:root {
  --bg: #fff;
  --surface: #fff;
  --ink: #1d1d1f;
  --muted: #6e6e73;
  --line: #e5e5ea;
  --accent: #0066cc;
  --accent-soft: #f0f6ff;
  --subtle: #f5f5f7;
  --error: #b3261e;
  --radius: 20px;
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI", "PingFang SC", sans-serif;
  color: var(--ink);
  background: var(--bg);
  font-size: 16px;
  line-height: 1.6;
}
* { box-sizing: border-box; }
body { margin: 0; }
a { color: var(--accent); text-underline-offset: 4px; }
button, input, select, textarea { font: inherit; }
button, a, input, select, textarea { touch-action: manipulation; }
button {
  min-height: 44px;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 10px 18px;
  background: var(--surface);
  color: var(--ink);
  cursor: pointer;
  transition: background .16s, border-color .16s;
}
button:hover { background: var(--subtle); border-color: #c7c7cc; }
button.primary { background: var(--accent); color: #fff; border-color: var(--accent); }
button.primary:hover { background: #005bb5; }
button:disabled { opacity: .5; cursor: wait; }
a:focus-visible, button:focus-visible, input:focus-visible, textarea:focus-visible, select:focus-visible, summary:focus-visible {
  outline: 3px solid var(--accent); outline-offset: 4px;
}
header { height: 78px; padding: 0 40px; display: flex; align-items: center; border-bottom: 1px solid var(--line); }
.brand { display: flex; gap: 12px; align-items: center; text-decoration: none; color: var(--ink); font-weight: 600; font-size: 21px; letter-spacing: -.4px; }
.mark { font: 600 27px -apple-system, sans-serif; color: var(--accent); width: 36px; line-height: 36px; }
.layout { max-width: 1440px; margin: auto; display: grid; grid-template-columns: 210px minmax(0,1fr); min-height: calc(100vh - 78px); }
nav { padding: 32px 18px; display: flex; flex-direction: column; gap: 8px; border-right: 1px solid var(--line); }
nav a { padding: 11px 18px; border-radius: 9px; text-decoration: none; color: var(--muted); font-size: 15px; }
nav a[aria-current="page"] { background: var(--accent-soft); color: var(--accent); font-weight: 600; }
main { padding: 54px 56px 80px; max-width: 1000px; width: 100%; }
h1 { font-size: 34px; line-height: 1.2; letter-spacing: -1px; font-weight: 600; margin: 8px 0 32px; }
h2 { font-size: 18px; font-weight: 600; margin: 0 0 12px; letter-spacing: -.3px; }
h3 { font-size: 17px; margin: 0 0 10px; }
p { margin: 8px 0 16px; }
.eyebrow { font-size: 13px; color: var(--muted); letter-spacing: .4px; }
.muted, small { color: var(--muted); }
.card { padding: 28px; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); margin: 24px 0; }
.hero { padding: 36px; }
.hero .lesson-title { font-size: 40px; font-weight: 600; line-height: 1.2; margin: 30px 0 10px; letter-spacing: -1.2px; }
.lesson-name { color: var(--muted); font-size: 18px; margin: 0; }
.start-actions { margin-top: 36px; }
.start-actions button span { margin-left: 8px; font-size: 13px; }
.quiet-link { font-size: 14px; text-decoration: none; }
.row { display: flex; gap: 12px; align-items: center; flex-wrap: wrap; }
.between { justify-content: space-between; }
.row h1, .row h2 { margin-bottom: 0; }
.tag { display: inline-block; font-size: 12px; border-radius: 6px; padding: 3px 9px; background: var(--subtle); color: var(--muted); }
.tag.configured { background: var(--accent-soft); color: var(--accent); }
.warning { background: var(--subtle); padding: 12px 16px; border-radius: 10px; margin: 16px 0; font-size: 14px; }
.error { color: var(--error); white-space: pre-wrap; }
.notice { border-left: 3px solid var(--accent); padding: 4px 16px; margin: 24px 0; }
.target { font-size: 32px; line-height: 1.3; font-weight: 500; letter-spacing: -.6px; margin: 16px 0; }
