:root {
  --bg: #f3eee4;
  --paper: #fffdf8;
  --ink: #1b2a32;
  --muted: #5d6c74;
  --line: #e4d9c8;
  --teal: #0d6e6a;
  --teal-dark: #0a4f4c;
  --amber: #c97816;
  --ok: #2c8a5c;
  --bad: #c2413b;
  --shadow: 0 10px 30px rgba(27, 42, 50, 0.08);
  --radius: 18px;
}
* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
html { -webkit-text-size-adjust: 100%; }
img, svg, video { max-width: 100%; height: auto; }
.katex-display {
  overflow-x: auto;
  overflow-y: hidden;
  max-width: 100%;
  padding-bottom: 4px;
}
.md-body, .q-prompt, .opt { overflow-wrap: break-word; }
.md-body table {
  display: block;
  max-width: 100%;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}
body {
  font-family: Manrope, system-ui, sans-serif;
  color: var(--ink);
  background:
    radial-gradient(1200px 500px at 10% -10%, #e7f3f1 0%, transparent 50%),
    radial-gradient(900px 400px at 100% 0%, #f8e9d4 0%, transparent 46%),
    var(--bg);
  min-height: 100vh;
}
a { color: var(--teal-dark); text-decoration: none; }
a:hover { text-decoration: underline; }
h1, h2, h3 { font-weight: 800; letter-spacing: -0.03em; margin: 0 0 .4em; }
h1 { font-size: clamp(1.6rem, 3vw, 2.2rem); }
.muted { color: var(--muted); }
.wrap { width: min(1120px, calc(100% - 32px)); margin: 0 auto 64px; padding-bottom: env(safe-area-inset-bottom); }
.crumb { color: var(--muted); margin: 0 0 12px; line-height: 1.4; }
.crumb a { font-weight: 600; }
.topbar {
  display: flex; align-items: center; gap: 18px;
  width: min(1120px, calc(100% - 32px)); margin: 16px auto 28px;
  padding: 10px 14px; background: rgba(255,253,248,.86);
  border: 1px solid var(--line); border-radius: 999px; backdrop-filter: blur(10px);
}
.brand { display: flex; align-items: center; gap: 10px; color: inherit; }
.brand small { display: block; color: var(--muted); font-size: 12px; }
.brand-mark {
  width: 34px; height: 34px; border-radius: 12px;
  background: conic-gradient(from 220deg, var(--teal), #7bc4b8, var(--amber), var(--teal));
  box-shadow: inset 0 0 0 3px #fff;
}
.brand-mark.lg { width: 52px; height: 52px; border-radius: 16px; }
.topnav { display: flex; gap: 14px; margin-left: 8px; }
.topnav a { color: var(--ink); font-weight: 600; }
.who { margin-left: auto; display: flex; align-items: center; gap: 10px; min-width: 0; }
.who span { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; min-width: 0; }
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  border: 0; border-radius: 999px; padding: 10px 16px; font-weight: 700;
  cursor: pointer; font-family: inherit; text-decoration: none;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }
.btn-primary { background: var(--teal); color: #fff; }
.btn-ghost { background: transparent; border: 1px solid var(--line); color: var(--ink); }
.btn-sm { padding: 6px 10px; font-size: 13px; }
.btn-block { width: 100%; }
.card, .paper, .hero-card, .stat, .auth-card {
  background: var(--paper); border: 1px solid var(--line);
  border-radius: var(--radius); box-shadow: var(--shadow);
}
.card, .paper { padding: 22px; margin: 16px 0; }
.hero-card {
  display: flex; justify-content: space-between; align-items: center; gap: 16px;
  padding: 28px; margin: 0 0 18px;
}
.hero-card.compact { padding: 18px 22px; }
.eyebrow { text-transform: uppercase; letter-spacing: .12em; font-size: 12px; color: var(--teal); font-weight: 800; margin: 0 0 6px; }
.stat-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; }
.stat { padding: 18px; }
.stat span, .stat small { color: var(--muted); }
.stat strong { display: block; font-size: 1.6rem; margin: 6px 0; }
.stat.mini { min-width: 140px; text-align: right; }
.bar { height: 8px; background: #efe6d8; border-radius: 99px; overflow: hidden; }
.bar i { display: block; height: 100%; background: linear-gradient(90deg, var(--teal), #7bc4b8); }
.bar-lg { height: 10px; }
.lesson-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(160px, 1fr)); gap: 10px; }
.lesson-tile {
  display: flex; flex-direction: column; gap: 6px; min-height: 118px;
  padding: 14px; border-radius: 16px; border: 1px solid var(--line);
