:root {
  --bg: #eef1ec;
  --panel: #ffffff;
  --panel-2: #f6f8f4;
  --ink: #1d2320;
  --muted: #5f6b63;
  --line: #d9dfd6;
  --line-strong: #c3ccc0;
  --accent: #1f7a33;
  --accent-hover: #186629;
  --accent-soft: #e2f1e4;
  --accent-ink: #ffffff;
  --err: #c0322b;
  --err-soft: #fdecea;
  --warn: #9a5b00;
  --warn-soft: #fff4dc;
  --ok: #1f7a33;
  --ok-soft: #e2f1e4;
  --code-bg: #ffffff;
  --mark: #ffe066;
  --mark-cur: #ff9f1a;
  --mark-ink: #1d2320;
  --logo-bg: #289628;

  --radius: 10px;
  --radius-sm: 7px;
  --shadow: 0 1px 2px rgba(20, 30, 20, 0.06), 0 2px 10px rgba(20, 30, 20, 0.05);
  --font: "Segoe UI", system-ui, -apple-system, Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: "Cascadia Mono", Consolas, "JetBrains Mono", "DejaVu Sans Mono", Menlo, monospace;
  --serif: Georgia, "Times New Roman", "PT Serif", serif;
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #111513;
    --panel: #1a1f1c;
    --panel-2: #20261f;
    --ink: #e5ebe6;
    --muted: #9aa69d;
    --line: #2c342f;
    --line-strong: #3b453e;
    --accent: #3fae5a;
    --accent-hover: #4cc068;
    --accent-soft: #1d3324;
    --accent-ink: #07140b;
    --err: #ff7b72;
    --err-soft: #3a1d1b;
    --warn: #f0b44c;
    --warn-soft: #33290f;
    --ok: #5fd07a;
    --ok-soft: #173020;
    --code-bg: #161a18;
    --mark: #6b5a00;
    --mark-cur: #b35c00;
    --mark-ink: #ffffff;
    --shadow: 0 1px 2px rgba(0, 0, 0, 0.3);
    color-scheme: dark;
  }
}

:root[data-theme="dark"] {
  --bg: #111513;
  --panel: #1a1f1c;
  --panel-2: #20261f;
  --ink: #e5ebe6;
  --muted: #9aa69d;
  --line: #2c342f;
  --line-strong: #3b453e;
  --accent: #3fae5a;
  --accent-hover: #4cc068;
  --accent-soft: #1d3324;
  --accent-ink: #07140b;
  --err: #ff7b72;
  --err-soft: #3a1d1b;
  --warn: #f0b44c;
  --warn-soft: #33290f;
  --ok: #5fd07a;
  --ok-soft: #173020;
  --code-bg: #161a18;
  --mark: #6b5a00;
  --mark-cur: #b35c00;
  --mark-ink: #ffffff;
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.3);
  color-scheme: dark;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  height: 100%;
}

body {
  background: var(--bg);
  color: var(--ink);
  font: 15px/1.5 var(--font);
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

h1, h2, h3 { margin: 0; line-height: 1.25; }
code, kbd, pre { font-family: var(--mono); }
code { font-size: 0.92em; background: var(--panel-2); border: 1px solid var(--line); border-radius: 4px; padding: 0 4px; overflow-wrap: anywhere; }
kbd { font-size: 0.85em; border: 1px solid var(--line-strong); border-bottom-width: 2px; border-radius: 4px; padding: 0 5px; background: var(--panel); }
.muted { color: var(--muted); }
.small { font-size: 13px; }
.spacer { flex: 1; }
[hidden] { display: none !important; }

