body {
    background: linear-gradient(180deg, #f8fafc 0%, #eef2f7 100%);
}

.page-shell {
    width: min(var(--lab-shell-max, 1760px), calc(100% - var(--lab-shell-gutter, 24px)));
    padding: 22px 0 34px;
}

.app-header {
    align-items: center;
    margin-bottom: 16px;
    padding: 10px 2px 4px;
}

.app-header h1 {
    font-size: clamp(34px, 5vw, 54px);
    line-height: 1;
    color: #1e293b;
    background: none;
    -webkit-text-fill-color: #1e293b;
}

.subtitle {
    max-width: 360px;
    color: #64748b;
}

.hero-card,
.chart-card,
.compare-slider,
.control-panel,
.experiment-card,
.conv-hero,
.conv-panel {
    border-radius: 18px;
    background: rgba(255, 255, 255, 0.86);
    box-shadow: 0 14px 34px rgba(15, 23, 42, 0.07);
    backdrop-filter: blur(14px);
}

.primary-button {
    background: #2563eb;
    box-shadow: 0 12px 24px rgba(37, 99, 235, 0.24);
}

.ghost-button,
.download-button {
    border-radius: 12px;
    box-shadow: inset 0 0 0 1px rgba(203, 213, 225, 0.85), 0 8px 18px rgba(15, 23, 42, 0.06);
}

.lesson-accordion {
    margin-bottom: 18px;
    border: 1px solid rgba(226, 232, 240, 0.95);
    border-radius: 20px;
    background: rgba(255, 255, 255, 0.72);
    box-shadow: 0 14px 34px rgba(15, 23, 42, 0.06);
    overflow: hidden;
}

.lesson-accordion-header {
    display: flex;
    width: 100%;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    border: 0;
    padding: 18px 22px;
    color: #0f172a;
    text-align: left;
    cursor: pointer;
    background: rgba(255, 255, 255, 0.86);
}

.lesson-accordion-header strong {
    display: block;
    margin-bottom: 5px;
    font-size: 21px;
    line-height: 1.2;
}

.lesson-accordion-header small {
    display: block;
    color: #64748b;
    font-size: 14px;
    font-weight: 600;
}

.accordion-icon {
    display: grid;
    flex: 0 0 auto;
    width: 34px;
    height: 34px;
    place-items: center;
    border-radius: 50%;
    color: #2563eb;
    font-size: 22px;
    font-style: normal;
    font-weight: 800;
    background: #eff6ff;
}

.lesson-accordion.is-open .lesson-accordion-header {
    border-bottom: 1px solid rgba(226, 232, 240, 0.86);
}

.lesson-panel {
    display: none;
    padding: 18px;
}

.lesson-panel.is-active {
    display: block;
}

.convolution-lesson .is-hidden {
    display: none;
}

.conv-hero {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
    margin-bottom: 16px;
    padding: 18px;
}

.conv-hero h2 {
    margin: 0 0 8px;
    font-size: 30px;
}

.conv-hero p {
    max-width: 720px;
    margin: 0;
    color: #64748b;
}

.conv-actions {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    justify-content: flex-end;
}

.conv-actions .primary-button,
.conv-actions .ghost-button {
    width: auto;
    min-width: 128px;
    min-height: 42px;
    padding: 0 22px;
    border-radius: 999px;
    font-size: 14px;
    font-weight: 900;
}

.conv-layout {
    display: grid;
    grid-template-columns: 220px minmax(0, 1fr);
    grid-template-areas:
        "controls main";
    gap: 16px;
    align-items: start;
}

.conv-controls {
    display: grid;
    gap: 5px;
}

.conv-controls {
    grid-area: controls;
    align-self: start;
    max-height: var(--conv-controls-max-height, none);
    overflow-y: auto;
    overflow-x: hidden;
    overscroll-behavior: contain;
    padding-right: 8px;
    scrollbar-gutter: stable;
    scrollbar-width: thin;
    scrollbar-color: rgba(37, 99, 235, 0.34) transparent;
}

.conv-controls::-webkit-scrollbar {
    width: 8px;
}

.conv-controls::-webkit-scrollbar-track {
    background: transparent;
}

.conv-controls::-webkit-scrollbar-thumb {
    border: 2px solid transparent;
    border-radius: 999px;
    background: linear-gradient(180deg, rgba(37, 99, 235, 0.38), rgba(99, 102, 241, 0.3));
    background-clip: padding-box;
}

.conv-controls::-webkit-scrollbar-thumb:hover {
    background: linear-gradient(180deg, rgba(37, 99, 235, 0.56), rgba(99, 102, 241, 0.46));
}

.conv-panel {
    min-width: 0;
    padding: 16px;
}

.conv-kernel-template {
    display: grid;
    gap: 6px;
    margin: 10px 0 12px;
    color: #475569;
    font-size: 13px;
    font-weight: 800;
}

.conv-kernel-template select {
    min-height: 38px;
    border: 1px solid #cbd5e1;
    border-radius: 12px;
    padding: 0 10px;
    background: #ffffff;
}

.conv-canvas-controls {
    display: grid;
    grid-template-columns: minmax(150px, 1.1fr) minmax(150px, 1fr) minmax(140px, 0.86fr) minmax(140px, 0.86fr);
    gap: 10px;
    margin: 8px 0 10px;
    align-items: end;
}

