/* Hallmark · genre: modern-minimal · macrostructure: Workbench (app) / Split Diptych (landing) / Letter (forms)
 * theme: Coral · design-system: design.md · designed-as-app · nav: edge-aligned app header · footer: none
 * audience: high-school students + teachers · use: live classroom coding on tablet/desktop · tone: utilitarian, warmed
 * pre-emit critique: P4 H4 E4 S4 R5 V4 */

/* ============================== base ============================== */

*,
*::before,
*::after {
    box-sizing: border-box;
}

html,
body {
    overflow-x: clip;
}

body {
    background: var(--color-paper);
    color: var(--color-ink);
    font-family: var(--font-body);
    font-size: var(--text-base);
    line-height: 1.55;
}

h1,
h2,
h3,
h4,
h5,
h6 {
    font-style: normal;
    overflow-wrap: anywhere;
    min-width: 0;
}

pre {
    white-space: pre-wrap;
}

::selection {
    background: var(--color-accent-tint);
}

/* Focus is instant, visible, and identical everywhere. */
a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible,
summary:focus-visible,
[tabindex]:focus-visible {
    outline: 2px solid var(--color-focus);
    outline-offset: 2px;
    border-radius: var(--radius-sm);
    transition: none;
}

@media (prefers-reduced-motion: reduce) {

    *,
    *::before,
    *::after {
        animation-duration: 1ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 120ms !important;
        transition-property: opacity, color, background-color, border-color !important;
    }
}

/* Touch floor: controls are comfortably tappable on tablets. */
button,
select,
input:not([type="checkbox"]):not([type="radio"]),
.toolbar-btn,
.btn-primary,
.tab-pill {
    min-height: var(--tap-min-fine);
}

@media (pointer: coarse) {

    button,
    select,
    input:not([type="checkbox"]):not([type="radio"]),
    .toolbar-btn,
    .btn-primary,
    .tab-pill {
        min-height: var(--tap-min);
    }
}

/* ============================== app chrome ============================== */

.app-header {
    position: sticky;
    top: 0;
    z-index: var(--z-nav);
    background: var(--color-paper);
    border-bottom: var(--rule-hairline) solid var(--color-rule);
}

.wordmark {
    font-family: var(--font-display);
    font-weight: 700;
    font-size: var(--text-md);
    letter-spacing: -0.02em;
    color: var(--color-ink);
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    min-height: var(--tap-min-fine);
}

.wordmark-mark {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 1.6rem;
    height: 1.6rem;
    border-radius: var(--radius-sm);
    background: var(--color-accent);
    color: var(--color-surface);
    font-family: var(--font-mono);
    font-size: 0.7rem;
    font-weight: 600;
}

.nav-link {
    position: relative;
    display: inline-flex;
    align-items: center;
    min-height: var(--tap-min-fine);
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-sm);
    font-weight: 500;
    color: var(--color-ink-2);
    text-decoration: none;
    white-space: nowrap;
    transition: color var(--dur-short) var(--ease-out), background-color var(--dur-short) var(--ease-out);
}

.nav-link:hover {
    color: var(--color-ink);
    background: var(--color-paper-2);
}

.nav-link[aria-current="page"] {
    color: var(--color-ink);
}

.nav-link[aria-current="page"]::after {
    content: "";
    position: absolute;
    left: 0.75rem;
    right: 0.75rem;
    bottom: 0.15rem;
    height: 2px;
    border-radius: var(--radius-pill);
    background: var(--color-accent);
}

.lang-switch {
    display: inline-flex;
    border: var(--rule-hairline) solid var(--color-rule-2);
    border-radius: var(--radius-pill);
    overflow: hidden;
}

.lang-btn {
    border: 0;
    background: var(--color-surface);
    color: var(--color-ink-2);
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    font-weight: 600;
    letter-spacing: 0.06em;
    padding: 0.35rem 0.65rem;
    cursor: pointer;
    min-height: var(--tap-min-fine);
    transition: color var(--dur-short) var(--ease-out), background-color var(--dur-short) var(--ease-out);
}

.lang-btn:hover {
    color: var(--color-ink);
    background: var(--color-paper-2);
}

.lang-btn[aria-current="true"] {
    background: var(--color-ink);
    color: var(--color-surface);
    cursor: default;
    opacity: 1;
}

.skip-link {
    position: absolute;
    left: -999px;
    top: 0.5rem;
    z-index: var(--z-modal);
    background: var(--color-surface);
    color: var(--color-ink);
    border: 1px solid var(--color-rule-2);
    border-radius: var(--radius-sm);
    padding: 0.5rem 0.75rem;
}

