:root {
    --bg: #0b0d10;
    --surface: #111419;
    --surface-raised: #171b21;
    --surface-soft: #1c2128;
    --border: #272d35;
    --border-strong: #39414b;
    --text: #f2f2ed;
    --muted: #929ba6;
    --muted-strong: #bac1c8;
    --accent: #d7ff64;
    --accent-ink: #111609;
    --accent-soft: rgba(215, 255, 100, 0.1);
    --blue: #74a7ff;
    --orange: #f2ae62;
    --red: #ff7f76;
    --green: #73d89d;
    --mono: 'SFMono-Regular', 'Cascadia Code', Consolas, monospace;
    --sans: Inter, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    color-scheme: dark;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
    margin: 0;
    min-width: 320px;
    background:
        radial-gradient(circle at 65% -20%, rgba(116, 167, 255, 0.07), transparent 32rem),
        var(--bg);
    color: var(--text);
    font: 14px/1.55 var(--sans);
}

button, input, select, textarea { font: inherit; }
button, select { cursor: pointer; }

button:focus-visible, input:focus-visible, select:focus-visible, textarea:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

h1, h2, h3, p { margin-top: 0; }
h1, h2 { letter-spacing: -0.035em; }
h2 { font-size: 18px; line-height: 1.25; margin-bottom: 0; }
h3 { font-size: 13px; margin-bottom: 10px; color: var(--muted-strong); }

.app-shell { min-height: 100vh; }

.topbar {
    position: sticky;
    top: 0;
    z-index: 30;
    height: 68px;
    display: grid;
    grid-template-columns: 260px 1fr auto;
    align-items: center;
    gap: 24px;
    padding: 0 28px;
    background: rgba(11, 13, 16, 0.86);
    border-bottom: 1px solid var(--border);
    backdrop-filter: blur(18px);
}

.brand {
    display: inline-flex;
    gap: 11px;
    align-items: center;
    color: var(--text);
    font-size: 16px;
    font-weight: 700;
    text-decoration: none;
}

.brand-mark {
    display: grid;
    place-items: center;
    width: 31px;
    height: 31px;
    border: 1px solid rgba(215, 255, 100, 0.35);
    border-radius: 9px;
    background: var(--accent-soft);
    color: var(--accent);
    font: 500 13px var(--mono);
}

.topbar-copy { margin: 0; color: var(--muted); }

.topbar-stats { display: flex; gap: 22px; color: var(--muted); font-size: 12px; }
.topbar-stats strong { margin-right: 4px; color: var(--text); font: 500 13px var(--mono); }

.workspace { display: grid; grid-template-columns: 260px minmax(0, 1fr); min-height: calc(100vh - 68px); }

.sidebar {
    position: sticky;
    top: 68px;
    align-self: start;
    height: calc(100vh - 68px);
    overflow-y: auto;
    border-right: 1px solid var(--border);
    background: rgba(14, 17, 21, 0.72);
}

.sidebar-section { padding: 24px 22px; border-bottom: 1px solid var(--border); }
.setup-section { display: grid; gap: 9px; }
.setup-section .button { margin-top: 10px; }
.filter-notice { display: grid; gap: 8px; margin-top: 4px; padding: 10px; border: 1px solid rgba(242, 174, 98, 0.3); border-radius: 8px; background: rgba(242, 174, 98, 0.07); color: var(--muted-strong); font-size: 11px; }
.filter-notice[hidden] { display: none; }
.filter-notice button { width: fit-content; padding: 0; border: 0; background: transparent; color: var(--accent); font-weight: 700; }
.mode-note { margin: 0; color: var(--muted); font-size: 10px; }

.eyebrow {
    margin-bottom: 9px;
    color: var(--muted);
    font: 500 10px/1.2 var(--mono);
    letter-spacing: 0.12em;
    text-transform: uppercase;
}

.field-label { margin-top: 6px; color: var(--muted-strong); font-size: 12px; font-weight: 600; }

select, input, textarea {
    width: 100%;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: var(--surface-raised);
    color: var(--text);
}

select { height: 39px; padding: 0 34px 0 11px; }

textarea {
    padding: 14px 15px;
    resize: vertical;
    line-height: 1.6;
}

textarea::placeholder, input::placeholder { color: var(--muted); }

.button {
    min-height: 39px;
    padding: 9px 14px;
    border: 1px solid transparent;
    border-radius: 8px;
    font-size: 12px;
    font-weight: 700;
    transition: transform 120ms ease, background 120ms ease, border-color 120ms ease;
}