.prompt { font-size: 18px; white-space: pre-wrap; }
label { display: block; font-size: 14px; font-weight: 500; margin: 18px 0 8px; }
input, select, textarea { border: 1px solid #aaaab0; border-radius: 10px; background: var(--surface); color: var(--ink); padding: 10px 12px; max-width: 100%; }
textarea { width: 100%; min-height: 160px; resize: vertical; line-height: 1.7; }
input[type=number] { width: 100px; }
input[type=checkbox] { width: 18px; height: 18px; vertical-align: middle; margin-right: 8px; accent-color: var(--accent); }
input[type=file] { width: 100%; font-size: 14px; }
#draft-status { display: block; margin: 5px 0 20px; font-size: 12px; }
.exercise-nav { display: flex; gap: 8px; flex-wrap: wrap; margin: 24px 0; }
.exercise-nav button { min-width: 44px; }
.exercise-nav button[aria-pressed=true] { background: var(--accent); color: #fff; border-color: var(--accent); }
.feedback { background: var(--subtle); padding: 20px; border-radius: 12px; margin: 14px 0; white-space: pre-wrap; }
.feedback p:last-child { margin-bottom: 0; }
blockquote { margin: 10px 0; padding: 4px 14px; border-left: 2px solid var(--line); white-space: pre-wrap; }
.attempt { padding: 16px 0; border-bottom: 1px solid var(--line); }
.attempt:last-child { border: 0; }
details { margin: 14px 0; }
summary { cursor: pointer; padding: 10px 0; color: var(--muted); font-size: 14px; }
details.card > summary { color: var(--ink); font-size: 16px; }
.source-body { white-space: pre-wrap; overflow-wrap: anywhere; line-height: 1.85; margin: 24px 0; }
.table-wrap { overflow: auto; }
table { width: 100%; border-collapse: collapse; font-size: 14px; }
th, td { text-align: left; padding: 12px 10px; border-bottom: 1px solid var(--line); white-space: nowrap; }
th { color: var(--muted); font-weight: 500; }
audio { display: block; max-width: 100%; width: 100%; margin: 16px 0; }
code { font-family: ui-monospace, monospace; overflow-wrap: anywhere; }
pre { white-space: pre-wrap; background: var(--subtle); padding: 16px; border-radius: 10px; font-size: 13px; }
dialog { max-width: 780px; width: calc(100% - 32px); max-height: 85vh; border: 1px solid var(--line); border-radius: 20px; padding: 32px; color: var(--ink); }
dialog::backdrop { background: #0005; }
#status:not(:empty) { position: fixed; bottom: 24px; left: 50%; transform: translateX(-50%); padding: 12px 20px; max-width: 90vw; min-width: 240px; background: var(--ink); color: white; border-radius: 12px; z-index: 10; white-space: pre-wrap; font-size: 14px; }
.skip { position: absolute; top: -100px; left: 20px; background: white; padding: 12px; z-index: 20; }
.skip:focus { top: 10px; }
.recording { color: var(--error); font-weight: 600; }
.source-link { border: 0; padding: 4px 6px; min-height: 44px; color: var(--accent); }
.list-row { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 16px 0; border-bottom: 1px solid var(--line); }
.list-row:last-child { border: 0; }
.connections { padding: 8px 28px; }
.connection-row { display: grid; grid-template-columns: 1fr auto auto; gap: 24px; align-items: center; padding: 24px 0; border-bottom: 1px solid var(--line); }
.connection-row:last-child { border: 0; }
.connection-row h2 { margin-bottom: 2px; }
.connection-row a { text-decoration: none; font-size: 14px; }
.hint { color: var(--muted); font-size: 13px; margin: 16px 0 0; }
.setup-steps { padding-left: 22px; font-size: 14px; }
.setup-steps li { padding: 6px 0; }
@media(max-width:900px) {
  header { padding: 0 24px; }
  .layout { grid-template-columns: 170px minmax(0,1fr); }
  main { padding: 36px 28px; }
  nav { padding: 28px 12px; }
}
@media(max-width:600px) {
  header { height: 64px; padding: 0 20px; }
  .layout { display: block; }