.conv-canvas-controls label {
    display: grid;
    gap: 6px;
    color: #475569;
    font-size: 11px;
    font-weight: 800;
}

.conv-canvas-controls select {
    min-height: 36px;
    border: 1px solid #cbd5e1;
    border-radius: 12px;
    padding: 0 10px;
    background: #ffffff;
}

.conv-canvas-controls .conv-switch {
    min-height: 36px;
    padding: 0 10px;
}

.conv-canvas-controls .conv-switch span {
    font-size: 11px;
}

.conv-canvas-controls .conv-switch input {
    width: 15px;
    height: 15px;
}

.conv-controls .conv-panel {
    padding: 14px;
}

.conv-controls .conv-panel + .conv-panel {
    margin-top: 0;
}

.conv-panel h3 {
    margin: 0 0 10px;
    font-size: 18px;
}

.conv-controls label {
    display: grid;
    gap: 6px;
    color: #475569;
    font-size: 13px;
    font-weight: 800;
}

.conv-controls select {
    min-height: 38px;
    border: 1px solid #cbd5e1;
    border-radius: 12px;
    padding: 0 10px;
    background: #ffffff;
}

.conv-switch {
    display: flex !important;
    grid-template-columns: none !important;
    align-items: center;
    gap: 9px !important;
    min-height: 38px;
    padding: 0 10px;
    border: 1px solid #cbd5e1;
    border-radius: 12px;
    background: #ffffff;
}

.conv-switch input {
    width: 16px;
    height: 16px;
    accent-color: #2563eb;
}

.conv-workspace {
    display: grid;
    grid-area: main;
    gap: 16px;
    align-content: start;
}

.conv-overview-panel {
    display: grid;
    gap: 12px;
}

.conv-panel-note {
    margin: 4px 0 0;
    color: #64748b;
    font-size: 13px;
    line-height: 1.6;
}

.conv-overview-flow {
    position: relative;
    display: grid;
    grid-template-columns: minmax(230px, 0.88fr) minmax(250px, 0.92fr) minmax(280px, 0.9fr);
    gap: 48px;
    align-items: stretch;
    padding: 4px 2px 8px;
}

.conv-overview-input,
.conv-overview-relation,
.conv-overview-output {
    min-height: 0;
    padding: 0;
    border: 0;
    border-radius: 0;
    background: transparent;
}

.conv-overview-relation {
    display: grid;
    grid-template-rows: auto minmax(0, 1fr);
    gap: 5px;
    align-content: stretch;
}

.conv-overview-output {
    display: grid;
    grid-template-rows: auto minmax(0, 1fr);
    align-content: stretch;
    justify-content: center;
    justify-items: center;
    min-width: 280px;
}

.overview-flow-svg {
    position: absolute;
    inset: 0;
    z-index: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    overflow: visible;
}

.overview-curve {
    fill: none;
    stroke: rgba(37, 99, 235, 0.28);
    stroke-width: 2.2;
    stroke-linecap: round;
    stroke-linejoin: round;
    filter: drop-shadow(0 6px 8px rgba(37, 99, 235, 0.13));
}

.overview-curve.is-active,
.overview-curve.to-output {
    stroke: rgba(37, 99, 235, 0.66);
    stroke-width: 2.8;
}

.conv-section-title.compact h3 {
    margin-bottom: 4px;
}

.conv-overlay-relation {
    position: relative;
    z-index: 1;
    display: grid;
    gap: 10px;
    align-self: center;
    justify-items: center;
}

.overview-input-stack {
    position: relative;
    z-index: 1;
    flex-direction: column;
    align-items: flex-start;
    overflow-x: hidden;
    overflow-y: auto;
    max-height: none;
    padding-right: 5px;
}

.overview-input-stack .matrix-card {
    width: fit-content;
    max-width: 100%;
    align-self: flex-start;
}

.overview-input-stack .matrix-card h4 {
    margin-bottom: 6px;
}

.overview-channel-relations {
    display: grid;
    gap: 5px;
    max-height: none;
    overflow: visible;
    padding-right: 5px;
    justify-items: center;
}

.overview-relation-block {
    display: grid;
    gap: 4px;
    padding: 2px 0 0;
    border: 0;
    border-radius: 0;
    background: transparent;
}

.overview-relation-block.is-active-channel {
    box-shadow: none;
}

.overview-overlap-stage {
    position: relative;
    width: var(--overview-stage-width, calc(var(--overview-cell-size, 34px) * 7 + 56px));
    height: var(--overview-stage-height, calc(var(--overview-cell-size, 34px) * 5 + 40px));
    background: transparent;
    border-radius: 0;
}

.overview-overlap-layer {
    position: absolute;
    display: grid;
    gap: 5px;
    justify-items: center;
}

.overview-overlap-layer > span {
    border-radius: 999px;
    padding: 4px 8px;
    font-size: 11px;
    font-weight: 950;
}

.overview-patch-layer {
    left: var(--overview-patch-left, 16px);
    top: var(--overview-patch-top, 14px);
    z-index: 1;
}

