:root {
    --algo-bg: #f6f8fb;
    --algo-surface: #ffffff;
    --algo-surface-2: #f9fbfd;
    --algo-ink: #17212b;
    --algo-muted: #5f6b7a;
    --algo-line: #dbe3ec;
    --algo-line-strong: #b7c6d8;
    --algo-teal: #07816f;
    --algo-teal-soft: #e8f6f3;
    --algo-blue: #2563eb;
    --algo-blue-soft: #eaf1ff;
    --algo-amber: #d97706;
    --algo-amber-soft: #fff4dd;
    --algo-red: #dc2626;
    --algo-red-soft: #feecec;
    --algo-green: #16a34a;
    --algo-green-soft: #ecfdf3;
    --algo-purple: #7c3aed;
    --algo-shadow: 0 18px 42px rgba(32, 44, 63, 0.09);
    --algo-radius: 8px;
    --algo-font: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
    --algo-heading: "Space Grotesk", "Noto Sans SC", sans-serif;
    --algo-mono: "SFMono-Regular", "JetBrains Mono", "Fira Code", monospace;
}

* {
    box-sizing: border-box;
}

body.algorithm-page {
    margin: 0;
    min-height: 100vh;
    color: var(--algo-ink);
    background:
        linear-gradient(90deg, rgba(37, 99, 235, 0.045) 1px, transparent 1px),
        linear-gradient(rgba(37, 99, 235, 0.045) 1px, transparent 1px),
        var(--algo-bg);
    background-size: 28px 28px;
    font-family: var(--algo-font);
    overflow-x: hidden;
}

button,
input,
textarea {
    font: inherit;
}

button {
    cursor: pointer;
}

.algorithm-shell {
    width: min(100%, 1720px);
    margin: 0 auto;
    padding: 18px;
}

.app-topbar {
    height: 58px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    border: 1px solid var(--algo-line);
    border-radius: var(--algo-radius);
    background: rgba(255, 255, 255, 0.94);
    box-shadow: 0 10px 26px rgba(32, 44, 63, 0.06);
    padding: 0 16px;
}

.brand-mark {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    color: var(--algo-ink);
    text-decoration: none;
    font-weight: 800;
    white-space: nowrap;
}

.brand-symbol {
    width: 32px;
    height: 32px;
    display: inline-grid;
    place-items: center;
    border-radius: 7px;
    color: #fff;
    background: linear-gradient(135deg, var(--algo-teal), var(--algo-blue));
    font-family: var(--algo-heading);
    font-weight: 700;
}

.top-links {
    display: flex;
    align-items: center;
    justify-content: flex-end;
    gap: 4px;
    flex-wrap: wrap;
}

.top-links a {
    min-height: 34px;
    display: inline-flex;
    align-items: center;
    padding: 0 10px;
    border-radius: 7px;
    color: var(--algo-muted);
    font-size: 0.9rem;
    font-weight: 700;
    text-decoration: none;
}

.top-links a:hover {
    color: var(--algo-teal);
    background: var(--algo-teal-soft);
}

.workbench {
    margin-top: 0;
    display: grid;
    grid-template-columns: minmax(220px, 270px) minmax(0, 1fr) minmax(300px, 360px);
    gap: 14px;
    align-items: stretch;
    height: calc(100vh - 102px);
    min-height: 680px;
}

.library-panel,
.studio-panel,
.inspector-panel {
    min-width: 0;
    border: 1px solid var(--algo-line);
    border-radius: var(--algo-radius);
    background: rgba(255, 255, 255, 0.96);
    box-shadow: var(--algo-shadow);
}

.library-panel {
    padding: 14px;
    display: flex;
    flex-direction: column;
    gap: 14px;
    min-height: 0;
    overflow: hidden;
}

.library-heading,
.studio-header,
.section-title,
.canvas-toolbar,
.playback-panel,
.transport-buttons,
.speed-control {
    display: flex;
    align-items: center;
}

.library-heading,
.studio-header,
.section-title,
.canvas-toolbar,
.playback-panel {
    justify-content: space-between;
}

.library-heading h1,
.studio-header h2,
.section-title h2 {
    margin: 0;
    font-family: var(--algo-heading);
}