  background: #fff; color: inherit; text-decoration: none;
}
.lesson-tile:hover { border-color: var(--teal); text-decoration: none; }
.lesson-tile b { font-size: 1.2rem; }
.lesson-tile span { color: var(--ink); font-size: 13px; line-height: 1.3; }
.lesson-tile em { font-style: normal; color: var(--muted); font-size: 12px; }
.lesson-tile.done { background: #eef8f2; border-color: #cfe8d9; }
.lesson-tile.locked { opacity: .55; background: #f3eee6; }
.split { display: grid; grid-template-columns: 1.2fr .8fr; gap: 16px; }
.card-head { display: flex; justify-content: space-between; gap: 12px; align-items: baseline; flex-wrap: wrap; }
.ach-list, .plain-list, .timeline, .result-list, .attempt-feed { list-style: none; padding: 0; margin: 0; }
.ach-list li, .plain-list li, .timeline li, .result-list li {
  padding: 10px 0; border-bottom: 1px solid var(--line);
}
.result-list li { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.ach-list li { opacity: .45; }
.ach-list li.on { opacity: 1; }
.ach-list li span, .ach-list li small { display: block; color: var(--muted); font-size: 13px; }
.plain-list li, .timeline li { display: flex; justify-content: space-between; gap: 10px; align-items: center; }
.timeline time { color: var(--muted); min-width: 140px; font-size: 13px; }
.pill { display: inline-flex; border-radius: 99px; padding: 3px 8px; font-size: 12px; font-weight: 700; background: #efe6d8; }
.pill.ok { background: #e1f4e8; color: var(--ok); }
.pill.bad { background: #fde8e6; color: var(--bad); }
.pill.lock { background: #ece7df; color: var(--muted); }
.path { display: grid; gap: 12px; }
.path-card {
  display: grid; grid-template-columns: auto 1fr auto; gap: 14px; align-items: center;
  padding: 18px; border-radius: 16px; background: var(--paper); border: 1px solid var(--line);
  color: inherit; text-decoration: none;
}
.path-card:hover { border-color: var(--teal); text-decoration: none; }
.path-card.disabled { opacity: .55; }
.path-card b {
  width: 36px; height: 36px; border-radius: 50%; display: grid; place-items: center;
  background: var(--teal); color: #fff;
}
.path-card .bar { margin-top: 8px; max-width: 280px; }
.path-progress { margin: 4px 0 0; font-size: 14px; font-weight: 700; color: var(--teal-dark); }
.goals-card .card-head { margin-bottom: 4px; }
.goals-card .card-head h2 { margin-bottom: 2px; }
.goals-grid {
  list-style: none;
  padding: 0;
  margin: 14px 0 0;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  counter-reset: none;
}
.goals-grid li {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 12px;
  align-items: start;
  margin: 0;
  padding: 14px 16px;
  background: linear-gradient(180deg, #fff, #f7f3eb);
  border: 1px solid var(--line);
  border-radius: 14px;
}
.goal-n {
  width: 28px; height: 28px; border-radius: 50%;
  display: grid; place-items: center;
  background: var(--teal); color: #fff;
  font-weight: 800; font-size: 13px; line-height: 1;
  box-shadow: 0 0 0 4px rgba(13, 110, 106, 0.08);
}
.goal-text, .goal-text p {
  margin: 0;
  font-family: Manrope, system-ui, sans-serif;
  font-size: 15px;
  line-height: 1.45;
}
.goal-text p { display: inline; }
.md-body { font-family: Literata, Georgia, serif; line-height: 1.65; }
.md-body h1, .md-body h2, .md-body h3, .md-body h4 { font-family: Manrope, sans-serif; }
.md-body table { width: 100%; border-collapse: collapse; margin: 12px 0; }
.md-body td, .md-body th { border: 1px solid var(--line); padding: 6px 8px; }
.md-body img { max-width: 100%; border-radius: 12px; }
.theory-progress { background: rgba(243,238,228,.92); padding: 10px 0 8px; backdrop-filter: blur(8px); }
.theory-progress-meta { display: flex; justify-content: space-between; margin-top: 6px; font-size: 13px; }
.sticky-actions {
  position: sticky; bottom: max(12px, env(safe-area-inset-bottom));
  display: flex; justify-content: flex-end; z-index: 15;
  padding: 10px 0 4px;
  background: linear-gradient(180deg, transparent, var(--bg) 36%);
}
.q-card { min-inline-size: 0; padding-top: 22px; }
.q-card legend {
  display: flex; flex-wrap: wrap; gap: 8px; align-items: center;