.overview-patch-layer > span {
    color: #1d4ed8;
    background: #dbeafe;
}

.overview-kernel-layer {
    top: var(--overview-kernel-top, 15px);
    left: var(--overview-kernel-left, 64px);
    z-index: 2;
}

.overview-kernel-layer > span {
    color: #c2410c;
    background: #ffedd5;
}

.overview-patch-grid {
    background: rgba(219, 234, 254, 0.9);
    box-shadow: inset 0 0 0 2px rgba(37, 99, 235, 0.68), 0 14px 28px rgba(37, 99, 235, 0.12);
}

.overview-kernel-grid {
    background: rgba(255, 237, 213, 0.93);
    box-shadow: inset 0 0 0 2px rgba(249, 115, 22, 0.82), 0 18px 34px rgba(249, 115, 22, 0.2);
}

.overview-kernel-grid .calc-cell {
    border-color: rgba(251, 146, 60, 0.62);
    background: rgba(255, 247, 237, 0.96);
}

.overview-kernel-grid .calc-cell.is-active {
    border-color: #c2410c;
    background: #fb923c;
    box-shadow: 0 0 0 3px rgba(251, 146, 60, 0.24), 0 10px 22px rgba(249, 115, 22, 0.22);
}

.overview-relation-summary {
    display: grid;
    gap: 2px;
    width: auto;
    padding: 0;
    border: 0;
    border-radius: 0;
    background: transparent;
}

.overview-relation-total strong {
    color: #1d4ed8;
    font-size: 13px;
}

.overview-relation-total span {
    color: #475569;
    font-size: 11px;
    line-height: 1.55;
}

.conv-overview-input,
.conv-overview-relation,
.conv-overview-output {
    position: relative;
    z-index: 1;
}

.convolution-lesson.is-multi-channel .overview-input-stack {
    gap: 10px;
}

.convolution-lesson.is-multi-channel .matrix-card h4,
.convolution-lesson.is-multi-channel .feature-card h4 {
    font-size: 11px;
}

.convolution-lesson.is-multi-channel .matrix-grid {
    gap: 2px;
    padding: 6px;
}

.convolution-lesson.is-multi-channel .matrix-cell {
    border-radius: 7px;
}

.convolution-lesson.is-multi-channel .overview-overlap-stage {
    position: relative;
    width: var(--overview-stage-width, calc(var(--overview-cell-size, 34px) * 7 + 56px));
    height: var(--overview-stage-height, calc(var(--overview-cell-size, 34px) * 5 + 40px));
    background: transparent;
    border-radius: 0;
}

.convolution-lesson.is-multi-channel .overview-overlap-layer > span {
    padding: 4px 8px;
    font-size: 11px;
}

.convolution-lesson.is-multi-channel .overview-relation-summary,
.convolution-lesson.is-multi-channel .overview-relation-total {
    width: calc(var(--overview-cell-size, 25px) * 7 + 50px);
}

.convolution-lesson.is-multi-channel .feature-output-wrap {
    min-height: 260px;
    width: 100%;
}

.convolution-lesson.is-multi-channel .feature-map-gallery {
    min-height: 230px;
    width: 100%;
}

.convolution-lesson.is-multi-channel .feature-card {
    display: grid;
    justify-items: center;
    min-width: 236px;
}

.convolution-lesson.is-multi-channel .feature-card .matrix-grid {
    --matrix-cell-size: 34px;
    --matrix-cell-font-size: 11px;
    gap: 2px;
    padding: 6px;
}

.overview-relation-summary strong {
    color: #0f172a;
    font-size: 13px;
    line-height: 1.2;
}

.overview-relation-summary span {
    color: #64748b;
    font-size: 12px;
    line-height: 1.45;
}

.kernel-gallery {
    align-items: stretch;
}

.kernel-card {
    display: grid;
    gap: 8px;
    align-content: start;
    justify-items: center;
}

.kernel-channel {
    display: grid;
    gap: 4px;
    justify-items: center;
}

.kernel-channel h4 {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: fit-content;
    min-width: 48px;
    height: 20px;
    margin: 0 0 2px;
    padding: 0 8px;
    border-radius: 999px;
    color: #475569;
    font-size: 11px;
    font-weight: 900;
    background: #eff6ff;
}

.convolution-lesson.is-multi-channel .kernel-card {
    gap: 6px;
}

.convolution-lesson.is-multi-channel .kernel-channel h4 {
    min-width: 44px;
    height: 18px;
    padding: 0 7px;
    font-size: 10px;
}

.feature-output-wrap {
    display: grid;
    align-items: center;
    justify-items: center;
    align-self: stretch;
    width: 100%;
    min-height: 270px;
}

.feature-map-gallery {
    align-items: center;
    justify-items: center;
    align-self: center;
    width: 100%;
    min-height: 235px;
}

.feature-map-gallery .feature-card {
    width: fit-content;
    padding: 6px;
    border-radius: 12px;
    border: 1px solid transparent;
}

.feature-card.is-active-output-map {
    border-color: rgba(37, 99, 235, 0.55);
    background: rgba(239, 246, 255, 0.82);
    box-shadow: 0 10px 24px rgba(37, 99, 235, 0.14);
}

.output-kernel-selector {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 8px;
    width: 100%;
    padding-top: 4px;
}

