:root {
  color-scheme: light;
  --bg: #f6f8f7;
  --panel: #ffffff;
  --border: #d9e2dc;
  --text: #14201a;
  --muted: #5e6c63;
  --accent: #16735b;
  --accent-strong: #0f5c49;
  --incoming: #eef5f1;
  --outgoing: #eaf0fb;
  --danger: #a93636;
  --shadow: 0 16px 45px rgba(21, 39, 30, 0.1);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--text); }
button, textarea { font: inherit; }

.app-shell {
  display: grid;
  grid-template-columns: minmax(280px, 360px) minmax(0, 1fr);
  min-height: 100vh;
}

.sidebar {
  border-right: 1px solid var(--border);
  background: var(--panel);
  padding: 20px;
  overflow-y: auto;
}

.brand-row, .thread-header, .reply-row {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-row { justify-content: space-between; margin-bottom: 16px; }
h1, h2, p { margin: 0; }
h1 { font-size: 21px; line-height: 1.2; }
.brand-row p, .eyebrow, .reply-hint, .status-bar { color: var(--muted); }

.icon-button {
  width: 38px;
  height: 38px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fff;
  cursor: pointer;
  color: var(--accent);
  font-size: 21px;
}

.status-bar {
  display: grid;
  gap: 6px;
  margin-bottom: 16px;
  font-size: 13px;
  line-height: 1.4;
}

.status-pill { display: inline-flex; align-items: center; gap: 6px; }
.status-dot { width: 8px; height: 8px; border-radius: 50%; background: var(--danger); }
.status-dot.ok { background: var(--accent); }
.conversation-list { display: grid; gap: 8px; }

.conversation-button {
  width: 100%;
  border: 1px solid transparent;
  border-radius: 8px;
  background: #f7faf8;
  color: var(--text);
  cursor: pointer;
  padding: 12px;
  text-align: left;
}

.conversation-button:hover, .conversation-button.active {
  border-color: #b7cec3;
  background: #edf6f1;
}

.conversation-name {
  display: flex;
  justify-content: space-between;
  gap: 8px;
  font-weight: 700;
}

.conversation-preview {
  margin-top: 6px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.4;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.thread {
  display: grid;
  grid-template-rows: auto minmax(0, 1fr) auto;
  min-width: 0;
  min-height: 100vh;
}

.thread-header {
  justify-content: space-between;
  padding: 20px 28px;
  border-bottom: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.86);
  backdrop-filter: blur(12px);
}

.eyebrow { margin-bottom: 4px; font-size: 12px; letter-spacing: 0; }
h2 { font-size: 20px; line-height: 1.2; }

.phone-chip {
  border: 1px solid var(--border);
  border-radius: 999px;
  color: var(--muted);
  padding: 7px 11px;
  font-size: 13px;
  white-space: nowrap;
}

.message-list { padding: 24px 28px; overflow-y: auto; }
.empty-state { display: grid; place-items: center; color: var(--muted); text-align: center; }

.message {
  max-width: 820px;
  margin-bottom: 14px;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 14px;
  box-shadow: var(--shadow);
}

.message.incoming { background: var(--incoming); }
.message.outgoing { margin-left: auto; background: var(--outgoing); }

.message-meta {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  color: var(--muted);
  font-size: 12px;
  margin-bottom: 10px;
}

.message-block { display: grid; gap: 4px; margin-top: 10px; }
.message-label { color: var(--muted); font-size: 12px; }
.message-text { white-space: pre-wrap; line-height: 1.55; }
.message-error { color: var(--danger); font-size: 13px; margin-top: 10px; }

.reply-form {
  border-top: 1px solid var(--border);
  background: var(--panel);
  padding: 18px 28px 22px;
}

.reply-form label {
  display: block;
  margin-bottom: 8px;
  color: var(--muted);
  font-size: 13px;
}

.reply-row { align-items: stretch; }

textarea {
  width: 100%;
  min-height: 82px;
  resize: vertical;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px;
  color: var(--text);
}

textarea:focus {
  border-color: var(--accent);
  outline: 3px solid rgba(22, 115, 91, 0.16);
}

#sendButton {
  min-width: 112px;
  border: 0;
  border-radius: 8px;
  background: var(--accent);
  color: #fff;
  cursor: pointer;
  padding: 0 16px;
  font-weight: 700;
}

#sendButton:hover { background: var(--accent-strong); }
#sendButton:disabled, textarea:disabled { cursor: not-allowed; opacity: 0.55; }
.reply-hint { min-height: 20px; margin-top: 8px; font-size: 13px; }

@media (max-width: 820px) {
  .app-shell { grid-template-columns: 1fr; }
  .sidebar { border-right: 0; border-bottom: 1px solid var(--border); max-height: 42vh; }
  .thread { min-height: 58vh; }
  .thread-header, .message-list, .reply-form { padding-left: 16px; padding-right: 16px; }
  .reply-row { display: grid; }
  #sendButton { min-height: 46px; }
}