  float: left; width: 100%;
  margin: 0 0 4px; padding: 0;
  font-weight: 700;
}
.q-card::after { content: ""; display: block; clear: both; }
.q-num { background: var(--ink); color: #fff; border-radius: 8px; padding: 3px 8px; font-size: 13px; letter-spacing: 0.02em; }
.q-topic { color: var(--muted); font-weight: 600; }
.q-prompt {
  font-family: Manrope, system-ui, sans-serif;
  font-size: 1.18rem;
  font-weight: 700;
  line-height: 1.45;
  letter-spacing: -0.02em;
  color: var(--ink);
  margin: 12px 0 4px;
  padding: 12px 14px;
  background: #f7f3eb;
  border-radius: 12px;
  border-left: 4px solid var(--teal);
}
.q-prompt p { margin: 0 0 .45em; font-family: inherit; font-size: inherit; font-weight: inherit; line-height: inherit; }
.q-prompt p:last-child { margin-bottom: 0; }
.opts { display: grid; gap: 8px; margin-top: 14px; }
.opt {
  display: flex; gap: 10px; align-items: flex-start;
  padding: 12px 14px; border: 1px solid var(--line); border-radius: 12px; cursor: pointer;
  background: #fff;
}
.opt .md-body, .opt .md-body p {
  margin: 0; font-family: Manrope, system-ui, sans-serif; font-size: 15px; line-height: 1.45;
}
.opt .md-body p { display: inline; }
.opt:has(input:checked) { border-color: var(--teal); background: #f0f8f6; }
.task-dots { display: flex; flex-wrap: wrap; gap: 8px; margin: 8px 0 16px; }
.task-dots a {
  min-width: 52px; padding: 8px 12px; border-radius: 12px; border: 1px solid var(--line);
  background: #fff; text-align: center; color: inherit; font-weight: 800;
}
.task-dots a.on { border-color: var(--teal); box-shadow: 0 0 0 3px rgba(13,110,106,.12); }
.task-dots a.ok { background: #eef8f2; }
.task-dots a.wait { background: #f8efd8; }
.pill.wait { background: #f8efd8; color: var(--amber); }
.wait-card { background: #fbf6ea; }
.tips ul { margin: 8px 0 0 18px; color: var(--muted); }
.drop {
  position: relative;
  display: grid; place-items: center; min-height: 120px; border: 2px dashed var(--line);
  border-radius: 16px; cursor: pointer; background: #fbf7f0;
  padding: 16px;
  text-align: center;
}
.drop input[type="file"] {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
  font-size: 0;
}
.photo-preview-wrap {
  position: relative;
  display: inline-block;
  max-width: min(100%, 280px);
}
.photo-actions {
  display: flex;
  align-items: flex-end;
  gap: 12px;
  margin: 14px 0 4px;
}
.photo-actions[hidden] { display: none !important; }
#photoPreview { display: block; max-width: 100%; max-height: 280px; margin: 0; border-radius: 12px; }
.upload-form {
  display: flex;
  flex-direction: column;
}
.upload-submit {
  align-self: center;
  margin-top: 20px;
}
#waitHint { text-align: center; }
.attempt-feed li { display: grid; gap: 8px; padding: 14px 0; border-bottom: 1px solid var(--line); }
.thumb img { max-width: 220px; border-radius: 10px; }
.ai-feedback { white-space: pre-wrap; }
.cell-stack { display: flex; flex-direction: column; gap: 6px; min-width: 9rem; }
.chip-row { display: flex; flex-wrap: wrap; gap: 6px; }
.chip {
  display: inline-flex;
  align-items: center;
  padding: 3px 8px;
  border-radius: 8px;
  border: 1px solid var(--line);
  background: #fff;
  white-space: nowrap;
  font-size: 12px;
  font-weight: 700;
  color: inherit;
  line-height: 1.3;
}
a.chip:hover { text-decoration: none; border-color: var(--teal); }
.chip.ok { background: #eef8f2; border-color: #cfe8d9; color: var(--ok); }
.chip.bad { background: #fde8e6; border-color: #f3c9c6; color: var(--bad); }
.progress-table { min-width: 760px; }
.progress-table td, .progress-table th { vertical-align: top; }
table { width: 100%; border-collapse: collapse; }
th, td { text-align: left; padding: 10px 8px; border-bottom: 1px solid var(--line); vertical-align: top; }
.inline { display: inline; }
.nowrap { white-space: nowrap; }
.form-card label, .auth-form label { display: grid; gap: 6px; margin: 12px 0; font-weight: 600; }
input, select, textarea {
  font: inherit; font-size: 16px; padding: 10px 12px; border-radius: 12px;
  border: 1px solid var(--line); background: #fff; max-width: 100%;
}