/* ---------- Кнопки и поля ---------- */

.btn {
  font: inherit;
  font-size: 14px;
  color: var(--ink);
  background: var(--panel);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-sm);
  padding: 6px 12px;
  min-height: 34px;
  cursor: pointer;
  white-space: nowrap;
  transition: background 0.12s, border-color 0.12s;
}
.btn:hover:not(:disabled) { background: var(--panel-2); border-color: var(--muted); }
.btn:active:not(:disabled) { transform: translateY(1px); }
.btn:disabled { opacity: 0.45; cursor: default; }
.btn:focus-visible, button:focus-visible, select:focus-visible, input:focus-visible, a:focus-visible, .viewer-body:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}
.btn.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--accent-ink);
  font-weight: 600;
}
.btn.primary:hover:not(:disabled) { background: var(--accent-hover); border-color: var(--accent-hover); }
.btn.ghost { background: transparent; border-color: transparent; }
.btn.ghost:hover:not(:disabled) { background: var(--panel-2); border-color: var(--line); }
.btn.small { min-height: 26px; padding: 2px 8px; font-size: 13px; }
.btn.icon { min-width: 34px; padding: 4px 8px; font-size: 16px; line-height: 1; }
.btn[aria-pressed="true"], .btn[aria-expanded="true"] { background: var(--accent-soft); border-color: var(--accent); }
.btn-row { display: flex; gap: 8px; }
.btn-row > .btn { flex: 1; }
a.btn { display: inline-flex; align-items: center; text-decoration: none; }

.inp {
  font: inherit;
  font-size: 14px;
  color: var(--ink);
  background: var(--code-bg);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-sm);
  padding: 6px 10px;
  min-height: 34px;
}
.inp:disabled { opacity: 0.55; }

.seg {
  display: inline-flex;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-sm);
  overflow: hidden;
  flex: none;
}
.seg button {
  font: inherit;
  font-size: 13.5px;
  color: var(--ink);
  background: var(--panel);
  border: 0;
  padding: 6px 11px;
  min-height: 32px;
  cursor: pointer;
  white-space: nowrap;
}
.seg button + button { border-left: 1px solid var(--line-strong); }
.seg button[aria-checked="true"] { background: var(--accent); color: var(--accent-ink); font-weight: 600; }

/* ---------- Шапка ---------- */

.topbar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  background: var(--panel);
  border-bottom: 1px solid var(--line);
  flex: none;
}
.brand { display: flex; align-items: center; gap: 10px; color: inherit; text-decoration: none; border-radius: var(--radius-sm); margin-right: 8px; }
.brand:hover strong { color: var(--accent); }
.brand:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }
.brand-logo { width: 32px; height: 32px; flex: none; }
.brand-logo rect { fill: var(--logo-bg); }
.brand-logo path { fill: #ffffff; }
.brand-text { display: flex; flex-direction: column; line-height: 1.15; }
.brand-text strong { font-size: 16px; }
.brand-text span { font-size: 12.5px; color: var(--muted); }

/* Вкладки панелей — только на узком экране */
.mtabs { display: none; }

/* ---------- Раскладка ---------- */

.layout {
  flex: 1;
  min-height: 0;
  display: grid;
  grid-template-columns: minmax(290px, 350px) minmax(400px, 1.1fr) minmax(320px, 1fr);
  gap: 12px;
  padding: 12px;
  height: calc(100vh - 57px);
}
/* Две колонки: задание и проводник, без просмотра файла */
.layout.two { grid-template-columns: minmax(300px, 380px) minmax(0, 1fr); }

.side, .pane {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  min-height: 0;
  min-width: 0;
}
.side { overflow: auto; padding: 14px; }
.pane { display: flex; flex-direction: column; overflow: hidden; }

.toolbar {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 10px;
  border-bottom: 1px solid var(--line);
  flex-wrap: wrap;
  flex: none;
}

/* ---------- Боковая панель: задание ---------- */

.panel { display: flex; flex-direction: column; gap: 14px; }
.panel h1 { font-size: 19px; }
.panel h2 { font-size: 15px; margin-bottom: 8px; }
.task-picker { display: flex; gap: 6px; }
.task-picker select {
  flex: 1 1 0;
  width: 0;
  min-width: 0;
  font: inherit;
  font-size: 14px;
  color: var(--ink);
  background: var(--panel);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-sm);
  padding: 6px 8px;
  min-height: 34px;
}
.task-card { display: flex; flex-direction: column; gap: 10px; }
.task-card > p { margin: 0; }
.task-meta { display: flex; gap: 6px; flex-wrap: wrap; }
.chip {
  font-size: 12px;
  font-weight: 600;
  padding: 2px 9px;
  border-radius: 999px;
  background: var(--panel-2);
  border: 1px solid var(--line);
  color: var(--muted);
}
.chip-score.s2 { background: var(--ok-soft); border-color: var(--ok); color: var(--ok); }
.task-text p { margin: 0 0 8px; }
.task-text p:last-child { margin-bottom: 0; }
.rules { font-size: 13.5px; color: var(--muted); }
.rules summary { cursor: pointer; color: var(--ink); }
.rules ul { margin: 6px 0 0; padding-left: 18px; }
.rules li { margin-bottom: 4px; }