.skip-link:focus-visible {
    left: 0.5rem;
}

/* ============================== containers ============================== */

/* One containment layer: page → card → flat content. */
.card {
    background: var(--color-surface);
    border: var(--rule-hairline) solid var(--color-rule);
    border-radius: var(--radius-card);
    padding: var(--space-sm);
}

.card-roomy {
    padding: var(--space-md);
}

.page-title {
    font-family: var(--font-display);
    font-weight: 600;
    font-size: var(--text-lg);
    letter-spacing: -0.02em;
    line-height: 1.15;
}

.page-title-lg {
    font-size: var(--text-display);
    font-weight: 700;
}

.panel-title {
    font-family: var(--font-mono);
    letter-spacing: 0.08em;
    text-transform: uppercase;
    font-size: var(--text-xs);
    font-weight: 600;
    color: var(--color-ink-3);
}

.help-note {
    border-left: 2px solid var(--color-rule-2);
    padding-left: var(--space-xs);
    font-size: var(--text-sm);
    color: var(--color-ink-2);
}

.warn-card {
    border: var(--rule-hairline) solid var(--status-bad);
    background: var(--status-bad-tint);
    border-radius: var(--radius-card);
    padding: var(--space-xs) var(--space-sm);
    color: var(--color-ink);
}

.warn-card .warn-title {
    font-weight: 600;
    color: var(--status-bad);
}

/* ============================== buttons ============================== */

.btn-primary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    background: var(--color-ink);
    color: var(--color-surface);
    font-weight: 600;
    font-size: var(--text-sm);
    padding: 0.55rem 1.1rem;
    border: var(--rule-hairline) solid var(--color-ink);
    border-radius: var(--radius-pill);
    cursor: pointer;
    text-decoration: none;
    white-space: nowrap;
    transition: transform var(--dur-short) var(--ease-out), background-color var(--dur-short) var(--ease-out);
}

.btn-primary:hover {
    background: var(--color-accent-deep);
    border-color: var(--color-accent-deep);
}

.btn-primary:active {
    transform: translateY(1px);
}

.btn-primary:disabled {
    opacity: 0.55;
    cursor: not-allowed;
    transform: none;
}

.toolbar-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.4rem;
    border: var(--rule-hairline) solid var(--color-rule-2);
    border-radius: var(--radius-pill);
    padding: 0.45rem 0.9rem;
    font-size: var(--text-sm);
    font-weight: 500;
    color: var(--color-ink-2);
    background: var(--color-surface);
    cursor: pointer;
    text-decoration: none;
    white-space: nowrap;
    transition: color var(--dur-short) var(--ease-out), border-color var(--dur-short) var(--ease-out), background-color var(--dur-short) var(--ease-out), transform var(--dur-short) var(--ease-out);
}

.toolbar-btn:hover {
    color: var(--color-ink);
    border-color: var(--color-ink-3);
    background: var(--color-paper);
}

.toolbar-btn:active {
    transform: translateY(1px);
}

.toolbar-btn:disabled {
    cursor: not-allowed;
    opacity: 0.55;
    transform: none;
}

.toolbar-btn-danger {
    border-color: var(--status-bad);
    color: var(--status-bad);
    background: var(--status-bad-tint);
}

.toolbar-btn-danger:hover {
    color: var(--status-bad);
    border-color: var(--status-bad);
    background: var(--color-surface);
}

.link-quiet {
    color: var(--color-accent-deep);
    text-decoration: none;
    border-radius: var(--radius-sm);
    padding: 0.25rem 0.15rem;
}

.link-quiet:hover {
    text-decoration: underline;
    text-underline-offset: 3px;
}

.link-danger {
    color: var(--status-bad);
    text-decoration: none;
    background: none;
    border: 0;
    padding: 0.25rem 0.15rem;
    font-size: inherit;
    cursor: pointer;
    border-radius: var(--radius-sm);
}

.link-danger:hover {
    text-decoration: underline;
    text-underline-offset: 3px;
}

.timer-start-btn:disabled {
    border-style: dashed;
    background: var(--color-paper-2);
    color: var(--color-ink-3);
}

.timer-start-btn:disabled::after {
    content: "· used";
    font-family: var(--font-mono);
    font-size: 0.65rem;
    letter-spacing: 0.06em;
    text-transform: uppercase;
}

/* ============================== status vocabulary ============================== */

.status-pill {
    border-radius: var(--radius-pill);
    border: var(--rule-hairline) solid var(--color-rule);
    background: var(--color-surface);
    padding: 0.275rem 0.65rem;
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    font-size: var(--text-xs);
    color: var(--color-ink-2);
}

.status-dot {
    width: 0.5rem;
    height: 0.5rem;
    border-radius: var(--radius-pill);
    display: inline-block;
    flex: 0 0 auto;
}

