.app-shell.home-module-view .practice-page { inset: 0; }
.practice-page { position: absolute; z-index: 25; inset: 52px 0 0; overflow: hidden; background: var(--surface); color: var(--text); }
.practice-page[hidden] { display: none; }
.practice-page-head { display: flex; min-height: 86px; align-items: center; justify-content: space-between; gap: 24px; padding: 18px clamp(20px, 3.5vw, 52px); border-bottom: 1px solid var(--border-soft); background: color-mix(in srgb, var(--surface) 96%, var(--chrome-bg)); }
.practice-page-title { display: flex; min-width: 0; align-items: flex-start; gap: 12px; }.practice-page-title > button { display: grid; width: 36px; height: 36px; flex: 0 0 auto; place-items: center; cursor: pointer; border: 1px solid var(--border); border-radius: 9px; background: var(--surface); color: var(--text-secondary); }.practice-page-title > button:hover { background: var(--surface-hover); color: var(--accent); }.practice-page-title svg { width: 17px; height: 17px; stroke: currentColor; stroke-width: 1.8; }.practice-page-title span { color: var(--accent); font: 700 9px/1.3 var(--font-mono); letter-spacing: .11em; }.practice-page-title h1 { margin: 4px 0 2px; font-family: var(--font-document); font-size: 28px; font-weight: 740; letter-spacing: -.04em; }.practice-page-title p { margin: 0; color: var(--text-tertiary); font-size: 11px; }.practice-page-stats { display: flex; flex: 0 0 auto; gap: 7px; }.practice-page-stats span { display: inline-flex; min-height: 29px; align-items: center; padding: 0 9px; border: 1px solid var(--border); border-radius: 7px; background: var(--surface-soft); color: var(--text-tertiary); font-size: 10px; }.practice-page-stats b { margin-right: 4px; color: var(--accent); font-size: 11px; }
.practice-layout { display: grid; height: calc(100% - 86px); grid-template-columns: 218px minmax(0, 1fr); }
.practice-workbench { display: grid; min-width: 0; min-height: 0; grid-template-columns: minmax(300px, 1fr) 8px minmax(420px, 1.35fr); }
.practice-library { min-width: 0; overflow: hidden; border-right: 1px solid var(--border); background: var(--chrome-bg); }.practice-library-head { display: flex; align-items: baseline; justify-content: space-between; padding: 15px 13px 8px; }.practice-library-head strong { font-size: 12px; font-weight: 680; }.practice-library-head small { color: var(--text-tertiary); font-size: 9px; }.practice-search { display: block; width: calc(100% - 22px); height: 30px; margin: 0 11px 8px; padding: 0 8px; outline: 0; border: 1px solid transparent; border-radius: 6px; background: var(--surface-hover); color: var(--text); font-size: 11px; }.practice-search:focus { border-color: var(--accent); background: var(--surface); }.practice-filters { display: flex; flex-wrap: wrap; gap: 3px; padding: 0 9px 8px; border-bottom: 1px solid var(--border); }.practice-filter { height: 26px; padding: 0 7px; cursor: pointer; border: 0; border-radius: 6px; background: transparent; color: var(--text-tertiary); font-size: 10px; }.practice-filter:hover { background: var(--surface-hover); color: var(--text); }.practice-filter.active { background: var(--accent-soft); color: var(--accent); font-weight: 650; }.practice-question-list { height: calc(100% - 143px); overflow-y: auto; padding: 8px; scrollbar-width: thin; scrollbar-color: var(--border) transparent; }.practice-question { display: grid; width: 100%; min-height: 48px; grid-template-columns: 22px minmax(0,1fr) 12px; align-items: center; gap: 5px; padding: 6px 7px; cursor: pointer; border: 0; border-radius: 7px; background: transparent; color: var(--text-secondary); text-align: left; }.practice-question:hover { background: var(--surface-hover); }.practice-question.active { background: var(--surface); color: var(--text); box-shadow: 0 1px 5px rgba(24,31,38,.07); }.practice-number { align-self: start; padding-top: 2px; color: var(--text-tertiary); font: 10px var(--font-mono); }.practice-question-copy { display: grid; gap: 3px; min-width: 0; }.practice-question-copy b { overflow: hidden; font-size: 11px; font-weight: 620; text-overflow: ellipsis; white-space: nowrap; }.practice-question-copy small { overflow: hidden; color: var(--text-tertiary); font-size: 9px; text-overflow: ellipsis; white-space: nowrap; }.practice-state { display: grid; width: 12px; height: 12px; place-items: center; border-radius: 50%; font-size: 9px; }.practice-state.solved { background: var(--success); color: white; }.practice-state.active { border: 2px solid color-mix(in srgb, var(--accent) 55%, var(--border)); }.practice-empty { padding: 24px 10px; color: var(--text-tertiary); font-size: 11px; text-align: center; }
.practice-problem { min-width: 0; overflow-y: auto; padding: 30px clamp(22px, 3.5vw, 54px) 70px; scrollbar-width: thin; scrollbar-color: var(--border) transparent; }.practice-problem-top { display: flex; align-items: center; justify-content: space-between; gap: 12px; }.practice-problem-top > span { color: var(--accent); font: 10px var(--font-mono); }.practice-problem-top button { height: 27px; margin-left: 4px; padding: 0 7px; cursor: pointer; border: 1px solid var(--border); border-radius: 6px; background: var(--surface); color: var(--text-secondary); font-size: 10px; }.practice-problem-top button:hover,.practice-problem-top button.active { border-color: var(--accent); background: var(--accent-soft); color: var(--accent); }.practice-problem h2 { margin: 15px 0 7px; font-family: var(--font-document); font-size: 29px; font-weight: 740; letter-spacing: -.045em; }.practice-summary { margin: 0 0 16px; color: var(--text-secondary); font-size: 13px; line-height: 1.7; }.practice-tags { display: flex; flex-wrap: wrap; gap: 5px; margin-bottom: 25px; }.practice-tags span { display: inline-flex; height: 22px; align-items: center; padding: 0 7px; border: 1px solid var(--border); border-radius: 5px; color: var(--text-tertiary); font-size: 10px; }.practice-problem section { margin-top: 24px; }.practice-problem h3 { display: flex; align-items: center; gap: 7px; margin: 0 0 9px; font-size: 12px; font-weight: 680; }.practice-problem h3::before { width: 3px; height: 13px; border-radius: 2px; background: var(--accent); content: ""; }.practice-problem section > p { margin: 0; color: var(--text-secondary); font-size: 12px; line-height: 1.85; }.practice-example { display: grid; gap: 6px; margin: 7px 0; padding: 9px 10px; border: 1px solid var(--border); border-radius: 7px; background: var(--surface-soft); }.practice-example-row { display: grid; grid-template-columns: 38px minmax(0,1fr); gap: 7px; }.practice-example-row span { color: var(--text-tertiary); font-size: 9px; }.practice-example-row code { overflow-wrap: anywhere; color: var(--text-secondary); font: 10px/1.55 var(--font-mono); }.practice-complexity { display: inline-block; padding: 7px 9px !important; border-left: 2px solid var(--accent); background: var(--accent-soft); font: 10px/1.5 var(--font-mono) !important; }.practice-hint { padding: 9px 10px; border-radius: 7px; background: #fff7dc; color: #725c28 !important; font-size: 11px !important; }.practice-link-note { height: 29px; padding: 0 9px; cursor: pointer; border: 1px dashed var(--border); border-radius: 6px; background: transparent; color: var(--text-secondary); font-size: 10px; }.practice-link-note:hover { border-color: var(--accent); background: var(--accent-soft); color: var(--accent); }