.button:hover:not(:disabled) { transform: translateY(-1px); }
.button:disabled { cursor: not-allowed; opacity: 0.42; }
.button-block { width: 100%; }
.button-primary { background: var(--accent); color: var(--accent-ink); }
.button-primary:hover:not(:disabled) { background: #e1ff8c; }
.button-secondary { border-color: var(--border-strong); background: var(--surface-soft); color: var(--text); }
.button-secondary:hover:not(:disabled) { border-color: #59636f; background: #232931; }
.button-quiet { border-color: var(--border); background: transparent; color: var(--muted-strong); }
.button-quiet:hover:not(:disabled) { border-color: var(--border-strong); color: var(--text); }

kbd {
    margin-left: 6px;
    padding: 2px 5px;
    border: 1px solid var(--border-strong);
    border-radius: 4px;
    color: var(--muted);
    font: 10px var(--mono);
}

.section-heading-row { display: flex; align-items: center; justify-content: space-between; }
.muted { color: var(--muted); }
.small { font-size: 12px; }

.pattern-progress { display: grid; gap: 14px; margin-top: 17px; }
.pattern-row { display: grid; grid-template-columns: 1fr auto; gap: 7px; }
.pattern-row span { font-size: 11px; color: var(--muted-strong); }
.pattern-row strong { color: var(--muted); font: 400 10px var(--mono); }
.progress-track { grid-column: 1 / -1; height: 4px; overflow: hidden; border-radius: 10px; background: #242a31; }
.progress-fill { height: 100%; border-radius: inherit; background: var(--accent); }
.review-summary { display: grid; gap: 2px; margin-top: 18px; padding: 10px; border: 1px solid var(--border); border-radius: 8px; background: var(--surface-raised); }
.review-summary strong { font-size: 11px; }
.review-summary span { color: var(--muted); font-size: 10px; }

