:root {
  --brand: #0a6aa1; --brand-dark: #05507c; --brand-soft: #e6f1f8; --accent: #f28c28;
  --bg: #f3f5f7; --card: #ffffff; --fg: #1f2933; --muted: #5f6b76; --line: #dfe4e9; --soft: #f7f9fb;
  --ok: #1a8f4a; --ok-soft: #e6f6ec; --bad: #d23c2f; --bad-soft: #fdecea;
}
@media (prefers-color-scheme: dark) {
  :root { --brand: #1a7fbd; --brand-dark: #0c5d8f; --brand-soft: #14283a; --bg: #14181d; --card: #1c2229; --fg: #e8ecf0; --muted: #98a4b0; --line: #2c343d; --soft: #222a33; --ok-soft: #14301f; --bad-soft: #3a1c19; }
}
* { box-sizing: border-box; }
html { font-size: 16px; }
body { margin: 0; background: var(--bg); color: var(--fg); font-family: "Helvetica Neue", -apple-system, "PingFang TC", "Noto Sans TC", "Microsoft JhengHei", sans-serif; line-height: 1.7; }
a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }
.container { max-width: 1040px; margin: 0 auto; padding: 1.2rem 1rem 2rem; }

/* 頂欄 */
.topbar { background: var(--brand); color: #fff; position: sticky; top: 0; z-index: 10; box-shadow: 0 2px 6px rgba(0,0,0,.18); }
.topbar-inner { max-width: 1040px; margin: 0 auto; padding: 0 1rem; min-height: 60px; display: flex; align-items: center; gap: 1.2rem; flex-wrap: wrap; }
.brand { color: #fff; font-weight: 800; font-size: 1.2rem; display: flex; align-items: center; gap: .5rem; }
.brand:hover { text-decoration: none; }
.logo { display: inline-grid; place-items: center; width: 34px; height: 34px; border-radius: 9px; background: var(--accent); color: #fff; font-size: 1.05rem; }
.topnav { display: flex; gap: .2rem; }
.topnav a { color: rgba(255,255,255,.85); padding: .4rem .8rem; border-radius: 8px; font-weight: 600; }
.topnav a.on, .topnav a:hover { background: rgba(255,255,255,.14); color: #fff; text-decoration: none; }
.search { margin-left: auto; display: flex; background: rgba(255,255,255,.16); border-radius: 999px; padding: .2rem .2rem .2rem .9rem; min-width: 260px; }
.search input { flex: 1; background: transparent; border: 0; color: #fff; font-size: .95rem; outline: none; }
.search input::placeholder { color: rgba(255,255,255,.7); }
.search button { border: 0; background: #fff; color: var(--brand); border-radius: 999px; width: 34px; height: 34px; cursor: pointer; }

/* 首頁 */
.hero { display: grid; grid-template-columns: 1.6fr 1fr; gap: 2rem; align-items: center; background: linear-gradient(135deg, var(--brand) 0%, var(--brand-dark) 100%); color: #fff; border-radius: 18px; padding: 2.2rem 2rem; margin-bottom: 1.6rem; }
.hero h1 { margin: 0 0 .4rem; font-size: 2rem; letter-spacing: .02em; }
.hero p { margin: 0 0 1.2rem; opacity: .92; }
.hero-search { display: flex; gap: .5rem; }
.hero-search input { flex: 1; padding: .7rem 1rem; border-radius: 10px; border: 0; font-size: 1rem; }
.hero-search button { padding: .7rem 1.2rem; border-radius: 10px; border: 0; background: var(--accent); color: #fff; font-weight: 700; cursor: pointer; }
.hero-stats { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(3, 1fr); gap: .6rem; }
.hero-stats li { background: rgba(255,255,255,.14); border-radius: 12px; padding: .8rem .4rem; text-align: center; }
.hero-stats b { display: block; font-size: 1.4rem; }
.hero-stats span { font-size: .8rem; opacity: .85; }
.block { margin-bottom: 2rem; }
.block-head { display: flex; align-items: baseline; gap: .8rem; margin-bottom: .8rem; }
.block-head h2 { margin: 0; font-size: 1.25rem; border-left: 4px solid var(--accent); padding-left: .6rem; }
.block-head .more { margin-left: auto; font-weight: 600; }
.filter { padding: .55rem .9rem; border: 1px solid var(--line); border-radius: 10px; background: var(--card); color: var(--fg); font-size: 1rem; min-width: 260px; }
.hero-stats.dark { margin-bottom: 1.4rem; }
.hero-stats.dark li { background: var(--card); border: 1px solid var(--line); }
.hero-stats.dark b { color: var(--brand); }
.hero-stats.dark span { color: var(--muted); }
.menu-btn { display: none; background: none; border: 0; color: #fff; font-size: 1.4rem; cursor: pointer; padding: 0 .2rem; }
.cards { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: .8rem; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: .9rem 1rem; display: flex; flex-direction: column; gap: .6rem; transition: box-shadow .15s, transform .15s; }
.card:hover { box-shadow: 0 6px 18px rgba(0,0,0,.08); transform: translateY(-1px); }
.card-title { font-weight: 700; color: var(--fg); line-height: 1.45; }
.card-foot { display: flex; justify-content: space-between; align-items: center; margin-top: auto; }
.years { list-style: none; padding: 0; margin: 0; display: grid; grid-template-columns: repeat(auto-fill, minmax(150px, 1fr)); gap: .6rem; }
.years a { display: block; background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: .7rem 1rem; color: var(--fg); }
.years a:hover { border-color: var(--brand); text-decoration: none; }
.years b { font-size: 1.3rem; color: var(--brand); margin-right: .2rem; }
.years span { color: var(--muted); font-size: .85rem; }