.answer-row { display: flex; gap: 8px; align-items: flex-end; flex-wrap: wrap; }
.answer-row .field { flex: 1 1 140px; min-width: 0; }
.answer-row .field input { width: 100%; }
.answer-row .btn { min-height: 38px; }
.field { display: flex; flex-direction: column; gap: 4px; font-size: 13px; color: var(--muted); }
.field input {
  font: inherit;
  font-size: 16px;
  color: var(--ink);
  background: var(--code-bg);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-sm);
  padding: 7px 10px;
}
.q-result { border-radius: var(--radius-sm); padding: 10px 12px; font-size: 14px; margin-top: 10px; }
.q-result.ok { background: var(--ok-soft); border: 1px solid var(--ok); }
.q-result.bad { background: var(--err-soft); border: 1px solid var(--err); }

.note {
  background: var(--warn-soft);
  border: 1px solid color-mix(in srgb, var(--warn) 35%, transparent);
  border-radius: var(--radius-sm);
  padding: 10px 12px;
  font-size: 14px;
}
.solution {
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 10px 12px;
  background: var(--panel-2);
  font-size: 14px;
}
.solution ol, .solution ul { margin: 0; padding-left: 20px; }
.solution li { margin-bottom: 6px; }
.solution p { margin: 8px 0 0; }
.solution table { border-collapse: collapse; margin: 6px 0; font-size: 13.5px; }
.solution td, .solution th { border-top: 1px solid var(--line); padding: 3px 12px 3px 0; text-align: left; }
.solution td:last-child { text-align: right; font-variant-numeric: tabular-nums; }

/* ---------- Проводник ---------- */

.ico {
  flex: none;
  width: 18px;
  height: 18px;
  background: center / contain no-repeat;
}
.ico-dir { background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 18 18'%3E%3Cpath d='M1.5 4.5a1 1 0 0 1 1-1h4l1.6 1.8h7.4a1 1 0 0 1 1 1v7.7a1 1 0 0 1-1 1h-13a1 1 0 0 1-1-1z' fill='%23e8b33a' stroke='%23b98512'/%3E%3C/svg%3E"); }
.ico-txt { background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 18 18'%3E%3Cpath d='M4 1.5h7l3.5 3.5v11.5h-10.5z' fill='%23fff' stroke='%23708090'/%3E%3Cpath d='M6 7h6M6 9.5h6M6 12h4' stroke='%23708090'/%3E%3C/svg%3E"); }
.ico-doc { background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 18 18'%3E%3Cpath d='M4 1.5h7l3.5 3.5v11.5h-10.5z' fill='%23e8f0ff' stroke='%232b5fb8'/%3E%3Cpath d='M6 7h6M6 9.5h6M6 12h4' stroke='%232b5fb8'/%3E%3C/svg%3E"); }
.ico-pdf { background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 18 18'%3E%3Cpath d='M4 1.5h7l3.5 3.5v11.5h-10.5z' fill='%23ffecec' stroke='%23c0322b'/%3E%3Cpath d='M6 9h6M6 12h6' stroke='%23c0322b'/%3E%3C/svg%3E"); }
.ico-web { background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 18 18'%3E%3Ccircle cx='9' cy='9' r='6.5' fill='%23e9f7ff' stroke='%231d7fb3'/%3E%3Cpath d='M2.5 9h13M9 2.5c-3 3.5-3 9.5 0 13M9 2.5c3 3.5 3 9.5 0 13' fill='none' stroke='%231d7fb3'/%3E%3C/svg%3E"); }
.ico-img { background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 18 18'%3E%3Crect x='1.5' y='3' width='15' height='12' rx='1' fill='%23eaf7ea' stroke='%232f8f46'/%3E%3Cpath d='M3 13l4-4.5 3 3 2-2 3 3.5z' fill='%232f8f46'/%3E%3Ccircle cx='12.5' cy='6.5' r='1.3' fill='%23e8b33a'/%3E%3C/svg%3E"); }
.ico-snd { background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 18 18'%3E%3Cpath d='M7 4.5l7-2v9' fill='none' stroke='%237a3fb3' stroke-width='1.5'/%3E%3Ccircle cx='5' cy='13' r='2.2' fill='%237a3fb3'/%3E%3Ccircle cx='12' cy='11.5' r='2.2' fill='%237a3fb3'/%3E%3Cpath d='M7 4.5v8.5' stroke='%237a3fb3' stroke-width='1.5'/%3E%3C/svg%3E"); }
.ico-file { background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 18 18'%3E%3Cpath d='M4 1.5h7l3.5 3.5v11.5h-10.5z' fill='%23f3f3f3' stroke='%23888'/%3E%3C/svg%3E"); }