.output-kernel-selector button {
    min-height: 30px;
    padding: 0 10px;
    border: 1px solid #cbd5e1;
    border-radius: 999px;
    color: #334155;
    font-size: 12px;
    font-weight: 900;
    background: #ffffff;
    cursor: pointer;
}

.output-kernel-selector button.is-active {
    color: #ffffff;
    border-color: #2563eb;
    background: #2563eb;
    box-shadow: 0 8px 18px rgba(37, 99, 235, 0.22);
}

.overview-kernel-strip {
    display: grid;
    gap: 8px;
    min-width: 0;
}

.kernel-strip-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    color: #64748b;
    font-size: 11px;
    font-weight: 900;
}

.conv-detail-row {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(270px, 0.42fr);
    gap: 16px;
    align-items: start;
}

.conv-process-panel {
    align-self: stretch;
    gap: 8px;
    padding: 14px;
}

.conv-process-panel .conv-section-title,
.conv-formula-panel .conv-section-title {
    margin-bottom: 2px;
}

.conv-process-panel .conv-section-title h3,
.conv-formula-panel .conv-section-title h3 {
    margin: 0;
    font-size: 16px;
    line-height: 1.2;
}

.conv-formula-panel {
    gap: 8px;
    padding: 14px;
}

.conv-bottom-row {
    display: grid;
    grid-template-columns: minmax(0, 1.35fr) minmax(280px, 0.65fr);
    gap: 16px;
    align-items: start;
}

/* Make the canvas panel fill the available grid row height and align its content to top */
.conv-canvas-panel {
    display: flex;
    flex-direction: column;
    height: auto;
    align-self: start;
}

.convolution-lesson.is-single-channel .conv-layout {
    grid-template-areas:
        "controls main";
    grid-template-columns: 220px minmax(0, 1fr);
}

.conv-main-panel {
    display: grid;
    gap: 5px;
    align-content: start;
}

.conv-main-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 5px;
    align-items: start;
}

.conv-subpanel {
    display: grid;
    gap: 10px;
    min-width: 0;
}

.conv-main-grid > .conv-subpanel:nth-child(1) {
    min-width: 0;
}

.conv-main-grid > .conv-subpanel:nth-child(2) {
    width: 100%;
    justify-self: stretch;
}

.convolution-lesson.is-single-channel .conv-main-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 5px;
    align-items: start;
}

.convolution-lesson.is-single-channel .conv-main-grid > .conv-subpanel:nth-child(2) {
    width: 100%;
    justify-self: stretch;
}

.convolution-lesson.is-single-channel .feature-output-wrap {
    width: 100%;
}

.convolution-lesson.is-single-channel .feature-output-wrap {
    grid-template-columns: 1fr;
    align-items: start;
}

.convolution-lesson.is-single-channel .feature-map-gallery {
    width: 100%;
}

.convolution-lesson.is-single-channel .feature-card {
    min-width: 0;
    width: max-content;
}

.conv-section-title {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 5px;
}

.conv-section-title strong,
#convOutputShape {
    border-radius: 999px;
    padding: 4px 8px;
    color: #ffffff;
    font-size: 11px;
    background: #334155;
}

.matrix-gallery,
.kernel-gallery,
.feature-map-gallery {
    display: flex;
    gap: 12px;
    flex-wrap: nowrap;
    align-items: flex-start;
    max-width: 100%;
    overflow-x: auto;
    overflow-y: hidden;
    padding-bottom: 6px;
    scrollbar-width: thin;
}

.feature-map-gallery {
    flex-direction: column;
    align-items: center;
    overflow-x: hidden;
    overflow-y: auto;
}

.matrix-gallery {
    min-height: 302px;
}

.kernel-gallery {
    max-height: 390px;
    overflow-y: auto;
}

.calculation-detail {
    max-height: 460px;
    overflow-y: auto;
    padding-right: 3px;
    font-size: 12px;
    line-height: 1.5;
}

.formula-box {
    max-height: 220px;
    overflow-y: auto;
    font-size: 12px;
    line-height: 1.5;
}

.matrix-card,
.kernel-card,
.feature-card {
    flex: 0 0 auto;
    min-width: max-content;
}

.matrix-card h4,
.kernel-card h4,
.feature-card h4 {
    margin: 0 0 8px;
    color: #334155;
    font-size: 13px;
}

.matrix-grid {
    display: grid;
    gap: 3px;
    padding: 8px;
    --matrix-cell-size: 34px;
    --matrix-cell-font-size: 13px;
    border-radius: 14px;
    background: #eff6ff;
    box-shadow: inset 0 0 0 1px rgba(147, 197, 253, 0.45);
}

.kernel-grid {
    background: #fff7ed;
    box-shadow: inset 0 0 0 1px rgba(251, 146, 60, 0.45);
}

.output-grid {
    background: #f8fafc;
    box-shadow: inset 0 0 0 1px rgba(148, 163, 184, 0.32);
}

