:root {
  --ink: #eaf7ff;
  --muted: #91a9ba;
  --panel: #102335;
  --panel-2: #16334b;
  --line: rgba(159, 211, 239, .18);
  --cyan: #38d8ff;
  --orange: #ffb65b;
  --navy: #06121e;
}

* { box-sizing: border-box; }
html { color-scheme: dark; scroll-behavior: smooth; }
body {
  margin: 0;
  min-width: 320px;
  color: var(--ink);
  background:
    radial-gradient(circle at 88% 7%, rgba(56, 216, 255, .13), transparent 27rem),
    linear-gradient(160deg, #081827 0%, var(--navy) 58%, #0a1d2c 100%);
  font-family: "Noto Sans TC", "Microsoft JhengHei", system-ui, sans-serif;
}

button, a { font: inherit; }
button { touch-action: manipulation; }
.shell { width: min(1180px, calc(100% - 32px)); margin: 0 auto; }
.topbar { padding: 26px 0 18px; border-bottom: 1px solid var(--line); }
.eyebrow { margin: 0 0 8px; color: var(--cyan); font-size: .88rem; font-weight: 800; letter-spacing: .14em; }
h1 { margin: 0; max-width: 760px; font-size: clamp(2rem, 6vw, 4.6rem); line-height: .98; letter-spacing: -.045em; }
.lede { margin: 16px 0 0; color: var(--muted); font-size: 1rem; }
.months { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 18px; padding: 28px 0 80px; }
.month { padding: 22px; border: 1px solid var(--line); border-radius: 24px; background: linear-gradient(145deg, rgba(22, 51, 75, .96), rgba(9, 27, 42, .96)); box-shadow: 0 22px 60px rgba(0,0,0,.2); }
.month h2 { margin: 0 0 16px; font-size: 1.4rem; }
.word-list { display: grid; gap: 10px; }
.audio-btn { width: 100%; min-height: 64px; display: grid; grid-template-columns: 42px 1fr auto; align-items: center; gap: 12px; padding: 10px 14px; border: 1px solid var(--line); border-radius: 16px; color: var(--ink); background: rgba(3, 14, 23, .58); text-align: left; cursor: pointer; transition: transform .2s ease, border-color .2s ease, background .2s ease; }
.audio-btn:hover { transform: translateY(-2px); border-color: rgba(56,216,255,.55); }
.audio-btn:focus-visible { outline: 3px solid var(--orange); outline-offset: 3px; }
.audio-btn.is-playing { border-color: var(--cyan); background: rgba(56, 216, 255, .12); }
.play { width: 38px; height: 38px; display: grid; place-items: center; border-radius: 50%; background: var(--cyan); color: #02111d; font-size: .85rem; font-weight: 900; }
.word { display: block; font-size: 1.05rem; font-weight: 800; }
.meaning { display: block; margin-top: 3px; color: var(--muted); font-size: .9rem; }
.pos { color: var(--orange); font-size: .78rem; font-weight: 800; }
.status { position: fixed; left: 50%; bottom: 20px; z-index: 20; transform: translateX(-50%) translateY(130%); padding: 10px 16px; border: 1px solid var(--line); border-radius: 999px; background: #10263a; color: var(--ink); box-shadow: 0 12px 40px rgba(0,0,0,.35); transition: transform .25s ease; }
.status.show { transform: translateX(-50%) translateY(0); }

@media (max-width: 860px) { .months { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
@media (max-width: 560px) {
  .shell { width: min(100% - 22px, 1180px); }
  .topbar { padding-top: 20px; }
  .months { grid-template-columns: 1fr; gap: 12px; padding-top: 18px; }
  .month { padding: 16px; border-radius: 20px; }
  .audio-btn { min-height: 68px; }
}
@media (prefers-reduced-motion: reduce) { * { scroll-behavior: auto !important; transition: none !important; } }