/* 通用 */
.muted { color: var(--muted); } .small { font-size: .85rem; }
.crumbs { font-size: .85rem; color: var(--muted); margin-bottom: .6rem; }
.page-title { font-size: 1.5rem; margin: .1rem 0 .4rem; }
.eyebrow { display: block; font-size: .8rem; color: var(--muted); letter-spacing: .04em; }
.page-head { display: flex; justify-content: space-between; align-items: flex-end; gap: 1rem; flex-wrap: wrap; margin-bottom: .6rem; }
.page-actions { display: flex; gap: .5rem; }
.btn { display: inline-block; padding: .5rem 1rem; border: 1px solid var(--brand); border-radius: 8px; background: var(--brand); color: #fff; font-weight: 600; font-size: .95rem; cursor: pointer; line-height: 1.4; }
.btn:hover { background: var(--brand-dark); text-decoration: none; }
.btn.small { padding: .3rem .7rem; font-size: .85rem; }
.btn.big { padding: .7rem 1.4rem; font-size: 1.05rem; }
.btn.ghost { background: transparent; color: var(--brand); }
.btn.ghost:hover { background: var(--brand-soft); }
.pill { display: inline-block; background: var(--brand-soft); color: var(--brand); border-radius: 999px; padding: 0 .6rem; font-size: .78rem; font-weight: 600; margin-right: .3rem; }
.pill.alt { background: #fdf0e3; color: #b3621a; }
.tag { display: inline-block; background: var(--brand); color: #fff; border-radius: 6px; padding: 0 .5rem; font-size: .78rem; font-weight: 700; margin-right: .5rem; }
.tag.ai { background: var(--accent); }
.rows { list-style: none; padding: 0; margin: 0; background: var(--card); border: 1px solid var(--line); border-radius: 12px; overflow: hidden; }
.rows li { display: flex; align-items: center; gap: .8rem; padding: .7rem 1rem; border-bottom: 1px solid var(--line); flex-wrap: wrap; }
.rows li:last-child { border-bottom: 0; }
.rows li > a:first-child { flex: 1; min-width: 200px; color: var(--fg); font-weight: 600; }
.rows li > a:first-child:hover { color: var(--brand); }
.rows .meta { display: flex; gap: .2rem; }
.results li { flex-direction: column; align-items: flex-start; gap: .2rem; }
.tabs { display: flex; gap: .3rem; border-bottom: 2px solid var(--line); margin: .8rem 0 1rem; }
.tab { background: none; border: 0; padding: .5rem 1rem; font-size: 1rem; color: var(--muted); cursor: pointer; border-bottom: 3px solid transparent; margin-bottom: -2px; font-weight: 600; }
.tab.on { color: var(--brand); border-bottom-color: var(--brand); }
.panel { background: var(--card); border: 1px solid var(--line); border-radius: 12px; margin-bottom: .6rem; }
.panel summary { cursor: pointer; padding: .7rem 1rem; font-weight: 700; list-style: none; display: flex; align-items: center; gap: .6rem; }
.panel summary::before { content: "▸"; color: var(--brand); transition: transform .15s; }
.panel[open] summary::before { transform: rotate(90deg); }
.panel .rows { border: 0; border-top: 1px solid var(--line); border-radius: 0; }

