/* ===== Apple 風格深色主題 ===== */
:root {
  color-scheme: dark;
  --bg: #000000;
  --surface: #1c1c1e;      /* 卡片 */
  --surface2: #2c2c2e;     /* 輸入框 / 泡泡 / 高一層 */
  --surface3: #3a3a3c;     /* hover */
  --ink: #f5f5f7;          /* 主要文字 */
  --muted: #98989f;        /* 次要文字 */
  --faint: #6c6c70;        /* 更淡 */
  --accent: #0a84ff;       /* iOS 系統藍 */
  --accent-press: #0060df;
  --red: #ff453a;
  --green: #30d158;
  --line: rgba(255, 255, 255, 0.09);
  --line-strong: rgba(255, 255, 255, 0.16);
  --radius: 16px;
  --radius-sm: 12px;
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "SF Pro Display",
    "Helvetica Neue", "PingFang TC", "Microsoft JhengHei", system-ui, sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  letter-spacing: -0.01em;
}

::selection { background: rgba(10, 132, 255, 0.35); }
::placeholder { color: var(--faint); }

/* ===== 頂欄:毛玻璃 sticky ===== */
header {
  position: sticky;
  top: 0;
  z-index: 20;
  padding: 1rem 1.2rem .7rem;
  background: rgba(0, 0, 0, 0.72);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--line);
}
header > * { max-width: 780px; margin-inline: auto; }
h1 {
  font-size: 1.4rem;
  font-weight: 700;
  margin: 0 0 .85rem;
  letter-spacing: -0.02em;
}

/* ===== 分頁(可橫向捲動)===== */
nav {
  display: flex;
  gap: .4rem;
  overflow-x: auto;
  scrollbar-width: none;
  padding-bottom: 2px;
}
nav::-webkit-scrollbar { display: none; }
.tab {
  flex: 0 0 auto;
  border: 1px solid var(--line);
  background: var(--surface2);
  padding: .5rem .95rem;
  border-radius: 999px;
  cursor: pointer;
  font-size: .92rem;
  font-weight: 500;
  color: var(--muted);
  white-space: nowrap;
  transition: background .2s, color .2s, transform .1s;
}
.tab:hover { background: var(--surface3); }
.tab.active {
  background: var(--accent);
  color: #fff;
  border-color: transparent;
}
.tab:active { transform: scale(.96); }

main { max-width: 780px; margin: 1.1rem auto 4rem; padding: 0 1.2rem; }
.panel { display: none; }
.panel.active { display: block; animation: fadeUp .35s ease both; }

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ===== 通用元件 ===== */
button {
  border: none;
  background: var(--accent);
  color: #fff;
  padding: .6rem 1.05rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 1rem;
  font-weight: 500;
  font-family: inherit;
  transition: background .15s, transform .08s, opacity .15s;
}
button:hover { background: var(--accent-press); }
button:active { transform: scale(.96); }
button:disabled { opacity: .4; cursor: default; }

input, select {
  font-family: inherit;
  color: var(--ink);
  background: var(--surface2);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: .65rem .85rem;
  font-size: 1rem;
  transition: border-color .15s, box-shadow .15s;
}
input:focus, select:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(10, 132, 255, 0.25);
}

.hint { color: var(--muted); font-size: .86rem; }

/* ===== 情境單元 / 分類 chips ===== */
.scenarios { margin-bottom: .8rem; }
.scenarios-label { display: block; font-size: .8rem; color: var(--faint); margin-bottom: .45rem; text-transform: uppercase; letter-spacing: .04em; }
.scenario-chips { display: flex; flex-wrap: wrap; gap: .45rem; }
.scenario-chip {
  background: var(--surface2);
  color: var(--muted);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: .4rem .85rem;
  font-size: .87rem;
  font-weight: 500;
  cursor: pointer;
  transition: background .15s, color .15s, border-color .15s;
}
.scenario-chip:hover { background: var(--surface3); color: var(--ink); }
.scenario-chip.active { background: var(--accent); color: #fff; border-color: transparent; }

/* ===== 範例對話 ===== */
.sample-wrap { max-width: 100%; }
.sample-body { margin-top: .6rem; display: flex; flex-direction: column; gap: .5rem; }
.sample-line { padding: .55rem .7rem; border-radius: var(--radius-sm); background: var(--surface2); border: 1px solid var(--line); }
.sample-line.you { background: rgba(10, 132, 255, 0.14); border-color: rgba(10, 132, 255, 0.3); }
.sample-fr { font-weight: 600; display: flex; align-items: center; gap: .4rem; }
.sample-zh { color: var(--muted); font-size: .84rem; margin-top: .15rem; }
.sample-play {
  background: transparent; color: var(--accent); padding: 0 .2rem;
  font-size: .95rem; line-height: 1; margin-left: auto; width: auto;
}
.sample-play:hover { background: transparent; opacity: .7; }