.ex-bar { flex-wrap: nowrap; align-items: flex-start; }
.crumbs { display: flex; flex-wrap: wrap; align-items: center; gap: 2px; min-width: 0; min-height: 34px; font-size: 14px; }
.crumbs button {
  font: inherit;
  color: var(--ink);
  background: none;
  border: 0;
  border-radius: 5px;
  padding: 3px 6px;
  cursor: pointer;
}
.crumbs button:hover { background: var(--panel-2); }
.crumbs button[aria-current] { font-weight: 600; }
.crumbs .sep { color: var(--muted); }

.ex-search .inp { flex: 1 1 150px; min-width: 0; }
.ex-scope { flex-basis: 100%; font-size: 12.5px; color: var(--muted); }
.ex-scope b { color: var(--ink); }

.ex-body { flex: 1; min-height: 0; display: grid; grid-template-columns: minmax(150px, 32%) minmax(0, 1fr); }
.ex-tree { overflow: auto; border-right: 1px solid var(--line); padding: 8px 6px; background: var(--panel-2); }
.ex-tree ul { list-style: none; margin: 0; padding: 0; }
.ex-tree ul ul { padding-left: 14px; }
.tree-row { display: flex; align-items: center; border-radius: 6px; }
.tree-row:hover { background: var(--panel); }
.tree-row.is-current { background: var(--accent-soft); }
.tree-toggle {
  flex: none;
  width: 22px;
  height: 28px;
  padding: 0;
  border: 0;
  background: none;
  color: var(--muted);
  font-size: 12px;
  cursor: pointer;
}
.tree-toggle:disabled { cursor: default; }
.tree-name {
  flex: 1;
  min-width: 0;
  display: flex;
  align-items: center;
  gap: 6px;
  font: inherit;
  font-size: 14px;
  color: var(--ink);
  background: none;
  border: 0;
  border-radius: 6px;
  padding: 4px 6px 4px 0;
  text-align: left;
  cursor: pointer;
}
.tree-name span:last-child { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.tree-row.is-current .tree-name { font-weight: 600; }