.library-heading h1 {
    font-size: 1.08rem;
}

#library-count,
#stateBadge,
.algorithm-category,
.run-stats span,
.canvas-toolbar span {
    min-height: 26px;
    display: inline-flex;
    align-items: center;
    border-radius: 999px;
    font-size: 0.76rem;
    font-weight: 800;
}

#library-count {
    padding: 0 9px;
    color: var(--algo-blue);
    background: var(--algo-blue-soft);
}

.category-tabs {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 6px;
}

.category-tab,
.algorithm-item,
.tool-button,
.icon-button,
.play-button {
    border: 1px solid var(--algo-line);
    border-radius: 7px;
    background: var(--algo-surface);
    color: var(--algo-ink);
    transition: background-color 0.18s ease, border-color 0.18s ease, color 0.18s ease, transform 0.18s ease;
}

.category-tab {
    min-height: 34px;
    padding: 0 8px;
    color: var(--algo-muted);
    font-size: 0.82rem;
    font-weight: 800;
}

.category-tab:hover,
.category-tab.active,
.algorithm-item:hover,
.algorithm-item.active {
    border-color: rgba(7, 129, 111, 0.45);
    background: var(--algo-teal-soft);
    color: var(--algo-teal);
}

.algorithm-list {
    display: grid;
    gap: 8px;
    overflow: auto;
    padding-right: 2px;
}

.algorithm-item {
    width: 100%;
    min-height: 62px;
    display: grid;
    gap: 4px;
    padding: 9px 10px;
    text-align: left;
}

.algorithm-item strong {
    display: block;
    font-size: 0.94rem;
    line-height: 1.28;
}

.algorithm-item span {
    color: var(--algo-muted);
    font-size: 0.78rem;
    line-height: 1.35;
}

.algorithm-item.active span {
    color: #345f59;
}

.studio-panel {
    padding: 14px;
    display: grid;
    grid-template-rows: auto auto minmax(280px, 1fr) auto;
    gap: 12px;
    min-height: 0;
    overflow: hidden;
}

.algorithm-category {
    width: fit-content;
    padding: 0 9px;
    color: var(--algo-teal);
    background: var(--algo-teal-soft);
}

.studio-header h2 {
    margin-top: 6px;
    font-size: clamp(1.42rem, 2.1vw, 2rem);
    line-height: 1.16;
}

.run-stats {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    justify-content: flex-end;
}

.run-stats span {
    padding: 0 10px;
    color: var(--algo-muted);
    background: var(--algo-surface-2);
    border: 1px solid var(--algo-line);
}

.run-stats strong {
    color: var(--algo-blue);
    font-family: var(--algo-heading);
}

.input-strip {
    display: grid;
    grid-template-columns: minmax(280px, 1fr) minmax(120px, 180px) auto auto;
    gap: 8px;
    align-items: end;
}

.data-field,
.target-field,
.speed-control {
    display: grid;
    gap: 5px;
}

.data-field span,
.target-field span,
.speed-control span {
    color: var(--algo-muted);
    font-size: 0.78rem;
    font-weight: 800;
}

textarea,
input[type="text"] {
    width: 100%;
    min-height: 38px;
    border: 1px solid var(--algo-line);
    border-radius: 7px;
    color: var(--algo-ink);
    background: #fff;
    outline: none;
}

textarea {
    resize: vertical;
    padding: 8px 10px;
    line-height: 1.45;
    font-family: var(--algo-mono);
    font-size: 0.86rem;
}

input[type="text"] {
    padding: 0 10px;
    font-family: var(--algo-mono);
    font-size: 0.9rem;
}

textarea:focus,
input[type="text"]:focus {
    border-color: var(--algo-teal);
    box-shadow: 0 0 0 3px rgba(7, 129, 111, 0.12);
}

.tool-button,
.play-button {
    min-height: 38px;
    padding: 0 13px;
    font-size: 0.86rem;
    font-weight: 800;
    white-space: nowrap;
}

.tool-button:hover,
.play-button:hover,
.icon-button:hover {
    transform: translateY(-1px);
    border-color: var(--algo-line-strong);
}

.tool-button.primary,
.play-button.playing {
    color: #fff;
    border-color: var(--algo-teal);
    background: var(--algo-teal);
}

.tool-button.primary:hover,
.play-button.playing:hover {
    background: #056c5d;
}