.status-dot-green {
    background: var(--status-ok);
}

.status-dot-amber {
    background: var(--status-warn);
}

.status-dot-red {
    background: var(--status-bad);
}

.status-dot-gray {
    background: var(--status-off);
}

.state-chip {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    border-radius: var(--radius-pill);
    padding: 0.15rem 0.55rem;
    font-size: var(--text-xs);
    font-weight: 500;
    border: var(--rule-hairline) solid transparent;
}

.state-chip-ok {
    background: var(--status-ok-tint);
    color: var(--status-ok);
}

.state-chip-warn {
    background: var(--status-warn-tint);
    color: var(--status-warn);
}

.state-chip-bad {
    background: var(--status-bad-tint);
    color: var(--status-bad);
}

.state-chip-off {
    background: var(--status-off-tint);
    color: var(--status-off);
}

.state-chip-accent {
    background: var(--color-accent-tint);
    color: var(--color-accent-deep);
}

/* ============================== tabs ============================== */

.tab-strip {
    display: flex;
    align-items: center;
    gap: 0.25rem;
    border-bottom: var(--rule-hairline) solid var(--color-rule);
    margin-bottom: var(--space-xs);
    overflow-x: auto;
}

.tab-pill {
    display: inline-flex;
    align-items: center;
    font-size: var(--text-sm);
    font-weight: 500;
    padding: 0.45rem 0.8rem;
    border: 0;
    border-bottom: 2px solid transparent;
    background: none;
    color: var(--color-ink-2);
    cursor: pointer;
    white-space: nowrap;
    transition: color var(--dur-short) var(--ease-out);
}

.tab-pill:hover {
    color: var(--color-ink);
}

.tab-pill-active {
    color: var(--color-ink);
    border-bottom-color: var(--color-accent);
}

/* ============================== forms ============================== */

.session-form p,
.builder-form p {
    margin-bottom: var(--space-xs);
    max-width: 100%;
}

.builder-form {
    width: 100%;
    min-width: 0;
}

.session-form label,
.builder-form label {
    font-size: var(--text-sm);
    font-weight: 500;
    color: var(--color-ink-2);
}

.session-form input:not([type="checkbox"]),
.session-form select,
.session-form textarea,
.builder-form input:not([type="checkbox"]),
.builder-form select,
.builder-form textarea,
.field-input {
    width: 100%;
    margin-top: 0.3rem;
    border: var(--rule-hairline) solid var(--color-rule-2);
    border-radius: var(--radius-input);
    padding: 0.5rem 0.7rem;
    font-size: var(--text-base);
    background: var(--color-surface);
    color: var(--color-ink);
}

.session-form input:focus,
.session-form select:focus,
.session-form textarea:focus,
.builder-form input:focus,
.builder-form select:focus,
.builder-form textarea:focus,
.field-input:focus {
    outline: 2px solid var(--color-focus);
    outline-offset: 1px;
}

.session-form input[type="checkbox"],
.builder-form input[type="checkbox"] {
    width: 1.1rem;
    height: 1.1rem;
    margin: 0;
    accent-color: var(--color-accent-deep);
}

.session-option,
.builder-checkbox-row {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

.builder-checkbox-row {
    margin-bottom: var(--space-xs);
    min-height: var(--tap-min-fine);
}

.builder-checkbox-row label {
    margin: 0;
    line-height: 1.2;
}

.study-search-input {
    height: var(--tap-min);
    width: 100%;
    border: var(--rule-hairline) solid var(--color-rule-2);
    border-radius: var(--radius-input);
    padding: 0 0.85rem;
    font-size: var(--text-base);
    background: var(--color-surface);
    color: var(--color-ink);
}

.study-search-btn {
    height: var(--tap-min);
    min-height: var(--tap-min);
    border: var(--rule-hairline) solid var(--color-rule-2);
    border-radius: var(--radius-pill);
    background: var(--color-surface);
    color: var(--color-ink-2);
    padding: 0 1.1rem;
    font-size: var(--text-sm);
    font-weight: 500;
    appearance: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    white-space: nowrap;
    align-self: flex-end;
    cursor: pointer;
    transition: color var(--dur-short) var(--ease-out), border-color var(--dur-short) var(--ease-out);
}

.study-search-btn:hover {
    border-color: var(--color-ink-3);
    color: var(--color-ink);
}

@media (min-width: 1024px) {

    .builder-form input:not([type="checkbox"]),
    .builder-form select {
        height: 2.4rem;
    }

    .builder-form textarea {
        min-height: 5rem;
    }

    #id_question {
        min-height: 7.5rem;
    }
}

/* ============================== editor & console ============================== */

.CodeMirror {
    border: var(--rule-hairline) solid var(--color-rule-2);
    border-radius: var(--radius-input);
    min-height: 16rem;
    font-family: var(--font-mono);
    font-size: 14px;
}