.ex-list { display: flex; flex-direction: column; min-width: 0; min-height: 0; }
.ex-info {
  flex: none;
  display: flex;
  gap: 8px;
  align-items: center;
  justify-content: space-between;
  padding: 6px 10px;
  font-size: 13px;
  background: var(--accent-soft);
  border-bottom: 1px solid var(--line);
}
.ex-info span { min-width: 0; overflow-wrap: anywhere; }
.ex-table-wrap { flex: 1; min-height: 0; overflow: auto; }
.ex-table { width: 100%; border-collapse: collapse; font-size: 14px; }
.ex-table th {
  position: sticky;
  top: 0;
  z-index: 1;
  padding: 0;
  text-align: left;
  white-space: nowrap;
  background: var(--panel);
  box-shadow: inset 0 -1px 0 var(--line);
}
.ex-table th button {
  width: 100%;
  font: inherit;
  font-size: 13px;
  font-weight: 600;
  color: var(--muted);
  text-align: left;
  background: none;
  border: 0;
  padding: 7px 10px;
  cursor: pointer;
}
.ex-table th button:hover { color: var(--ink); background: var(--panel-2); }
.ex-table th[aria-sort] button { color: var(--ink); }
.ex-table th[aria-sort="ascending"] button::after { content: " ▲"; font-size: 10px; }
.ex-table th[aria-sort="descending"] button::after { content: " ▼"; font-size: 10px; }
.ex-table th.c-size button { text-align: right; }
.ex-table td { padding: 0 10px; border-bottom: 1px solid var(--line); vertical-align: top; }
.ex-table td.c-type { color: var(--muted); font-size: 13px; padding-top: 7px; }
.ex-table td.c-size { text-align: right; white-space: nowrap; font-variant-numeric: tabular-nums; padding-top: 6px; }
.ex-table tbody tr:hover td { background: var(--panel-2); }
.ex-table tr.is-selected td, .ex-table tr.is-open td { background: var(--accent-soft); }
.ex-table tr.is-selected .c-name { box-shadow: inset 3px 0 0 var(--accent); }
.ex-table tr.is-empty td { padding: 14px 10px; color: var(--muted); }
.ex-item {
  display: flex;
  gap: 8px;
  align-items: flex-start;
  width: 100%;
  font: inherit;
  color: var(--ink);
  text-align: left;
  background: none;
  border: 0;
  padding: 6px 0;
  cursor: pointer;
}
.ex-item .ico { margin-top: 2px; }
.ex-item .nm { min-width: 0; overflow-wrap: anywhere; }
.ex-item:hover .nm { text-decoration: underline; }
.ex-snippet { padding: 0 0 4px 26px; font-size: 12.5px; color: var(--muted); overflow-wrap: anywhere; }
.ex-count { white-space: nowrap; }
.ex-where {
  display: block;
  margin: 0 0 6px 26px;
  padding: 0;
  font: inherit;
  font-size: 12.5px;
  color: var(--muted);
  text-align: left;
  background: none;
  border: 0;
  cursor: pointer;
  overflow-wrap: anywhere;
}
.ex-where:hover { color: var(--accent); text-decoration: underline; }
mark { background: var(--mark); color: var(--mark-ink); border-radius: 2px; }
.ex-status {
  flex: none;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 4px 12px;
  min-height: 34px;
  padding: 4px 10px;
  font-size: 13px;
  color: var(--muted);
  border-top: 1px solid var(--line);
}
.ex-status b { color: var(--ink); }

/* ---------- Просмотр файла ---------- */

.viewer-file { display: flex; flex-direction: column; flex: 1 1 100%; min-width: 0; line-height: 1.25; }
.viewer-file strong, .viewer-file span { overflow-wrap: anywhere; }
.viewer-find { display: flex; align-items: center; gap: 6px; flex: 1 1 100%; min-width: 0; }
.viewer-find .inp { flex: 1; min-width: 0; }
.viewer-count { min-width: 74px; font-size: 13px; color: var(--muted); white-space: nowrap; }
.viewer-count.is-none { color: var(--err); }
.viewer-body { flex: 1; min-height: 0; overflow: auto; padding: 14px 18px 30px; background: var(--code-bg); }
.viewer-text { white-space: pre-wrap; overflow-wrap: anywhere; font: 16px/1.6 var(--serif); }
.viewer-text mark.cur { background: var(--mark-cur); outline: 2px solid var(--mark-cur); }
.viewer-empty { margin: 0; color: var(--muted); }

/* ---------- Справка ---------- */

.help {
  width: min(760px, calc(100vw - 24px));
  max-height: calc(100vh - 40px);
  padding: 0;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  background: var(--panel);
  color: var(--ink);
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}
.help::backdrop { background: rgba(10, 20, 12, 0.45); }
.help-head {
  position: sticky;
  top: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 18px;
  background: var(--panel);
  border-bottom: 1px solid var(--line);
}
.help-body { padding: 4px 18px 20px; }
.help-body h3 { font-size: 15.5px; margin: 18px 0 8px; }
.help-body p { margin: 6px 0; }
.help-body table { border-collapse: collapse; width: 100%; font-size: 14px; }
.help-body td { border-top: 1px solid var(--line); padding: 6px 8px 6px 0; vertical-align: top; }
.help-body td:first-child { width: 34%; }
.help-body ul, .help-body ol { padding-left: 20px; margin: 6px 0; }
.help-body li { margin-bottom: 4px; }

