:root {
    --bg: #0c0e12;
    --bg-raised: #13161c;
    --bg-card: #181b22;
    --bg-hover: #1e222b;
    --border: #252a35;
    --border-subtle: #1c2029;

    --text: #e8eaed;
    --text-secondary: #9ba1ad;
    --text-muted: #5a6170;

    --accent: #2563eb;
    --accent-dim: rgba(37, 99, 235, 0.12);
    --green: #16a34a;
    --green-dim: rgba(22, 163, 74, 0.12);
    --orange: #ea580c;
    --orange-dim: rgba(234, 88, 12, 0.12);

    --font-display: 'Crimson Pro', Georgia, serif;
    --font-body: 'DM Sans', -apple-system, sans-serif;
    --font-mono: 'JetBrains Mono', 'Menlo', monospace;

    --radius: 8px;
    --radius-lg: 12px;
}

:root.light {
    --bg: #f0f0f2;
    --bg-raised: #e8e8ec;
    --bg-card: #ebebef;
    --bg-hover: #dddde1;
    --border: #d4d4d8;
    --border-subtle: #e4e4e7;

    --text: #18181b;
    --text-secondary: #52525b;
    --text-muted: #a1a1aa;

    --accent: #2563eb;
    --accent-dim: rgba(37, 99, 235, 0.08);
    --green: #16a34a;
    --green-dim: rgba(22, 163, 74, 0.08);
    --orange: #ea580c;
    --orange-dim: rgba(234, 88, 12, 0.08);
}

*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    background: var(--bg);
    color: var(--text);
    font-family: var(--font-body);
    font-size: 14px;
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    -webkit-font-smoothing: antialiased;
}

.grain-overlay {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 9999;
    opacity: 0.025;
    background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)'/%3E%3C/svg%3E");
    background-repeat: repeat;
    background-size: 256px 256px;
}

:root.light .grain-overlay {
    display: none;
}

/* Theme Toggle */
.theme-toggle {
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 4px;
    display: flex;
    align-items: center;
    transition: color 0.15s;
}

.theme-toggle:hover {
    color: var(--text);
}

.theme-toggle svg {
    width: 18px;
    height: 18px;
}

.theme-toggle .icon-sun { display: none; }
.theme-toggle .icon-moon { display: block; }
:root.light .theme-toggle .icon-sun { display: block; }
:root.light .theme-toggle .icon-moon { display: none; }

/* Header */
header {
    border-bottom: 1px solid var(--border-subtle);
    padding: 16px 0;
}

.header-inner {
    max-width: 80%;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-mark {
    flex-shrink: 0;
}

.title-link {
    text-decoration: none;
    color: inherit;
}

h1 {
    font-family: var(--font-body);
    font-weight: 600;
    font-size: 20px;
    letter-spacing: -0.01em;
    color: var(--text);
}

.beta-badge {
    font-size: 7px;
    font-weight: 500;
    font-family: var(--font-mono);
    color: var(--accent);
    border: 1px solid var(--accent);
    border-radius: 2px;
    padding: 0px 3px;
    margin-left: 3px;
    vertical-align: top;
    letter-spacing: 0.04em;
    opacity: 0.8;
    position: relative;
    top: 2px;
}

.subtitle {
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-muted);
    margin-left: auto;
    font-weight: 500;
}

.header-nav {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-left: auto;
}

.nav-link {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-muted);
    text-decoration: none;
    letter-spacing: 0.02em;
    padding: 4px 8px;
    border-radius: 4px;
    transition: color 0.15s, background 0.15s;
}

.nav-link:hover {
    color: var(--text);
    background: var(--bg-hover);
}

.nav-link.active {
    color: var(--accent);
}

/* Nav Search */
.nav-search-wrap {
    position: relative;
}

.nav-search {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text);
    background: var(--bg-raised);
    border: 1px solid var(--border-subtle);
    border-radius: 4px;
    padding: 5px 10px;
    width: 200px;
    outline: none;
    transition: border-color 0.15s, background 0.15s, width 0.2s;
}

.nav-search::placeholder {
    color: var(--text-muted);
}

.nav-search:focus {
    border-color: var(--accent);
    background: var(--bg-card);
    width: 280px;
}

.nav-search-dropdown {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    margin-top: 4px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    max-height: 320px;
    overflow-y: auto;
    z-index: 100;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
    min-width: 280px;
}

.nav-search-dropdown.visible {
    display: block;
}

.nav-search-dropdown::-webkit-scrollbar {
    width: 6px;
}

.nav-search-dropdown::-webkit-scrollbar-track {
    background: transparent;
}

.nav-search-dropdown::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 3px;
}

.nav-search-item {
    padding: 7px 12px;
    font-family: var(--font-mono);
    font-size: 12px;
    color: var(--text-secondary);
    cursor: pointer;
    border-bottom: 1px solid var(--border-subtle);
    transition: background 0.1s, color 0.1s;
}

.nav-search-item:last-child {
    border-bottom: none;
}

.nav-search-item:hover,
.nav-search-item.selected {
    background: var(--bg-hover);
    color: var(--text);
}

/* Main */
main {
    max-width: 80%;
    width: 100%;
    margin: 0 auto;
    padding: 40px 24px 80px;
    flex: 1;
}

/* Hero */
.hero-section {
    text-align: center;
    max-width: 560px;
    margin: 20px auto 8px;
}

.hero-link {
    color: var(--text-secondary);
    text-decoration: underline;
    text-underline-offset: 2px;
    transition: color 0.15s;
}

.hero-link:hover {
    color: var(--text);
}

.hero-text {
    font-size: 13px;
    line-height: 1.7;
    color: var(--text-muted);
}
.try-example {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    margin: 16px 0 8px;
    font-family: var(--font-mono);
    font-size: 13px;
    color: var(--text-muted);
}
.try-example-label {
    color: var(--text-muted);
}
.try-instance-btn {
    display: inline-block;
    padding: 5px 14px;
    background: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-family: var(--font-mono);
    font-size: 13px;
    font-weight: 500;
    text-decoration: none;
    transition: border-color 0.15s, color 0.15s;
}
.try-instance-btn:hover {
    border-color: var(--text-muted);
    color: var(--accent);
}

/* Upload */
.upload-section {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.drop-zone {
    width: 100%;
    max-width: 640px;
    border: 1.5px dashed var(--border);
    border-radius: var(--radius-lg);
    background: var(--bg-raised);
    transition: border-color 0.2s, background 0.2s;
    cursor: pointer;
}

.drop-zone:hover,
.drop-zone.drag-over {
    border-color: var(--accent);
    background: var(--accent-dim);
}