.CodeMirror-lines {
    line-height: 1.5;
}

.console-pane {
    border-radius: var(--radius-input);
    background: var(--color-console-bg);
    color: var(--color-console-ink);
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    line-height: 1.5;
    padding: var(--space-xs) var(--space-sm);
    overflow: auto;
}

.code-chip {
    font-family: var(--font-mono);
    font-variant-numeric: tabular-nums;
    letter-spacing: 0.12em;
}

.join-code-display {
    font-family: var(--font-mono);
    font-variant-numeric: tabular-nums;
    font-size: var(--text-2xl);
    font-weight: 600;
    letter-spacing: 0.18em;
    color: var(--color-ink);
}

kbd {
    font-family: var(--font-mono);
    font-size: 0.75em;
    border: var(--rule-hairline) solid var(--color-rule-2);
    border-bottom-width: 2px;
    border-radius: var(--radius-sm);
    padding: 0.1rem 0.35rem;
    background: var(--color-surface);
}

/* ============================== data tables ============================== */

.data-table {
    width: 100%;
    font-size: var(--text-sm);
    border-collapse: collapse;
}

.data-table thead th {
    text-align: left;
    font-weight: 500;
    color: var(--color-ink-3);
    padding: 0.5rem 0.5rem;
    border-bottom: var(--rule-hairline) solid var(--color-rule-2);
}

.data-table tbody td {
    padding: 0.65rem 0.5rem;
    border-bottom: var(--rule-hairline) solid var(--color-rule);
    color: var(--color-ink-2);
}

.data-table tbody td:first-child {
    color: var(--color-ink);
    font-weight: 500;
}

.data-table .cell-actions {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    justify-content: flex-end;
    flex-wrap: wrap;
}

/* ============================== modal ============================== */

.modal-overlay.hidden {
    display: none;
}

.modal-overlay {
    position: fixed;
    inset: 0;
    z-index: var(--z-modal);
    background: var(--color-scrim);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-sm);
}

.modal-card {
    background: var(--color-surface);
    border: var(--rule-hairline) solid var(--color-rule);
    border-radius: var(--radius-card);
    box-shadow: var(--shadow-pop);
    padding: var(--space-md);
    width: min(24rem, 100%);
}

.modal-close {
    background: none;
    border: 0;
    color: var(--color-ink-3);
    font-size: var(--text-md);
    line-height: 1;
    cursor: pointer;
    border-radius: var(--radius-sm);
    min-width: var(--tap-min-fine);
    min-height: var(--tap-min-fine);
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.modal-close:hover {
    color: var(--color-ink);
}

/* ============================== lesson broadcast / preview ============================== */

.lesson-preview-surface {
    border: var(--rule-hairline) solid var(--color-rule);
    border-radius: var(--radius-card);
    background: var(--color-surface);
    padding: var(--space-sm);
}

.lesson-preview-header {
    margin-bottom: var(--space-sm);
    padding-bottom: var(--space-xs);
    border-bottom: var(--rule-hairline) solid var(--color-rule);
}

.lesson-preview-kicker {
    font-family: var(--font-mono);
    font-size: var(--text-xs);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--color-ink-3);
}

.lesson-preview-title {
    margin-top: 0.2rem;
    font-family: var(--font-display);
    font-size: var(--text-md);
    font-weight: 600;
    letter-spacing: -0.01em;
    color: var(--color-ink);
}

.timer-display-wrap {
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
    border: var(--rule-hairline) solid var(--color-rule);
    border-radius: var(--radius-input);
    background: var(--color-paper);
    padding: 0.5rem 0.8rem;
    color: var(--color-ink);
}

.timer-display-wrap [data-timer-display] {
    font-family: var(--font-mono);
    font-variant-numeric: tabular-nums;
    font-size: var(--text-md);
    font-weight: 600;
    line-height: 1;
}

.lesson-preview-flow {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}

.lesson-preview-block {
    border: var(--rule-hairline) solid var(--color-rule);
    border-radius: var(--radius-card);
    padding: var(--space-xs) var(--space-sm);
    background: var(--color-surface);
}

.lesson-preview-block-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.5rem;
    margin-bottom: 0.55rem;
}

.lesson-preview-block-header h5 {
    font-size: var(--text-base);
    font-weight: 600;
    color: var(--color-ink);
}

.preview-pill {
    font-family: var(--font-mono);
    font-size: 0.65rem;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    padding: 0.18rem 0.5rem;
    border-radius: var(--radius-pill);
    font-weight: 600;
}

.preview-pill-markdown {
    background: var(--status-off-tint);
    color: var(--color-ink-2);
}

