/* A study journal on the site's own paper. All component rules are scoped. */
.fs-app {
  --fs-paper: var(--background, #F5F2EA);
  --fs-surface: var(--surface, #F8F5EE);
  --fs-ink: var(--foreground, #1F1F1F);
  --fs-body: var(--body, #383630);
  --fs-muted: var(--muted, #6F6A63);
  --fs-rule: var(--border, rgba(0,0,0,.12));
  --fs-soft: var(--surface-soft, #ECE7DD);
  --fs-control: var(--control-border, #837C72);
  --fs-radius: var(--fanfan-radius-md, 8px);
  --fs-success: var(--wp--preset--color--success, #52664D);
  --fs-error: var(--wp--preset--color--danger, #9B4C45);
  display: grid; grid-template-columns: 210px minmax(0, 1fr);
  gap: 40px; max-width: 1280px; margin: 0 auto; padding: 32px 32px 80px;
  color: var(--fs-body); font: 400 15px/1.65 var(--font-body, system-ui, sans-serif);
  min-height: 80vh; overflow-wrap: anywhere;
}
.fs-app *, .fs-app *::before, .fs-app *::after { box-sizing: border-box; }
.fs-app h1, .fs-app h2, .fs-app h3, .fs-app p { margin: 0; }
.fs-app h1, .fs-app h2, .fs-app h3 { color: var(--fs-ink); }
.fs-app h1 { font: 400 clamp(32px,3.4vw,44px)/1.15 var(--font-hand, inherit); letter-spacing: -.018em; }
.fs-app h1[tabindex='-1']:focus { outline: none; }
.fs-app h2 { font: 400 25px/1.3 var(--font-hand, inherit); }
.fs-app h3 { font-size: 16px; font-weight: 500; line-height: 1.45; }
.fs-app a { color: inherit; text-underline-offset: 4px; }
.fs-app a[data-study-link] { text-decoration: none; }
.fs-app a[data-study-link]:hover { text-decoration: underline; }
.fs-app :is(button, input, select, textarea, summary, a):focus-visible { outline: 2px solid var(--fs-ink); outline-offset: 4px; }
.fs-app :is(input, select, textarea) { border: 1px solid var(--fs-control); border-radius: 4px; padding: 10px 12px; background: var(--fs-surface); color: var(--fs-ink); font: inherit; min-height: 44px; max-width: 100%; }
.fs-app :is(input,select,textarea):not([type='radio']):not([type='checkbox']) { width: 100%; min-width: 0; }
.fs-app textarea { resize: vertical; line-height: 1.8; }
.fs-app :is(input, textarea)::placeholder { color: var(--fs-muted); opacity: 1; }
.fs-app :is(input[type='radio'],input[type='checkbox']) { width: 18px; height: 18px; min-height: 18px; accent-color: var(--fs-ink); flex-shrink: 0; margin: 0; }
.fs-app .fs-muted { color: var(--fs-muted); }
.fs-app .fs-small { font-size: 12px; line-height: 1.65; }
.fs-app .fs-eyebrow { font: 400 11px/1.5 var(--font-body, sans-serif); letter-spacing: .075em; text-transform: uppercase; color: var(--fs-muted); }
.fs-app .fs-error { color: var(--fs-error); }
.fs-app .fs-preserve { white-space: pre-wrap; }
.fs-app .fs-button { display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-height: 42px; padding: 9px 14px; border: 1px solid var(--fs-control); border-radius: 4px; color: var(--fs-ink); background: transparent; font: 400 14px/1.4 var(--font-body, sans-serif); text-align: center; cursor: pointer; text-decoration: none; box-shadow: none; transition: background-color 180ms ease; }
.fs-app .fs-button:hover { background: var(--fs-soft); transform: none; text-decoration: none; }
.fs-app .fs-button-primary { background: var(--fs-ink); color: var(--fs-paper); border-color: var(--fs-ink); }
.fs-app .fs-button-primary:hover { background: var(--fs-body); color: var(--fs-paper); }
.fs-app .fs-button-quiet { border-color: transparent; }
.fs-app .fs-button:disabled { opacity: .5; cursor: not-allowed; }