.drop-zone-inner {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 56px 32px;
    gap: 8px;
}

.upload-icon {
    opacity: 0.5;
    margin-bottom: 8px;
}

.drop-text {
    font-family: var(--font-body);
    font-size: 15px;
    font-weight: 500;
    color: var(--text-secondary);
}

.drop-subtext {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-muted);
    letter-spacing: 0.02em;
}

.file-label {
    margin-top: 12px;
}

.file-label input {
    display: none;
}

.file-label span {
    font-size: 12px;
    color: var(--accent);
    cursor: pointer;
    border-bottom: 1px solid transparent;
    transition: border-color 0.15s;
    font-weight: 500;
}

.file-label span:hover {
    border-bottom-color: var(--accent);
}

.upload-status {
    margin-top: 16px;
    font-size: 13px;
    color: var(--text-muted);
    font-family: var(--font-mono);
    font-size: 12px;
}

.upload-status.error {
    color: #ef4444;
}

.upload-status.loading::after {
    content: '';
    display: inline-block;
    width: 12px;
    height: 12px;
    border: 1.5px solid var(--text-muted);
    border-top-color: var(--accent);
    border-radius: 50%;
    margin-left: 8px;
    vertical-align: middle;
    animation: spin 0.6s linear infinite;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Library */
.library-section {
    max-width: 640px;
    margin: 32px auto 0;
    width: 100%;
}

.library-header {
    font-family: var(--font-body);
    font-size: 13px;
    color: var(--text-muted);
    text-align: center;
    margin-bottom: 16px;
    font-weight: 500;
}

.library-search {
    width: 100%;
    padding: 12px 16px;
    font-family: var(--font-mono);
    font-size: 13px;
    color: var(--text);
    background: var(--bg-raised);
    border: 1.5px solid var(--border);
    border-radius: var(--radius);
    outline: none;
    transition: border-color 0.2s, background 0.2s;
    -webkit-appearance: none;
    appearance: none;
}

.library-search::placeholder {
    color: var(--text-muted);
}

.library-search:focus {
    border-color: var(--accent);
    background: var(--bg-card);
}

.library-list {
    max-height: 360px;
    overflow-y: auto;
    margin-top: 8px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: var(--bg-raised);
}

.library-list:empty {
    display: none;
}

.library-list::-webkit-scrollbar {
    width: 6px;
}

.library-list::-webkit-scrollbar-track {
    background: transparent;
}

.library-list::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 3px;
}

.library-item {
    padding: 9px 16px;
    font-family: var(--font-mono);
    font-size: 12.5px;
    color: var(--text-secondary);
    cursor: pointer;
    border-bottom: 1px solid var(--border-subtle);
    transition: background 0.1s, color 0.1s;
    letter-spacing: 0.01em;
}

.library-item:last-child {
    border-bottom: none;
}

.library-item:hover,
.library-item.selected {
    background: var(--bg-hover);
    color: var(--text);
}

/* Results */
.results-section {
    animation: fadeUp 0.4s ease-out;
}

@keyframes fadeUp {
    from { opacity: 0; transform: translateY(12px); }
    to { opacity: 1; transform: translateY(0); }
}

.results-header {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    margin-bottom: 28px;
}

.model-name {
    font-family: var(--font-body);
    font-weight: 600;
    font-size: 28px;
    letter-spacing: -0.02em;
    color: var(--text);
}

.parse-time {
    font-family: var(--font-mono);
    font-size: 13px;
    font-weight: 400;
    color: var(--text-muted);
    margin-left: 12px;
    opacity: 0.7;
}

.model-name::before {
    content: '//';
    color: var(--text-muted);
    margin-right: 10px;
    font-size: 22px;
    font-weight: 400;
}

.results-actions {
    display: flex;
    gap: 8px;
    align-items: center;
}

.btn-ghost {
    text-decoration: none;
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-muted);
    background: none;
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 6px 14px;
    cursor: pointer;
    transition: color 0.15s, border-color 0.15s;
    letter-spacing: 0.02em;
}

.btn-ghost:hover {
    color: var(--text);
    border-color: var(--text-muted);
}

.btn-ghost.active {
    color: var(--accent);
    border-color: var(--accent);
}

.btn-ghost:disabled {
    opacity: 0.5;
    cursor: default;
}

.solver-picker {
    display: flex;
    align-items: stretch;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
}

.solver-option {
    display: flex;
    align-items: center;
    gap: 4px;
    padding: 4px 10px;
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-secondary);
    background: none;
    border: none;
    cursor: pointer;
    transition: background 0.15s, color 0.15s;
}

.solver-option:first-child {
    border-right: 1px solid var(--border);
}

.solver-option:hover {
    background: var(--bg-hover);
    color: var(--text);
}

.solver-option.active {
    background: var(--bg-hover);
    color: var(--text);
    font-weight: 600;
}

.solver-logo {
    width: 16px;
    height: 16px;
    object-fit: contain;
}

/* Presolve Summary */
.presolve-summary {
    font-family: var(--font-body);
    font-size: 13px;
    color: var(--text-secondary);
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius);
    padding: 10px 16px;
    margin-bottom: 16px;
    line-height: 1.6;
}

.presolve-summary strong {
    color: var(--text);
    font-weight: 600;
}

.presolve-icon {
    margin-right: 4px;
}

.stat-delta {
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.01em;
}

.stat-delta.delta-down {
    color: var(--green);
}

.stat-delta.delta-up {
    color: var(--orange);
}

.stat-delta.delta-none {
    color: var(--text-muted);
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1px;
    background: var(--border-subtle);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    overflow: hidden;
    margin-bottom: 32px;
}

.stat-card {
    background: var(--bg-card);
    padding: 20px 24px;
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.stat-card:hover {
    background: var(--bg-hover);
}

.stat-value {
    font-family: var(--font-mono);
    font-size: 24px;
    font-weight: 400;
    color: var(--text);
    letter-spacing: -0.02em;
}

.stat-label {
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-muted);
    font-weight: 500;
}

.stat-card.accent-blue .stat-value { color: var(--orange); }
.stat-card.accent-green .stat-value { color: var(--green); }
.stat-card.accent-orange .stat-value { color: var(--accent); }

/* Legend */
.legend {
    display: flex;
    gap: 20px;
    margin-bottom: 32px;
    padding: 0 2px;
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 11px;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    font-weight: 500;
}

.legend-dot {
    width: 8px;
    height: 8px;
    border-radius: 2px;
}

.legend-dot.continuous { background: var(--orange); }
.legend-dot.integer { background: var(--green); }
.legend-dot.binary { background: var(--accent); }