.preview-pill-code {
    background: var(--status-ok-tint);
    color: var(--status-ok);
}

.preview-pill-quiz {
    background: var(--color-accent-tint);
    color: var(--color-accent-deep);
}

.preview-markdown {
    color: var(--color-ink);
    line-height: 1.6;
}

.preview-markdown p {
    margin: 0.45rem 0;
}

.preview-markdown h1,
.preview-markdown h2,
.preview-markdown h3,
.preview-markdown h4 {
    color: var(--color-ink);
    line-height: 1.25;
    margin-top: 0.8rem;
    margin-bottom: 0.45rem;
    font-weight: 600;
    font-family: var(--font-display);
    letter-spacing: -0.01em;
}

.preview-markdown h1 {
    font-size: var(--text-lg);
}

.preview-markdown h2 {
    font-size: var(--text-md);
}

.preview-markdown h3 {
    font-size: var(--text-base);
}

.preview-markdown ul,
.preview-markdown ol {
    margin: 0.4rem 0 0.55rem 1.2rem;
}

.preview-markdown li {
    margin: 0.2rem 0;
}

.preview-markdown :not(pre)>code {
    font-family: var(--font-mono);
    background: var(--color-paper-2);
    border-radius: var(--radius-sm);
    padding: 0.05rem 0.3rem;
    font-size: 0.85em;
}

.preview-markdown pre,
.prose pre {
    margin: 0.65rem 0;
    padding: var(--space-xs) var(--space-sm);
    border: var(--rule-hairline) solid var(--color-rule);
    border-radius: var(--radius-input);
    background: var(--color-paper);
    overflow-x: auto;
    white-space: pre-wrap;
    word-break: break-word;
}

.preview-markdown pre code,
.prose pre code {
    display: block;
    background: transparent;
    border-radius: 0;
    padding: 0;
    color: var(--color-ink);
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    line-height: 1.5;
}

.preview-code-area {
    width: 100%;
    min-height: 3rem;
    border: var(--rule-hairline) solid var(--color-rule);
    border-radius: var(--radius-input);
    background: var(--color-paper);
    color: var(--color-ink);
    font-family: var(--font-mono);
    font-size: var(--text-sm);
    line-height: 1.5;
    padding: var(--space-xs) var(--space-sm);
    white-space: pre-wrap;
    word-break: break-word;
    overflow: visible;
}

/* ---- quiz ---- */

.preview-quiz-list {
    margin-top: 0.45rem;
    display: flex;
    flex-direction: column;
    gap: 0.45rem;
}

.preview-quiz-answer {
    border: var(--rule-hairline) solid var(--color-rule);
    border-radius: var(--radius-input);
    padding: 0.45rem 0.6rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.45rem;
    background: var(--color-surface);
}

.preview-quiz-answer-selectable {
    transition: border-color var(--dur-short) var(--ease-out), background-color var(--dur-short) var(--ease-out);
}

.preview-quiz-answer-selectable:hover {
    border-color: var(--color-ink-3);
    background: var(--color-paper);
}

.preview-quiz-answer-option {
    width: 100%;
    display: flex;
    align-items: center;
    gap: 0.6rem;
    cursor: pointer;
    min-height: var(--tap-min-fine);
}

.preview-quiz-answer-option input[type="checkbox"] {
    width: 1.15rem;
    height: 1.15rem;
    accent-color: var(--color-accent-deep);
    flex: 0 0 auto;
}

.preview-quiz-answer-locked {
    opacity: 0.65;
}

.quiz-feedback {
    margin-top: 0.35rem;
    width: fit-content;
    border-radius: var(--radius-pill);
    border: var(--rule-hairline) solid transparent;
    padding: 0.2rem 0.6rem;
    font-size: var(--text-sm);
    font-weight: 600;
}

.quiz-feedback-correct {
    border-color: var(--status-ok);
    color: var(--status-ok);
    background: var(--status-ok-tint);
}

.quiz-feedback-wrong {
    border-color: var(--status-bad);
    color: var(--status-bad);
    background: var(--status-bad-tint);
}

.quiz-feedback-pop {
    animation: quiz-feedback-pop var(--dur-med) var(--ease-out);
}

@keyframes quiz-feedback-pop {
    from {
        opacity: 0;
        transform: translateY(2px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.preview-quiz-answer-correct {
    border-color: var(--status-ok);
    background: var(--status-ok-tint);
}

.preview-correct-badge {
    font-size: var(--text-xs);
    font-weight: 600;
    color: var(--status-ok);
    background: var(--status-ok-tint);
    padding: 0.12rem 0.45rem;
    border-radius: var(--radius-pill);
}

/* ============================== lesson flow builder ============================== */