  nav { padding: 8px 12px; flex-direction: row; overflow-x: auto; border-right: 0; border-bottom: 1px solid var(--line); gap: 4px; }
  nav a { white-space: nowrap; padding: 10px; font-size: 14px; }
  main { padding: 32px 20px 72px; }
  h1 { font-size: 28px; margin-bottom: 24px; }
  .card, .hero { padding: 22px; }
  .hero .lesson-title { font-size: 34px; }
  .brand { font-size: 19px; }
  .row { gap: 10px; }
  .start-actions { flex-direction: column; align-items: stretch; }
  .connection-row { grid-template-columns: 1fr auto; gap: 8px; }
  .connection-row a { grid-column: 1 / -1; }
  .list-row { flex-wrap: wrap; }
}
@media(prefers-reduced-motion:reduce) { * { transition: none !important; } }

.course-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(65px,1fr));gap:8px}.course-grid a{padding:10px;text-align:center;border:1px solid #e5e7eb;border-radius:10px;text-decoration:none}.course-grid small{display:block;font-size:11px;color:#737780}.course-grid .available{background:#eef6ff;border-color:#0066cc}.lesson-tabs{display:flex;gap:24px;margin:16px 0 24px}.reading-body{white-space:pre-wrap;font-size:20px;line-height:1.9;max-width:70ch;margin:24px auto}.study-item{padding:18px 0;border-bottom:1px solid #eceef1}.study-item:last-child{border:0}.study-item p{white-space:pre-wrap}.course-answer textarea{min-height:100px}section[id]{scroll-margin-top:24px}
/* Original textbook and local listening */
.reader-player audio{width:100%;margin:8px 0}.player-tools{display:flex;gap:12px;align-items:center;flex-wrap:wrap}.player-tools label{display:flex;align-items:center;gap:6px;margin:0}.player-tools select{width:auto;min-height:40px}.player-tools input[type=checkbox]{width:auto}.captions{position:relative;max-height:300px;overflow:auto;margin-top:16px;scroll-behavior:smooth}.captions:empty{display:none}.captions button{display:block;text-align:left;width:100%;border:0;background:transparent;padding:12px;line-height:1.6}.captions small{display:block;color:#667085}.captions [aria-current=true]{background:#edf5ff;color:#0066cc}.hide-translations small{display:none}.lesson-tabs{position:sticky;top:0;z-index:2;background:white;padding:12px 0;display:flex;flex-wrap:wrap;gap:8px;border-bottom:1px solid #e7ebf0}.lesson-tabs button[aria-pressed=true]{color:#fff;background:#0066cc;border-color:#0066cc}.pdf-link{margin-left:auto;align-self:center;font-size:14px}.book-page{margin:20px 0;background:#fff;border:1px solid #e7ebf0;border-radius:12px;overflow:hidden}.book-page figcaption{display:flex;justify-content:space-between;padding:12px 18px;color:#667085;font-size:13px}.book-page img{display:block;width:100%;height:auto}.textbook-layout{display:grid;grid-template-columns:minmax(0,1fr);gap:20px}.textbook-layout:has(#textbook-work:not([hidden])){grid-template-columns:minmax(0,1fr) 310px}#textbook-work{align-self:start;margin-top:20px;position:sticky;top:90px}#textbook-work[hidden]{display:none}#textbook-work textarea{min-height:160px}.saved-answer{white-space:pre-wrap;overflow-wrap:anywhere}.reader-player h2{margin:0}#saved-answers{margin-top:20px}button,a,input,select,textarea{touch-action:manipulation}@media(max-width:800px){.textbook-layout:has(#textbook-work:not([hidden])){grid-template-columns:1fr}#textbook-work{position:static;grid-row:1}.pdf-link{font-size:12px}.player-tools{gap:8px}.player-tools button{font-size:13px}.book-page figcaption{padding:10px}.lesson-tabs button{padding:9px 13px}}