/* 題目卡 */
.qcard { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 1.1rem 1.3rem; margin: .9rem 0; }
.qcard.center { text-align: center; padding: 2.5rem 1rem; }
.passage { white-space: pre-wrap; background: var(--soft); border-left: 3px solid var(--brand); border-radius: 8px; padding: .7rem .9rem; margin: .4rem 0 .8rem; font-size: .93rem; }
.stem { display: flex; gap: .7rem; align-items: flex-start; margin: .3rem 0 .7rem; font-size: 1.05rem; }
.stem-text { white-space: pre-wrap; flex: 1; }
.qno { flex: none; min-width: 2rem; height: 2rem; padding: 0 .5rem; display: inline-grid; place-items: center; border-radius: 8px; background: var(--brand); color: #fff; font-weight: 700; font-size: .9rem; }
.options { list-style: none; padding: 0; margin: 0 0 .6rem; display: grid; gap: .35rem; }
.options li { display: flex; gap: .6rem; align-items: flex-start; padding: .35rem .5rem; border-radius: 8px; }
.letter { flex: none; width: 1.7rem; height: 1.7rem; border-radius: 50%; border: 1.5px solid var(--brand); color: var(--brand); display: inline-grid; place-items: center; font-weight: 700; font-size: .85rem; margin-top: .15rem; }
.qcard-foot { display: flex; align-items: center; gap: 1rem; margin-top: .6rem; }
.permalink { font-size: .82rem; color: var(--muted); margin-left: auto; }
.answer-area:not(:empty) { margin-top: .8rem; border-top: 1px dashed var(--line); padding-top: .8rem; }
.official { margin: 0 0 .6rem; font-size: 1.05rem; }
.official strong { color: var(--ok); }
.explanation { background: var(--soft); border-radius: 10px; padding: .9rem 1.1rem; }
.explanation-head { display: flex; align-items: center; gap: .4rem; margin-bottom: .4rem; }
.explanation p { margin: .4rem 0; }
.explanation ul, .explanation ol { margin: .3rem 0 .3rem 1.2rem; padding: 0; }
.pager { display: flex; justify-content: space-between; align-items: center; gap: .6rem; margin: 1rem 0; }

/* 練題 */
.quiz-head { display: flex; justify-content: space-between; align-items: flex-end; gap: 1rem; flex-wrap: wrap; }
.quiz-stats { display: flex; gap: .5rem; }
.stat { background: var(--card); border: 1px solid var(--line); border-radius: 10px; padding: .3rem .8rem; font-size: .9rem; color: var(--muted); }
.stat b { font-size: 1.15rem; color: var(--fg); }
.stat.ok b { color: var(--ok); } .stat.bad b { color: var(--bad); }
.progress { height: 8px; background: var(--line); border-radius: 999px; margin: .8rem 0 .2rem; overflow: hidden; }
.progress div { height: 100%; background: var(--accent); transition: width .3s; }
.choices { display: grid; gap: .5rem; margin: .6rem 0; }
.choice { display: flex; gap: .7rem; align-items: flex-start; text-align: left; padding: .7rem .9rem; border: 1.5px solid var(--line); border-radius: 12px; background: var(--card); color: var(--fg); font-size: 1rem; cursor: pointer; line-height: 1.6; }
.choice:hover:not(:disabled) { border-color: var(--brand); background: var(--brand-soft); }
.choice:disabled { cursor: default; opacity: .9; }
.choice.correct { border-color: var(--ok); background: var(--ok-soft); }
.choice.correct .letter { background: var(--ok); border-color: var(--ok); color: #fff; }
.choice.wrong { border-color: var(--bad); background: var(--bad-soft); }
.choice.wrong .letter { background: var(--bad); border-color: var(--bad); color: #fff; }
.verdict { font-weight: 800; font-size: 1.1rem; margin: .6rem 0; }
.verdict.ok { color: var(--ok); } .verdict.bad { color: var(--bad); }
.big { font-size: 2rem; font-weight: 800; color: var(--brand); margin: .2rem 0 .6rem; }
.review { padding-left: 1.4rem; }
.review li { margin: .3rem 0; }
.review .miss { color: var(--bad); }