.unit-nav { display: inline-flex; gap: 5px; margin-bottom: 42px; padding: 5px; border: 1px solid var(--line); border-radius: 999px; background: rgba(4, 16, 27, .58); }
.unit-nav a { padding: 9px 15px; border-radius: 999px; color: var(--muted); text-decoration: none; font-size: .88rem; font-weight: 800; }
.unit-nav a:hover, .unit-nav a.active { color: #03131f; background: var(--cyan); }
.month-jump, .lesson-jump { display: flex; gap: 8px; margin-top: 24px; padding-bottom: 4px; overflow-x: auto; scrollbar-width: thin; }
.month-jump a, .lesson-jump a { flex: 0 0 auto; padding: 8px 12px; border: 1px solid var(--line); border-radius: 999px; color: var(--ink); text-decoration: none; font-size: .8rem; font-weight: 800; background: rgba(4,16,27,.45); }
.month-jump a:hover, .lesson-jump a:hover, .month-jump a.current, .lesson-jump a.current { border-color: var(--cyan); color: #03131f; background: var(--cyan); }
.entry-back { width: min(1180px, calc(100% - 32px)); margin: 24px auto -8px; }
.entry-back a { display: inline-flex; padding: 9px 14px; border: 1px solid var(--line); border-radius: 999px; color: var(--cyan); text-decoration: none; font-size: .86rem; font-weight: 900; background: rgba(4,16,27,.55); }
.entry-back a:hover { border-color: var(--cyan); background: rgba(56,216,255,.1); }
.standalone-entry .topbar { padding-top: 34px; }
body[data-view="article"] .lesson { grid-template-columns: 1fr; max-width: 820px; margin-inline: auto; }
body[data-view="article"] .article-btn { min-height: 230px; }
body[data-view="keywords-phrases"] .lesson { grid-template-columns: 1fr; }
body[data-view="keywords-phrases"] .lesson-content { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.month { scroll-margin-top: 16px; }
.month-index { display: inline-grid; place-items: center; min-width: 42px; height: 28px; margin-right: 8px; border-radius: 99px; color: #03131f; background: var(--orange); font-size: .75rem; font-weight: 900; }
.missing { opacity: .52; cursor: not-allowed; }
.missing .play { background: var(--muted); }

.topbar.compact h1 { max-width: 850px; font-size: clamp(2rem, 5vw, 4rem); }
.level-lockup { display: flex; align-items: center; gap: clamp(18px, 4vw, 44px); }
.level-mark { flex: 0 0 auto; display: grid; place-items: center; width: clamp(88px, 13vw, 150px); aspect-ratio: 1; border: 1px solid rgba(56,216,255,.5); border-radius: 34% 66% 62% 38% / 42% 36% 64% 58%; color: #02111d; background: var(--cyan); box-shadow: 0 0 80px rgba(56,216,255,.22); font: 900 clamp(2.3rem, 6vw, 5rem)/1 system-ui; letter-spacing: -.08em; transform: rotate(-4deg); }
.page-b1 { --cyan: #ffb65b; --orange: #38d8ff; --panel: #18283b; --panel-2: #1c3a50; }
.page-b1 .level-mark { border-radius: 18px; transform: rotate(0); background: linear-gradient(145deg, #ffcf73, #ff8c47); box-shadow: 12px 12px 0 rgba(56,216,255,.13); }
.lessons { display: grid; gap: 24px; padding: 32px 0 88px; }
.lesson { position: relative; scroll-margin-top: 16px; display: grid; grid-template-columns: minmax(0, .86fr) minmax(0, 1.4fr); gap: 18px; padding: 24px; border: 1px solid var(--line); border-radius: 28px; background: linear-gradient(145deg, rgba(22,51,75,.93), rgba(7,23,36,.96)); overflow: hidden; }
.page-b1 .lesson { border-radius: 8px 28px 8px 28px; border-left: 4px solid var(--cyan); }
.lesson-head { grid-column: 1 / -1; display: grid; grid-template-columns: auto 1fr; gap: 16px; align-items: start; }
.lesson-no { display: grid; place-items: center; width: 48px; height: 48px; border-radius: 15px; color: #03131f; background: var(--orange); font-weight: 900; }
.lesson-meta { color: var(--cyan); font-size: .78rem; font-weight: 900; letter-spacing: .11em; }
.article-btn { width: 100%; min-height: 150px; display: flex; flex-direction: column; justify-content: space-between; padding: 22px; border: 1px solid var(--line); border-radius: 22px; color: var(--ink); background: linear-gradient(145deg, rgba(56,216,255,.14), rgba(4,16,27,.65)); text-align: left; cursor: pointer; }
.page-b1 .article-btn { border-radius: 5px 20px 5px 20px; background: linear-gradient(145deg, rgba(255,182,91,.16), rgba(4,16,27,.72)); }
.article-btn:hover { border-color: var(--cyan); }
.article-title { display: block; margin-top: 8px; font-size: clamp(1.35rem, 3vw, 2.2rem); line-height: 1.08; font-weight: 900; letter-spacing: -.025em; }
.article-topic { display: block; color: var(--muted); font-weight: 700; }
.listen-label { display: inline-flex; align-items: center; gap: 9px; margin-top: 22px; color: var(--cyan); font-weight: 900; }
.lesson-content { display: grid; gap: 18px; }
.section-label { margin: 0 0 10px; color: var(--muted); font-size: .76rem; font-weight: 900; letter-spacing: .16em; }
.keywords { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 9px; }
.phrases { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 9px; }
.phrases .audio-btn { grid-template-columns: 42px 1fr; }
.phrases .meaning { color: var(--orange); }