.lesson-flow-surface {
    border: var(--rule-hairline) solid var(--color-rule);
    border-radius: var(--radius-card);
    background: var(--color-surface);
    padding: var(--space-sm);
}

.lesson-flow-header {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-xs);
    margin-bottom: var(--space-sm);
    padding-bottom: var(--space-xs);
    border-bottom: var(--rule-hairline) solid var(--color-rule);
}

.flow-header-actions {
    display: inline-flex;
    align-items: center;
    gap: 0.55rem;
    flex-wrap: wrap;
    justify-content: flex-end;
}

.lesson-flow-grid {
    position: relative;
    display: grid;
    grid-template-columns: minmax(0, 1fr);
    gap: var(--space-xs);
}

@media (min-width: 1100px) {
    .lesson-flow-grid {
        grid-template-columns: minmax(0, 2.1fr) minmax(230px, 0.9fr);
        align-items: start;
    }
}

.lesson-flow-editor {
    position: relative;
    width: 100%;
    height: 28rem;
    min-height: 28rem;
    border: var(--rule-hairline) solid var(--color-rule);
    border-radius: var(--radius-card);
    background: var(--color-paper);
    overflow: hidden;
}

.flow-node-menu {
    position: absolute;
    z-index: var(--z-overlay);
    min-width: 140px;
    border: var(--rule-hairline) solid var(--color-rule-2);
    border-radius: var(--radius-input);
    background: var(--color-surface);
    box-shadow: var(--shadow-pop);
    overflow: visible;
}

.flow-node-menu-group {
    position: relative;
}

.flow-node-menu-parent::after {
    content: "\203A";
    float: right;
    color: var(--color-ink-3);
}

.flow-node-submenu {
    position: absolute;
    top: -1px;
    left: 100%;
    min-width: 160px;
    border: var(--rule-hairline) solid var(--color-rule-2);
    border-radius: var(--radius-input);
    background: var(--color-surface);
    box-shadow: var(--shadow-pop);
    overflow: hidden;
    display: none;
}

.flow-node-menu-group:hover .flow-node-submenu,
.flow-node-menu-group:focus-within .flow-node-submenu,
.flow-node-menu-group.is-open .flow-node-submenu {
    display: block;
}

.flow-node-menu-group.is-disabled .flow-node-menu-parent {
    color: var(--color-ink-3);
    cursor: not-allowed;
    background: transparent;
}

.flow-node-menu-group.is-disabled .flow-node-submenu {
    display: none;
}

.flow-node-menu button {
    width: 100%;
    border: 0;
    background: transparent;
    text-align: left;
    padding: 0.55rem 0.7rem;
    font-size: var(--text-sm);
    color: var(--color-ink-2);
    cursor: pointer;
}

.flow-node-menu button:hover {
    background: var(--color-paper-2);
    color: var(--color-ink);
}

.flow-node-menu button:disabled {
    color: var(--color-ink-3);
    cursor: not-allowed;
    background: transparent;
}

.flow-confirm-modal {
    position: fixed;
    inset: 0;
    z-index: var(--z-modal);
    background: var(--color-scrim);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-sm);
}

.flow-confirm-modal[hidden] {
    display: none !important;
}

.flow-confirm-dialog {
    width: min(28rem, 100%);
    border: var(--rule-hairline) solid var(--color-rule);
    border-radius: var(--radius-card);
    background: var(--color-surface);
    box-shadow: var(--shadow-pop);
    padding: var(--space-md);
}

.flow-confirm-title {
    margin: 0;
    font-family: var(--font-display);
    font-size: var(--text-md);
    font-weight: 600;
    color: var(--color-ink);
}

.flow-confirm-copy {
    margin-top: 0.55rem;
    font-size: var(--text-sm);
    line-height: 1.5;
    color: var(--color-ink-2);
}

.flow-confirm-actions {
    margin-top: var(--space-sm);
    display: flex;
    justify-content: flex-end;
    gap: 0.5rem;
}

.flow-react-root .react-flow__node.flow-node-shell {
    border-radius: var(--radius-input);
    transition: box-shadow var(--dur-short) var(--ease-out), border-color var(--dur-short) var(--ease-out);
    box-shadow: var(--shadow-card);
}

.flow-react-root .react-flow__node.flow-node-shell:hover,
.flow-react-root .react-flow__node.flow-node-shell.selected {
    border-color: var(--color-accent-deep) !important;
    box-shadow: var(--shadow-pop);
}

.flow-block-node {
    position: relative;
    font-size: 12px;
    padding: 0.45rem 0.5rem;
    min-height: 3rem;
}

.flow-node-title {
    font-weight: 600;
    color: inherit;
    line-height: 1.25;
}