/* ===== 菜單 ===== */
.menu-body { margin-top: .6rem; display: flex; flex-direction: column; gap: .25rem; }
.menu-cat { font-weight: 700; margin: .6rem 0 .25rem; color: var(--accent); font-size: .95rem; }
.menu-item {
  display: flex; align-items: center; gap: .5rem;
  padding: .4rem .55rem; border-radius: 10px; background: var(--surface2);
}
.menu-fr { font-weight: 600; }
.menu-zh { color: var(--muted); font-size: .84rem; }
.menu-item .sample-play { margin-left: auto; }

/* ===== 對話 ===== */
.messages {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1rem;
  height: 52vh;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: .55rem;
}
.messages::-webkit-scrollbar { width: 6px; }
.messages::-webkit-scrollbar-thumb { background: var(--surface3); border-radius: 3px; }

.msg {
  padding: .6rem .9rem;
  border-radius: 18px;
  max-width: 85%;
  white-space: pre-wrap;
  word-break: break-word;
  font-size: .98rem;
  animation: fadeUp .25s ease both;
}
.msg.bot {
  background: var(--surface2);
  align-self: flex-start;
  border-bottom-left-radius: 6px;
}
.msg.user {
  background: linear-gradient(180deg, #0a84ff, #0060df);
  color: #fff;
  align-self: flex-end;
  border-bottom-right-radius: 6px;
}
.msg.tip { font-size: .85rem; color: var(--muted); background: transparent; }
.msg .replay {
  margin-top: .45rem;
  font-size: .76rem;
  padding: .25rem .7rem;
  background: rgba(255, 255, 255, 0.12);
  color: #fff;
  border-radius: 999px;
  backdrop-filter: blur(4px);
}
.msg .replay:hover { background: rgba(255, 255, 255, 0.22); }

.chat-controls { display: flex; gap: .5rem; margin-top: .8rem; align-items: center; }
.chat-controls input { flex: 1; }
.mic {
  background: var(--surface2);
  font-size: 1.25rem;
  width: 3rem;
  height: 3rem;
  border-radius: 50%;
  padding: 0;
  border: 1px solid var(--line);
  flex: 0 0 auto;
}
.mic:hover { background: var(--surface3); }
.mic.recording {
  background: var(--red);
  border-color: transparent;
  animation: pulse 1.2s infinite;
}
@keyframes pulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(255, 69, 58, 0.5); }
  50% { box-shadow: 0 0 0 10px rgba(255, 69, 58, 0); }
}

.autospeak {
  display: flex; align-items: center; gap: .5rem;
  margin-top: .8rem; font-size: .9rem; color: var(--muted);
}
.autospeak input { accent-color: var(--accent); width: auto; }

.voice-row { display: flex; align-items: center; flex-wrap: wrap; gap: .5rem; margin-top: .7rem; font-size: .88rem; color: var(--muted); }
.voice-row select { padding: .4rem .55rem; font-size: .88rem; max-width: 100%; }
.voice-row button { padding: .4rem .7rem; font-size: .85rem; }
.voice-row .hint { flex-basis: 100%; }

/* ===== 學片語 ===== */
.learn-list { display: flex; flex-direction: column; gap: .5rem; margin-top: 1rem; }
.learn-card {
  display: flex; align-items: center; gap: .6rem;
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius-sm); padding: .7rem .9rem;
}
.learn-txt { flex: 1; min-width: 0; }
.learn-fr { font-weight: 600; font-size: 1.02rem; }
.learn-zh { color: var(--muted); font-size: .85rem; margin-top: .1rem; }
.learn-btn { flex: 0 0 auto; padding: .45rem .65rem; font-size: 1rem; border-radius: 10px; }
.more-btn { display: block; width: 100%; margin-top: 1rem; }

/* ===== 不熟片語 ===== */
.add-phrase { display: flex; gap: .5rem; flex-wrap: wrap; margin-bottom: 1.1rem; }
.add-phrase input { flex: 1 1 45%; }
.phrase-list { display: flex; flex-direction: column; gap: .6rem; }
.phrase-card {
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius-sm); padding: .85rem 1rem;
}
.phrase-card .fr { font-weight: 600; font-size: 1.05rem; }
.phrase-card .note { color: var(--muted); font-size: .88rem; margin-top: .2rem; }
.phrase-card .explain {
  margin-top: .55rem; font-size: .9rem; color: var(--ink);
  background: var(--surface2); padding: .55rem .75rem;
  border-radius: 10px; white-space: pre-wrap;
}
.phrase-card .row { display: flex; gap: .4rem; margin-top: .6rem; flex-wrap: wrap; }
.phrase-card .row button { font-size: .82rem; padding: .38rem .75rem; background: var(--surface2); color: var(--ink); }
.phrase-card .row button:hover { background: var(--surface3); }
.phrase-card .row button.speak { background: var(--accent); color: #fff; }
.phrase-card .row button.speak:hover { background: var(--accent-press); }
.phrase-card .row button.del { background: transparent; color: var(--red); }
.phrase-card .row button.del:hover { background: rgba(255, 69, 58, 0.15); }