.fs-app .fs-actions { display: flex; align-items: center; flex-wrap: wrap; gap: 10px; }
.fs-app .fs-icon-button { padding: 4px 8px; min-width: 36px; min-height: 36px; border-color: transparent; font-size: 18px; }
.fs-app .fs-loading { padding: 80px 24px; color: var(--fs-muted); text-align: center; grid-column: 1/-1; }
.fs-app .fs-empty { padding: 36px 24px; border: 1px dashed var(--fs-rule); border-radius: var(--fs-radius); text-align: center; }
.fs-app .fs-empty h2 { font-size: 23px; margin-bottom: 8px; }
.fs-app .fs-empty p { color: var(--fs-muted); max-width: 460px; margin: 0 auto 20px; }
.fs-app .fs-empty .fs-button + .fs-button { margin-left: 8px; }
.fs-app .fs-sidebar { align-self: start; position: sticky; top: 96px; min-width: 0; padding-right: 24px; border-right: 1px solid var(--fs-rule); }
.fs-app .fs-sidebar-brand { padding: 6px 8px 27px; display: grid; grid-template-columns: 36px 1fr; column-gap: 8px; align-items: center; }
.fs-app .fs-sidebar-brand .fs-book-icon { width: 36px; }
.fs-app .fs-wordmark { font: 400 28px/1.3 var(--font-hand, inherit); color: var(--fs-ink); }
.fs-app .fs-sidebar-brand > span { font-size: 11px; grid-column: 1/-1; padding-top: 5px; }
.fs-app .fs-nav-link { display: flex; align-items: center; gap: 11px; padding: 10px; margin-bottom: 3px; border-radius: 4px; font-size: 13px; min-height: 42px; }
.fs-app .fs-nav-icon { width: 20px; flex: 0 0 20px; text-align: center; font: 400 17px/1 var(--font-hand, inherit); }
.fs-app #fs-nav a[aria-current='page'] { background: var(--fs-soft); color: var(--fs-ink); }
.fs-app .fs-nav-link:hover { background: var(--fs-surface); text-decoration: none; }
.fs-app .fs-nav-group { margin-top: 20px; padding: 0 10px; font-size: 12px; }
.fs-app .fs-nav-group summary { padding: 5px 0; color: var(--fs-muted); cursor: pointer; font-size: 11px; letter-spacing: .045em; }
.fs-app .fs-nav-subject { font-size: 11px; color: var(--fs-muted); padding: 10px 0 2px 12px; }
.fs-app .fs-nav-course { display: block; padding: 5px 10px 5px 12px; margin-left: 12px; border-left: 1px solid var(--fs-rule); min-height: 34px; border-radius: 0 4px 4px 0; }
.fs-app .fs-admin-link { display: flex; justify-content: space-between; margin: 24px 10px 0; font-size: 12px; color: var(--fs-muted); }
.fs-app .fs-mobile-toggle { display: none; }
.fs-app .fs-timer { margin-top: 30px; padding: 18px 12px; border-top: 1px solid var(--fs-rule); border-bottom: 1px solid var(--fs-rule); }
.fs-app .fs-timer-clock { display: block; margin: 10px 0 5px; font: 400 24px/1.3 var(--font-mono, monospace); font-variant-numeric: tabular-nums; color: var(--fs-ink); letter-spacing: -.045em; }
.fs-app .fs-timer-status, .fs-app .fs-timer-topic { font-size: 11px; color: var(--fs-muted); margin: 8px 0; }
.fs-app .fs-timer select { font-size: 11px; padding: 7px; margin: 8px 0 12px; min-height: 36px; }
.fs-app .fs-timer .fs-button { font-size: 12px; padding: 8px 10px; flex: 1; }
.fs-app .fs-timer .fs-actions { gap: 6px; }
.fs-app .fs-workspace, .fs-app .fs-content { min-width: 0; }
.fs-app .fs-topbar { display: flex; align-items: center; gap: 20px; padding-bottom: 25px; margin-bottom: 28px; border-bottom: 1px solid var(--fs-rule); }
.fs-app #fs-search-form { display: flex; align-items: center; gap: 10px; flex: 1; max-width: 500px; }
.fs-app #fs-search-form > span { font-size: 26px; line-height: 1; }
.fs-app #fs-search-form input { background: transparent; border-color: transparent; font-size: 13px; padding: 6px 0; min-height: 36px; }