.coach-status-section { display: grid; gap: 11px; }
.model-status-heading { display: flex; gap: 10px; align-items: flex-start; }
.model-status-copy { min-width: 0; flex: 1; }
.model-status-copy .eyebrow { margin-bottom: 4px; }
.model-status-line { display: flex; gap: 7px; align-items: center; justify-content: space-between; }
.model-status-line strong { min-width: 0; overflow: hidden; font-size: 12px; text-overflow: ellipsis; white-space: nowrap; }
.model-status-copy p { margin: 2px 0 0; color: var(--muted); font-size: 10px; }
.model-status-badge { flex: 0 0 auto; padding: 2px 5px; border: 1px solid rgba(115, 216, 157, 0.22); border-radius: 999px; color: var(--green); font: 500 9px var(--mono); text-transform: uppercase; }
.model-status-badge.checking, .model-status-badge.built-in { border-color: rgba(242, 174, 98, 0.24); color: var(--orange); }
.model-status-badge.busy { border-color: rgba(116, 167, 255, 0.28); color: var(--blue); }
.model-status-badge.unavailable { border-color: rgba(255, 127, 118, 0.28); color: var(--red); }
.coach-status-section .field-label { margin-top: 1px; }
.coach-status-section select { height: 36px; font: 10px var(--mono); }
.coach-status-section select:disabled { cursor: default; opacity: 0.72; }
.model-description { margin: -3px 0 1px; color: var(--muted); font-size: 10px; line-height: 1.45; }
.model-facts { display: grid; gap: 0; margin: 1px 0 0; }
.model-facts div { display: grid; grid-template-columns: 64px minmax(0, 1fr); gap: 8px; padding: 5px 0; border-top: 1px solid rgba(39, 45, 53, 0.72); }
.model-facts dt { color: var(--muted); font-size: 10px; }
.model-facts dd { min-width: 0; margin: 0; overflow: hidden; color: var(--muted-strong); font: 10px/1.45 var(--mono); text-align: right; text-overflow: ellipsis; white-space: nowrap; }
.model-details { padding-top: 2px; border-top: 1px solid var(--border); }
.model-details summary { padding-top: 8px; color: var(--muted-strong); font-size: 10px; cursor: pointer; }
.model-details code { display: block; margin-top: 8px; padding: 7px; overflow-wrap: anywhere; border: 1px solid var(--border); border-radius: 6px; background: #0c0f13; color: var(--accent); font: 9px/1.5 var(--mono); }
.model-details p { margin: 7px 0 0; color: var(--muted); font-size: 10px; line-height: 1.45; }
.privacy-note { margin: 0; padding: 15px 22px; color: var(--muted); font-size: 10px; line-height: 1.5; }
.data-tools-section { padding-block: 17px; }
.data-tools > summary { color: var(--muted-strong); font-size: 11px; font-weight: 700; cursor: pointer; }
.data-tools > p { margin: 10px 0; color: var(--muted); font-size: 10px; }
.data-actions { display: flex; gap: 7px; }
.data-actions .button { flex: 1; min-height: 34px; padding-inline: 8px; font-size: 10px; }
.import-preview { margin-top: 10px; padding: 10px; border: 1px solid rgba(115, 216, 157, 0.22); border-radius: 8px; background: rgba(115, 216, 157, 0.05); color: var(--muted-strong); font-size: 10px; }
.import-preview.invalid { border-color: rgba(255, 127, 118, 0.28); background: rgba(255, 127, 118, 0.05); color: var(--red); }
.import-preview strong { color: var(--text); }
.import-preview ul { margin: 7px 0; padding-left: 17px; }
.import-preview p { margin: 7px 0 0; }
.import-preview + .data-actions { margin-top: 7px; }
.clear-data-button { margin-top: 12px; padding: 0; border: 0; background: transparent; color: var(--red); font-size: 10px; text-decoration: underline; text-underline-offset: 2px; }
.offline-availability { margin: -6px 22px 16px; padding: 8px 10px; border: 1px solid var(--border); border-radius: 7px; background: var(--surface-raised); color: var(--muted); font: 9px/1.45 var(--mono); }
.offline-availability.ready { border-color: rgba(115, 216, 157, 0.22); color: var(--green); }
.offline-availability.active { border-color: rgba(242, 174, 98, 0.28); color: var(--orange); }
.status-dot { flex: 0 0 auto; width: 7px; height: 7px; margin-top: 7px; border-radius: 50%; background: var(--orange); box-shadow: 0 0 0 4px rgba(242, 174, 98, 0.08); }
.status-dot.online { background: var(--green); box-shadow: 0 0 0 4px rgba(115, 216, 157, 0.08); }
.status-dot.busy { background: var(--blue); box-shadow: 0 0 0 4px rgba(116, 167, 255, 0.1); animation: model-pulse 1.2s ease-in-out infinite; }
.status-dot.unavailable { background: var(--red); box-shadow: 0 0 0 4px rgba(255, 127, 118, 0.08); }

@keyframes model-pulse {
    50% { opacity: 0.45; }
}

.practice { min-width: 0; padding: 38px clamp(22px, 4vw, 62px) 80px; }
.offline-banner { display: flex; gap: 9px; align-items: baseline; max-width: 1260px; margin: 0 auto 18px; padding: 10px 13px; border: 1px solid rgba(242, 174, 98, 0.3); border-radius: 9px; background: rgba(242, 174, 98, 0.08); color: var(--muted-strong); font-size: 11px; }
.offline-banner[hidden] { display: none; }
.offline-banner strong { flex: 0 0 auto; color: var(--orange); }
.problem-header { display: flex; align-items: flex-start; justify-content: space-between; gap: 20px; max-width: 1260px; margin: 0 auto 24px; }
.problem-header h1 { margin: 6px 0 0; font-size: clamp(26px, 3vw, 38px); line-height: 1.12; }
.recommendation-reason { margin: 8px 0 0; color: var(--muted); font: 10px var(--mono); }
.problem-meta { display: flex; gap: 8px; align-items: center; min-height: 22px; }

.pill {
    display: inline-flex;
    align-items: center;
    height: 22px;
    padding: 0 8px;
    border: 1px solid var(--border);
    border-radius: 999px;
    color: var(--muted-strong);
    font: 500 10px var(--mono);
    text-transform: uppercase;
}
.pill.easy { color: var(--green); border-color: rgba(115, 216, 157, 0.25); }
.pill.medium { color: var(--orange); border-color: rgba(242, 174, 98, 0.25); }
.pill.hard { color: var(--red); border-color: rgba(255, 127, 118, 0.25); }