.practice-editor { display: flex; min-width: 0; min-height: 0; flex-direction: column; border-left: 1px solid var(--border); background: var(--code-bg); }.practice-editor-head { display: flex; min-height: 49px; align-items: center; justify-content: space-between; gap: 8px; padding: 0 12px; border-bottom: 1px solid var(--border); background: var(--surface); }.practice-editor-head > div:first-child { display: flex; align-items: center; gap: 7px; min-width: 0; }.practice-java-mark { display: grid; width: 20px; height: 20px; place-items: center; border-radius: 5px; background: #f0e8ff; color: #7446a9; font: 700 10px var(--font-mono); }.practice-editor-head strong { color: var(--text-secondary); font-size: 11px; }.practice-editor-head small { color: var(--text-tertiary); font-size: 9px; }.practice-editor-head button { height: 27px; margin-left: 3px; padding: 0 8px; cursor: pointer; border: 1px solid var(--border); border-radius: 6px; background: var(--surface); color: var(--text-secondary); font-size: 10px; }.practice-editor-head button:hover { border-color: var(--accent); color: var(--accent); }.practice-editor-head button.primary { border-color: var(--accent); background: var(--accent); color: white; }
.practice-editor-body { display: grid; min-width: 0; min-height: 0; flex: 1; grid-template-columns: 156px minmax(0, 1fr); }
.practice-solutions { min-width: 0; overflow-y: auto; border-right: 1px solid var(--border); background: var(--surface); }
.practice-solutions-head { display: flex; align-items: center; justify-content: space-between; gap: 8px; min-height: 50px; padding: 0 9px 0 12px; border-bottom: 1px solid var(--border-soft); }
.practice-solutions-head div { display: grid; gap: 2px; min-width: 0; }.practice-solutions-head strong { color: var(--text-secondary); font-size: 11px; }.practice-solutions-head small { color: var(--text-tertiary); font-size: 8px; white-space: nowrap; }
.practice-solutions-head button { display: grid; width: 27px; height: 27px; place-items: center; cursor: pointer; border: 1px solid var(--border); border-radius: 7px; background: var(--surface-soft); color: var(--accent); font-size: 16px; line-height: 1; }.practice-solutions-head button:hover { border-color: var(--accent); background: var(--accent-soft); }
.practice-solution-list { display: grid; gap: 3px; padding: 8px 7px; }.practice-solution-item { display: grid; min-height: 38px; grid-template-columns: minmax(0, 1fr) 20px; align-items: center; gap: 3px; padding: 4px 4px 4px 8px; cursor: pointer; border: 1px solid transparent; border-radius: 7px; background: transparent; color: var(--text-secondary); text-align: left; }.practice-solution-item:hover { background: var(--surface-hover); }.practice-solution-item.active { border-color: color-mix(in srgb, var(--accent) 30%, var(--border)); background: var(--accent-soft); color: var(--accent); }.practice-solution-item strong { overflow: hidden; font-size: 10px; font-weight: 650; text-overflow: ellipsis; white-space: nowrap; }.practice-solution-item small { overflow: hidden; color: var(--text-tertiary); font-size: 8px; text-overflow: ellipsis; white-space: nowrap; }.practice-solution-item.active small { color: color-mix(in srgb, var(--accent) 70%, var(--text-tertiary)); }.practice-solution-delete { display: grid; width: 20px; height: 24px; place-items: center; cursor: pointer; border: 0; border-radius: 5px; background: transparent; color: var(--text-tertiary); font-size: 13px; opacity: 0; }.practice-solution-item:hover .practice-solution-delete, .practice-solution-item.active .practice-solution-delete { opacity: 1; }.practice-solution-delete:hover { background: var(--danger-bg); color: var(--danger); }
.practice-solution-content { display: flex; min-width: 0; min-height: 0; flex-direction: column; background: var(--code-bg); }.practice-solution-title-row { display: flex; align-items: center; gap: 8px; min-height: 43px; padding: 0 14px; border-bottom: 1px solid var(--border); background: color-mix(in srgb, var(--surface) 92%, var(--code-bg)); }.practice-solution-title-row input { min-width: 0; flex: 1; height: 28px; padding: 0 7px; outline: 0; border: 1px solid transparent; border-radius: 5px; background: transparent; color: var(--text); font-size: 12px; font-weight: 680; }.practice-solution-title-row input:hover, .practice-solution-title-row input:focus { border-color: var(--border); background: var(--surface); }.practice-solution-title-row span { color: var(--text-tertiary); font-size: 9px; white-space: nowrap; }