.fs-app .fs-search-submit { min-width: 32px; min-height: 30px; padding: 3px 6px; background: transparent; border: 1px solid var(--fs-rule); font-size: 15px; border-radius: 4px; }
.fs-app .fs-user { margin-left: auto; font-size: 12px; color: var(--fs-muted); max-width: 160px; }
.fs-app .fs-login-banner { padding: 12px 16px; margin-bottom: 28px; background: var(--fs-soft); border-radius: 4px; font-size: 13px; }
.fs-app .fs-page-heading { display: flex; align-items: center; justify-content: space-between; gap: 24px; margin-bottom: 30px; }
.fs-app .fs-page-heading .fs-eyebrow { margin-bottom: 12px; }
.fs-app .fs-page-heading h1 + p { font-size: 14px; margin-top: 12px; max-width: 580px; }
.fs-app .fs-page-heading .fs-book-icon { width: 84px; flex-shrink: 0; margin-right: 14px; }
.fs-app .fs-page-heading .fs-actions { flex-shrink: 0; }
.fs-app .fs-section-title { display: flex; align-items: baseline; justify-content: space-between; gap: 16px; margin: 32px 0 16px; }
.fs-app .fs-section-title > :is(span,a,p) { color: var(--fs-muted); font-size: 12px; }
.fs-app .fs-stat-grid { display: grid; grid-template-columns: repeat(4,minmax(0,1fr)); border-top: 1px solid var(--fs-rule); border-bottom: 1px solid var(--fs-rule); padding: 22px 0; margin: 34px 0; }
.fs-app .fs-stat { padding: 0 20px; border-right: 1px solid var(--fs-rule); }
.fs-app .fs-stat:first-child { padding-left: 0; }
.fs-app .fs-stat:last-child { padding-right: 0; border: 0; }
.fs-app .fs-stat p { font-size: 12px; color: var(--fs-muted); margin-bottom: 10px; }
.fs-app .fs-stat strong { color: var(--fs-ink); font: 400 26px/1.25 var(--font-mono,monospace); letter-spacing: -.05em; }
.fs-app .fs-stat-grid-three { grid-template-columns: repeat(3,minmax(0,1fr)); }
.fs-app .fs-course-grid { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 16px; }
.fs-app .fs-course-grid-four { grid-template-columns: repeat(2,minmax(0,1fr)); }
.fs-app .fs-course-card { border: 1px solid var(--fs-rule); background: var(--fs-surface); border-radius: var(--fs-radius); padding: 22px; display: flex; flex-direction: column; min-width: 0; transition: border-color 180ms ease; }
.fs-app .fs-course-card:hover { border-color: var(--fs-control); }
.fs-app .fs-card-top { display: flex; align-items: center; justify-content: space-between; gap: 14px; }
.fs-app .fs-course-code { font: 400 28px/1.3 var(--font-hand,inherit); color: var(--fs-ink); }
.fs-app .fs-course-card h3 { font-size: 17px; margin: 25px 0 5px; }
.fs-app .fs-course-card > .fs-muted { font-size: 12px; margin-bottom: 22px; }
.fs-app .fs-course-progress { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin: auto 0 8px; font-size: 11px; color: var(--fs-muted); }
.fs-app .fs-course-progress > span:first-child { color: var(--fs-ink); font-family: var(--font-mono,monospace); }
.fs-app .fs-progress { display: block; width: 100%; height: 3px; border: 0; border-radius: 8px; background: var(--fs-soft); accent-color: var(--fs-ink); overflow: hidden; }
.fs-app .fs-progress::-webkit-progress-bar { background: var(--fs-soft); }
.fs-app .fs-progress::-webkit-progress-value { background: var(--fs-ink); }
.fs-app .fs-progress::-moz-progress-bar { background: var(--fs-ink); }
.fs-app .fs-card-chapters { font-size: 11px; color: var(--fs-muted); margin: 8px 0 22px; }
.fs-app .fs-continue { font-size: 13px; color: var(--fs-ink); display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.fs-app .fs-course-card > .fs-continue { padding-top: 16px; border-top: 1px solid var(--fs-rule); }