.player-transport{display:flex;align-items:center;gap:12px;margin-top:20px}.player-transport output{margin-left:auto;font-variant-numeric:tabular-nums;font-size:14px;color:var(--muted)}#audio-seek{display:block;width:100%;padding:0;min-height:32px;margin:8px 0 16px;accent-color:var(--accent)}.player-settings{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;margin-top:16px}.player-settings label{margin:0}.player-settings input[type=checkbox]{width:auto}.reader-player .captions{max-height:380px;overscroll-behavior:contain}.reader-player[data-display=english] .cue-zh{display:none}.reader-player[data-display=chinese] [data-translated=true] .cue-en{display:none}.reader-player[data-display=blur] .cue-zh{filter:blur(5px)}.reader-player[data-display=blur] [data-cue]:hover .cue-zh,.reader-player[data-display=blur] [data-cue]:focus .cue-zh{filter:none}.reader-player[data-display=hidden] .captions{display:none}.reader-player[data-size=large] .captions{font-size:20px}.reader-player[data-size=larger] .captions{font-size:24px}.player-focus-open{overflow:hidden}#study-player.player-focused{position:fixed;inset:16px;z-index:100;max-width:1000px;margin:0 auto;overflow:auto;box-shadow:0 0 0 100vmax rgba(0,0,0,.3)}#study-player.player-focused .captions{max-height:55vh}.reader-player.player-night{background:#171d29;color:#edf2fa;border-color:#344155}.player-night button,.player-night select{background:#222c3c;color:#edf2fa;border-color:#43516a}.player-night .captions button{background:transparent}.player-night .captions [aria-current=true]{background:#193c62;color:#b8ddff}.player-night .hint,.player-night .captions small,.player-night output{color:#b6c3d7}.player-night .primary{background:#0066cc}.player-night input{color-scheme:dark}.player-options{margin:16px 0}@media(max-width:600px){.player-transport{gap:6px;flex-wrap:wrap}.player-transport button{padding:8px 12px}.player-settings{grid-template-columns:repeat(2,minmax(0,1fr))}#study-player.player-focused{inset:8px;padding:16px;padding-bottom:calc(16px + env(safe-area-inset-bottom))}.player-transport output{font-size:12px}}@media(prefers-reduced-motion:reduce){.reader-player .captions{scroll-behavior:auto}}
.player-course-nav{display:flex;gap:8px;margin-top:12px}

/* Reading-first workspace: white surfaces, restrained blue, compact course rows. */
:root{--radius:14px}
main{max-width:1160px;padding:40px 48px 80px;min-width:0}
h1{font-size:30px;letter-spacing:-.8px;margin:0 0 24px}h2{font-size:21px}
.card{padding:24px;border-radius:14px}.page-heading{display:flex;align-items:center;justify-content:space-between;gap:16px;margin-bottom:24px}.page-heading h1{margin:4px 0 0}.eyebrow{letter-spacing:.08em;font-size:12px}.muted,small{color:#626872}
nav a{min-height:44px;display:flex;align-items:center}.coach-shortcut{float:right;font-size:14px;padding:8px 0}.continue-course{display:flex;justify-content:space-between;align-items:center;gap:20px;padding:24px;background:#f1f7ff;border:1px solid #d8e8fd;border-radius:14px;text-decoration:none;margin-bottom:24px;color:#1763bd}.continue-course h2{font-size:26px;margin:8px 0}.continue-course p{margin:0;color:#3d526c}.continue-course>span{white-space:nowrap;font-size:14px}
.catalog-tools{display:flex;align-items:end;gap:16px;margin-bottom:20px}.catalog-tools label{margin:0}.search-label{flex:1}.catalog-tools input,.catalog-tools select{margin:6px 0 0;width:100%;min-height:44px}.catalog-tools select{border:1px solid #dce0e6;border-radius:10px;background:white;padding:10px;font:inherit}
.lesson-list{display:grid;grid-template-columns:1fr 1fr;column-gap:32px}.lesson-row{display:flex;align-items:center;gap:16px;min-height:80px;border-bottom:1px solid #eceef1;text-decoration:none;color:#202329;padding:12px 8px}.lesson-row[hidden]{display:none}.lesson-row:hover{background:#f5f8fc}.lesson-number{font-size:16px;color:#697585;min-width:26px;font-variant-numeric:tabular-nums}.lesson-row-title{flex:1;min-width:0;font-size:16px;font-weight:550}.lesson-row small{display:block;font-size:12px;font-weight:400;margin-top:4px}.lesson-state{font-size:12px;color:#1763bd}.lesson-row>span:last-child{color:#728093}