.timer-card { display: flex; align-items: center; gap: 11px; min-width: 158px; padding: 9px 10px 9px 14px; border: 1px solid var(--border); border-radius: 10px; background: var(--surface); }
.timer-label { color: var(--muted); font-size: 10px; text-transform: uppercase; }
.timer-card strong { margin-left: auto; font: 500 14px var(--mono); }
.timer-card.warning strong { color: var(--red); }

.icon-button { display: grid; place-items: center; width: 30px; height: 30px; padding: 0; border: 1px solid var(--border); border-radius: 7px; background: var(--surface-soft); color: var(--muted-strong); }
.icon-button:hover { border-color: var(--border-strong); color: var(--text); }

.stage-nav { display: flex; max-width: 1260px; margin: 0 auto 20px; border-bottom: 1px solid var(--border); }
.stage-tab { position: relative; display: flex; gap: 8px; align-items: center; padding: 0 18px 13px; border: 0; background: transparent; color: var(--muted); font-size: 12px; font-weight: 600; }
.stage-tab span { display: grid; place-items: center; width: 19px; height: 19px; border: 1px solid var(--border-strong); border-radius: 50%; font: 10px var(--mono); }
.stage-tab.active { color: var(--text); }
.stage-tab.active::after { position: absolute; right: 12px; bottom: -1px; left: 12px; height: 2px; content: ''; background: var(--accent); }
.stage-tab.active span { border-color: var(--accent); color: var(--accent); }

.practice-columns { display: grid; grid-template-columns: minmax(0, 1.65fr) minmax(300px, 0.85fr); gap: 20px; max-width: 1260px; margin: 0 auto; align-items: start; }
.problem-column { display: grid; gap: 16px; min-width: 0; }
.coach-column { position: sticky; top: 92px; display: grid; gap: 16px; min-width: 0; }

.card, .coach-card, .attempts-card { border: 1px solid var(--border); border-radius: 12px; background: var(--surface); }
.card { padding: clamp(20px, 3vw, 30px); }
.problem-card { background: linear-gradient(145deg, rgba(255,255,255,0.015), transparent 45%), var(--surface); }
.problem-card p { max-width: 78ch; color: #d6d9d9; font-size: 14px; }
.signature { margin: 22px 0; padding: 12px 14px; overflow-x: auto; border: 1px solid var(--border); border-radius: 8px; background: #0c0f13; color: var(--accent); font: 12px var(--mono); }
.example { display: grid; grid-template-columns: 1fr 1fr; gap: 1px; margin-top: 10px; overflow: hidden; border: 1px solid var(--border); border-radius: 8px; background: var(--border); }
.example-code { min-width: 0; padding: 13px; background: #0e1115; }
.example-code span { display: block; margin-bottom: 5px; color: var(--muted); font: 9px var(--mono); text-transform: uppercase; }
.example-code code { color: #dce0e2; font: 11px/1.55 var(--mono); white-space: pre-wrap; word-break: break-word; }
.example-explanation { grid-column: 1 / -1; margin: 0; padding: 9px 13px; background: var(--surface-raised); color: var(--muted) !important; font-size: 11px !important; }
.constraints-block { margin-top: 25px; }
.constraints-block ul { display: grid; gap: 5px; margin: 0; padding-left: 19px; color: var(--muted-strong); font: 11px/1.5 var(--mono); }

.card-heading, .editor-toolbar { display: flex; align-items: flex-start; justify-content: space-between; gap: 16px; margin-bottom: 15px; }
.shortcut-hint, .run-support { color: var(--muted); font-size: 10px; }
.card-actions, .editor-actions { display: flex; align-items: center; gap: 10px; margin-top: 12px; }
.save-state { color: var(--muted); font-size: 11px; }

.editor-toolbar { align-items: center; }
.editor-toolbar .eyebrow { margin-bottom: 5px; }
.editor-toolbar select { width: auto; height: 30px; padding: 0 30px 0 0; border: 0; background: transparent; font: 12px var(--mono); }
.run-support { padding: 4px 7px; border: 1px solid rgba(115, 216, 157, 0.2); border-radius: 5px; color: var(--green); }
.run-support.unavailable { border-color: var(--border); color: var(--muted); }