.matrix-cell {
    position: relative;
    display: grid;
    width: var(--matrix-cell-size, 34px);
    height: var(--matrix-cell-size, 34px);
    place-items: center;
    border: 1px solid rgba(148, 163, 184, 0.42);
    border-radius: 8px;
    color: #0f172a;
    font-size: var(--matrix-cell-font-size, 13px);
    font-weight: 800;
    background: rgba(255, 255, 255, 0.92);
    text-shadow: 0 1px 8px rgba(255, 255, 255, 0.6);
    transition: transform 0.16s ease, box-shadow 0.16s ease, border-color 0.16s ease;
}

.matrix-cell.output-muted {
    border-color: rgba(148, 163, 184, 0.32);
}

.matrix-cell.padding-cell {
    color: #94a3b8;
    border-style: dashed;
    background: #e5e7eb;
}

.matrix-cell.window-cell {
    border-color: #d97706;
    background: #fef3c7;
    box-shadow:
        inset 0 0 0 2px rgba(217, 119, 6, 0.58),
        0 0 0 2px rgba(245, 158, 11, 0.2),
        0 8px 18px rgba(245, 158, 11, 0.18);
    transform: translateY(-1px);
    z-index: 1;
}

.matrix-cell.sample-cell {
    border-color: #c2410c;
    background: #ffedd5 !important;
    box-shadow:
        inset 0 0 0 3px rgba(234, 88, 12, 0.72),
        0 0 0 3px rgba(251, 146, 60, 0.22),
        0 10px 22px rgba(234, 88, 12, 0.2);
    color: #7c2d12 !important;
    transform: translateY(-2px) scale(1.04);
    z-index: 2;
}

.matrix-cell.channel-0.sample-cell {
    border-color: #dc2626;
    background: #fee2e2 !important;
    box-shadow:
        inset 0 0 0 3px rgba(220, 38, 38, 0.72),
        0 0 0 3px rgba(248, 113, 113, 0.22),
        0 10px 22px rgba(220, 38, 38, 0.18);
    color: #7f1d1d !important;
}

.matrix-cell.channel-1.sample-cell {
    border-color: #16a34a;
    background: #dcfce7 !important;
    box-shadow:
        inset 0 0 0 3px rgba(22, 163, 74, 0.72),
        0 0 0 3px rgba(74, 222, 128, 0.22),
        0 10px 22px rgba(22, 163, 74, 0.18);
    color: #14532d !important;
}

.matrix-cell.channel-2.sample-cell {
    border-color: #2563eb;
    background: #dbeafe !important;
    box-shadow:
        inset 0 0 0 3px rgba(37, 99, 235, 0.72),
        0 0 0 3px rgba(96, 165, 250, 0.22),
        0 10px 22px rgba(37, 99, 235, 0.18);
    color: #1e3a8a !important;
}

.matrix-cell.skipped-cell {
    color: #94a3b8;
    border-style: dashed;
    background: #f8fafc;
}

.matrix-cell.active-output {
    color: #ffffff;
    border-color: #1d4ed8;
    background: #2563eb !important;
    box-shadow:
        inset 0 0 0 2px rgba(255, 255, 255, 0.42),
        0 0 0 4px rgba(37, 99, 235, 0.24),
        0 14px 28px rgba(37, 99, 235, 0.34);
    transform: translateY(-2px) scale(1.05);
    z-index: 3;
}

.matrix-cell.kernel-active {
    border-color: #c2410c;
    background: #fdba74 !important;
    box-shadow:
        inset 0 0 0 2px rgba(194, 65, 12, 0.58),
        0 0 0 3px rgba(251, 146, 60, 0.22);
    color: #7c2d12 !important;
}

.matrix-cell.editable-cell {
    cursor: text;
    outline: none;
}

.matrix-cell.editable-cell:focus {
    border-color: #2563eb;
    background: #eff6ff !important;
    color: #0f172a !important;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.18);
}

.path-index {
    position: absolute;
    top: -7px;
    right: -7px;
    display: grid;
    width: 18px;
    height: 18px;
    place-items: center;
    border-radius: 50%;
    color: #ffffff;
    font-size: 10px;
    background: #0f766e;
}

.formula-box,
.calculation-detail,
.conv-explain {
    color: #334155;
    line-height: 1.65;
}

.conv-controls .conv-explain-compact {
    display: grid;
    gap: 6px;
    margin-top: 6px;
    padding: 12px 12px 10px;
    border: 1px solid rgba(226, 232, 240, 0.92);
    border-radius: 14px;
    background: #f8fafc;
}

.conv-controls .conv-explain-compact h3 {
    margin: 0;
    font-size: 14px;
    line-height: 1.25;
}

.conv-controls .conv-explain-compact #convExplanation {
    display: grid;
    gap: 6px;
    color: #475569;
    font-size: 12px;
    line-height: 1.55;
}

.conv-controls .conv-explain-compact #convExplanation p {
    margin: 0;
}

.conv-controls .conv-explain-compact #convExplanation ul,
.conv-controls .conv-explain-compact #convExplanation ol {
    margin: 0;
    padding-left: 18px;
}

.conv-controls .conv-explain-compact #convExplanation li + li {
    margin-top: 2px;
}

.conv-controls .conv-explain-compact .snake-path-box {
    margin-top: 4px;
}

.conv-controls .conv-explain-compact .snake-path-box p {
    margin: 0 0 6px;
    font-size: 12px;
}