/* Constraint Types */
.constraint-types {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 8px;
    margin-bottom: 24px;
}

.constraint-types:empty {
    display: none;
}

.type-label {
    font-family: var(--font-body);
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--text-muted);
    font-weight: 500;
    margin-right: 4px;
}

.type-tag {
    font-family: var(--font-mono);
    font-size: 11px;
    border-radius: 4px;
    padding: 3px 8px;
    cursor: pointer;
    transition: opacity 0.15s, box-shadow 0.15s;
    border: 1px solid transparent;
}

.type-tag:hover {
    opacity: 0.85;
}

.type-tag.active {
    box-shadow: 0 0 0 2px var(--text-muted);
}

.type-count {
    font-weight: 500;
}

/* Type tag colors — tinted grays */
.type-tag[data-type="set partitioning"] { background: rgba(139, 92, 246, 0.15); color: #a78bfa; }
.type-tag[data-type="set packing"]      { background: rgba(59, 130, 246, 0.15); color: #60a5fa; }
.type-tag[data-type="set covering"]     { background: rgba(16, 185, 129, 0.15); color: #34d399; }
.type-tag[data-type="cardinality"]      { background: rgba(245, 158, 11, 0.15); color: #fbbf24; }
.type-tag[data-type="knapsack"]         { background: rgba(239, 68, 68, 0.15); color: #f87171; }
.type-tag[data-type="bin. knapsack eq."]{ background: rgba(236, 72, 153, 0.15); color: #f472b6; }
.type-tag[data-type="integer knapsack"] { background: rgba(251, 146, 60, 0.15); color: #fb923c; }
.type-tag[data-type="variable bound"]   { background: rgba(6, 182, 212, 0.15); color: #22d3ee; }
.type-tag[data-type="bound"]            { background: rgba(148, 163, 184, 0.15); color: #94a3b8; }
.type-tag[data-type="mixed"]            { background: rgba(148, 163, 184, 0.1); color: #94a3b8; }
.type-tag[data-type="equality"]         { background: rgba(168, 85, 247, 0.15); color: #c084fc; }
.type-tag[data-type="continuous"]       { background: rgba(234, 88, 12, 0.15); color: #fb923c; }
.type-tag[data-type="pure binary"]      { background: rgba(37, 99, 235, 0.15); color: #60a5fa; }
.type-tag[data-type="mixed binary"]     { background: rgba(14, 165, 233, 0.15); color: #38bdf8; }
.type-tag[data-type="mixed integer"]    { background: rgba(22, 163, 74, 0.15); color: #4ade80; }
.type-tag[data-type="empty"]            { background: rgba(148, 163, 184, 0.08); color: #64748b; }

.constraint-type-tag[data-type="set partitioning"] { background: rgba(139, 92, 246, 0.12); color: #a78bfa; border-color: rgba(139, 92, 246, 0.2); }
.constraint-type-tag[data-type="set packing"]      { background: rgba(59, 130, 246, 0.12); color: #60a5fa; border-color: rgba(59, 130, 246, 0.2); }
.constraint-type-tag[data-type="set covering"]     { background: rgba(16, 185, 129, 0.12); color: #34d399; border-color: rgba(16, 185, 129, 0.2); }
.constraint-type-tag[data-type="cardinality"]      { background: rgba(245, 158, 11, 0.12); color: #fbbf24; border-color: rgba(245, 158, 11, 0.2); }
.constraint-type-tag[data-type="knapsack"]         { background: rgba(239, 68, 68, 0.12); color: #f87171; border-color: rgba(239, 68, 68, 0.2); }
.constraint-type-tag[data-type="bin. knapsack eq."]{ background: rgba(236, 72, 153, 0.12); color: #f472b6; border-color: rgba(236, 72, 153, 0.2); }
.constraint-type-tag[data-type="integer knapsack"] { background: rgba(251, 146, 60, 0.12); color: #fb923c; border-color: rgba(251, 146, 60, 0.2); }
.constraint-type-tag[data-type="variable bound"]   { background: rgba(6, 182, 212, 0.12); color: #22d3ee; border-color: rgba(6, 182, 212, 0.2); }
.constraint-type-tag[data-type="bound"]            { background: rgba(148, 163, 184, 0.1); color: #94a3b8; border-color: rgba(148, 163, 184, 0.15); }
.constraint-type-tag[data-type="mixed"]            { background: rgba(148, 163, 184, 0.08); color: #94a3b8; border-color: rgba(148, 163, 184, 0.12); }
.constraint-type-tag[data-type="equality"]         { background: rgba(168, 85, 247, 0.12); color: #c084fc; border-color: rgba(168, 85, 247, 0.2); }
.constraint-type-tag[data-type="continuous"]       { background: rgba(234, 88, 12, 0.12); color: #fb923c; border-color: rgba(234, 88, 12, 0.2); }
.constraint-type-tag[data-type="pure binary"]      { background: rgba(37, 99, 235, 0.12); color: #60a5fa; border-color: rgba(37, 99, 235, 0.2); }
.constraint-type-tag[data-type="mixed binary"]     { background: rgba(14, 165, 233, 0.12); color: #38bdf8; border-color: rgba(14, 165, 233, 0.2); }
.constraint-type-tag[data-type="mixed integer"]    { background: rgba(22, 163, 74, 0.12); color: #4ade80; border-color: rgba(22, 163, 74, 0.2); }
.constraint-type-tag[data-type="empty"]            { background: rgba(148, 163, 184, 0.06); color: #64748b; border-color: rgba(148, 163, 184, 0.1); }

.constraint-row.filtered-out {
    display: none;
}

/* Collapsible sections */
.collapsible {
    margin-top: 32px;
}

.collapsible summary {
    list-style: none;
}

.collapsible summary::-webkit-details-marker {
    display: none;
}

.section-header {
    display: flex;
    align-items: baseline;
    gap: 12px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border-subtle);
    cursor: pointer;
    user-select: none;
}

.section-header:hover h3 {
    color: var(--text-secondary);
}

.section-header h3 {
    font-family: var(--font-body);
    font-weight: 500;
    font-size: 16px;
    color: var(--text);
    transition: color 0.15s;
}

.chevron {
    margin-left: auto;
    display: inline-block;
    width: 0;
    height: 0;
    border-left: 5px solid transparent;
    border-right: 5px solid transparent;
    border-top: 5px solid var(--text-muted);
    transition: transform 0.2s;
}