.editor-wrap { display: grid; grid-template-columns: 42px 1fr; min-height: 330px; overflow: hidden; border: 1px solid var(--border); border-radius: 9px; background: #090c0f; }
.line-numbers { padding: 16px 10px; border-right: 1px solid #1b2026; color: #515a64; font: 12px/1.65 var(--mono); text-align: right; white-space: pre; user-select: none; }
#solutionInput { min-height: 330px; padding: 16px; resize: vertical; border: 0; border-radius: 0; background: transparent; color: #dfe3df; font: 12px/1.65 var(--mono); tab-size: 4; white-space: pre; overflow-wrap: normal; }
#solutionInput:focus { outline: 0; }
#solutionInput:focus-visible { box-shadow: inset 0 0 0 2px var(--accent); }
.editor-actions { justify-content: flex-end; }

.test-results { display: none; margin-top: 13px; padding: 12px 14px; border: 1px solid var(--border); border-radius: 8px; background: #0d1014; font: 11px/1.55 var(--mono); }
.test-results.visible { display: block; }
.test-results.pass { border-color: rgba(115, 216, 157, 0.25); color: var(--green); }
.test-results.fail { border-color: rgba(255, 127, 118, 0.25); color: var(--red); }
.test-case-row { display: flex; justify-content: space-between; gap: 12px; padding: 5px 0; border-bottom: 1px solid var(--border); }
.test-case-row:last-child { border: 0; }
.test-case-row code { max-width: 70%; overflow: hidden; color: var(--muted-strong); text-overflow: ellipsis; white-space: nowrap; }

.reflection-card { border-color: rgba(215, 255, 100, 0.16); }
.completion-summary { margin-top: 14px; padding: 12px; border: 1px solid var(--border); border-radius: 8px; background: #0d1014; color: var(--muted-strong); font-size: 11px; }
.completion-summary[hidden] { display: none; }
.completion-summary ul { display: grid; gap: 3px; margin: 8px 0; padding-left: 18px; }
.completion-summary p { margin: 0; color: var(--text); }
.outcome-evidence { margin-top: 14px; padding: 10px 12px; border: 1px solid var(--border); border-radius: 8px; background: var(--surface-raised); color: var(--muted-strong); font-size: 11px; }
.outcome-evidence[hidden] { display: none; }
.outcome-evidence.verified { border-color: rgba(115, 216, 157, 0.25); color: var(--green); }
.outcome-evidence.failed { border-color: rgba(255, 127, 118, 0.25); color: var(--red); }
.outcome-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; margin: 18px 0; }
.outcome-button { padding: 13px 10px; border: 1px solid var(--border); border-radius: 8px; background: var(--surface-raised); color: var(--text); text-align: left; }
.outcome-button:hover, .outcome-button.selected { border-color: var(--accent); background: var(--accent-soft); }
.outcome-button span, .outcome-button small { display: block; }
.outcome-button span { font-size: 11px; font-weight: 700; }
.outcome-button small { margin-top: 4px; color: var(--muted); font-size: 9px; }
.reflection-card .button { margin-top: 12px; }
.session-saved { margin-top: 15px; padding: 12px; border: 1px solid rgba(115, 216, 157, 0.2); border-radius: 8px; color: var(--green); font-size: 12px; }

.coach-card, .attempts-card { padding: 20px; }
.coach-heading { display: flex; gap: 11px; align-items: center; }
.coach-avatar { display: grid; place-items: center; width: 34px; height: 34px; border: 1px solid rgba(215, 255, 100, 0.25); border-radius: 10px; background: var(--accent-soft); color: var(--accent); font: 500 10px var(--mono); }
.coach-heading .eyebrow { margin: 0 0 3px; }
.coach-promise { margin: 16px 0; color: var(--muted); font-size: 11px; }
.quick-actions { display: grid; gap: 7px; }
.quick-action { display: flex; gap: 10px; align-items: center; width: 100%; padding: 9px; border: 1px solid var(--border); border-radius: 8px; background: var(--surface-raised); color: var(--text); text-align: left; }
.quick-action:hover { border-color: var(--border-strong); background: var(--surface-soft); }
.quick-action:disabled { opacity: 0.5; cursor: wait; }
.quick-action span:last-child { min-width: 0; }
.quick-action strong, .quick-action small { display: block; }
.quick-action strong { font-size: 11px; }
.quick-action small { margin-top: 2px; color: var(--muted); font-size: 9px; }
.quick-icon { display: grid; place-items: center; flex: 0 0 auto; width: 27px; height: 27px; border: 1px solid var(--border); border-radius: 6px; color: var(--accent); }