.fs-app .fs-dashboard-bottom { display: grid; grid-template-columns: 1fr 1fr; gap: 32px; margin-top: 14px; }
.fs-app .fs-history-row { display: flex; align-items: center; gap: 14px; border-bottom: 1px solid var(--fs-rule); padding: 18px 0; }
.fs-app .fs-history-row h3 { font-size: 14px; }
.fs-app .fs-history-row p { font-size: 11px; margin-top: 3px; }
.fs-app .fs-history-row > div { flex: 1; min-width: 0; }
.fs-app .fs-history-row strong { font: 400 12px var(--font-mono,monospace); color: var(--fs-muted); flex-shrink: 0; }
.fs-app .fs-history-dot { width: 6px; height: 6px; background: var(--fs-control); border-radius: 50%; flex-shrink: 0; }
.fs-app .fs-dashboard-bottom .fs-empty { padding: 24px 18px; }
.fs-app .fs-dashboard-bottom .fs-small { margin-top: 16px; }
.fs-app .fs-task { display: flex; align-items: center; gap: 4px; padding: 7px 0; border-bottom: 1px solid var(--fs-rule); font-size: 13px; }
.fs-app .fs-task > span { flex: 1; }
.fs-app .fs-task.is-completed > span { text-decoration: line-through; color: var(--fs-muted); }
.fs-app .fs-task-form { display: flex; gap: 8px; margin-top: 16px; }
.fs-app .fs-task-form input { font-size: 12px; }
.fs-app .fs-task-form .fs-button { flex: 0 0 auto; }
.fs-app .fs-course-overview { padding: 24px; background: var(--fs-surface); border: 1px solid var(--fs-rule); border-radius: var(--fs-radius); display: grid; grid-template-columns: 80px minmax(0,1fr); gap: 24px; }
.fs-app .fs-course-overview > .fs-course-code { font-size: 42px; }
.fs-app .fs-course-overview .fs-rich { font-size: 13px; color: var(--fs-muted); margin-bottom: 18px; }
.fs-app .fs-unit { border: 1px solid var(--fs-rule); border-radius: var(--fs-radius); margin: 16px 0; }
.fs-app .fs-unit > header { display: flex; align-items: baseline; gap: 16px; padding: 22px 24px; background: var(--fs-surface); border-bottom: 1px solid var(--fs-rule); border-radius: var(--fs-radius) var(--fs-radius) 0 0; }
.fs-app .fs-unit header .fs-rich { margin-top: 6px; font-size: 13px; color: var(--fs-muted); }
.fs-app .fs-unit-index { color: var(--fs-muted); font: 400 12px var(--font-mono,monospace); flex-shrink: 0; }
.fs-app .fs-topic-row { display: flex; align-items: center; gap: 16px; padding: 18px 24px; border-bottom: 1px solid var(--fs-rule); }
.fs-app .fs-topic-row:last-child { border: 0; }
.fs-app .fs-topic-row > div { flex: 1; }
.fs-app .fs-topic-row > div > a { font-size: 14px; }
.fs-app .fs-topic-row p { font-size: 11px; color: var(--fs-muted); margin-top: 3px; }
.fs-app .fs-topic-row > span:last-child { color: var(--fs-muted); }
.fs-app .fs-status { display: inline-flex; align-items: center; gap: 7px; font-size: 11px; color: var(--fs-muted); white-space: nowrap; }
.fs-app .fs-status i { width: 7px; height: 7px; border: 1px solid var(--fs-control); border-radius: 50%; }
.fs-app .fs-status-in_progress i { background: var(--fs-control); }
.fs-app .fs-status-completed, .fs-app .fs-status-mastered { color: var(--fs-success); }
.fs-app .fs-status-completed i, .fs-app .fs-status-mastered i { background: currentColor; border-color: currentColor; }
.fs-app .fs-end-link { margin-top: 28px; text-align: right; font-size: 13px; }
.fs-app .fs-practice-list { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 20px; }
.fs-app .fs-practice-back { margin-bottom: 22px; font-size: 13px; color: var(--fs-muted); }