/* ---------- Адаптивность ---------- */

@media (max-width: 1280px) {
  .link-other span { display: none; }
}

@media (max-width: 1180px) {
  .layout {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr);
    grid-template-rows: auto 640px;
    height: auto;
    flex: none;
  }
  .layout.two { grid-template-columns: minmax(0, 1fr); }
  .side { grid-column: 1 / -1; overflow: visible; }
}

@media (max-width: 800px) {
  /* Страница прокручивается целиком, вкладки панелей остаются у верхнего края */
  html, body { height: auto; }
  .topbar { flex-wrap: wrap; gap: 4px 6px; padding: 8px 12px; }
  .brand-text span { display: none; }
  .topbar .btn { padding: 6px 8px; }

  .mtabs {
    display: flex;
    position: sticky;
    top: 0;
    z-index: 5;
    flex: none;
    background: var(--panel);
    border-bottom: 1px solid var(--line);
  }
  .mtabs button {
    flex: 1;
    font: inherit;
    font-size: 14px;
    color: var(--muted);
    background: none;
    border: 0;
    border-bottom: 3px solid transparent;
    padding: 10px 4px 7px;
    cursor: pointer;
  }
  .mtabs button[aria-selected="true"] { color: var(--ink); font-weight: 600; border-bottom-color: var(--accent); }

  /* Одна панель на экране: её выбирают вкладками */
  .layout { display: block; padding: 8px; height: auto; flex: none; }
  .layout > .side, .layout > .pane { display: none; }
  .layout[data-tab="task"] > .side { display: block; }
  .layout[data-tab="tree"] > .pane-files, .layout[data-tab="list"] > .pane-files, .layout[data-tab="text"] > .pane-viewer { display: flex; }
  .side { padding: 12px; }
  .pane { overflow: visible; min-height: 60vh; }
  .ex-body { display: block; }
  .layout[data-tab="tree"] .ex-list, .layout[data-tab="list"] .ex-tree { display: none; }
  .ex-tree { border-right: 0; background: transparent; overflow: visible; }
  .tree-name { padding-top: 8px; padding-bottom: 8px; font-size: 15px; }
  .tree-toggle { width: 30px; height: 36px; font-size: 14px; }
  .ex-table-wrap { overflow: visible; }
  .ex-table th { position: static; }
  .ex-table td.c-type { max-width: 96px; overflow-wrap: anywhere; }
  .ex-item { padding: 9px 0; }
  .viewer-bar { position: sticky; top: 41px; z-index: 4; background: var(--panel); border-radius: var(--radius) var(--radius) 0 0; }
  .viewer-body { overflow: visible; padding: 12px 14px 30px; }
  .answer-row .field { flex-basis: 100%; }
  .answer-row .btn { flex: 1; }
}

@media (max-width: 480px) {
  .topbar { gap: 2px; padding: 6px 8px; }
  .topbar .btn { padding: 6px; }
  .brand { margin-right: 2px; gap: 8px; }
  .seg button { padding: 6px 8px; }
}

/* Внутри платформы репетитора готовое решение не показываем: балл идёт в домашнее задание */
.in-platform #btn-solution, .in-platform #solution { display: none !important; }

/* ---------- Школьный режим (?school): полоса с кнопкой «Начать с чистого листа» ---------- */
.school-bar {
  flex: none;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 6px 12px;
  padding: 6px 12px;
  background: #fff4d6;
  color: #5a4300;
  border-bottom: 1px solid #e6c766;
  font-size: 13px;
  line-height: 1.3;
}

.school-reset {
  font: inherit;
  font-weight: 600;
  padding: 4px 12px;
  border: 1px solid #b98a00;
  border-radius: 6px;
  background: #fff;
  color: #5a4300;
  cursor: pointer;
}

.school-reset:hover {
  background: #ffe9a8;
}