:root {
  --bg: #000000;
  --rail: #0a0a0a;
  --paper: #f3eee4;
  --paper-2: #ebe4d6;
  --paper-3: #e2d9c8;
  --ink: #1a1714;
  --ink-soft: #3d3830;
  --muted: #7a7266;
  --accent: #0f766e;
  --accent-2: #14b8a6;
  --user: #dce7f2;
  --border: rgba(26, 23, 20, 0.12);
  --border-strong: rgba(26, 23, 20, 0.2);
  --danger: #b91c1c;
  --radius: 16px;
  --font: "Segoe UI", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --mono: "Cascadia Code", "Consolas", ui-monospace, monospace;
  --rail-w: 168px;
}

* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
  margin: 0;
}

body {
  font-family: var(--font);
  color: #e8e8e8;
  background: var(--bg);
}

.shell {
  display: grid;
  grid-template-columns: var(--rail-w) minmax(0, 1fr);
  height: 100%;
  width: 100%;
}

/* —— 左侧单词列表 —— */
.word-rail {
  display: flex;
  flex-direction: column;
  min-height: 0;
  background: var(--rail);
  border-right: 1px solid rgba(255, 255, 255, 0.08);
  padding: 14px 10px calc(12px + env(safe-area-inset-bottom));
}

.rail-head {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 4px 8px 12px;
}

.rail-title {
  font-size: 0.82rem;
  font-weight: 650;
  letter-spacing: 0.04em;
  color: #f5f5f5;
}

.rail-hint {
  font-size: 0.72rem;
  color: #777;
}

.word-list {
  display: flex;
  flex-direction: column;
  gap: 4px;
  overflow: auto;
  min-height: 0;
  flex: 1;
  padding: 0 2px;
}

.word-list:empty::after {
  content: "发送单词后出现在这里";
  display: block;
  padding: 10px 8px;
  color: #555;
  font-size: 0.78rem;
  line-height: 1.4;
}

.word-item {
  appearance: none;
  border: 1px solid transparent;
  background: transparent;
  color: #cfcfcf;
  text-align: left;
  font: inherit;
  font-size: 0.9rem;
  padding: 9px 10px;
  border-radius: 10px;
  cursor: pointer;
  word-break: break-word;
}

.word-item:hover {
  background: rgba(255, 255, 255, 0.06);
  color: #fff;
}

.word-item.active {
  background: color-mix(in srgb, var(--accent-2) 18%, transparent);
  border-color: color-mix(in srgb, var(--accent-2) 45%, transparent);
  color: #fff;
}

/* —— 主栏：铺满剩余宽度 —— */
.app {
  width: 100%;
  min-width: 0;
  height: 100%;
  display: grid;
  grid-template-rows: auto 1fr auto;
  padding: 12px 14px calc(12px + env(safe-area-inset-bottom));
  gap: 10px;
}

.top {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
  padding: 4px 2px;
}

.top h1 {
  margin: 0;
  font-size: 1.3rem;
  letter-spacing: 0.02em;
  color: #f5f5f5;
}

.sub {
  margin: 4px 0 0;
  color: #888;
  font-size: 0.85rem;
}

.ghost {
  border: 1px solid rgba(255, 255, 255, 0.16);
  background: transparent;
  color: #aaa;
  border-radius: 999px;
  padding: 8px 14px;
  cursor: pointer;
}

.ghost:hover {
  color: #fff;
  border-color: rgba(255, 255, 255, 0.35);
}

.messages {
  overflow: auto;
  padding: 6px 2px 16px;
  display: flex;
  flex-direction: column;
  gap: 14px;
  scroll-behavior: smooth;
}

/* 纸张色对话框 */
.bubble {
  max-width: min(100%, 720px);
  padding: 14px 16px;
  border-radius: var(--radius);
  border: 1px solid var(--border-strong);
  line-height: 1.55;
  white-space: pre-wrap;
  word-break: break-word;
  color: var(--ink);
  box-shadow: 0 8px 28px rgba(0, 0, 0, 0.35);
}

.bubble.user {
  align-self: flex-end;
  background: var(--user);
  color: var(--ink-soft);
}

.bubble.bot {
  align-self: stretch;
  max-width: 100%;
  background: var(--paper);
}

.bubble.bot.flash {
  outline: 2px solid var(--accent-2);
  outline-offset: 2px;
}

.bubble.bot.streaming::after {
  content: "▍
  animation: blink 1s steps(1) infinite;
  color: var(--accent);
}

@keyframes blink {
  50% {
    opacity: 0;
  }
}

.bubble.error {
  border-color: color-mix(in srgb, var(--danger) 45%, transparent);
  color: #7f1d1d;
  background: #fde8e8;
}

.bubble.bot .md {
  white-space: normal;
  color: var(--ink);
}

.bubble.bot .md h1,
.bubble.bot .md h2,
.bubble.bot .md h3 {
  margin: 1.1em 0 0.45em;
  font-size: 1.05rem;
  line-height: 1.35;
  color: var(--ink);
}

.bubble.bot .md h2:first-child,
.bubble.bot .md h3:first-child {
  margin-top: 0;
}