.formula-box code,
.calculation-detail code {
    display: block;
    margin-top: 6px;
    padding: 10px;
    border-radius: 12px;
    color: #0f172a;
    white-space: pre-wrap;
    overflow-wrap: anywhere;
    background: #f8fafc;
}

.formula-box code {
    padding: 8px;
    font-size: 11px;
    line-height: 1.45;
}

.partial-line {
    margin: 0 0 6px;
    padding: 8px 10px;
    border-radius: 12px;
    background: #f8fafc;
}

.process-meta {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 6px;
    margin-bottom: 8px;
}

.process-meta span,
.final-output {
    display: block;
    padding: 7px 10px;
    border-radius: 12px;
    background: #f8fafc;
    color: #334155;
    font-weight: 800;
}

.partial-line h4 {
    margin: 0 0 4px;
    color: #334155;
    font-size: 12px;
}

.final-output {
    color: #ffffff;
    background: #2563eb;
}

.calc-channel-tabs {
    display: flex;
    gap: 8px;
    margin: 4px 0 12px;
    overflow-x: auto;
}

.calc-channel-tabs button {
    border: 0;
    border-radius: 999px;
    padding: 7px 12px;
    color: #475569;
    font-size: 11px;
    font-weight: 900;
    cursor: pointer;
    background: #f1f5f9;
}

.calc-channel-tabs button.is-active {
    color: #ffffff;
    background: #2563eb;
    box-shadow: 0 8px 18px rgba(37, 99, 235, 0.24);
}

.calc-canvas {
    overflow-x: auto;
    padding-bottom: 4px;
}

.calc-flow-board {
    position: relative;
    display: grid;
    min-width: 620px;
    grid-template-columns: max-content 28px max-content 28px max-content 30px minmax(96px, 0.8fr) 28px minmax(96px, 0.8fr);
    align-items: center;
    gap: 10px;
    padding: 12px;
    border: 1px solid rgba(226, 232, 240, 0.92);
    border-radius: 16px;
    background: linear-gradient(180deg, #ffffff, #f8fafc);
}

.calc-flow-svg {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    overflow: visible;
}

.calc-block {
    position: relative;
    z-index: 1;
    display: grid;
    gap: 8px;
}

.calc-block h4 {
    margin: 0;
    color: #334155;
    font-size: 11px;
}

.calc-mini-grid {
    display: grid;
    gap: 3px;
    padding: 7px;
    --calc-cell-size: 31px;
    --calc-cell-font-size: 11px;
    border-radius: 13px;
    background: #eef6ff;
    box-shadow: inset 0 0 0 1px rgba(147, 197, 253, 0.42);
}

.calc-kernel-grid {
    background: #fff7ed;
    box-shadow: inset 0 0 0 1px rgba(251, 146, 60, 0.42);
}

.calc-product-grid {
    background: #f8fafc;
    box-shadow: inset 0 0 0 1px rgba(148, 163, 184, 0.32);
}

.calc-cell {
    position: relative;
    display: grid;
    width: var(--calc-cell-size, 31px);
    height: var(--calc-cell-size, 31px);
    place-items: center;
    border: 1px solid rgba(148, 163, 184, 0.44);
    border-radius: 8px;
    color: #0f172a;
    font-size: var(--calc-cell-font-size, 12px);
    font-weight: 900;
    background: #ffffff;
}

.calc-cell.is-muted {
    color: #94a3b8;
    border-style: dashed;
    background: #f8fafc;
}

.calc-cell.is-active {
    color: #ffffff;
    border-color: #1d4ed8;
    background: #2563eb;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.22), 0 10px 22px rgba(37, 99, 235, 0.24);
    transform: scale(1.06);
    z-index: 2;
}

.calc-operator {
    position: relative;
    z-index: 1;
    color: #64748b;
    font-size: 22px;
    font-weight: 900;
    text-align: center;
}

.calc-result-box {
    position: relative;
    z-index: 1;
    display: grid;
    gap: 6px;
    min-height: 76px;
    align-content: center;
    border-radius: 14px;
    padding: 12px;
    background: #f8fafc;
    box-shadow: inset 0 0 0 1px rgba(226, 232, 240, 0.9);
}

.calc-result-box span {
    color: #64748b;
    font-size: 11px;
    font-weight: 800;
}

.calc-result-box strong {
    color: #0f172a;
    font-size: 17px;
}

.calc-result-box.final {
    color: #ffffff;
    background: #2563eb;
    box-shadow: 0 12px 24px rgba(37, 99, 235, 0.24);
}

.calc-result-box.final span,
.calc-result-box.final strong {
    color: #ffffff;
}

.calc-line {
    stroke: rgba(100, 116, 139, 0.2);
    stroke-width: 1.25;
    fill: none;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.calc-line.is-active {
    stroke: #2563eb;
    stroke-width: 3.2;
    filter: drop-shadow(0 4px 7px rgba(37, 99, 235, 0.28));
}

.calc-line.is-path {
    stroke: #0f766e;
    stroke-dasharray: 5 5;
}

.anim-stage {
    position: relative;
    min-width: 620px;
    overflow-x: auto;
    overflow-y: hidden;
    scrollbar-width: thin;
    border: 1px solid rgba(226, 232, 240, 0.92);
    border-radius: 18px;
    padding: 14px;
    background:
        linear-gradient(180deg, rgba(255, 255, 255, 0.94), rgba(248, 250, 252, 0.96)),
        radial-gradient(circle at 50% 20%, rgba(37, 99, 235, 0.08), transparent 42%);
}