.fs-app .fs-practice-card { padding: 24px; border: 1px solid var(--fs-rule); border-radius: var(--fs-radius); background: var(--fs-surface); }
.fs-app .fs-practice-card h2 { margin: 16px 0 12px; }
.fs-app .fs-practice-card .fs-rich { font-size: 13px; color: var(--fs-muted); margin-bottom: 24px; }
.fs-app .fs-lesson-meta { display: flex; align-items: center; flex-wrap: wrap; gap: 20px; padding: 0 0 22px; margin-bottom: 30px; border-bottom: 1px solid var(--fs-rule); font-size: 12px; color: var(--fs-muted); }
.fs-app .fs-lesson-meta .fs-bookmark-button { margin-left: auto; }
.fs-app .fs-bookmark-button { border-color: transparent; min-height: 36px; font-size: 12px; padding: 6px 8px; white-space: nowrap; }
.fs-app .fs-lesson-layout { display: grid; grid-template-columns: minmax(0,1fr) 245px; gap: 32px; }
.fs-app .fs-lesson-main, .fs-app .fs-lesson-aside { min-width: 0; }
.fs-app .fs-rich { line-height: 1.9; }
.fs-app .fs-rich > * + * { margin-top: 16px; }
.fs-app .fs-rich h2 { margin-top: 26px; font-size: 27px; }
.fs-app .fs-rich h3 { margin-top: 20px; }
.fs-app .fs-rich :is(ul,ol) { padding-left: 22px; }
.fs-app .fs-rich :is(img,video,audio) { max-width: 100%; height: auto; }
.fs-app .fs-rich pre { overflow-x: auto; max-width: 100%; font-size: 13px; }
.fs-app .fs-rich table { width: 100%; border-collapse: collapse; font-size: 13px; }
.fs-app .fs-rich :is(th,td) { border: 1px solid var(--fs-rule); padding: 9px; text-align: left; }
.fs-app .katex-display { overflow-x: auto; overflow-y: hidden; padding: 8px 0; max-width: 100%; }
.fs-app .katex { font-size: 1.12em; }
.fs-app .fs-formula-card { border: 1px solid var(--fs-rule); border-radius: var(--fs-radius); padding: 20px; margin-bottom: 14px; background: var(--fs-surface); }
.fs-app .fs-formula-card .fs-rich { color: var(--fs-muted); font-size: 13px; }
.fs-app .fs-formula-math { text-align: center; padding: 12px 0; min-width: 0; }
.fs-app .fs-example { border-left: 2px solid var(--fs-control); padding: 4px 0 8px 22px; margin: 28px 0; }
.fs-app .fs-example h3 { margin: 16px 0 8px; font-size: 14px; }
.fs-app details:not(.fs-nav-group) { border-top: 1px solid var(--fs-rule); margin-top: 20px; padding-top: 14px; }
.fs-app details:not(.fs-nav-group) summary { cursor: pointer; min-height: 30px; font-size: 13px; color: var(--fs-ink); }
.fs-app details[open]:not(.fs-nav-group) summary { margin-bottom: 14px; }
.fs-app .fs-notes-card { position: sticky; top: 100px; padding: 20px; background: var(--fs-surface); border: 1px solid var(--fs-rule); border-radius: var(--fs-radius); }
.fs-app .fs-notes-card .fs-section-title { margin: 0 0 12px; }
.fs-app .fs-notes-card h2 { font-size: 25px; }
.fs-app .fs-notes-card textarea { margin-top: 14px; font-size: 13px; min-height: 220px; }
.fs-app .fs-save-status { font-size: 11px; color: var(--fs-muted); margin: 10px 0 14px; }
.fs-app .fs-lesson-complete { border-top: 1px solid var(--fs-rule); margin-top: 36px; padding-top: 24px; display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 20px; }
.fs-app .fs-lesson-complete h2 { font-size: 25px; }
.fs-app .fs-lesson-complete p { font-size: 13px; margin-top: 8px; }
.fs-app .fs-lesson-pagination { display: flex; justify-content: space-between; gap: 16px; margin-top: 24px; }
.fs-app .fs-filters { display: flex; flex-wrap: wrap; align-items: end; gap: 12px; background: var(--fs-surface); border: 1px solid var(--fs-rule); border-radius: var(--fs-radius); padding: 18px; }