.practice-code { min-height: 0; flex: 1; width: 100%; resize: none; padding: 20px; outline: 0; border: 0; background: transparent; color: var(--text); font: 14px/1.72 var(--font-mono); tab-size: 4; }.practice-code:focus { box-shadow: inset 2px 0 var(--accent); }
.practice-runtime-error { color: var(--danger); }
.practice-tags .practice-difficulty { border-color: transparent; background: var(--accent-soft); color: var(--accent); font-weight: 650; }.practice-tags .practice-difficulty.medium { background: #fff3d7; color: #9a6500; }.practice-tags .practice-difficulty.hard { background: var(--danger-bg); color: var(--danger); }
.practice-resizer { position: relative; z-index: 2; cursor: col-resize; background: var(--border-soft); transition: background .16s ease; }
.practice-resizer::after { position: absolute; top: 50%; left: 50%; width: 2px; height: 34px; border-radius: 2px; background: var(--border); content: ""; transform: translate(-50%, -50%); }
.practice-resizer:hover, .practice-resizer:focus-visible { outline: none; background: var(--accent-soft); }
.practice-resizer:hover::after, .practice-resizer:focus-visible::after { background: var(--accent); }
.practice-resizing, .practice-resizing * { cursor: col-resize !important; user-select: none !important; }
.practice-layout.problem-collapsed .practice-workbench { grid-template-columns: 0 0 minmax(420px, 1fr); }
.practice-layout.problem-collapsed .practice-problem { visibility: hidden; overflow: hidden; padding-inline: 0; }
.practice-layout.problem-collapsed .practice-resizer { visibility: hidden; pointer-events: none; }
.practice-editor-head > div:last-child { display: flex; align-items: center; gap: 3px; flex-wrap: wrap; justify-content: flex-end; }
.practice-editor-head button[data-active="true"] { border-color: var(--accent); background: var(--accent-soft); color: var(--accent); }
.practice-code { min-height: 260px; padding: 20px; font-size: 14px; line-height: 1.72; }
.practice-notes-wrap { flex: 0 0 148px; padding: 12px; border-top: 1px solid var(--border); background: var(--surface); }
.practice-notes-label { display: flex; align-items: baseline; gap: 8px; margin-bottom: 7px; }
.practice-notes-label strong { color: var(--text-secondary); font-size: 11px; }
.practice-notes-label span { color: var(--text-tertiary); font-size: 9px; }
.practice-notes-wrap textarea { display: block; box-sizing: border-box; width: 100%; height: 92px; resize: vertical; padding: 9px; outline: 0; border: 1px solid var(--border); border-radius: 7px; background: var(--surface-soft); color: var(--text-secondary); font: 11px/1.6 var(--font-document); }
.practice-notes-wrap textarea:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.practice-editor { border-left: 0; }
.practice-note-editor { background: var(--surface); }
.practice-note-tabs { display: flex; min-height: 44px; align-items: stretch; gap: 4px; overflow-x: auto; padding: 6px 12px 0; border-bottom: 1px solid var(--border); background: var(--surface-soft); scrollbar-width: thin; }
.practice-note-tabs > #practiceSolutionList { display: flex; min-width: 0; gap: 4px; padding: 0; }
.practice-note-tabs > #practiceAddSolution { width: 36px; height: 36px; flex: 0 0 auto; cursor: pointer; border: 1px solid var(--border); border-radius: 7px; background: transparent; color: var(--accent); font-size: 18px; }
.practice-note-tabs > #practiceAddSolution:hover { background: var(--accent-soft); }
.practice-note-tabs .practice-solution-item { display: inline-flex; min-width: 76px; height: 38px; align-items: center; justify-content: center; padding: 0 12px; cursor: pointer; border: 1px solid transparent; border-bottom: 0; border-radius: 7px 7px 0 0; background: transparent; color: var(--text-tertiary); font-size: 11px; white-space: nowrap; }
.practice-note-tabs .practice-solution-item:hover { background: var(--surface-hover); color: var(--text-secondary); }
