform='rotate(216)'/%3E%3Cellipse cx='0' cy='-19' rx='8.5' ry='19' transform='rotate(288)'/%3E%3Ccircle r='5'/%3E%3C/g%3E%3Cg transform='translate(113 113)'%3E%3Cellipse cx='0' cy='-19' rx='8.5' ry='19'/%3E%3Cellipse cx='0' cy='-19' rx='8.5' ry='19' transform='rotate(72)'/%3E%3Cellipse cx='0' cy='-19' rx='8.5' ry='19' transform='rotate(144)'/%3E%3Cellipse cx='0' cy='-19' rx='8.5' ry='19' transform='rotate(216)'/%3E%3Cellipse cx='0' cy='-19' rx='8.5' ry='19' transform='rotate(288)'/%3E%3Ccircle r='5'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E"),
    linear-gradient(160deg, var(--page-bg-from), var(--page-bg-to));
  background-size: 150px 150px, cover;
  background-repeat: repeat, no-repeat;
  background-attachment: fixed, fixed;
  color: var(--text);
}

.app {
  /*
   * dvh, not vh: on mobile browsers 100vh includes the area behind the
   * URL bar, so the app renders taller than the visible screen and the
   * composer at the bottom ends up off-screen -- unreachable, because
   * html/body have overflow: hidden. dvh tracks the actually-visible
   * height. The vh line stays first as a fallback for old browsers.
   */
  height: calc(100vh - 32px);
  height: calc(100dvh - 32px);
  height: calc(var(--app-h, 100dvh) - 32px);
  max-width: 860px;
  margin: 16px auto;
  background: var(--panel);
  display: flex;
  flex-direction: column;
  border-radius: 18px;
  /* Positioning context for .jump-btn, which floats over the transcript. */
  position: relative;

  overflow: hidden;
  box-shadow: 0 2px 6px rgba(15, 40, 30, 0.05),
              0 12px 32px rgba(15, 40, 30, 0.08);
}

.header {
  background: var(--green);
  color: #fff;
  padding: 12px 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex: none;
}
.header-left { display: flex; align-items: center; gap: 12px; min-width: 0; }
.avatar {
  width: 38px; height: 38px;
  border-radius: 50%;
  display: grid; place-items: center;
  font-size: 1.15rem;
  flex: none;
}
.avatar-bot { background: rgba(255,255,255,0.18); }
.header-text { min-width: 0; }
.header-title {
  font-size: 1rem; font-weight: 600;
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.header-subtitle { font-size: 0.75rem; opacity: 0.85; }
.header-actions { display: flex; gap: 8px; }
.icon-btn {
  background: rgba(255,255,255,0.15);
  border: none; color: #fff;
  width: 34px; height: 34px;
  border-radius: 8px;
  cursor: pointer;
  display: grid; place-items: center;
}
.icon-btn:hover { background: rgba(255,255,255,0.28); }
.icon-btn svg { width: 17px; height: 17px; }