.canvas-shell {
    min-height: 0;
    display: grid;
    grid-template-rows: auto 1fr;
    overflow: hidden;
    border: 1px solid var(--algo-line);
    border-radius: var(--algo-radius);
    background: var(--algo-surface-2);
}

.canvas-toolbar {
    min-height: 42px;
    gap: 10px;
    padding: 0 12px;
    border-bottom: 1px solid var(--algo-line);
    background: #fff;
}

.canvas-toolbar span {
    padding: 0 9px;
    color: var(--algo-muted);
    background: var(--algo-surface-2);
    border: 1px solid var(--algo-line);
}

.visual-stage {
    position: relative;
    min-height: 0;
    padding: 22px;
    overflow: auto;
    background:
        linear-gradient(90deg, rgba(183, 198, 216, 0.24) 1px, transparent 1px),
        linear-gradient(rgba(183, 198, 216, 0.24) 1px, transparent 1px),
        #fbfdff;
    background-size: 24px 24px;
}

.array-visual {
    min-height: 338px;
    display: flex;
    align-items: end;
    justify-content: center;
    gap: clamp(8px, 1.1vw, 14px);
}

.bar-wrap {
    min-width: 38px;
    max-width: 76px;
    flex: 1 1 44px;
    display: grid;
    grid-template-rows: auto 1fr auto;
    gap: 8px;
    align-items: end;
    justify-items: center;
}

.bar-pointer {
    height: 22px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--algo-amber);
    font-size: 0.74rem;
    font-weight: 900;
}

.bar {
    width: 100%;
    min-height: 22px;
    border-radius: 7px 7px 4px 4px;
    border: 1px solid rgba(37, 99, 235, 0.2);
    background: linear-gradient(180deg, #60a5fa, var(--algo-blue));
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.35), 0 10px 18px rgba(37, 99, 235, 0.16);
    transition: height 0.26s ease, background 0.18s ease, transform 0.18s ease;
}

.bar.compare {
    border-color: rgba(217, 119, 6, 0.36);
    background: linear-gradient(180deg, #fbbf24, var(--algo-amber));
}

.bar.swap,
.bar.move {
    border-color: rgba(220, 38, 38, 0.3);
    background: linear-gradient(180deg, #fb7185, var(--algo-red));
    transform: translateY(-8px);
}

.bar.sorted,
.bar.found,
.bar.active {
    border-color: rgba(22, 163, 74, 0.3);
    background: linear-gradient(180deg, #86efac, var(--algo-green));
}

.bar.pivot {
    border-color: rgba(124, 58, 237, 0.3);
    background: linear-gradient(180deg, #c4b5fd, var(--algo-purple));
}

.bar.discarded {
    opacity: 0.34;
    filter: saturate(0.4);
}

.bar-label {
    display: grid;
    place-items: center;
    min-width: 34px;
    min-height: 28px;
    padding: 0 6px;
    border-radius: 7px;
    color: var(--algo-ink);
    background: #fff;
    border: 1px solid var(--algo-line);
    font-family: var(--algo-mono);
    font-size: 0.86rem;
    font-weight: 800;
}

.linear-visual,
.hash-visual {
    min-height: 338px;
    display: grid;
    align-content: center;
    gap: 18px;
}

.node-row,
.bucket-row,
.heap-array {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    align-items: center;
    justify-content: center;
}

.ds-node,
.bucket-cell,
.queue-slot,
.stack-cell {
    min-width: 58px;
    min-height: 48px;
    display: grid;
    place-items: center;
    border: 1px solid var(--algo-line-strong);
    border-radius: 7px;
    background: #fff;
    color: var(--algo-ink);
    font-family: var(--algo-mono);
    font-weight: 900;
    box-shadow: 0 8px 18px rgba(32, 44, 63, 0.08);
}

.ds-node.active,
.queue-slot.active,
.stack-cell.active,
.bucket-cell.active {
    color: #fff;
    border-color: var(--algo-teal);
    background: var(--algo-teal);
}

.ds-node.visited,
.queue-slot.visited,
.stack-cell.visited,
.bucket-cell.visited {
    border-color: var(--algo-green);
    background: var(--algo-green-soft);
}

.ds-node.target,
.bucket-cell.target {
    border-color: var(--algo-amber);
    background: var(--algo-amber-soft);
}