.anim-stage-svg {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 1;
}

.anim-stage-header {
    position: relative;
    z-index: 2;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 5px;
    margin-bottom: 14px;
    color: #334155;
    font-weight: 900;
}

.anim-stage-header span {
    color: #2563eb;
}

.anim-stage-body {
    position: relative;
    z-index: 2;
    display: grid;
    grid-template-columns: max-content 24px max-content 28px max-content minmax(104px, 0.8fr) minmax(104px, 0.8fr);
    gap: 9px;
    align-items: center;
    width: max-content;
    min-width: 100%;
    padding-right: 12px;
}

.anim-block {
    display: grid;
    gap: 8px;
    padding: 10px;
    border-radius: 16px;
    background: rgba(255, 255, 255, 0.9);
    box-shadow: inset 0 0 0 1px rgba(226, 232, 240, 0.9);
    transition: transform 0.36s ease, box-shadow 0.36s ease;
}

.anim-block.is-floating {
    box-shadow: 0 16px 34px rgba(15, 23, 42, 0.12), inset 0 0 0 1px rgba(226, 232, 240, 0.9);
}

.anim-block h4 {
    margin: 0;
    color: #334155;
    font-size: 11px;
}

.anim-grid {
    display: grid;
    gap: 4px;
    padding: 8px;
    --anim-cell-size: 38px;
    --anim-cell-font-size: 13px;
    border-radius: 14px;
    background: #eef6ff;
    box-shadow: inset 0 0 0 1px rgba(147, 197, 253, 0.42);
}

.anim-kernel-grid {
    background: #fff7ed;
    box-shadow: inset 0 0 0 1px rgba(251, 146, 60, 0.42);
}

.anim-product-grid {
    background: #f8fafc;
    box-shadow: inset 0 0 0 1px rgba(148, 163, 184, 0.32);
}

.anim-cell {
    display: grid;
    width: var(--anim-cell-size, 38px);
    height: var(--anim-cell-size, 38px);
    place-items: center;
    border: 1px solid rgba(148, 163, 184, 0.42);
    border-radius: 10px;
    color: #0f172a;
    font-size: var(--anim-cell-font-size, 13px);
    font-weight: 950;
    background: #ffffff;
    transition: transform 0.24s ease, background 0.24s ease, box-shadow 0.24s ease, color 0.24s ease;
}

.anim-stage.is-large-kernel {
    --anim-cell-size: 33px;
    --anim-cell-font-size: 11px;
}

.anim-stage.is-large-kernel .anim-stage-body {
    gap: 5px;
}

.anim-stage.is-large-kernel .anim-block {
    padding: 8px;
}

.anim-stage.is-large-kernel .anim-grid {
    gap: 3px;
    padding: 7px;
}

.anim-stage.is-large-kernel .anim-cell {
    border-radius: 9px;
}

.anim-cell.is-muted {
    color: transparent;
    border-style: dashed;
    background: #f8fafc;
}

.anim-cell.is-active {
    color: #ffffff;
    border-color: #1d4ed8;
    background: #2563eb;
    box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.2), 0 12px 24px rgba(37, 99, 235, 0.25);
    transform: scale(1.1);
}

.anim-stage.is-moving .anim-cell.is-approach-from-left {
    animation: approachFromLeft 0.42s ease both;
}

.anim-stage.is-moving .anim-cell.is-approach-from-right {
    animation: approachFromRight 0.42s ease both;
}

.anim-cell.is-filled {
    animation: productPop 0.32s ease both;
}

.anim-cell.is-gathering {
    animation: gatherPulse 0.56s ease both;
}

.anim-symbol {
    color: #64748b;
    font-size: 24px;
    font-weight: 950;
    text-align: center;
}

.anim-partials {
    display: grid;
    gap: 8px;
}

.anim-partial-pill,
.anim-final {
    display: grid;
    gap: 5px;
    min-height: 68px;
    align-content: center;
    border-radius: 14px;
    padding: 10px 12px;
    background: #f8fafc;
    box-shadow: inset 0 0 0 1px rgba(226, 232, 240, 0.9);
}

.anim-partial-pill {
    animation: partialIn 0.32s ease both;
}

.anim-partial-pill.is-gathering {
    animation: gatherPulse 0.5s ease both;
}

.anim-partial-pill span,
.anim-final span {
    color: #64748b;
    font-size: 11px;
    font-weight: 800;
}

.anim-partial-pill strong,
.anim-final strong {
    color: #0f172a;
    font-size: 18px;
}

.anim-final.is-ready {
    color: #ffffff;
    background: #2563eb;
    box-shadow: 0 14px 28px rgba(37, 99, 235, 0.25);
    animation: finalIn 0.42s ease both;
}

.anim-final.is-ready span,
.anim-final.is-ready strong {
    color: #ffffff;
}

.anim-guide-line {
    stroke: #2563eb;
    stroke-width: 2.6;
    fill: none;
    stroke-linecap: round;
    filter: drop-shadow(0 4px 7px rgba(37, 99, 235, 0.24));
}