.collapsible:not([open]) .chevron {
    transform: rotate(-90deg);
}

/* Objective */
.objective-expr {
    padding: 12px 0;
    margin-bottom: 8px;
}

/* Variables */
.variables-list {
    display: flex;
    flex-direction: column;
}

.variable-row {
    display: flex;
    align-items: baseline;
    gap: 16px;
    padding: 6px 0;
    border-bottom: 1px solid var(--border-subtle);
    font-family: var(--font-mono);
    font-size: 12.5px;
}

.variable-row:last-child {
    border-bottom: none;
}

.variable-name {
    font-weight: 500;
    min-width: 120px;
    flex-shrink: 0;
}

.variable-bounds {
    color: var(--text-muted);
}

.variable-obj {
    margin-left: auto;
    color: var(--text-muted);
    font-size: 11px;
}

/* Constraints */

.constraints-count {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-muted);
}

.constraints-list {
    display: flex;
    flex-direction: column;
}

.constraint-row {
    display: flex;
    align-items: baseline;
    gap: 16px;
    padding: 7px 0;
    border-bottom: 1px solid var(--border-subtle);
    animation: fadeIn 0.15s ease-out both;
}

.constraint-row:last-child {
    border-bottom: none;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.constraint-name {
    font-family: var(--font-mono);
    font-size: 10px;
    color: var(--text-muted);
    min-width: 64px;
    flex-shrink: 0;
    letter-spacing: 0.02em;
}

.constraint-tags {
    display: flex;
    gap: 3px;
    flex-shrink: 0;
    flex-wrap: wrap;
}

.constraint-type-tag {
    font-family: var(--font-mono);
    font-size: 9px;
    color: var(--text-muted);
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: 3px;
    padding: 1px 5px;
    flex-shrink: 0;
    text-transform: uppercase;
    letter-spacing: 0.03em;
    white-space: nowrap;
}

.constraint-expr {
    font-family: var(--font-mono);
    font-size: 12.5px;
    line-height: 1.7;
    color: var(--text-secondary);
    word-break: break-word;
}

.var-hover {
    cursor: pointer;
    border-bottom: 1px dashed currentColor;
    padding-bottom: 1px;
    transition: background 0.1s, box-shadow 0.1s;
    border-radius: 2px;
}

.var-highlight-hover {
    background: rgba(255, 255, 255, 0.1);
    box-shadow: 0 0 0 2px rgba(255, 255, 255, 0.06);
}

.var-highlight-persist {
    background: rgba(37, 99, 235, 0.18);
    box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.12);
}

:root.light .var-highlight-hover {
    background: rgba(0, 0, 0, 0.06);
    box-shadow: 0 0 0 2px rgba(0, 0, 0, 0.04);
}

:root.light .var-highlight-persist {
    background: rgba(37, 99, 235, 0.12);
    box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.08);
}

.var-tooltip {
    position: fixed;
    pointer-events: none;
    background: var(--bg-card);
    color: var(--text);
    border: 1px solid var(--border);
    border-radius: 6px;
    padding: 5px 10px;
    font-family: var(--font-mono);
    font-size: 11px;
    white-space: nowrap;
    transform: translate(-50%, -100%);
    opacity: 0;
    transition: opacity 0.1s;
    z-index: 1000;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

.var-tooltip.visible {
    opacity: 1;
}

.constraint-expr .var-continuous {
    color: var(--orange);
    font-weight: 500;
}

.constraint-expr .var-integer {
    color: var(--green);
    font-weight: 500;
}

.constraint-expr .var-binary {
    color: var(--accent);
    font-weight: 500;
}

.constraint-expr .coeff {
    color: var(--text);
}

.constraint-expr .op {
    color: var(--text-muted);
    margin: 0 2px;
}

.constraint-expr .relation {
    color: var(--text);
    margin: 0 6px;
    font-weight: 500;
}

.constraint-expr .bound-val {
    color: var(--text);
    font-weight: 400;
}

/* Sparsity Plot */
#sparsity-canvas {
    display: block;
    max-width: 100%;
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius);
    image-rendering: pixelated;
    margin-top: 12px;
    cursor: pointer;
    transition: opacity 0.15s;
}
#sparsity-canvas:hover {
    opacity: 0.85;
}

/* Sparsity fullscreen modal */
.sparsity-modal {
    display: none;
    position: fixed;
    inset: 0;
    z-index: 1000;
    align-items: center;
    justify-content: center;
}
.sparsity-modal.open {
    display: flex;
}
.sparsity-modal-backdrop {
    position: absolute;
    inset: 0;
    background: rgba(0, 0, 0, 0.75);
    backdrop-filter: blur(4px);
}
#sparsity-canvas-full {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    image-rendering: pixelated;
    cursor: grab;
}
.sparsity-modal-close {
    position: absolute;
    top: 16px;
    right: 16px;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    border: 1px solid var(--border);
    background: var(--bg-raised);
    color: var(--text-primary);
    font-size: 20px;
    line-height: 1;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1002;
    opacity: 0.7;
    transition: opacity 0.15s;
}
.sparsity-modal-close:hover {
    background: var(--bg-hover);
    opacity: 1;
}

/* Sparsity component tooltip */
.sparsity-tooltip {
    display: none;
    position: fixed;
    z-index: 1100;
    background: var(--bg-raised);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 10px 14px;
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-primary);
    pointer-events: none;
    box-shadow: 0 4px 20px rgba(0,0,0,0.25);
    min-width: 180px;
    max-width: 300px;
}
.sparsity-tooltip.visible { display: block; }
.stt-header {
    font-weight: 600;
    font-size: 12px;
    margin-bottom: 6px;
    padding-bottom: 5px;
    border-bottom: 1px solid var(--border-subtle);
}
.stt-row {
    display: flex;
    justify-content: space-between;
    gap: 12px;
    padding: 2px 0;
}
.stt-label {
    color: var(--text-muted);
}
.stt-var {
    margin-left: 4px;
}
.stt-var.continuous { color: var(--accent); }
.stt-var.integer { color: var(--green); }
.stt-var.binary { color: var(--orange); }
.stt-tags {
    margin-top: 6px;
    padding-top: 5px;
    border-top: 1px solid var(--border-subtle);
    display: flex;
    flex-wrap: wrap;
    gap: 4px;
}
.stt-tag {
    background: var(--bg);
    border: 1px solid var(--border-subtle);
    border-radius: 3px;
    padding: 1px 5px;
    font-size: 10px;
    color: var(--text-secondary);
    white-space: nowrap;
}