.flow-node-preview {
    margin-top: 0.35rem;
    font-size: 11px;
    line-height: 1.35;
    color: var(--color-ink-2);
    max-height: 3.1em;
    overflow: hidden;
}

/* + buttons: visible on hover, keyboard focus, AND always on touch. */
.flow-node-plus {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    width: 1.5rem;
    height: 1.5rem;
    border-radius: var(--radius-pill);
    border: var(--rule-hairline) solid var(--color-rule-2);
    background: var(--color-surface);
    color: var(--color-accent-deep);
    font-size: 1rem;
    line-height: 1;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    pointer-events: none;
    box-shadow: var(--shadow-card);
    z-index: 3;
    transition: opacity var(--dur-short) var(--ease-out);
}

.flow-node-plus:hover {
    background: var(--color-accent-tint);
    border-color: var(--color-accent-deep);
}

.flow-node-plus:focus-visible {
    opacity: 1;
    pointer-events: auto;
}

.flow-node-plus-top {
    top: -0.75rem;
}

.flow-node-plus-bottom {
    bottom: -0.75rem;
}

.flow-react-root .react-flow__node.flow-node-shell:hover .flow-node-plus,
.flow-react-root .react-flow__node.flow-node-shell:focus-within .flow-node-plus,
.flow-react-root .react-flow__node.flow-node-shell.selected .flow-node-plus {
    opacity: 1;
    pointer-events: auto;
}

@media (pointer: coarse) {
    .flow-node-plus {
        opacity: 0.75;
        pointer-events: auto;
        width: 1.75rem;
        height: 1.75rem;
    }
}

.flow-node-handle {
    width: 0.42rem;
    height: 0.42rem;
    border: var(--rule-hairline) solid var(--color-rule-2);
    background: var(--color-surface);
}

.flow-react-root .react-flow__edge .react-flow__edge-path {
    transition: stroke var(--dur-short) var(--ease-out), stroke-width var(--dur-short) var(--ease-out);
}

.flow-react-root .react-flow__edge:hover .react-flow__edge-path {
    stroke: var(--color-accent-deep);
    stroke-width: 2.5;
}

.lesson-flow-surface:fullscreen,
.lesson-flow-surface:-webkit-full-screen,
.lesson-flow-surface.flow-surface-fallback-fullscreen {
    position: fixed;
    inset: 0;
    z-index: var(--z-overlay);
    width: 100%;
    height: 100vh;
    max-width: none;
    margin: 0;
    border-radius: 0;
    padding: var(--space-sm);
    overflow: auto;
    background: var(--color-paper);
}

.lesson-flow-surface:fullscreen .lesson-flow-grid,
.lesson-flow-surface:-webkit-full-screen .lesson-flow-grid,
.lesson-flow-surface.flow-surface-fallback-fullscreen .lesson-flow-grid {
    min-height: calc(100vh - 8.5rem);
}

.lesson-flow-surface:fullscreen .lesson-flow-editor,
.lesson-flow-surface:-webkit-full-screen .lesson-flow-editor,
.lesson-flow-surface.flow-surface-fallback-fullscreen .lesson-flow-editor {
    height: calc(100vh - 10rem);
    min-height: 22rem;
}

.lesson-flow-surface:fullscreen .flow-inspector,
.lesson-flow-surface:-webkit-full-screen .flow-inspector,
.lesson-flow-surface.flow-surface-fallback-fullscreen .flow-inspector {
    max-height: calc(100vh - 10rem);
    overflow: auto;
}

.flow-inspector {
    border: var(--rule-hairline) solid var(--color-rule);
    border-radius: var(--radius-card);
    background: var(--color-surface);
    padding: var(--space-xs);
}

.flow-hint {
    color: var(--color-ink-3);
    font-size: var(--text-xs);
}

.lesson-flow-stack {
    display: flex;
    flex-direction: column;
    gap: 0.65rem;
}

.flow-node {
    position: relative;
    border: var(--rule-hairline) solid var(--color-rule);
    border-radius: var(--radius-card);
    background: var(--color-surface);
    padding: var(--space-xs);
}

.flow-node-quiz {
    border-color: var(--color-accent);
    background: var(--color-accent-tint);
}

.flow-node-code {
    border-color: var(--status-ok);
    background: var(--status-ok-tint);
}

.flow-node-markdown {
    border-color: var(--color-rule-2);
    background: var(--color-paper);
}

.flow-node-head {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: var(--space-xs);
}

.flow-node-head h5,
.flow-remediation-node h5 {
    margin-top: 0.1rem;
    font-size: var(--text-base);
    font-weight: 600;
    color: var(--color-ink);
}

.flow-node-kicker {
    font-family: var(--font-mono);
    font-size: 0.68rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--color-ink-3);
}