.notes-workspace{display:grid;grid-template-columns:180px minmax(0,1fr);gap:32px}.notes-index{display:flex;flex-direction:column;gap:4px;align-self:start;position:sticky;top:20px}.notes-index a{padding:12px;border-radius:8px;text-decoration:none;color:#5a6471;overflow-wrap:anywhere}.notes-index a[aria-current=page]{background:#edf5ff;color:#0064ce}.note-reading{min-width:0}.note-reading>h2{font-size:28px;margin-top:20px}.note-entry{display:grid;grid-template-columns:1fr auto;gap:8px;padding:20px 0;border-bottom:1px solid #e9edf2;text-decoration:none;color:#252b33}.note-entry small{grid-row:2}.note-entry>span{grid-column:2;grid-row:1/3;align-self:center;color:#1763bd}.prose{font-size:16px;line-height:1.85;overflow-wrap:anywhere;max-width:760px}.prose h2,.prose h3{margin-top:36px;scroll-margin-top:20px}.prose p{margin:12px 0}.prose table{font-size:14px}.prose td{min-width:130px;vertical-align:top}.prose pre{white-space:pre-wrap}.note-toc{background:#f7f9fc;border-radius:10px;padding:12px 16px;margin:20px 0}.toc-link{display:block;border:0;background:none;text-align:left;color:#1763bd;padding:8px 0;min-height:44px}.reading-actions{border-bottom:1px solid #e8edf3;padding:8px 0 20px}
.chat-log{max-width:800px;margin:24px auto}.chat-empty{padding:28px 0}.chat-suggestions{display:grid;gap:12px}.chat-suggestions button{text-align:left;background:#f7faff;border:1px solid #e1ebf7;padding:16px;line-height:1.6}.chat-turn{margin-bottom:32px;scroll-margin-top:24px}.chat-user{background:#f0f6ff;border-radius:14px;padding:16px 20px;margin-left:32px;white-space:pre-wrap}.chat-user p{margin:8px 0 0}.chat-assistant{padding:20px 0;line-height:1.8;overflow-wrap:anywhere}.chat-assistant p{white-space:pre-wrap}.chat-composer{background:white;border-top:1px solid #e6ebf1;padding-top:20px;max-width:800px;margin:auto}.chat-composer textarea{min-height:100px;margin:8px 0 12px}.chat-composer small{font-size:12px}.chat-composer .row{gap:12px}.chat-composer button{min-width:88px}button:active,a:active{opacity:.75}button:disabled{opacity:.55;cursor:wait}a:focus-visible,button:focus-visible{outline:3px solid #86b8f8;outline-offset:3px}
@media(max-width:1100px){main{padding:32px}.lesson-list{grid-template-columns:1fr}.notes-workspace{grid-template-columns:150px minmax(0,1fr);gap:24px}}
@media(max-width:700px){main{padding:24px 16px 64px}.layout{display:block}nav{display:flex;overflow-x:auto;gap:4px;position:static;padding:8px 12px;border-bottom:1px solid #e6ebf1}nav a{white-space:nowrap;padding:10px 12px;font-size:14px}h1{font-size:27px}.page-heading{gap:12px}.page-heading>span{font-size:12px}.continue-course{padding:20px}.continue-course>span{font-size:12px}.catalog-tools{gap:12px}.catalog-tools label{font-size:13px}.catalog-tools select{max-width:145px;font-size:14px}.notes-workspace{display:block}.notes-index{position:static;flex-direction:row;overflow-x:auto;margin-bottom:20px;gap:8px}.notes-index a{white-space:nowrap}.note-reading>h2{font-size:24px}.chat-user{margin-left:12px}.coach-shortcut{font-size:13px}.lesson-row{gap:12px}.card{padding:20px}.chat-composer .row{align-items:center}body{padding-bottom:env(safe-area-inset-bottom)}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important;animation:none!important}}
@media(max-width:700px){nav{flex-direction:row}nav a{flex-shrink:0}.lesson-row-title{overflow-wrap:anywhere}}
.prose img{display:block;max-width:100%;height:auto;border-radius:8px;margin:16px 0}
.prompt{white-space:pre-line}

header{display:flex;align-items:center;justify-content:space-between} #cloud-logout{margin-left:auto}