.search { display: flex; gap: 8px; margin-bottom: 12px; flex-wrap: wrap; }
.search input { flex: 1; min-width: 0; }
.flashes { display: grid; gap: 8px; margin-bottom: 12px; }
.flash { padding: 10px 12px; border-radius: 12px; background: #efe6d8; }
.flash-success { background: #e1f4e8; }
.flash-danger, .flash-warning { background: #fde8e6; }
.flash-info { background: #e7f1f8; }
.actions { display: flex; gap: 10px; margin-top: 16px; flex-wrap: wrap; }
.auth-body { display: grid; place-items: center; min-height: 100vh; padding: 12px; }
.auth-wrap { width: min(920px, calc(100% - 24px)); margin: 24px auto; }
.auth-card { display: grid; grid-template-columns: 1.1fr .9fr; overflow: hidden; }
.auth-side { padding: 36px; background: linear-gradient(160deg, #0d6e6a, #163a40); color: #fff; }
.auth-form { padding: 36px; }
.opts-admin { list-style: none; padding: 0; }
.opts-admin li { padding: 8px; border-radius: 10px; margin: 6px 0; border: 1px solid var(--line); }
.opts-admin li.exp { background: #eef8f2; }
.opts-admin li.sel { outline: 2px solid var(--amber); }
.split-photo { display: grid; grid-template-columns: 1fr 280px; gap: 16px; align-items: start; }
.split-photo img { width: 100%; border-radius: 12px; }
.check-wrap { margin-top: 16px; overflow-x: auto; }
.check-wrap h4 { font-size: 1rem; margin-bottom: 8px; }
.check-table { font-size: 14px; }
.check-table th { color: var(--muted); font-size: 12px; text-transform: uppercase; letter-spacing: .06em; }
.check-table tr.ok td:last-child { color: var(--ok); }
.check-table tr.bad td:last-child { color: var(--bad); }
.check-mark { font-weight: 800; }
.check-note { color: var(--ink); font-weight: 500; margin-top: 4px; white-space: pre-wrap; }
.check-conclusion { margin-top: 12px; padding: 10px 12px; background: #eef8f2; border-radius: 12px; }
.ok-card { background: #eef8f2; }
.end-cta { margin: 24px 0 48px; }
.check { display: flex !important; align-items: center; gap: 8px; }

@media (max-width: 960px) {
  .stat-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 860px) {
  .wrap, .topbar { width: min(1120px, calc(100% - 20px)); }
  .stat-grid, .split, .auth-card, .split-photo, .goals-grid { grid-template-columns: 1fr; }
  .topbar { border-radius: 20px; flex-wrap: wrap; gap: 10px; padding: 10px 12px; }
  .topnav { margin-left: 0; }
  .who { width: 100%; justify-content: space-between; }
  .hero-card { flex-direction: column; align-items: flex-start; padding: 20px; }
  .hero-card.compact { padding: 16px; }
  .stat.mini { text-align: left; min-width: 0; }
  .auth-side, .auth-form { padding: 24px; }
  .timeline time { min-width: 0; }
  .timeline li, .plain-list li { align-items: flex-start; }
}

@media (max-width: 640px) {
  body { background-attachment: scroll; }
  .wrap { margin-bottom: 40px; }
  .card, .paper { padding: 16px; margin: 12px 0; }
  .hero-card { padding: 16px; }
  h1 { font-size: 1.45rem; }
  .brand small { font-size: 11px; }
  .topnav { width: 100%; gap: 12px; }
  .path-card {
    grid-template-columns: auto 1fr;
    gap: 10px 12px;
    padding: 14px;
  }
  .path-card > .pill { grid-column: 2; justify-self: start; }
  .path-card .bar { max-width: none; }
  .q-prompt { font-size: 1.05rem; padding: 10px 12px; }
  .opt { padding: 12px; }
  .sticky-actions { justify-content: stretch; }
  .sticky-actions .btn, .actions .btn, .upload-submit, .end-cta .btn { width: 100%; }
  .upload-submit { max-width: none; }
  .photo-actions { flex-direction: column; align-items: stretch; }
  .photo-preview-wrap, #photoPreview, .thumb img { max-width: 100%; }
  .lesson-grid { grid-template-columns: repeat(2, 1fr); }
  .lesson-tile { min-height: 104px; padding: 12px; }
  .search { flex-direction: column; }
  .search .btn { width: 100%; }
  .table-wrap.card { padding: 0; }
  .table-wrap table { min-width: 560px; }
  .check-table { min-width: 480px; }
  .nowrap { white-space: normal; }
  td .inline { display: flex; flex-wrap: wrap; gap: 6px; }
}

@media (max-width: 400px) {
  .lesson-grid { grid-template-columns: 1fr; }
  .task-dots a { min-width: 46px; padding: 8px 10px; }
}