@keyframes productPop {
    0% {
        opacity: 0.1;
        transform: scale(0.78);
    }
    100% {
        opacity: 1;
        transform: scale(1);
    }
}

@keyframes approachFromLeft {
    0% {
        transform: scale(1.02) translateX(0);
    }
    45% {
        transform: scale(1.14) translateX(12px);
    }
    100% {
        transform: scale(1.1) translateX(0);
    }
}

@keyframes approachFromRight {
    0% {
        transform: scale(1.02) translateX(0);
    }
    45% {
        transform: scale(1.14) translateX(-12px);
    }
    100% {
        transform: scale(1.1) translateX(0);
    }
}

@keyframes gatherPulse {
    0% {
        transform: scale(1);
    }
    50% {
        transform: scale(0.9) translateY(4px);
    }
    100% {
        transform: scale(1);
    }
}

@keyframes partialIn {
    from {
        opacity: 0;
        transform: translateY(8px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes finalIn {
    from {
        opacity: 0;
        transform: scale(0.92);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.conv-results-row {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(300px, 0.42fr);
    gap: 12px;
    margin-top: 14px;
}

.conv-notes-row {
    grid-template-columns: 1fr;
}

.feature-output-wrap {
    display: grid;
    grid-template-columns: 1fr;
    gap: 5px;
    align-items: start;
}

.conv-image-controls {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    align-items: center;
    margin: 10px 0 12px;
}

.conv-image-controls input {
    max-width: 240px;
}

.conv-image-controls span {
    color: #64748b;
    font-size: 13px;
    font-weight: 700;
}

.conv-image-preview {
    display: grid;
    min-height: 160px;
    place-items: center;
    border-radius: 16px;
    background:
        linear-gradient(45deg, #e2e8f0 25%, transparent 25%),
        linear-gradient(-45deg, #e2e8f0 25%, transparent 25%),
        linear-gradient(45deg, transparent 75%, #e2e8f0 75%),
        linear-gradient(-45deg, transparent 75%, #e2e8f0 75%);
    background-color: #f8fafc;
    background-position: 0 0, 0 10px, 10px -10px, -10px 0;
    background-size: 20px 20px;
}

.conv-image-preview img {
    display: none;
    max-width: 100%;
    max-height: 320px;
    border-radius: 12px;
    box-shadow: 0 14px 30px rgba(15, 23, 42, 0.14);
}

.conv-image-preview img.is-visible {
    display: block;
}

.snake-path-box {
    margin-top: 12px;
}

.snake-grid {
    display: inline-grid;
    gap: 4px;
    padding: 8px;
    --snake-cell-size: 36px;
    --snake-cell-font-size: 13px;
    border-radius: 14px;
    background:
        linear-gradient(#d9ead3 1px, transparent 1px),
        linear-gradient(90deg, #d9ead3 1px, transparent 1px),
        #f7fbef;
    background-size: 40px 40px;
    box-shadow: inset 0 0 0 1px rgba(47, 92, 54, 0.22);
}

.snake-cell {
    display: grid;
    width: var(--snake-cell-size, 36px);
    height: var(--snake-cell-size, 36px);
    place-items: center;
    border-radius: 6px;
    color: #7f1d1d;
    font-size: var(--snake-cell-font-size, 13px);
    font-weight: 900;
    background: #a9c96f;
    box-shadow: inset 0 0 0 1px rgba(63, 98, 18, 0.32);
}

.snake-cell-muted {
    color: transparent;
    background: rgba(255, 255, 255, 0.42);
    box-shadow: inset 0 0 0 1px rgba(47, 92, 54, 0.14);
}

@media (max-width: 1080px) {
    .conv-layout {
        grid-template-columns: 1fr;
        grid-template-areas:
            "controls"
            "main";
    }

    .conv-controls {
        max-height: none;
        overflow: visible;
        padding-right: 0;
    }

    #convStepStatus {
        transform: translateX(-8px);
    }

    .convolution-lesson.is-single-channel .conv-layout {
        grid-template-areas:
            "controls"
            "main";
    }

    .conv-overview-flow {
        grid-template-columns: 1fr;
    }

    .overview-flow-svg {
        display: none;
    }

    .conv-overview-input,
    .conv-overview-relation,
    .conv-overview-output {
        min-height: auto;
    }

    .conv-detail-row,
    .conv-bottom-row,
    .feature-output-wrap {
        grid-template-columns: 1fr;
    }

    .conv-canvas-controls {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .conv-hero {
        align-items: flex-start;
        flex-direction: column;
    }

    .conv-actions {
        justify-content: flex-start;
    }
}

@media (max-width: 680px) {
    .page-shell {
        width: min(100% - 16px, var(--lab-shell-max, 1760px));
    }

    .lesson-panel {
        padding: 12px;
    }

    .lesson-accordion-header {
        padding: 15px;
    }

    .conv-canvas-controls {
        grid-template-columns: 1fr;
    }

    .lesson-accordion-header strong {
        font-size: 18px;
    }

    .matrix-cell {
        width: 28px;
        height: 28px;
        border-radius: 7px;
        font-size: 11px;
    }
}