.stt-hint {
    margin-top: 5px;
    padding-top: 4px;
    border-top: 1px solid var(--border-subtle);
    font-size: 10px;
    color: var(--text-muted);
    text-align: center;
    font-style: italic;
}

/* Loading details indicator */
.loading-details {
    margin: 16px 0;
    padding: 14px 20px;
    font-family: var(--font-mono);
    font-size: 12px;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    gap: 10px;
}
.loading-details.hidden { display: none; }
.loading-details::before {
    content: '';
    display: inline-block;
    width: 16px;
    height: 16px;
    border: 2px solid var(--border);
    border-top-color: var(--text-muted);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    flex-shrink: 0;
}
@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Component filter banner */
.component-filter-banner {
    margin: 16px 0;
    padding: 14px 20px;
    font-family: var(--font-mono);
    font-size: 12px;
    color: var(--text-primary);
    background: var(--bg-raised);
    border: 1px solid var(--orange);
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
}
.component-filter-banner.hidden { display: none; }
.comp-banner-clear {
    margin-left: auto;
    background: none;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    color: var(--text-muted);
    font-family: var(--font-mono);
    font-size: 11px;
    padding: 2px 10px;
    cursor: pointer;
    white-space: nowrap;
}
.comp-banner-clear:hover {
    color: var(--text-primary);
    border-color: var(--text-muted);
}

/* Component info */
.components-info {
    margin-top: 12px;
    font-family: var(--font-mono);
    font-size: 12px;
    color: var(--text-secondary);
}
.comp-summary {
    display: block;
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: 8px;
}
.comp-table-wrap {
    max-height: 200px;
    overflow-y: auto;
}
.comp-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 11px;
}
.comp-table th, .comp-table td {
    padding: 4px 10px;
    text-align: right;
    border-bottom: 1px solid var(--border-subtle);
}
.comp-table th {
    text-align: right;
    font-weight: 500;
    color: var(--text-muted);
    position: sticky;
    top: 0;
    background: var(--bg);
}
.comp-table th:first-child, .comp-table td:first-child {
    text-align: left;
}

/* Show More */
.btn-show-more {
    width: 100%;
    margin-top: 8px;
    padding: 12px;
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-muted);
    background: var(--bg-raised);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    cursor: pointer;
    transition: color 0.15s, border-color 0.15s, background 0.15s;
    letter-spacing: 0.03em;
}

.btn-show-more:hover {
    color: var(--text);
    border-color: var(--text-muted);
    background: var(--bg-card);
}

/* Footer */
.site-footer {
    border-top: 1px solid var(--border-subtle);
    padding: 24px 0;
    margin-top: auto;
}

.footer-inner {
    max-width: 80%;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    font-size: 12px;
    color: var(--text-muted);
}

.footer-sep {
    color: var(--border);
}

.footer-powered {
    display: flex;
    align-items: center;
    gap: 5px;
    line-height: 1;
}

.footer-powered a {
    color: var(--text-muted);
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 4px;
    transition: color 0.15s;
    line-height: 0;
}

.footer-powered a:hover {
    color: var(--text-secondary);
}


.footer-developed {
    display: flex;
    align-items: center;
    gap: 4px;
}

.footer-developed .footer-link {
    display: inline-flex;
    align-items: center;
    gap: 4px;
}

.footer-icon {
    vertical-align: middle;
}

.claude-logo {
    width: 16px;
    height: 16px;
    border-radius: 3px;
}

.footer-logo {
    display: block;
    width: 20px;
    height: 20px;
    object-fit: contain;
    vertical-align: middle;
}

.scip-light { display: none !important; }
:root.light .scip-dark { display: none !important; }
:root.light .scip-light { display: inline !important; }


.footer-link {
    color: var(--text-muted);
    text-decoration: none;
    transition: color 0.15s;
}

.footer-link:hover {
    color: var(--text-secondary);
}

/* Instance Bank */
.collection-tag {
    font-family: var(--font-mono);
    font-size: 9px;
    padding: 1px 6px;
    border-radius: 3px;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    white-space: nowrap;
}

.collection-tag {
    color: var(--text-muted);
    border: 1px solid var(--border);
    cursor: pointer;
    transition: color 0.15s, border-color 0.15s;
}

.collection-tag:hover {
    color: var(--text);
    border-color: var(--text-muted);
}

/* Collection tag colors are generated dynamically via JS (collectionColor function) */

.instance-status {
    font-family: var(--font-mono);
    font-size: 9px;
    padding: 1px 6px;
    border-radius: 3px;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    white-space: nowrap;
    border: 1px solid;
}

.status-easy { color: #34d399; border-color: #34d399; }
.status-hard { color: #f87171; border-color: #f87171; }
.status-open { color: #fbbf24; border-color: #fbbf24; }

.miplib-tag {
    font-family: var(--font-mono);
    font-size: 8px;
    padding: 1px 4px;
    border-radius: 3px;
    letter-spacing: 0.03em;
    white-space: nowrap;
    border: 1px solid;
    opacity: 0.85;
    cursor: pointer;
    transition: opacity 0.15s;
}

.miplib-tag:hover {
    opacity: 1;
}

.tag-filter-btn {
    font-family: var(--font-mono);
    font-size: 9px;
    color: var(--text-muted);
    background: none;
    border: 1px solid var(--border-subtle);
    border-radius: 3px;
    padding: 2px 7px;
    cursor: pointer;
    transition: color 0.15s, border-color 0.15s;
    white-space: nowrap;
}

.tag-filter-btn:hover {
    color: var(--tag-color, var(--text));
    border-color: var(--tag-color, var(--text-muted));
}

.tag-filter-btn.active {
    color: var(--tag-color, var(--accent));
    border-color: var(--tag-color, var(--accent));
}

.col-tags {
    white-space: nowrap;
}

.bank-filters {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 6px;
    margin: 12px 0 0;
}

.filter-btn {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-muted);
    background: none;
    border: 1px solid var(--border-subtle);
    border-radius: 4px;
    padding: 4px 10px;
    cursor: pointer;
    transition: color 0.15s, border-color 0.15s;
}

.filter-btn:hover {
    color: var(--col-color, var(--text));
    border-color: var(--col-color, var(--text-muted));
}

.filter-btn.active {
    color: var(--col-color, var(--accent));
    border-color: var(--col-color, var(--accent));
}

.bank-section {
    width: 100%;
}

.bank-header {
    display: flex;
    align-items: baseline;
    gap: 12px;
    margin-bottom: 20px;
}

.bank-header h2 {
    font-family: var(--font-body);
    font-size: 24px;
    font-weight: 600;
    color: var(--text);
}