.fs-app .fs-filters label { flex: 1 1 140px; font-size: 11px; color: var(--fs-muted); }
.fs-app .fs-filters :is(input,select) { display: block; margin-top: 6px; font-size: 12px; }
.fs-app .fs-filters .fs-button { min-height: 44px; }
.fs-app .fs-question-list { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 20px; }
.fs-app .fs-question-card, .fs-app .fs-question-workspace { border: 1px solid var(--fs-rule); border-radius: var(--fs-radius); background: var(--fs-surface); padding: 24px; min-width: 0; }
.fs-app .fs-question-card h2 { font-size: 24px; margin: 20px 0 8px; }
.fs-app .fs-question-card > .fs-muted { font-size: 12px; }
.fs-app .fs-question-card > .fs-rich { margin: 18px 0 24px; font-size: 14px; }
.fs-app .fs-question-card > .fs-card-top:last-child { padding-top: 18px; border-top: 1px solid var(--fs-rule); flex-wrap: wrap; }
.fs-app .fs-badge { display: inline-block; border: 1px solid var(--fs-rule); border-radius: 99px; padding: 3px 9px; font-size: 11px; text-transform: capitalize; color: var(--fs-muted); }
.fs-app .fs-badge-success { color: var(--fs-success); }
.fs-app .fs-question-workspace > .fs-rich { margin: 20px 0 28px; }
.fs-app .fs-tags { display: flex; flex-wrap: wrap; gap: 7px; font-size: 11px; color: var(--fs-muted); margin-bottom: 24px; }
.fs-app .fs-tags > span { padding: 2px 7px; background: var(--fs-soft); border-radius: 3px; }
.fs-app .fs-field { display: flex; flex-direction: column; gap: 9px; margin-bottom: 22px; font-size: 14px; }
.fs-app .fs-answer-disclosures { margin: 24px 0; }
.fs-app .fs-self-assessment { border: 1px solid var(--fs-rule); padding: 18px; margin: 24px 0; }
.fs-app .fs-self-assessment legend { font-size: 13px; padding: 0 6px; }
.fs-app .fs-self-assessment label { display: flex; align-items: center; gap: 10px; margin-bottom: 12px; font-size: 13px; }
.fs-app .fs-result { border: 1px solid var(--fs-rule); padding: 18px; margin-top: 20px; border-radius: 4px; }
.fs-app .fs-result strong { font-size: 14px; font-weight: 500; }
.fs-app .fs-result p { margin-top: 8px; font-size: 13px; }
.fs-app .fs-result-correct { border-left: 3px solid var(--fs-success); }
.fs-app .fs-result-review { border-left: 3px solid var(--fs-control); }
.fs-app .fs-tabs { display: flex; gap: 24px; border-bottom: 1px solid var(--fs-rule); margin-bottom: 28px; }
.fs-app .fs-tabs a { padding: 10px 0; font-size: 13px; }
.fs-app .fs-tabs .is-active { color: var(--fs-ink); border-bottom: 2px solid currentColor; }
.fs-app .fs-mistake-answers { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; font-size: 13px; }
.fs-app .fs-mistake-answers h3 { font-size: 12px; color: var(--fs-muted); margin-bottom: 8px; }
.fs-app .fs-question-card > .fs-actions { margin-top: 24px; }
.fs-app .fs-pagination { display: flex; align-items: center; justify-content: center; gap: 20px; margin-top: 28px; font-size: 12px; }
.fs-app .fs-search-result { padding: 24px 0; border-bottom: 1px solid var(--fs-rule); }
.fs-app .fs-search-result h2 { margin: 8px 0; }
.fs-app .fs-search-result > p { font-size: 13px; color: var(--fs-muted); }
.fs-app .fs-bookmark-row { display: flex; align-items: center; justify-content: space-between; gap: 24px; border-bottom: 1px solid var(--fs-rule); padding: 24px 0; }
.fs-app .fs-bookmark-row > div { flex: 1; min-width: 0; }
.fs-app .fs-bookmark-row h2 { margin: 8px 0; }
.fs-app .fs-bookmark-row p { font-size: 12px; }