.practice-note-tabs .practice-solution-item.active { border-color: var(--border); background: var(--surface); color: var(--text); font-weight: 650; }
.practice-note-tabs .practice-solution-item.active::after { position: absolute; right: 9px; bottom: -1px; left: 9px; height: 2px; border-radius: 2px; background: var(--accent); content: ""; }
.practice-note-formatbar { position: relative; z-index: 4; display: flex; min-height: 42px; flex: 0 0 auto; align-items: center; gap: 2px; overflow-x: auto; padding: 4px 12px; border-bottom: 1px solid var(--border); background: var(--surface); scrollbar-width: none; }
.practice-note-formatbar::-webkit-scrollbar { display: none; }
.practice-note-formatbar select { height: 30px; min-width: 92px; padding: 0 7px; cursor: pointer; border: 1px solid transparent; border-radius: 6px; background: transparent; color: var(--text-secondary); font-size: 11px; }
.practice-note-formatbar select:hover, .practice-note-formatbar select:focus { border-color: var(--border); background: var(--surface-hover); }
.practice-note-formatbar > button { display: grid; width: 30px; height: 30px; flex: 0 0 auto; cursor: pointer; place-items: center; border: 0; border-radius: 6px; background: transparent; color: var(--text-secondary); font-size: 12px; }
.practice-note-formatbar > button:hover { background: var(--surface-hover); color: var(--text); }.practice-note-formatbar > button:active { background: var(--accent-soft); color: var(--accent); }
.practice-toolbar-divider { width: 1px; height: 17px; flex: 0 0 auto; margin: 0 4px; background: var(--border); }
.practice-note-formatbar svg { width: 15px; height: 15px; }
.practice-note-tabs .practice-tab-rename { width: 78px; height: 25px; padding: 0 5px; border: 1px solid var(--accent); border-radius: 5px; outline: 0; background: var(--surface); color: var(--text); font-size: 11px; text-align: center; }
.practice-note-blocks { min-height: 0; flex: 1; overflow-y: auto; overflow-x: hidden; padding: 34px clamp(18px, 3vw, 44px) 60px 28px; background: var(--surface); scrollbar-width: thin; scrollbar-color: var(--border) transparent; }
.practice-note-block { position: relative; display: flex; min-height: 32px; align-items: flex-start; margin: 1px 0; padding-left: 28px; border-radius: 5px; transition: background-color .12s ease; }
.practice-note-block:hover, .practice-note-block.active { background: color-mix(in srgb, var(--surface-hover) 60%, transparent); }
.practice-note-content { width: 100%; min-width: 0; padding: 3px 5px 4px; outline: 0; color: var(--text); font-size: 16px; line-height: 1.65; overflow-wrap: anywhere; caret-color: var(--accent); }
.practice-note-content:empty::before { color: var(--text-tertiary); content: attr(data-placeholder); pointer-events: none; }
.practice-note-block.type-heading1 { margin-top: 22px; }.practice-note-block.type-heading2 { margin-top: 18px; }.practice-note-block.type-heading3 { margin-top: 13px; }
.practice-note-block.type-heading1 .practice-note-content { font-size: 28px; font-weight: 740; line-height: 1.35; letter-spacing: -.035em; }.practice-note-block.type-heading2 .practice-note-content { font-size: 22px; font-weight: 680; line-height: 1.4; }.practice-note-block.type-heading3 .practice-note-content { font-size: 18px; font-weight: 650; line-height: 1.45; }.practice-note-block.type-quote { margin: 7px 0; padding-left: 34px; border-radius: 0 6px 6px 0; background: var(--quote-bg, var(--surface-soft)); }.practice-note-block.type-quote::before { position: absolute; top: 0; bottom: 0; left: 28px; width: 3px; border-radius: 2px; background: var(--accent); content: ""; }.practice-note-block.type-quote .practice-note-content { color: var(--text-secondary); font-style: italic; }
.practice-note-block.type-bullet, .practice-note-block.type-numbered { padding-left: 48px; }.practice-list-marker { position: absolute; top: 3px; left: 34px; min-width: 15px; color: var(--text); font-size: 19px; line-height: 1.6; text-align: center; }.practice-list-marker.numbered { top: 4px; left: 31px; color: var(--text-secondary); font-size: 14px; }