.bank-count {
    font-family: var(--font-mono);
    font-size: 12px;
    color: var(--text-muted);
}

.bank-sort {
    display: flex;
    align-items: center;
    gap: 6px;
    margin: 12px 0;
}

.sort-label {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-muted);
    margin-right: 4px;
}

.sort-btn {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-muted);
    background: none;
    border: 1px solid var(--border-subtle);
    border-radius: 4px;
    padding: 4px 10px;
    cursor: pointer;
    transition: color 0.15s, border-color 0.15s;
}

.sort-btn:hover {
    color: var(--text);
    border-color: var(--text-muted);
}

.sort-btn.active {
    color: var(--accent);
    border-color: var(--accent);
}

.bank-table-wrap {
    overflow-x: auto;
}

.bank-table {
    width: 100%;
    border-collapse: collapse;
    font-family: var(--font-mono);
    font-size: 12px;
}

.bank-table thead th {
    text-align: left;
    font-size: 10px;
    font-weight: 500;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: 8px 12px;
    border-bottom: 1px solid var(--border);
    white-space: nowrap;
}

.bank-table tbody tr {
    border-bottom: 1px solid var(--border-subtle);
    transition: background 0.1s;
}

.bank-table tbody tr:hover {
    background: var(--bg-hover);
}

.bank-table td {
    padding: 6px 12px;
    color: var(--text-secondary);
    white-space: nowrap;
}

.bank-table .col-name {
    font-weight: 500;
}

.bank-table .col-name a {
    color: var(--accent);
    text-decoration: none;
    transition: color 0.15s;
}

.bank-table .col-name a:hover {
    color: var(--text);
}

.bank-table .col-num {
    text-align: right;
    font-variant-numeric: tabular-nums;
}

.bank-status {
    text-align: center;
    padding: 40px;
    font-family: var(--font-mono);
    font-size: 12px;
    color: var(--text-muted);
}

/* Model Ranges */
.model-ranges {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 4px 12px;
    margin-bottom: 24px;
}

.model-ranges:empty {
    display: none;
}

.range-item {
    font-family: var(--font-mono);
    font-size: 11px;
    display: inline-flex;
    gap: 6px;
    align-items: baseline;
}

.range-label {
    color: var(--text-muted);
}

.range-value {
    color: var(--text-secondary);
    font-weight: 500;
}

/* Lagrangian Panel */
body.lr-panel-open main {
    max-width: calc(100% - 640px);
    margin-left: 0;
    margin-right: auto;
    padding-left: 40px;
    transition: max-width 0.25s ease, margin 0.25s ease, padding 0.25s ease;
}

body:not(.lr-panel-open) main {
    transition: max-width 0.25s ease, margin 0.25s ease, padding 0.25s ease;
}

.lagrangian-panel {
    position: fixed;
    right: 0;
    top: 0;
    bottom: 0;
    width: 640px;
    background: var(--bg);
    border-left: 1px solid var(--border);
    z-index: 50;
    transform: translateX(100%);
    transition: transform 0.25s ease;
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.lagrangian-panel * {
    max-width: 100%;
    box-sizing: border-box;
}

.lagrangian-panel.open {
    transform: translateX(0);
}

.lr-header {
    position: relative;
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    padding: 16px 20px 12px;
    border-bottom: 1px solid var(--border-subtle);
    flex-shrink: 0;
}

.lr-title {
    font-family: var(--font-body);
    font-size: 14px;
    font-weight: 600;
    color: var(--text);
}

.lr-subtitle {
    font-size: 11px;
    color: var(--text-muted);
    margin-top: 2px;
}

.lr-help {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    border: 1px solid var(--text-muted);
    font-size: 9px;
    color: var(--text-muted);
    cursor: pointer;
    vertical-align: middle;
    margin-left: 4px;
    transition: color 0.15s, border-color 0.15s;
}

.lr-help:hover {
    color: var(--text);
    border-color: var(--text);
}

.lr-help-popover {
    position: absolute;
    top: 56px;
    left: 20px;
    right: 20px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.25);
    padding: 14px 16px;
    max-width: 340px;
    z-index: 60;
    font-family: var(--font-body);
    font-size: 12px;
    font-weight: 400;
    color: var(--text-secondary);
    line-height: 1.6;
}

.lr-help-popover p {
    margin-bottom: 8px;
}

.lr-help-popover .lr-help-formula {
    text-align: center;
    margin: 10px 0;
}

.lr-help-popover code {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text);
    background: var(--bg-hover);
    padding: 1px 5px;
    border-radius: 3px;
}

.lr-help-popover ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.lr-help-popover li {
    padding: 3px 0;
    padding-left: 12px;
    position: relative;
}

.lr-help-popover li::before {
    content: '·';
    position: absolute;
    left: 0;
    color: var(--text-muted);
    font-weight: 700;
}

.lr-help-popover strong {
    color: var(--text);
    font-weight: 600;
}

.lr-close {
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 20px;
    cursor: pointer;
    padding: 0 4px;
    line-height: 1;
    transition: color 0.15s;
}

.lr-close:hover {
    color: var(--text);
}

.lr-pills {
    display: flex;
    flex-wrap: wrap;
    align-content: flex-start;
    gap: 6px;
    padding: 12px 20px;
    overflow-y: auto;
    flex: 0 1 auto;
    max-height: 30%;
}

.lr-pills:empty {
    display: none;
}

.lr-actions {
    padding: 8px 20px 16px;
    flex-shrink: 0;
}

.lr-clear-btn {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-muted);
    background: none;
    border: 1px solid var(--border-subtle);
    border-radius: 4px;
    padding: 5px 12px;
    cursor: pointer;
    transition: color 0.15s, border-color 0.15s;
}

.lr-clear-btn:hover {
    color: var(--text);
    border-color: var(--text-muted);
}

.lr-pill {
    font-family: var(--font-mono);
    font-size: 11px;
    padding: 3px 10px;
    border: 1px solid;
    border-radius: 4px;
    cursor: pointer;
    transition: opacity 0.15s;
}

.lr-pill:hover {
    opacity: 0.7;
}

.lr-pill-x {
    margin-left: 4px;
    opacity: 0.5;
}

.lr-chart-wrap {
    padding: 0 20px;
    overflow: hidden;
    flex-shrink: 0;
}

.lr-chart-wrap canvas {
    display: block;
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius);
}

.lr-info {
    padding: 12px 20px;
    overflow-y: auto;
    flex: 1 1 0;
    min-height: 0;
}

