:root { font-family: "Segoe UI", "Microsoft YaHei", sans-serif; color: #24332c; background: #f6f7f3; font-synthesis: none; }
* { box-sizing: border-box; }
body { margin: 0; }
button, textarea { font: inherit; }
button { cursor: pointer; }
button:disabled { cursor: default; opacity: .48; }
button:focus-visible, a:focus-visible { outline: 3px solid #69b499; outline-offset: 4px; }
[hidden] { display: none !important; }
.app-shell { max-width: 1160px; min-height: 100dvh; margin: auto; padding: 0 42px; display: flex; flex-direction: column; }
.topbar { height: 98px; display: flex; align-items: center; justify-content: space-between; border-bottom: 1px solid #e2e6dd; }
.brand { text-decoration: none; color: inherit; display: flex; align-items: center; gap: 12px; font-weight: 650; font-size: 19px; }
.brand-mark { width: 46px; height: 46px; flex: none; display: grid; place-items: center; border-radius: 50%; border: 1px solid #e4e8df; color: #345c47; }
.brand-mark svg { width: 24px; height: 24px; display: block; }
.brand-subtitle { color: #8b948c; font-weight: 400; font-size: 14px; padding-left: 6px; }
.new-chat { background: #fff; border: 1px solid #dce2d7; border-radius: 9px; padding: 10px 15px; color: #3a5042; font-size: 13px; }
.new-chat:hover { background: #edf2e9; }
main { width: 100%; max-width: 780px; margin: 0 auto; flex: 1; }
.session-note { display: flex; align-items: center; gap: 8px; margin-top: 30px; font-size: 12px; color: #7b887d; }
.status-dot { width: 6px; height: 6px; border-radius: 50%; background: #83a38c; }
.welcome { padding: 62px 0 48px; }
.eyebrow { font-size: 10px; letter-spacing: 2.1px; font-weight: 600; color: #8b998c; }
h1 { font-size: clamp(38px, 5vw, 54px); line-height: 1.35; letter-spacing: -2px; margin: 20px 0 16px; font-weight: 600; }
h1 span { color: #65866c; }
.welcome p { font-size: 14px; color: #859085; margin: 0; line-height: 1.8; }
.suggestions { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin-top: 38px; }
.suggestions button { text-align: left; position: relative; background: #fff; border: 1px solid #e1e6dc; border-radius: 12px; min-height: 108px; padding: 17px 18px 24px; color: #4f6052; font-size: 12px; line-height: 1.65; transition: border-color .15s, transform .15s; }
.suggestions button:hover { border-color: #9db6a2; transform: translateY(-2px); }
.suggestions span { display: block; font-size: 11px; color: #94a092; margin-bottom: 10px; }
.suggestions b { position: absolute; right: 14px; bottom: 9px; color: #809880; font-weight: 400; }
.messages { padding: 28px 0 18px; }
.message { margin: 0 0 24px; }
.message-label { font-size: 11px; font-weight: 600; color: #75917b; margin-bottom: 9px; }
.message-body { font-size: 15px; line-height: 1.9; white-space: pre-wrap; overflow-wrap: anywhere; }
.message.user { margin-left: auto; width: fit-content; max-width: 90%; }
.message.user .message-label { text-align: right; color: #8a958a; }
.message.user .message-body { background: #e8eee3; border-radius: 14px 14px 3px 14px; padding: 13px 18px; }
.message.pending .message-body { color: #89998b; }
.message.failed .message-body { color: #9d5951; font-size: 13px; }
.composer-area { width: 100%; max-width: 780px; margin: 0 auto; padding-bottom: 25px; }
.feedback { color: #8e6550; font-size: 12px; line-height: 1.6; min-height: 20px; margin: 4px 0 10px; }
#chat-form { background: #fff; border: 1px solid #d7dfd1; border-radius: 16px; padding: 17px 18px 13px; box-shadow: 0 6px 25px #283e2610; }
#chat-form:focus-within { border-color: #82a18c; box-shadow: 0 0 0 3px #82a18c15; }
textarea { width: 100%; display: block; resize: none; min-height: 58px; max-height: 180px; background: transparent; border: 0; outline: 0; color: #263f2e; font-size: 14px; line-height: 1.7; padding: 0; }
textarea::placeholder { color: #a0a99d; }
.composer-bottom { display: flex; align-items: center; justify-content: space-between; gap: 8px; }
.composer-bottom > span { color: #a1ab9f; font-size: 10px; }
#send { color: #fff; background: #2d6349; border: 0; border-radius: 8px; padding: 9px 15px; font-size: 12px; }
#send:hover:enabled { background: #224e39; }
#send span { padding-left: 6px; }
footer { display: flex; gap: 15px; justify-content: space-between; margin-top: 15px; font-size: 10px; color: #98a193; line-height: 1.6; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; }
@media (max-width: 660px) {
  .app-shell { padding: 0 20px; }
  .topbar { height: 77px; }
  .brand-mark { width: 40px; height: 40px; }
  .brand-mark svg { width: 21px; height: 21px; }
  .brand-subtitle { display: none; }
  .session-note { margin-top: 24px; font-size: 11px; }
  .welcome { padding: 43px 0 30px; }
  h1 { letter-spacing: -1px; }
  .suggestions { grid-template-columns: 1fr; gap: 9px; margin-top: 25px; }
  .suggestions button { min-height: 0; padding: 13px 34px 13px 14px; }
  .suggestions span { display: inline; margin-right: 12px; }
  .suggestions b { bottom: 13px; }
  .composer-area { padding-bottom: 20px; }
  footer { font-size: 9px; flex-wrap: wrap; gap: 3px; }
  .desktop-hint { display: none; }
}
@media (prefers-reduced-motion: reduce) { .suggestions button { transition: none; } }