.fs-app .fs-card { border: 1px solid var(--fs-rule); border-radius: var(--fs-radius); background: var(--fs-surface); padding: 24px; margin-bottom: 20px; min-width: 0; }
.fs-app .fs-card > h2 { margin-bottom: 20px; }
.fs-app .fs-card > h3 { margin-bottom: 12px; }
.fs-app .fs-practice-grid { display: grid; grid-template-columns: minmax(0,1fr) 240px; gap: 24px; }
.fs-app .fs-practice-main, .fs-app .fs-practice-aside { min-width: 0; }
.fs-app .fs-practice-aside .fs-card { padding: 20px; }
.fs-app .fs-practice-aside .fs-muted { font-size: 12px; }
.fs-app .fs-practice-clock strong { display: block; font: 400 32px var(--font-mono,monospace); margin: 16px 0; color: var(--fs-ink); }
.fs-app .fs-practice-clock .fs-actions { margin: 16px 0 8px; }
.fs-app .fs-practice-clock .fs-small { margin-top: 16px; }
.fs-app .fs-practice-question { border: 0; border-top: 1px solid var(--fs-rule); padding: 18px 0; margin: 18px 0; min-width: 0; }
.fs-app .fs-practice-question legend { font-size: 14px; padding: 0; }
.fs-app .fs-question-number { font: 400 12px var(--font-mono,monospace); color: var(--fs-muted); padding-right: 8px; }
.fs-app .fs-radio { display: flex; gap: 10px; align-items: start; font-size: 13px; margin-bottom: 12px; }
.fs-app .fs-radio input { margin-top: 3px; }
.fs-app .fs-editor-meta { display: flex; justify-content: space-between; gap: 14px; font-size: 11px; color: var(--fs-muted); margin: -10px 0 24px; }
.fs-app .fs-writing-editor { min-height: 330px; }
.fs-app .fs-score { display: flex; flex-direction: column; gap: 10px; border-top: 1px solid var(--fs-rule); margin-top: 24px; padding-top: 20px; }
.fs-app .fs-score strong { font: 400 30px var(--font-mono,monospace); color: var(--fs-ink); }
.fs-app .fs-score span { font-size: 12px; color: var(--fs-muted); }
.fs-app audio { width: 100%; margin: 12px 0; }
.fs-app .fs-notice { position: fixed; bottom: 24px; left: 50%; transform: translateX(-50%); z-index: 10000; max-width: min(520px,calc(100vw - 32px)); width: max-content; border: 1px solid var(--fs-control); border-radius: 6px; background: var(--fs-surface); color: var(--fs-ink); padding: 14px 20px; font-size: 13px; box-shadow: 0 3px 12px rgba(0,0,0,.06); }
.fs-app .fs-notice-error { border-color: var(--fs-error); }
.fs-app .fs-notice[hidden] { display: none; }
.fs-app #fs-practice-root > .fs-notice { position: static; transform: none; width: auto; max-width: none; margin-bottom: 20px; box-shadow: none; }
@media (min-width: 1500px) { .fs-app { gap: 48px; } }
@media (max-width: 1100px) {
  .fs-app { grid-template-columns: 180px minmax(0,1fr); gap: 24px; padding-inline: 24px; }
  .fs-app .fs-sidebar { padding-right: 16px; }
  .fs-app .fs-course-grid { grid-template-columns: repeat(2,minmax(0,1fr)); }
  .fs-app .fs-course-grid:not(.fs-course-grid-four) .fs-course-card:last-child:nth-child(3) { grid-column: 1/-1; }
  .fs-app .fs-lesson-layout, .fs-app .fs-practice-grid { grid-template-columns: minmax(0,1fr); }
  .fs-app .fs-lesson-aside .fs-notes-card { position: static; }
  .fs-app .fs-practice-aside { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
  .fs-app .fs-stat { padding-inline: 12px; }
  .fs-app .fs-stat strong { font-size: 23px; }
  .fs-app .fs-dashboard-bottom { grid-template-columns: 1fr; gap: 0; }
}
@media (max-width: 780px) {
  .fs-app { display: block; padding: 18px 24px 52px; }
  .fs-app .fs-mobile-toggle { display: flex; width: 100%; justify-content: space-between; margin-bottom: 20px; }
