:root {
  color-scheme: light dark;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --chat-bg: #f8fafc;
  --chat-panel: #ffffff;
  --chat-border: #e2e8f0;
  --chat-text: #0f172a;
  --chat-muted: #64748b;
  --chat-primary: #4f46e5;
  --chat-primary-text: #ffffff;
  --chat-received: #ffffff;
  --chat-sent: #4f46e5;
  --chat-danger: #b91c1c;
  --chat-warning: #92400e;
}

@media (prefers-color-scheme: dark) {
  :root {
    --chat-bg: #020617;
    --chat-panel: #0f172a;
    --chat-border: #1e293b;
    --chat-text: #e2e8f0;
    --chat-muted: #94a3b8;
    --chat-received: #172033;
  }
}

* { box-sizing: border-box; }
html, body { margin: 0; min-height: 100%; background: var(--chat-bg); color: var(--chat-text); }
body { min-height: 100dvh; overflow: hidden; }
button, textarea, input { font: inherit; }
button { cursor: pointer; }
.hidden { display: none !important; }

.chat-app {
  min-height: 100dvh;
  height: 100dvh;
  display: grid;
  grid-template-rows: auto auto minmax(0, 1fr) auto;
  max-width: 980px;
  margin: 0 auto;
  background: var(--chat-panel);
  box-shadow: 0 0 0 1px var(--chat-border);
}

.chat-header {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: .75rem;
  padding: max(.75rem, env(safe-area-inset-top)) 1rem .75rem;
  border-bottom: 1px solid var(--chat-border);
  background: var(--chat-panel);
}
.chat-heading h1 { margin: 0; font-size: 1rem; }
.chat-heading p { margin: .15rem 0 0; color: var(--chat-muted); font-size: .78rem; }
.icon-button, .composer-button {
  border: 0;
  border-radius: .75rem;
  min-width: 2.5rem;
  min-height: 2.5rem;
  background: color-mix(in srgb, var(--chat-primary) 10%, transparent);
  color: var(--chat-text);
}

.chat-status {
  padding: .45rem 1rem;
  border-bottom: 1px solid var(--chat-border);
  color: var(--chat-muted);
  font-size: .78rem;
}
.chat-status[data-tone="error"] { color: var(--chat-danger); }
.chat-status[data-tone="warning"] { color: var(--chat-warning); }
.chat-status[data-tone="success"] { color: #047857; }

.chat-message-viewport {
  overflow-y: auto;
  overscroll-behavior: contain;
  padding: 1rem;
  background:
    radial-gradient(circle at 20% 10%, color-mix(in srgb, var(--chat-primary) 5%, transparent), transparent 35%),
    var(--chat-bg);
}
.chat-message-list { display: flex; flex-direction: column; gap: .55rem; min-height: 100%; }
.chat-empty { margin: auto; color: var(--chat-muted); text-align: center; padding: 2rem; }

.message-row { display: flex; width: 100%; }
.message-row.sent { justify-content: flex-end; }
.message-row.received { justify-content: flex-start; }
.message-bubble {
  max-width: min(78%, 640px);
  padding: .65rem .8rem;
  border-radius: 1rem;
  border: 1px solid var(--chat-border);
  background: var(--chat-received);
  box-shadow: 0 1px 2px rgb(15 23 42 / .08);
}
.message-row.sent .message-bubble {
  color: var(--chat-primary-text);
  background: var(--chat-sent);
  border-color: transparent;
  border-bottom-right-radius: .3rem;
}
.message-row.received .message-bubble { border-bottom-left-radius: .3rem; }
.message-text { white-space: pre-wrap; overflow-wrap: anywhere; line-height: 1.4; }
.message-meta { display: flex; gap: .5rem; justify-content: flex-end; margin-top: .3rem; font-size: .68rem; opacity: .75; }
.message-media { display: grid; gap: .5rem; }
.message-media img, .message-media video { display: block; max-width: min(100%, 480px); max-height: 420px; border-radius: .75rem; object-fit: contain; }
.message-media audio { width: min(100%, 360px); }
.media-link { color: inherit; font-weight: 700; text-decoration: underline; }
.media-tombstone { font-style: italic; opacity: .75; }

.chat-composer {
  display: grid;
  grid-template-columns: auto auto minmax(0, 1fr) auto;
  gap: .45rem;
  align-items: end;
  padding: .65rem 1rem max(.65rem, env(safe-area-inset-bottom));
  border-top: 1px solid var(--chat-border);
  background: var(--chat-panel);
}
.chat-composer textarea {
  width: 100%;
  resize: none;
  max-height: 9rem;
  min-height: 2.5rem;
  padding: .6rem .75rem;
  border: 1px solid var(--chat-border);
  border-radius: .9rem;
  color: var(--chat-text);
  background: var(--chat-bg);
  outline: none;
}
.chat-composer textarea:focus { border-color: var(--chat-primary); box-shadow: 0 0 0 2px color-mix(in srgb, var(--chat-primary) 20%, transparent); }
.send-button, .primary-button {
  border: 0;
  border-radius: .8rem;
  padding: .7rem 1rem;
  background: var(--chat-primary);
  color: white;
  font-weight: 700;
}
button:disabled { cursor: not-allowed; opacity: .5; }

.chat-dialog { border: 0; padding: 0; background: transparent; color: var(--chat-text); width: min(92vw, 560px); }
.chat-dialog::backdrop { background: rgb(2 6 23 / .6); }
.chat-dialog-card { border: 1px solid var(--chat-border); border-radius: 1rem; background: var(--chat-panel); padding: 1rem; box-shadow: 0 18px 48px rgb(2 6 23 / .35); }
.chat-dialog-head { display: flex; align-items: center; justify-content: space-between; gap: 1rem; }
.chat-dialog-head h2 { margin: 0; font-size: 1rem; }
.chat-dialog textarea { width: 100%; border: 1px solid var(--chat-border); border-radius: .75rem; padding: .7rem; background: var(--chat-bg); color: var(--chat-text); }
.warning-text { color: var(--chat-warning); }
.recovery-phrase { white-space: pre-wrap; overflow-wrap: anywhere; border: 1px dashed var(--chat-border); border-radius: .75rem; padding: .75rem; user-select: all; }
progress { width: 100%; }

@media (max-width: 640px) {
  .chat-app { max-width: none; box-shadow: none; }
  .chat-message-viewport { padding: .75rem; }
  .chat-composer { padding-left: .65rem; padding-right: .65rem; }
  .message-bubble { max-width: 88%; }
}