/* ===== 動詞變化 ===== */
.verb-search { display: flex; gap: .5rem; margin-bottom: .6rem; }
.verb-search input { flex: 1; }
.examples { cursor: default; }
.examples code {
  background: var(--surface2); color: var(--accent);
  padding: .18rem .5rem; border-radius: 7px; cursor: pointer;
  margin-right: .35rem; display: inline-block; font-size: .9rem;
  transition: background .15s;
}
.examples code:hover { background: var(--surface3); }
.verb-result { margin-top: 1.1rem; }
.verb-note {
  background: rgba(10, 132, 255, 0.12);
  border: 1px solid rgba(10, 132, 255, 0.28);
  color: var(--ink); font-size: .9rem;
  padding: .6rem .85rem; border-radius: var(--radius-sm); margin-bottom: .8rem;
}
.verb-head {
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius-sm); padding: .85rem 1rem; margin-bottom: .8rem;
}
.verb-head b { color: var(--accent); }
.tense {
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius-sm); padding: .8rem 1rem; margin-bottom: .7rem;
}
.tense h3 { margin: 0 0 .5rem; font-size: 1rem; color: var(--accent); }
.tense ul { margin: 0; padding-left: 1.1rem; columns: 2; column-gap: 1.2rem; }
.tense li { margin: .12rem 0; }
.imp { display: flex; gap: 1.2rem; flex-wrap: wrap; }
.err {
  color: var(--red); background: rgba(255, 69, 58, 0.12);
  border: 1px solid rgba(255, 69, 58, 0.25);
  padding: .65rem .85rem; border-radius: var(--radius-sm);
}

/* ===== 翻譯 ===== */
.trans-bar {
  display: flex; align-items: center; gap: .6rem;
  margin-bottom: .8rem;
}
.trans-lang {
  flex: 1; text-align: center;
  background: var(--surface2); border: 1px solid var(--line);
  border-radius: var(--radius-sm); padding: .6rem;
  font-weight: 600; font-size: .95rem;
}
.trans-swap {
  flex: 0 0 auto; width: 2.6rem; height: 2.6rem; padding: 0;
  border-radius: 50%; background: var(--surface2);
  border: 1px solid var(--line); color: var(--accent);
  font-size: 1.2rem;
}
.trans-swap:hover { background: var(--surface3); }
.trans-box {
  background: var(--surface); border: 1px solid var(--line);
  border-radius: var(--radius); padding: .9rem 1rem;
  margin-bottom: .7rem;
}
.trans-box.result { min-height: 5.5rem; display: flex; flex-direction: column; }
.trans-box textarea {
  width: 100%; border: none; background: transparent; color: var(--ink);
  font-size: 1.1rem; resize: vertical; padding: 0; min-height: 3.5rem;
  font-family: inherit; line-height: 1.5;
}
.trans-box textarea:focus { outline: none; box-shadow: none; }
.trans-output {
  flex: 1; font-size: 1.15rem; line-height: 1.5; color: var(--ink);
  white-space: pre-wrap; word-break: break-word; min-height: 2rem;
}
.trans-output.loading { color: var(--muted); }
.trans-ph { color: var(--faint); }
.trans-actions {
  display: flex; align-items: center; gap: .5rem;
  margin-top: .7rem; padding-top: .7rem; border-top: 1px solid var(--line);
}
.trans-actions #transBtn { margin-left: auto; padding: .5rem 1.4rem; }
.icon-btn {
  background: var(--surface2); color: var(--ink);
  width: 2.4rem; height: 2.4rem; padding: 0; border-radius: 50%;
  font-size: 1.05rem; border: 1px solid var(--line);
}
.icon-btn:hover { background: var(--surface3); }

/* ===== 不熟單字 ===== */
.word-head { display: flex; align-items: center; gap: .5rem; flex-wrap: wrap; }
.word-fr { font-weight: 700; font-size: 1.15rem; }
.gender {
  font-size: .78rem; font-weight: 600; padding: .12rem .5rem;
  border-radius: 999px; border: 1px solid transparent;
}
.gender.le { color: #64b5ff; background: rgba(10, 132, 255, 0.16); }
.gender.la { color: #ff9fc4; background: rgba(255, 55, 130, 0.16); }
.pos { font-size: .78rem; color: var(--muted); background: var(--surface2); padding: .12rem .5rem; border-radius: 999px; }
.word-dict {
  margin-top: .55rem; font-size: .92rem;
  background: var(--surface2); padding: .6rem .75rem; border-radius: 10px;
}
.word-dict .meaning { color: var(--ink); }
.word-dict .example { margin-top: .4rem; padding-top: .4rem; border-top: 1px solid var(--line); }
.word-dict .ex-fr { font-weight: 600; display: flex; align-items: center; gap: .4rem; }
.word-dict .ex-zh { color: var(--muted); font-size: .85rem; margin-top: .15rem; }
.word-dict .ex-play { background: transparent; color: var(--accent); padding: 0; width: auto; font-size: .9rem; }
.word-dict .ex-play:hover { background: transparent; opacity: .7; }

@media (max-width: 480px) {
  .tense ul { columns: 1; }
  h1 { font-size: 1.25rem; }
}