.site-footer { padding: 42px 0; border-top: 1px solid var(--line); background: rgba(2,11,18,.68); }
.footer-inner { width: min(1180px, calc(100% - 32px)); margin: 0 auto; }
.footer-kicker { margin: 0 0 20px; color: var(--muted); font-size: .78rem; font-weight: 900; letter-spacing: .12em; }
.orgs { display: grid; grid-template-columns: repeat(3, minmax(0,1fr)); gap: 14px; }
.org { min-height: 150px; padding: 18px; border: 1px solid var(--line); border-radius: 20px; background: rgba(12,31,47,.7); }
.org h3 { margin: 0 0 14px; color: var(--cyan); font-size: .82rem; letter-spacing: .1em; }
.logo-row { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.logo-row img { max-width: 170px; max-height: 72px; width: auto; height: auto; padding: 7px; border-radius: 10px; background: #fff; object-fit: contain; }
.org p { margin: 10px 0 0; color: var(--ink); font-size: .92rem; font-weight: 700; }

@media (max-width: 820px) {
  .lesson { grid-template-columns: 1fr; }
  .lesson-head { grid-column: 1; }
  .orgs { grid-template-columns: 1fr; }
}
@media (max-width: 560px) {
  .unit-nav { width: 100%; display: grid; grid-template-columns: repeat(3, 1fr); margin-bottom: 28px; }
  .unit-nav a { padding: 9px 6px; text-align: center; font-size: .76rem; }
  .level-lockup { align-items: flex-start; }
  .level-mark { width: 74px; border-radius: 20px; }
  .lesson { padding: 15px; border-radius: 22px; }
  .keywords, .phrases { grid-template-columns: 1fr; }
  .lesson-head { grid-template-columns: 42px 1fr; }
  .lesson-no { width: 42px; height: 42px; }
  .article-btn { min-height: 132px; }
  .logo-row img { max-width: 138px; max-height: 64px; }
  body[data-view="keywords-phrases"] .lesson-content { grid-template-columns: 1fr; }
}

/*
 * Standalone URLs must not expose navigation to the other course units.
 * Hide by default to prevent a flash before navigation.js has evaluated nav=1.
 * The root index adds nav=1, which gives the body the guided-entry class and
 * restores the normal desktop/mobile layout above.
 */
body:not(.guided-entry) .unit-nav,
body:not(.guided-entry) .month-jump,
body:not(.guided-entry) .lesson-jump,
body:not(.guided-entry) .entry-back,
body:not(.guided-entry) .topbar .lede {
  display: none !important;
}