.arrow-link {
    color: var(--algo-muted);
    font-family: var(--algo-heading);
    font-weight: 800;
}

.stack-column {
    width: min(100%, 220px);
    margin: 0 auto;
    display: flex;
    flex-direction: column-reverse;
    gap: 8px;
}

.stack-cell {
    min-height: 44px;
}

.queue-lane {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 8px;
}

.queue-labels {
    display: flex;
    justify-content: center;
    gap: 10px;
    color: var(--algo-muted);
    font-size: 0.82rem;
    font-weight: 800;
}

.svg-stage {
    width: 100%;
    min-height: 338px;
    display: block;
}

.edge-line {
    stroke: #94a3b8;
    stroke-width: 2.3;
}

.edge-line.active {
    stroke: var(--algo-amber);
    stroke-width: 3.3;
}

.edge-label {
    fill: var(--algo-muted);
    font-family: var(--algo-mono);
    font-size: 12px;
    font-weight: 700;
}

.graph-node,
.tree-node {
    fill: #fff;
    stroke: var(--algo-blue);
    stroke-width: 2.4;
}

.graph-node.active,
.tree-node.active {
    fill: var(--algo-amber-soft);
    stroke: var(--algo-amber);
    stroke-width: 3.4;
}

.graph-node.visited,
.tree-node.visited {
    fill: var(--algo-green-soft);
    stroke: var(--algo-green);
}

.graph-node.found,
.tree-node.found {
    fill: var(--algo-teal);
    stroke: var(--algo-teal);
}

.node-label {
    fill: var(--algo-ink);
    font-family: var(--algo-mono);
    font-size: 13px;
    font-weight: 900;
    text-anchor: middle;
    dominant-baseline: central;
}

.node-label.on-dark {
    fill: #fff;
}

.bucket-row {
    justify-content: stretch;
}

.bucket-label {
    width: 54px;
    color: var(--algo-muted);
    font-family: var(--algo-mono);
    font-weight: 800;
}

.bucket-chain {
    min-height: 48px;
    display: flex;
    flex: 1;
    flex-wrap: wrap;
    gap: 8px;
    align-items: center;
}

.playback-panel {
    gap: 14px;
    min-height: 56px;
    padding: 10px;
    border: 1px solid var(--algo-line);
    border-radius: var(--algo-radius);
    background: #fff;
}

.transport-buttons {
    gap: 8px;
}

.icon-button {
    width: 38px;
    height: 38px;
    display: inline-grid;
    place-items: center;
    color: var(--algo-muted);
}

.icon-button svg {
    width: 20px;
    height: 20px;
    fill: none;
    stroke: currentColor;
    stroke-width: 2.4;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.speed-control {
    grid-template-columns: auto minmax(150px, 220px) 46px;
    gap: 8px;
    align-items: center;
}

input[type="range"] {
    accent-color: var(--algo-teal);
}

#speedValue {
    color: var(--algo-muted);
    font-size: 0.78rem;
    font-family: var(--algo-mono);
    font-weight: 800;
}

.timeline {
    width: min(24%, 220px);
    min-width: 140px;
    height: 8px;
    overflow: hidden;
    border-radius: 999px;
    background: #e8eef5;
}

.timeline-fill {
    width: 0;
    height: 100%;
    border-radius: inherit;
    background: linear-gradient(90deg, var(--algo-teal), var(--algo-blue));
    transition: width 0.2s ease;
}

.inspector-panel {
    display: grid;
    grid-template-rows: auto minmax(220px, 1fr) minmax(150px, 0.72fr);
    gap: 12px;
    padding: 14px;
    overflow: hidden;
}

.inspector-section {
    min-height: 0;
    display: grid;
    grid-template-rows: auto auto 1fr;
    gap: 10px;
}

.code-section {
    grid-template-rows: auto 1fr;
}

.section-title {
    gap: 10px;
}

.section-title h2 {
    font-size: 1rem;
}

#stateBadge {
    padding: 0 9px;
    color: var(--algo-amber);
    background: var(--algo-amber-soft);
}

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

.state-grid div {
    min-width: 0;
    padding: 8px;
    border: 1px solid var(--algo-line);
    border-radius: 7px;
    background: var(--algo-surface-2);
}