.bubble.bot .md p {
  margin: 0.45em 0;
}

.bubble.bot .md ul,
.bubble.bot .md ol {
  margin: 0.4em 0;
  padding-left: 1.3em;
}

.bubble.bot .md li {
  margin: 0.25em 0;
}

.bubble.bot .md table {
  width: 100%;
  border-collapse: collapse;
  display: block;
  overflow-x: auto;
  margin: 0.75em 0;
  font-size: 0.92rem;
}

.bubble.bot .md th,
.bubble.bot .md td {
  border: 1px solid var(--border-strong);
  padding: 6px 8px;
  text-align: left;
  white-space: nowrap;
  color: var(--ink);
}

.bubble.bot .md th {
  background: var(--paper-3);
}

.bubble.bot .md code,
.bubble.bot .md em {
  font-style: normal;
  font-family: var(--mono);
  font-size: 0.92em;
}

.bubble.bot .md hr {
  border: 0;
  border-top: 1px solid var(--border-strong);
  margin: 1em 0;
}

/* 同源词表 + 英文侧栏 */
.bubble.bot .md .cognate-en-row {
  display: grid;
  gap: 12px;
  margin: 1em 0 0.5em;
  grid-template-columns: 1fr;
  align-items: start;
}

.bubble.bot .md .cognate-pane {
  min-width: 0;
}

.bubble.bot .md .cognate-pane > :first-child {
  margin-top: 0;
}

.bubble.bot .md .en-compact {
  min-width: 0;
  max-height: 20rem;
  overflow: auto;
  padding: 10px 12px;
  border-radius: 12px;
  border: 1px solid var(--border-strong);
  background: var(--paper-2);
  font-size: 0.86rem;
  line-height: 1.45;
  color: var(--ink-soft);
}

.bubble.bot .md .en-compact > :first-child {
  margin-top: 0;
  font-size: 0.9rem;
  color: var(--muted);
  font-weight: 600;
}

.bubble.bot .md .en-compact p {
  margin: 0.35em 0;
}

@media (min-width: 900px) {
  .bubble.bot .md .cognate-en-row {
    grid-template-columns: minmax(0, 1.45fr) minmax(220px, 0.75fr);
  }
}

/* 二外例句多栏：尽量铺满宽屏，最高 4 栏 */
.bubble.bot .md .lang-grid {
  display: grid;
  gap: 12px;
  margin: 1em 0 0.25em;
  grid-template-columns: 1fr;
  align-items: start;
}

.bubble.bot .md .lang-col {
  min-width: 0;
  padding: 10px 12px;
  border-radius: 12px;
  border: 1px solid var(--border-strong);
  background: var(--paper-2);
}

.bubble.bot .md .lang-col > :first-child {
  margin-top: 0;
}

.bubble.bot .md .lang-col h1,
.bubble.bot .md .lang-col h2,
.bubble.bot .md .lang-col h3,
.bubble.bot .md .lang-col h4 {
  margin-top: 0;
  font-size: 0.98rem;
  color: var(--accent);
}

@media (min-width: 700px), (orientation: landscape) and (min-width: 560px) {
  .bubble.bot .md .lang-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1100px) {
  .bubble.bot .md .lang-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 1400px) {
  .bubble.bot .md .lang-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.composer {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 8px;
  padding: 10px;
  border-radius: calc(var(--radius) + 4px);
  background: #141414;
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.composer input {
  border: 0;
  outline: 0;
  background: transparent;
  color: #f0f0f0;
  font: inherit;
  padding: 10px 8px;
  min-width: 0;
}

.composer input::placeholder {
  color: #777;
}

.composer button[type="submit"] {
  border: 0;
  border-radius: 999px;
  padding: 10px 18px;
  font: inherit;
  font-weight: 600;
  color: #041018;
  background: linear-gradient(135deg, var(--accent-2), #2dd4bf);
  cursor: pointer;
}

.composer button[type="submit"]:disabled {
  opacity: 0.55;
  cursor: not-allowed;
}

.empty {
  margin: auto;
  text-align: center;
  color: #888;
  padding: 24px;
}

.empty strong {
  display: block;
  color: #f0f0f0;
  font-size: 1.1rem;
  margin-bottom: 8px;
}

@media (max-width: 760px) {
  .shell {
    grid-template-columns: 1fr;
    grid-template-rows: auto 1fr;
  }

  .word-rail {
    border-right: 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    padding: 8px 10px;
    max-height: none;
  }

  .rail-head {
    flex-direction: row;
    align-items: baseline;
    gap: 8px;
    padding: 2px 4px 8px;
  }

  .word-list {
    flex-direction: row;
    overflow-x: auto;
    overflow-y: hidden;
    gap: 6px;
    padding-bottom: 2px;
  }

  .word-list:empty::after {
    white-space: nowrap;
    padding: 8px 4px;
  }

  .word-item {
    flex: 0 0 auto;
    white-space: nowrap;
    background: rgba(255, 255, 255, 0.05);
  }

  .top h1 {
    font-size: 1.15rem;
  }

  .bubble {
    padding: 12px 13px;
    border-radius: 14px;
  }
}