.lr-info-row {
    display: flex;
    align-items: baseline;
    gap: 12px;
    font-family: var(--font-mono);
    font-size: 11px;
    margin-bottom: 6px;
}

.lr-info-name {
    font-weight: 500;
    min-width: 40px;
}

.lr-info-val {
    color: var(--text-secondary);
}

/* Constraint name clickable for Lagrangian */
.constraint-name {
    cursor: pointer;
    border: 1px solid transparent;
    border-radius: 3px;
    padding: 1px 4px;
    margin: -1px -4px;
    transition: border-color 0.15s, background 0.15s;
}

.constraint-name:hover {
    border-color: var(--border);
    background: var(--bg-hover);
}

.constraint-name.lr-active {
    border-color: currentColor;
    background: var(--bg-hover);
}

.btn-plot-all-lr {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-muted);
    background: var(--bg-raised);
    border: 1px solid var(--border-subtle);
    border-radius: 4px;
    padding: 5px 12px;
    cursor: pointer;
    margin: 8px 0;
    transition: color 0.15s, border-color 0.15s;
}

.btn-plot-all-lr:hover {
    color: var(--text);
    border-color: var(--text-muted);
}

@media (max-width: 900px) {
    .lagrangian-panel {
        width: 100%;
    }
    body.lr-panel-open main {
        max-width: 100%;
        padding-left: 24px;
    }
}

/* Definitions Page */
.definitions-section {
    max-width: 80%;
    margin: 0 auto;
    padding: 40px 24px;
}

.definitions-title {
    font-family: var(--font-body);
    font-size: 24px;
    font-weight: 600;
    color: var(--text);
    margin-bottom: 8px;
}

.definitions-intro {
    font-size: 13px;
    color: var(--text-secondary);
    margin-bottom: 32px;
    line-height: 1.7;
}

.definitions-category {
    font-family: var(--font-body);
    font-size: 16px;
    font-weight: 600;
    color: var(--text);
    margin-bottom: 4px;
    margin-top: 32px;
}

.definitions-category:first-of-type {
    margin-top: 0;
}

.definitions-category-desc {
    font-size: 12px;
    color: var(--text-muted);
    margin-bottom: 16px;
}

.definitions-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 12px;
    margin-bottom: 24px;
}

.definition-card {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius);
    padding: 16px;
}

.definition-card .type-tag {
    cursor: default;
    margin-bottom: 8px;
    display: inline-block;
}

.definition-card p {
    font-size: 12px;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-top: 8px;
}

.definition-formula {
    margin-top: 10px;
    font-size: 14px;
    color: var(--text);
    text-align: center;
}

.type-info-link {
    font-family: var(--font-mono);
    font-size: 10px;
    color: var(--text-muted);
    text-decoration: none;
    margin-left: 8px;
    opacity: 0.7;
    transition: opacity 0.15s, color 0.15s;
}

.type-info-link:hover {
    opacity: 1;
    color: var(--text-secondary);
}

/* ── Matrix Explorer Page ─────────────────────────────────────────── */

.matrix-page {
    overflow: hidden;
}

.matrix-page header {
    flex-shrink: 0;
}

.matrix-loading {
    display: flex;
    align-items: center;
    justify-content: center;
    flex: 1;
}

.matrix-loading-text {
    font-family: var(--font-mono);
    font-size: 13px;
    color: var(--text-muted);
    letter-spacing: 0.5px;
}

.matrix-container {
    flex: 1;
    position: relative;
    overflow: hidden;
}

.matrix-container canvas {
    display: block;
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
}

.matrix-minimap {
    display: none;
    position: absolute;
    bottom: 84px;
    left: 12px;
    width: 160px;
    height: 120px;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    z-index: 10;
    cursor: pointer;
    opacity: 0.85;
    transition: opacity 0.15s;
}

.matrix-minimap:hover {
    opacity: 1;
}

.minimap-viewport {
    position: absolute;
    border: 1.5px solid var(--accent);
    border-radius: 1px;
    pointer-events: none;
    background: rgba(37, 99, 235, 0.06);
}

.matrix-info {
    display: none;
    position: absolute;
    top: 12px;
    left: 12px;
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-secondary);
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 4px 10px;
    pointer-events: none;
    z-index: 10;
}

.stepper-bar {
    display: flex;
    flex-direction: column;
    padding: 8px 20px 10px;
    background: var(--bg-raised);
    border-top: 1px solid var(--border);
    gap: 6px;
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    z-index: 20;
}

.stepper-top {
    display: flex;
    align-items: center;
    gap: 16px;
}

.stepper-left {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-shrink: 0;
}

.stepper-right {
    flex-shrink: 0;
    margin-left: auto;
}

.step-btn {
    font-family: var(--font-mono);
    font-size: 13px;
    color: var(--text-secondary);
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 4px 12px;
    cursor: pointer;
    transition: color 0.15s, border-color 0.15s, background 0.15s;
}

.step-btn:hover:not(:disabled) {
    color: var(--text);
    border-color: var(--text-muted);
    background: var(--bg-hover);
}

.step-btn:disabled {
    opacity: 0.3;
    cursor: not-allowed;
}

.step-label {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-muted);
    white-space: nowrap;
}

.step-info {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-secondary);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    flex: 1;
    min-width: 0;
}

.step-type {
    color: var(--accent);
    font-weight: 500;
}

.step-source {
    color: var(--text-muted);
}

.step-desc {
    color: var(--text-secondary);
}

.step-play {
    font-size: 10px;
    padding: 4px 8px;
    letter-spacing: -1px;
}

.step-reset {
    font-size: 11px;
    padding: 4px 10px;
}

.stepper-slider-wrap {
    padding: 0 2px;
}

.step-slider {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 4px;
    background: var(--border);
    border-radius: 2px;
    outline: none;
    cursor: pointer;
}

.step-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--accent);
    cursor: pointer;
    border: 2px solid var(--bg-raised);
    box-shadow: 0 0 4px rgba(37, 99, 235, 0.4);
    transition: transform 0.1s;
}

.step-slider::-webkit-slider-thumb:hover {
    transform: scale(1.2);
}

.step-slider::-moz-range-thumb {
    width: 14px;
    height: 14px;
    border-radius: 50%;
    background: var(--accent);
    cursor: pointer;
    border: 2px solid var(--bg-raised);
    box-shadow: 0 0 4px rgba(37, 99, 235, 0.4);
}

.step-slider::-webkit-slider-runnable-track {
    height: 4px;
    border-radius: 2px;
}

.step-slider::-moz-range-track {
    height: 4px;
    border-radius: 2px;
    background: var(--border);
}