.practice-note-handle { position: absolute; top: 3px; left: 1px; display: grid; width: 24px; height: 26px; cursor: pointer; place-items: center; border: 0; border-radius: 5px; background: transparent; color: transparent; font-size: 17px; }.practice-note-block:hover .practice-note-handle, .practice-note-block.active .practice-note-handle { color: var(--text-tertiary); }.practice-note-handle:hover { background: var(--surface-hover); color: var(--accent); }
.practice-note-source { display: block; width: 100%; min-height: 128px; resize: vertical; padding: 14px 16px; outline: 0; border: 1px solid var(--border); border-radius: 8px; background: var(--code-bg); color: var(--text); font: 13px/1.7 var(--font-mono); tab-size: 2; }
.practice-note-source:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.practice-note-block.type-code { padding-left: 28px; }
.practice-note-block.type-formula, .practice-note-block.type-table, .practice-note-block.type-mermaid, .practice-note-block.type-mindmap { padding-top: 4px; padding-bottom: 6px; }
.practice-note-block.type-callout { min-height: 48px; padding: 7px 9px 7px 54px; border: 1px solid color-mix(in srgb, #d9a900 28%, var(--border)); border-radius: 9px; background: color-mix(in srgb, #fff4b8 45%, var(--surface)); }
.practice-callout-mark { position: absolute; top: 13px; left: 32px; display: grid; width: 20px; height: 20px; place-items: center; border-radius: 6px; background: #f5bd23; color: #805400; font: 700 12px var(--font-mono); }
.practice-note-block.type-divider { min-height: 28px; padding-left: 28px; align-items: center; }
.practice-divider-line { width: 100%; height: 1px; background: var(--border); }
.practice-block-menu { position: fixed; z-index: 1000; width: 270px; max-height: min(78vh, 430px); overflow-y: auto; padding: 9px; border: 1px solid var(--border); border-radius: 10px; background: var(--surface); box-shadow: 0 14px 36px rgba(31,35,41,.18); }
.practice-block-menu-label { display: block; padding: 2px 6px 7px; color: var(--text-tertiary); font-size: 10px; font-weight: 700; }
.practice-block-menu-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 2px; }
.practice-block-menu-grid button { display: flex; height: 32px; align-items: center; gap: 7px; padding: 0 6px; cursor: pointer; border: 0; border-radius: 6px; background: transparent; color: var(--text-secondary); font-size: 11px; text-align: left; }
.practice-block-menu-grid button:hover, .practice-block-menu-grid button.active { background: var(--accent-soft); color: var(--accent); }
.practice-block-menu-grid button span { display: grid; width: 22px; height: 22px; place-items: center; border: 1px solid var(--border); border-radius: 5px; background: var(--surface-soft); color: inherit; font: 650 9px var(--font-mono); }
.practice-block-menu-close { width: 100%; height: 28px; margin-top: 7px; cursor: pointer; border: 0; border-top: 1px solid var(--border-soft); background: transparent; color: var(--text-tertiary); font-size: 10px; }
.practice-block-menu-close:hover { color: var(--text); }
.practice-block-menu-delete { width: 100%; height: 30px; margin-top: 7px; cursor: pointer; border: 0; border-top: 1px solid var(--border-soft); background: transparent; color: var(--danger); font-size: 10px; text-align: left; padding-left: 6px; }
.practice-block-menu-delete:hover { color: var(--danger); background: var(--danger-bg); border-radius: 5px; }
.practice-append-note { display: flex; height: 34px; align-items: center; margin: 0 0 16px 28px; padding: 0 10px; cursor: pointer; border: 1px dashed transparent; border-radius: 6px; background: transparent; color: var(--text-tertiary); font-size: 12px; opacity: .45; }.practice-append-note:hover { border-color: var(--border); background: var(--surface-hover); color: var(--accent); opacity: 1; }