.flow-node-body {
    margin-top: 0.7rem;
}

.flow-remediation-form {
    margin-top: var(--space-xs);
    padding: var(--space-xs);
    border-radius: var(--radius-input);
    border: var(--rule-hairline) solid var(--color-rule);
    background: var(--color-paper);
}

.flow-branch {
    margin-top: var(--space-xs);
    padding-left: 1.15rem;
}

.flow-branch-label {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--color-accent-deep);
    margin-bottom: 0.35rem;
}

.flow-edge {
    display: flex;
    align-items: flex-start;
    gap: 0.5rem;
}

.flow-edge-arrow {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 1.4rem;
    height: 1.4rem;
    border-radius: var(--radius-pill);
    background: var(--color-accent-tint);
    color: var(--color-accent-deep);
    font-size: var(--text-sm);
    flex: 0 0 auto;
}

.flow-remediation-node {
    flex: 1 1 auto;
    border: var(--rule-hairline) solid var(--color-accent);
    border-radius: var(--radius-input);
    background: var(--color-accent-tint);
    padding: 0.7rem;
}

.flow-connector {
    display: flex;
    justify-content: center;
    height: 0.9rem;
}

.flow-connector span {
    width: 1px;
    background: var(--color-rule-2);
}

/* ============================== monitor ============================== */

.monitor-dashboard-grid {
    display: grid;
    gap: var(--space-xs);
    grid-template-columns: repeat(2, minmax(0, 1fr));
}

@media (min-width: 700px) {
    .monitor-dashboard-grid {
        grid-template-columns: repeat(3, minmax(0, 1fr));
    }
}

@media (min-width: 1024px) {
    .monitor-dashboard-grid {
        grid-template-columns: repeat(6, minmax(0, 1fr));
    }
}

.monitor-card {
    border: var(--rule-hairline) solid var(--color-rule);
    border-radius: var(--radius-card);
    padding: var(--space-xs) var(--space-sm);
    background: var(--color-surface);
    border-top: 3px solid var(--color-rule-2);
}

.monitor-card-typing {
    border-top-color: var(--status-warn);
}

.monitor-card-thinking {
    border-top-color: var(--color-focus);
}

.monitor-card-running {
    border-top-color: var(--status-ok);
}

.monitor-card-stuck {
    border-top-color: var(--status-bad);
}

.monitor-card-offline {
    border-top-color: var(--status-off);
}

.monitor-card-total {
    border-top-color: var(--color-accent);
}

.monitor-kicker {
    font-family: var(--font-mono);
    text-transform: uppercase;
    letter-spacing: 0.07em;
    font-size: 0.68rem;
    color: var(--color-ink-3);
}

.monitor-metric {
    margin-top: 0.3rem;
    font-family: var(--font-mono);
    font-variant-numeric: tabular-nums;
    font-size: var(--text-xl);
    font-weight: 600;
    line-height: 1;
    color: var(--color-ink);
}

.monitor-caption {
    margin-top: 0.25rem;
    font-size: var(--text-xs);
    color: var(--color-ink-3);
}

.monitor-student-item {
    width: 100%;
    min-height: var(--tap-min-fine);
    border: var(--rule-hairline) solid var(--color-rule);
    border-radius: var(--radius-input);
    background: var(--color-surface);
    padding: 0.55rem 0.65rem;
    text-align: left;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-xs);
    cursor: pointer;
    transition: border-color var(--dur-short) var(--ease-out), background-color var(--dur-short) var(--ease-out);
}

@media (pointer: coarse) {
    .monitor-student-item {
        min-height: var(--tap-min);
    }
}

.monitor-student-item:hover {
    border-color: var(--color-ink-3);
    background: var(--color-paper);
}

.monitor-student-item-active {
    border-color: var(--color-accent-deep);
    background: var(--color-accent-tint);
}

.monitor-activity-pill {
    display: inline-flex;
    border: var(--rule-hairline) solid var(--color-rule);
    background: var(--color-paper);
    color: var(--color-ink-2);
    text-transform: capitalize;
    border-radius: var(--radius-pill);
}

.monitor-activity-pill-typing {
    border-color: var(--status-warn);
    background: var(--status-warn-tint);
    color: var(--status-warn);
}

.monitor-activity-pill-thinking {
    border-color: var(--color-focus);
    background: var(--color-focus-tint);
    color: var(--color-focus);
}

.monitor-activity-pill-running {
    border-color: var(--status-ok);
    background: var(--status-ok-tint);
    color: var(--status-ok);
}

.monitor-activity-pill-stuck {
    border-color: var(--status-bad);
    background: var(--status-bad-tint);
    color: var(--status-bad);
}

.monitor-activity-pill-offline {
    border-color: var(--color-rule-2);
    background: var(--status-off-tint);
    color: var(--status-off);
}