.site-footer { border-top: 1px solid var(--line); color: var(--muted); font-size: .82rem; margin-top: 1rem; }
@media (max-width: 720px) {
  .hero { grid-template-columns: 1fr; padding: 1.4rem 1.2rem; }
  .hero h1 { font-size: 1.5rem; }
  .menu-btn { display: block; }
  .topnav { display: none; width: 100%; flex-direction: column; padding-bottom: .5rem; }
  body.nav-open .topnav { display: flex; }
  .search { min-width: 0; flex: 1; }
  .qcard { padding: .9rem; }
}

/* 試卷頁作答 */
.scorebar { position: sticky; top: 64px; z-index: 5; display: flex; align-items: center; gap: 1rem; flex-wrap: wrap; background: var(--card); border: 1px solid var(--line); border-radius: 12px; padding: .5rem .9rem; margin: .6rem 0; font-size: .9rem; color: var(--muted); box-shadow: 0 2px 8px rgba(0,0,0,.06); }
.scorebar .quiz-stats { margin-left: auto; }
.answerable .opt { cursor: pointer; border: 1.5px solid transparent; }
.answerable:not(.done) .opt:hover { border-color: var(--brand); background: var(--brand-soft); }
.opt.correct { border-color: var(--ok) !important; background: var(--ok-soft); }
.opt.correct .letter { background: var(--ok); border-color: var(--ok); color: #fff; }
.opt.wrong { border-color: var(--bad) !important; background: var(--bad-soft); }
.opt.wrong .letter { background: var(--bad); border-color: var(--bad); color: #fff; }
.h-sm { font-size: 1.05rem; margin: 1rem 0 .4rem; }
.weak .rows li .topic { flex: 1; font-weight: 600; }

/* 目標類科 */
.goal-box { display: flex; justify-content: space-between; align-items: center; gap: 1rem; flex-wrap: wrap; background: var(--card); border: 1px solid var(--line); border-left: 5px solid var(--accent); border-radius: 14px; padding: 1rem 1.3rem; }
.goal-box h2 { margin: 0 0 .2rem; font-size: 1.2rem; }
.goal-box p { margin: 0; }
.goal-subjects li { flex-direction: column; align-items: stretch; gap: .3rem; }
.goal-main { display: flex; align-items: center; gap: .8rem; flex-wrap: wrap; }
.goal-main > a:first-child { flex: 1; min-width: 200px; color: var(--fg); font-weight: 600; }
.similar { display: flex; flex-wrap: wrap; gap: .35rem; align-items: center; margin: .2rem 0 0; }
.chip { display: inline-flex; align-items: center; gap: .3rem; background: var(--soft); border: 1px solid var(--line); border-radius: 999px; padding: .1rem .7rem; font-size: .82rem; color: var(--fg); }
.chip b { color: var(--brand); font-weight: 600; }
.chip:hover { border-color: var(--brand); text-decoration: none; }

/* 帳號 */
.account { display: flex; align-items: center; gap: .5rem; }
.btn.google { background: #fff; color: #1f2933; border-color: #fff; display: inline-flex; align-items: center; gap: .4rem; padding: .35rem .8rem; }
.btn.google .g { font-weight: 900; color: #4285f4; }
.avatar { display: inline-flex; align-items: center; gap: .4rem; color: #fff; font-weight: 600; }
.avatar img { width: 28px; height: 28px; border-radius: 50%; }
.linkbtn { background: none; border: 0; color: rgba(255,255,255,.8); cursor: pointer; font-size: .9rem; }
.linkbtn:hover { color: #fff; text-decoration: underline; }

/* 選擇考試類別 */
.welcome { max-width: 560px; margin: 2.5rem auto; text-align: center; }
.welcome h1 { font-size: 1.8rem; margin: 0 0 .4rem; }
.picker { display: grid; gap: .8rem; background: var(--card); border: 1px solid var(--line); border-radius: 16px; padding: 1.4rem; margin: 1.2rem 0; text-align: left; }
.picker label { display: grid; gap: .3rem; font-weight: 600; color: var(--muted); font-size: .9rem; }
.picker select { font-size: 1.05rem; padding: .6rem .7rem; border: 1px solid var(--line); border-radius: 10px; background: var(--bg); color: var(--fg); }
.picker .btn { margin-top: .3rem; }
.picker .btn:disabled { opacity: .5; cursor: default; }