@media (max-width: 1100px) { .practice-layout { grid-template-columns: 190px minmax(0, 1fr); }.practice-workbench { grid-template-columns: minmax(280px, 1fr) 8px minmax(360px, 1.15fr); }.practice-page-head { padding-inline: 18px; }.practice-problem { padding-inline: 24px; } }
@media (max-width: 760px) { .practice-page { overflow-y: auto; }.practice-page-head { align-items: flex-start; flex-direction: column; }.practice-page-stats { width: 100%; }.practice-layout { display: flex; height: auto; min-height: 0; flex-direction: column; }.practice-library { max-height: 235px; border-right: 0; border-bottom: 1px solid var(--border); }.practice-question-list { height: 118px; }.practice-filters { overflow-x: auto; flex-wrap: nowrap; }.practice-workbench { display: flex; min-height: 0; flex-direction: column; }.practice-problem { overflow: visible; padding: 25px 18px 35px; }.practice-resizer { display: none; }.practice-editor { min-height: 650px; border-top: 1px solid var(--border); border-left: 0; }.practice-editor-body { grid-template-columns: 132px minmax(0, 1fr); }.practice-editor-head { align-items: flex-start; flex-direction: column; padding-block: 8px; }.practice-editor-head > div:last-child { width: 100%; justify-content: flex-start; }.practice-layout.problem-collapsed { display: flex; }.practice-layout.problem-collapsed .practice-problem { display: none; } }
@media (prefers-reduced-motion: reduce) { .practice-page * { scroll-behavior: auto !important; transition-duration: .01ms !important; animation-duration: .01ms !important; } }

/* The solution editor is the primary surface, like the regular notes page.
   Problem details are progressive disclosure: a compact floating sheet opened
   from the header instead of a permanent middle column. */
.practice-workbench { position: relative; display: block; background: var(--surface); }
.practice-note-editor { width: 100%; height: 100%; border-left: 0; }
.practice-resizer { display: none; }
.practice-problem { position: absolute; z-index: 80; top: 14px; left: 14px; display: none; width: min(570px, calc(100% - 28px)); max-height: calc(100% - 28px); overflow-y: auto; padding: 24px 28px 42px; border: 1px solid var(--border); border-radius: 14px; background: color-mix(in srgb, var(--surface) 98%, var(--chrome-bg)); box-shadow: 0 18px 48px rgba(31,35,41,.18), 0 2px 8px rgba(31,35,41,.08); }
.practice-layout.problem-open .practice-problem { display: block; animation: practice-problem-in .2s ease-out both; }
@keyframes practice-problem-in { from { opacity: 0; transform: translateY(-5px) scale(.985); } to { opacity: 1; transform: none; } }
.practice-problem-top { position: sticky; top: -24px; z-index: 1; margin: -24px -28px 18px; padding: 14px 18px; border-bottom: 1px solid var(--border-soft); background: color-mix(in srgb, var(--surface) 95%, transparent); backdrop-filter: blur(12px); }
.practice-problem-close { width: 30px; height: 30px; margin-left: 6px; cursor: pointer; border: 0; border-radius: 7px; background: transparent; color: var(--text-tertiary); font-size: 18px; line-height: 1; }
.practice-problem-close:hover { background: var(--surface-hover); color: var(--text); }
.practice-page-head .practice-page-stats { align-items: center; }
.practice-page-stats button { min-height: 32px; padding: 0 11px; cursor: pointer; border: 1px solid var(--border); border-radius: 8px; background: var(--surface); color: var(--text-secondary); font-size: 11px; }
.practice-page-stats button:hover, .practice-page-stats button[data-active="true"] { border-color: var(--accent); background: var(--accent-soft); color: var(--accent); }
.practice-note-blocks { padding-top: 50px; }
@media (max-width: 760px) { .practice-problem { top: 8px; left: 8px; width: calc(100% - 16px); max-height: calc(100% - 16px); padding-inline: 18px; }.practice-problem-top { top: -18px; margin-inline: -18px; }.practice-note-blocks { padding-top: 34px; } }