.coach-conversation { display: grid; gap: 10px; max-height: 350px; margin-top: 14px; overflow-y: auto; }
.coach-message, .user-message { padding: 12px; border-radius: 8px; font-size: 11px; }
.coach-message { border: 1px solid rgba(116, 167, 255, 0.14); background: rgba(116, 167, 255, 0.055); color: #ccd6e3; }
.coach-message.loading { color: var(--muted); }
.user-message { margin-left: 25px; border: 1px solid var(--border); background: var(--surface-soft); }
.message-label { margin-bottom: 6px; color: var(--blue); font: 500 9px var(--mono); text-transform: uppercase; }
.user-message .message-label { color: var(--muted); }
.coach-message p, .user-message p { margin: 0; }
.coach-message p + p { margin-top: 8px; }
.coach-message ul { margin: 7px 0 0; padding-left: 16px; }
.coach-message code { padding: 1px 4px; border-radius: 3px; background: #0c1015; color: var(--accent); font: 10px var(--mono); }

.coach-form { display: grid; grid-template-columns: 1fr 30px; gap: 7px; margin-top: 12px; }
.coach-form input { height: 36px; padding: 0 10px; font-size: 11px; }
.send-button { align-self: center; border-color: var(--accent); background: var(--accent); color: var(--accent-ink); }

.attempts-card .section-heading-row { margin-bottom: 12px; }
.recent-attempts { display: grid; gap: 7px; }
.attempt-row { display: grid; grid-template-columns: 7px 1fr auto; gap: 9px; align-items: center; padding: 8px 0; border-bottom: 1px solid var(--border); }
.attempt-row:last-child { border: 0; }
.attempt-indicator { width: 6px; height: 6px; border-radius: 50%; background: var(--orange); }
.attempt-indicator.independent { background: var(--green); }
.attempt-indicator.stuck { background: var(--red); }
.attempt-row strong, .attempt-row span { display: block; }
.attempt-row strong { overflow: hidden; font-size: 10px; text-overflow: ellipsis; white-space: nowrap; }
.attempt-row span, .attempt-row time { color: var(--muted); font-size: 9px; }
.attempt-row .verified { color: var(--green); }
.attempt-row .failed { color: var(--red); }

.toast { position: fixed; right: 22px; bottom: 22px; z-index: 50; max-width: 340px; padding: 11px 14px; border: 1px solid var(--border-strong); border-radius: 8px; background: #20262d; color: var(--text); font-size: 11px; opacity: 0; transform: translateY(12px); pointer-events: none; transition: 180ms ease; }
.toast.visible { opacity: 1; transform: translateY(0); }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0; }

@media (max-width: 1080px) {
    .practice { padding-inline: 24px; }
    .practice-columns { grid-template-columns: minmax(0, 1.45fr) minmax(280px, 0.75fr); }
}

@media (max-width: 860px) {
    .topbar { grid-template-columns: 1fr auto; }
    .topbar-copy { display: none; }
    .workspace { grid-template-columns: 1fr; }
    .sidebar { position: static; display: grid; grid-template-columns: 1.1fr 1fr; height: auto; overflow: visible; border-right: 0; border-bottom: 1px solid var(--border); }
    .coach-status-section { grid-column: 1 / -1; padding-block: 13px; }
    .practice-columns { grid-template-columns: 1fr; }
    .coach-column { position: static; }
}

@media (max-width: 580px) {
    .topbar { height: 60px; padding: 0 16px; }
    .topbar-stats { gap: 10px; font-size: 10px; }
    .workspace { min-height: calc(100vh - 60px); }
    .sidebar { grid-template-columns: 1fr; }
    .coach-status-section { grid-column: auto; }
    .progress-section { display: block; padding-block: 18px; }
    .practice { padding: 25px 13px 60px; }
    .offline-banner { display: grid; gap: 3px; }
    .problem-header { align-items: center; }
    .problem-header h1 { font-size: 24px; }
    .timer-card { min-width: auto; }
    .timer-label { display: none; }
    .stage-nav { overflow-x: auto; }
    .stage-tab { flex: 0 0 auto; padding-inline: 12px; }
    .card { padding: 18px; }
    .example { grid-template-columns: 1fr; }
    .example-explanation { grid-column: 1; }
    .outcome-grid { grid-template-columns: 1fr; }
    .shortcut-hint { display: none; }
    .editor-actions { justify-content: stretch; }
    .editor-actions .button { flex: 1; }
}

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after { scroll-behavior: auto !important; transition: none !important; }
}