.state-grid dt {
    color: var(--algo-muted);
    font-size: 0.72rem;
    font-weight: 800;
}

.state-grid dd {
    margin: 4px 0 0;
    overflow-wrap: anywhere;
    font-family: var(--algo-mono);
    font-size: 0.84rem;
    font-weight: 800;
}

.step-description {
    margin: 0;
    min-height: 78px;
    padding: 10px;
    overflow: auto;
    border: 1px solid var(--algo-line);
    border-radius: 7px;
    background: #fff;
    color: var(--algo-muted);
    line-height: 1.62;
}

.pseudo-code {
    margin: 0;
    padding: 0;
    list-style: none;
    display: grid;
    grid-auto-rows: max-content;
    align-content: start;
    gap: 5px;
    overflow: auto;
}

.pseudo-code li {
    display: grid;
    grid-template-columns: 28px 1fr;
    gap: 8px;
    align-items: start;
    padding: 7px 8px;
    border-radius: 7px;
    color: var(--algo-muted);
    background: var(--algo-surface-2);
    font-family: var(--algo-mono);
    font-size: 0.78rem;
    line-height: 1.45;
}

.pseudo-code .line-no {
    color: #92a0b2;
    text-align: right;
}

.pseudo-code li.active {
    color: var(--algo-ink);
    background: var(--algo-amber-soft);
    box-shadow: inset 3px 0 0 var(--algo-amber);
}

.step-log {
    min-height: 0;
    overflow: auto;
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.log-row {
    display: grid;
    grid-template-columns: 42px 1fr;
    gap: 8px;
    align-items: start;
    padding: 8px;
    border-radius: 7px;
    background: var(--algo-surface-2);
    color: var(--algo-muted);
    font-size: 0.78rem;
    line-height: 1.45;
}

.log-row.active {
    color: var(--algo-ink);
    background: var(--algo-blue-soft);
}

.log-index {
    font-family: var(--algo-mono);
    font-weight: 900;
    color: var(--algo-blue);
}

.empty-visual {
    min-height: 330px;
    display: grid;
    place-items: center;
    color: var(--algo-muted);
    font-weight: 800;
}

@media (max-width: 1280px) {
    .workbench {
        grid-template-columns: minmax(210px, 250px) minmax(0, 1fr);
        height: auto;
        min-height: auto;
    }

    .inspector-panel {
        grid-column: 1 / -1;
        grid-template-columns: 1fr 1fr 1fr;
        grid-template-rows: minmax(240px, auto);
    }

    .inspector-section {
        min-height: 240px;
    }
}

@media (max-width: 920px) {
    .algorithm-shell {
        padding: 10px;
    }

    .app-topbar {
        height: auto;
        min-height: 58px;
        align-items: flex-start;
        flex-direction: column;
        padding: 12px;
    }

    .top-links {
        justify-content: flex-start;
    }

    .workbench {
        grid-template-columns: 1fr;
        min-height: auto;
        height: auto;
    }

    .library-panel {
        position: static;
    }

    .algorithm-list {
        grid-template-columns: repeat(2, minmax(0, 1fr));
        max-height: none;
    }

    .input-strip {
        grid-template-columns: 1fr 1fr;
    }

    .data-field {
        grid-column: 1 / -1;
    }

    .canvas-shell {
        min-height: 380px;
    }

    .visual-stage {
        min-height: 336px;
        padding: 16px;
    }

    .playback-panel {
        align-items: stretch;
        flex-direction: column;
    }

    .speed-control {
        grid-template-columns: auto 1fr 46px;
    }

    .timeline {
        width: 100%;
    }

    .inspector-panel {
        grid-template-columns: 1fr;
        grid-template-rows: auto;
    }
}

@media (max-width: 620px) {
    .category-tabs,
    .algorithm-list,
    .input-strip,
    .state-grid {
        grid-template-columns: 1fr;
    }

    .studio-header {
        align-items: flex-start;
        flex-direction: column;
    }

    .run-stats {
        justify-content: flex-start;
    }

    .bar-wrap {
        min-width: 30px;
    }

    .node-row,
    .bucket-row,
    .heap-array {
        justify-content: flex-start;
    }
}

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        scroll-behavior: auto !important;
        transition-duration: 0.01ms !important;
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
    }
}