.reduction-panel {
    position: absolute;
    top: 12px;
    right: 12px;
    width: 300px;
    max-height: calc(100% - 24px);
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
    z-index: 15;
    overflow-y: auto;
    font-family: var(--font-mono);
    font-size: 11px;
}

.reduction-panel-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 14px;
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    background: var(--bg-card);
}

.reduction-panel-title {
    font-weight: 500;
    color: var(--text-secondary);
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.reduction-panel-close {
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 16px;
    cursor: pointer;
    padding: 0 2px;
    line-height: 1;
    transition: color 0.15s;
}

.reduction-panel-close:hover {
    color: var(--text);
}

.reduction-panel-body {
    padding: 12px 14px;
}

.rdp-section {
    margin-bottom: 14px;
}

.rdp-section:last-child {
    margin-bottom: 0;
}

.rdp-label {
    color: var(--text-muted);
    font-size: 10px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 4px;
}

.rdp-value {
    color: var(--text);
    line-height: 1.6;
    word-break: break-word;
}

.rdp-type {
    color: var(--accent);
    font-weight: 500;
}

.rdp-source {
    color: var(--text-secondary);
}

.rdp-tag {
    display: inline-block;
    padding: 1px 6px;
    border-radius: 3px;
    font-size: 10px;
    font-weight: 500;
}

.rdp-tag-row {
    background: rgba(234, 88, 12, 0.12);
    color: var(--orange);
    border: 1px solid rgba(234, 88, 12, 0.25);
}

.rdp-tag-col {
    background: var(--accent-dim);
    color: var(--accent);
    border: 1px solid rgba(37, 99, 235, 0.25);
}

.rdp-tag-var {
    padding: 1px 5px;
    border-radius: 3px;
    font-size: 10px;
}

.rdp-tag-var.continuous { color: var(--accent); }
.rdp-tag-var.integer { color: var(--green); }
.rdp-tag-var.binary { color: var(--orange); }

.rdp-terms {
    max-height: 120px;
    overflow-y: auto;
    margin-top: 4px;
    padding: 6px 8px;
    background: var(--bg-hover);
    border-radius: 4px;
    line-height: 1.8;
}

.rdp-term-coeff {
    color: var(--text);
}

.rdp-term-var {
    color: var(--text-secondary);
}

.rdp-divider {
    border: none;
    border-top: 1px solid var(--border-subtle);
    margin: 10px 0;
}

.rdp-stats-row {
    display: flex;
    justify-content: space-between;
    padding: 2px 0;
    color: var(--text-secondary);
}

.rdp-stats-val {
    color: var(--text);
}

/* Utilities */
.hidden {
    display: none !important;
}

/* Responsive */
@media (max-width: 640px) {
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .model-name {
        font-size: 24px;
    }

    .constraint-name {
        min-width: 48px;
    }

    .drop-zone-inner {
        padding: 40px 20px;
    }
}

/* Solve MIP Modal */
.solve-modal {
    position: fixed;
    inset: 0;
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(4px);
}

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

.solve-modal-content {
    background: var(--bg-raised);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    width: min(1100px, 95vw);
    max-height: 90vh;
    display: flex;
    flex-direction: column;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.4);
}

.solve-modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 20px;
    border-bottom: 1px solid var(--border);
}

.solve-modal-header h3 {
    font-family: var(--font-mono);
    font-size: 14px;
    font-weight: 400;
    margin: 0;
}

.solve-modal-close {
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 24px;
    cursor: pointer;
    padding: 0 4px;
    line-height: 1;
}

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

.solve-log {
    flex: 1;
    overflow: auto;
    padding: 16px 20px;
    margin: 0;
    font-family: var(--font-mono);
    font-size: 12px;
    line-height: 1.5;
    color: var(--text-secondary);
    background: var(--bg);
    min-height: 300px;
    max-height: 75vh;
    white-space: pre;
}

.solve-modal-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 20px;
    border-top: 1px solid var(--border);
    gap: 12px;
}

.solve-modal-footer.hidden {
    display: none;
}

#solve-modal-status {
    font-family: var(--font-mono);
    font-size: 13px;
    color: var(--green);
}

/* Single-constraint solve */
.constraint-solve-btn {
    background: none;
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--text-muted);
    font-size: 10px;
    cursor: pointer;
    padding: 1px 5px;
    margin-right: 6px;
    line-height: 1.2;
    transition: color 0.15s, border-color 0.15s;
    flex-shrink: 0;
}

.constraint-solve-btn:hover {
    color: var(--accent);
    border-color: var(--accent);
}

.constraint-solve-btn:disabled {
    opacity: 0.5;
    cursor: wait;
}

.constraint-filter-btn {
    background: none;
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--text-muted);
    cursor: pointer;
    font-size: 11px;
    padding: 1px 5px;
    margin-right: 4px;
    line-height: 1;
    flex-shrink: 0;
}
.constraint-filter-btn:hover {
    color: var(--accent);
    border-color: var(--accent);
}
.constraint-filter-btn.active {
    color: var(--accent);
    border-color: var(--accent);
    background: rgba(37, 99, 235, 0.1);
}

.constraint-solve-result {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--green);
    margin-right: 8px;
    flex-shrink: 0;
}

.constraint-solve-table {
    width: 100%;
    margin-top: 8px;
    padding: 8px 0 4px 0;
    border-top: 1px solid var(--border-subtle);
}

.constraint-solve-summary {
    font-family: var(--font-mono);
    font-size: 12px;
    color: var(--green);
    margin-bottom: 6px;
}

.constraint-solve-table table {
    width: 100%;
    border-collapse: collapse;
    font-family: var(--font-mono);
    font-size: 11px;
}

.constraint-solve-table th {
    text-align: left;
    color: var(--text-muted);
    font-weight: 400;
    padding: 2px 8px 2px 0;
    border-bottom: 1px solid var(--border-subtle);
}

.constraint-solve-table td {
    padding: 2px 8px 2px 0;
    color: var(--text-secondary);
}

.constraint-solve-table .zero-summary td {
    color: var(--text-muted);
    font-style: italic;
    padding-top: 4px;
}

.constraint-solve-table .fractional {
    color: var(--orange);
    font-weight: 500;
}

.constraints-toolbar {
    display: flex;
    gap: 8px;
    margin-bottom: 8px;
}

/* LP solution values */
.variable-lp-val {
    font-family: var(--font-mono);
    font-size: 12px;
    color: var(--green);
    margin-left: 6px;
}

.variable-lp-val.fractional {
    color: var(--orange);
    font-weight: 500;
}