  .fs-app .fs-sidebar { display: none; position: static; padding: 0 18px 22px; border: 1px solid var(--fs-rule); border-radius: var(--fs-radius); margin-bottom: 24px; }
  .fs-app .fs-sidebar.is-open { display: block; }
  .fs-app .fs-sidebar-brand { padding-top: 18px; }
  .fs-app .fs-nav-group { display: inline-block; vertical-align: top; width: 49%; }
  .fs-app .fs-timer { margin-top: 22px; }
  .fs-app .fs-timer .fs-actions { max-width: 260px; }
  .fs-app .fs-timer select { max-width: 360px; }
  .fs-app .fs-topbar { margin-bottom: 24px; padding-bottom: 18px; }
  .fs-app .fs-page-heading { margin-bottom: 25px; }
  .fs-app .fs-question-list { grid-template-columns: 1fr; }
  .fs-app .fs-course-grid:not(.fs-course-grid-four) .fs-course-card:last-child:nth-child(3) { grid-column: auto; }
  .fs-app .fs-page-heading .fs-actions { flex-shrink: 1; }
}
@media (max-width: 520px) {
  .fs-app { padding-inline: 18px; }
  .fs-app h1 { font-size: 36px; }
  .fs-app .fs-page-heading { flex-wrap: wrap; gap: 18px; }
  .fs-app .fs-page-heading > div:first-child { flex: 1; min-width: 230px; }
  .fs-app .fs-page-heading .fs-book-icon { width: 54px; margin-right: 0; }
  .fs-app .fs-page-heading > .fs-actions:has(.fs-book-icon) { flex: 0 0 54px; }
  .fs-app .fs-stat-grid { grid-template-columns: repeat(2,minmax(0,1fr)); row-gap: 24px; padding-block: 20px; }
  .fs-app .fs-stat { padding: 0 16px; }
  .fs-app .fs-stat:nth-child(odd) { padding-left: 0; }
  .fs-app .fs-stat:nth-child(even) { border: 0; }
  .fs-app .fs-stat strong { font-size: 25px; }
  .fs-app .fs-stat-grid-three { grid-template-columns: repeat(3,minmax(0,1fr)); }
  .fs-app .fs-stat-grid-three .fs-stat { padding-inline: 10px; }
  .fs-app .fs-stat-grid-three .fs-stat:first-child { padding-left: 0; }
  .fs-app .fs-stat-grid-three .fs-stat strong { font-size: 19px; }
  .fs-app .fs-stat-grid-three .fs-stat p { font-size: 11px; }
  .fs-app .fs-course-grid, .fs-app .fs-practice-list { grid-template-columns: 1fr; }
  .fs-app .fs-course-card { padding: 22px; }
  .fs-app .fs-course-card h3 { margin-top: 14px; }
  .fs-app .fs-course-card > .fs-muted { margin-bottom: 20px; }
  .fs-app .fs-user { max-width: 75px; font-size: 11px; }
  .fs-app #fs-search-form { gap: 6px; }
  .fs-app #fs-search-form input { font-size: 12px; }
  .fs-app .fs-topbar { gap: 10px; }
  .fs-app .fs-course-overview { grid-template-columns: 1fr; gap: 12px; padding: 20px; }
  .fs-app .fs-unit > header { padding: 18px; }
  .fs-app .fs-topic-row { padding: 16px 18px; gap: 10px; flex-wrap: wrap; }
  .fs-app .fs-topic-row > div { min-width: 150px; }
  .fs-app .fs-status { font-size: 10px; }
  .fs-app .fs-unit h2 { font-size: 24px; }
  .fs-app .fs-lesson-meta { gap: 10px 18px; }
  .fs-app .fs-lesson-meta .fs-bookmark-button { margin-left: 0; }
  .fs-app .fs-card, .fs-app .fs-question-workspace, .fs-app .fs-question-card { padding: 20px; }
  .fs-app .fs-practice-aside { grid-template-columns: 1fr; gap: 0; }
  .fs-app .fs-formula-card .fs-card-top { align-items: start; flex-wrap: wrap; }
  .fs-app .fs-mistake-answers { grid-template-columns: 1fr; }
  .fs-app .fs-bookmark-row { gap: 12px; }
  .fs-app .fs-bookmark-row .fs-button { padding: 8px 10px; font-size: 12px; }
  .fs-app .fs-filters label { flex-basis: 120px; }
  .fs-app .fs-editor-meta { flex-wrap: wrap; }
}
@media (prefers-reduced-motion: reduce) { .fs-app *, .fs-app *::before, .fs-app *::after { transition: none !important; scroll-behavior: auto !important; } }