:root {
    --canvas: #f4f6f8;
    --surface: #ffffff;
    --ink: #0f172a;
    --muted: #4b5563;
    --line: #d7dde5;
    --tech: #2563eb;
    --tech-deep: #1d4ed8;
    --wide: 1140px;
    --narrow: 720px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    background: var(--canvas);
    color: var(--muted);
    font: 15px/1.55 "Source Sans 3", "Segoe UI", Tahoma, sans-serif;
}

img {
    max-width: 100%;
    height: auto;
}

a {
    color: inherit;
    text-decoration: none;
}

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

.hidden {
    display: none !important;
}

.skip {
    position: absolute;
    left: 8px;
    top: -40px;
    background: var(--tech);
    color: #fff;
    padding: 8px 12px;
    z-index: 80;
}

.skip:focus {
    top: 8px;
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.icon {
    width: 22px;
    height: 22px;
    display: inline-block;
    vertical-align: middle;
}

.icon-sm {
    width: 14px;
    height: 14px;
}

.site-logo {
    display: block;
    height: 36px;
    width: auto;
    max-width: 190px;
}

.wrap {
    width: min(var(--wide), calc(100% - 40px));
    margin-inline: auto;
}

.wrap-narrow {
    width: min(var(--narrow), calc(100% - 40px));
    margin-inline: auto;
}

.topbar {
    background: var(--ink);
    color: #cbd5e1;
    font-size: 12px;
}

.topbar-in {
    display: flex;
    align-items: center;
    justify-content: flex-end;
    gap: 20px;
    min-height: 34px;
}

.topbar a:hover {
    color: #fff;
}

.mast {
    background: #fff;
    border-bottom: 1px solid var(--line);
    position: sticky;
    top: 0;
    z-index: 40;
}

.mast-in {
    display: flex;
    align-items: center;
    gap: 20px;
    min-height: 72px;
}

.nav {
    display: flex;
    align-items: center;
    gap: 2px;
    margin-left: auto;
}

.nav a,
.nav-btn {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 10px 12px;
    color: var(--ink);
    font-weight: 600;
    font-size: 14px;
    background: none;
    border: 0;
    cursor: pointer;
}

.nav a:hover,
.nav-btn:hover,
.nav a.is-on,
.nav-btn.is-on {
    color: var(--tech);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 42px;
    padding: 0 18px;
    border: 1px solid var(--tech);
    background: var(--tech);
    color: #fff;
    font-weight: 700;
    font-size: 14px;
    letter-spacing: 0.02em;
    cursor: pointer;
}

.btn:hover {
    background: var(--tech-deep);
    border-color: var(--tech-deep);
    color: #fff;
}

.btn-ghost {
    background: #fff;
    color: var(--ink);
    border-color: #c5ced8;
}

.btn-ghost:hover {
    border-color: var(--ink);
    background: #fff;
    color: var(--ink);
}

.btn-info {
    text-transform: uppercase;
    letter-spacing: 0.06em;
    font-size: 13px;
    min-height: 40px;
}

.mast-cta {
    margin-left: 8px;
}

.burger {
    display: none;
    margin-left: auto;
}

.burger > summary {
    list-style: none;
    cursor: pointer;
    border: 1px solid var(--line);
    padding: 8px 12px;
    font-weight: 600;
    color: var(--ink);
}

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

.burger-list {
    position: absolute;
    right: 20px;
    top: 72px;
    width: 240px;
    background: #fff;
    border: 1px solid var(--line);
    padding: 8px;
    z-index: 50;
}

.burger-list a {
    display: block;
    padding: 10px 12px;
    color: var(--ink);
    font-weight: 600;
}

.mega {
    position: relative;
}

.mega-panel {
    display: none;
    position: absolute;
    left: 0;
    top: 100%;
    width: 520px;
    background: #fff;
    border: 1px solid var(--line);
    box-shadow: 0 8px 24px rgba(15, 23, 42, 0.08);
    padding: 12px;
    grid-template-columns: 1fr 1fr;
    gap: 4px;
}

.mega:hover .mega-panel,
.mega:focus-within .mega-panel {
    display: grid;
}

.mega-panel a {
    display: block;
    padding: 10px 12px;
}

.mega-panel strong {
    display: block;
    color: var(--ink);
    font-size: 14px;
}

.mega-panel span {
    display: block;
    color: var(--muted);
    font-size: 12px;
    font-weight: 400;
}

.mega-panel a:hover {
    background: var(--canvas);
}

.hero {
    position: relative;
    min-height: 420px;
    color: #fff;
    overflow: hidden;
}

.hero img {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.hero-shade {
    position: absolute;
    inset: 0;
    background: linear-gradient(90deg, rgba(15, 23, 42, 0.88) 0%, rgba(15, 23, 42, 0.55) 52%, rgba(15, 23, 42, 0.2) 100%);
}

.hero-in {
    position: relative;
    padding: 56px 0 48px;
    max-width: 34rem;
}

.hero-kicker {
    margin: 0 0 10px;
    font-size: 13px;
    font-weight: 700;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    color: #93c5fd;
}

.hero h1 {
    margin: 0;
    color: #fff;
    font-size: clamp(1.7rem, 3.2vw, 2.35rem);
    line-height: 1.25;
    font-weight: 700;
}

.hero p {
    margin: 14px 0 0;
    color: #e2e8f0;
    font-size: 16px;
}

.hero ul {
    margin: 16px 0 0;
    padding: 0 0 0 18px;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 22px;
}

.hero-credit {
    position: relative;
    display: block;
    padding: 6px 0 10px;
    font-size: 11px;
    color: #94a3b8;
}

.filter {
    background: #fff;
    border-bottom: 1px solid var(--line);
}

.filter-in {
    padding: 16px 0;
}

.filter p {
    margin: 0 0 6px;
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: #6b7280;
}

.filter-row {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-bottom: 10px;
}

.filter-row:last-child {
    margin-bottom: 0;
}

.chip {
    display: inline-block;
    border: 1px solid var(--line);
    background: #fff;
    color: var(--ink);
    padding: 6px 11px;
    font-size: 13px;
    font-weight: 600;
}

.chip.is-on {
    background: var(--ink);
    border-color: var(--ink);
    color: #fff;
}

.band {
    padding: 40px 0;
}

.band-white {
    background: #fff;
    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
}

.band h2 {
    margin: 0;
    color: var(--ink);
    font-size: 24px;
    font-weight: 700;
}

.band .lead {
    margin: 8px 0 0;
    max-width: 36rem;
}

.cat-tabs {
    display: flex;
    flex-wrap: wrap;
    gap: 0;
    margin: 22px 0 18px;
    border-bottom: 2px solid var(--line);
}

.cat-tab {
    appearance: none;
    border: 0;
    background: none;
    padding: 11px 16px;
    font-weight: 700;
    font-size: 14px;
    color: #6b7280;
    cursor: pointer;
    border-bottom: 3px solid transparent;
    margin-bottom: -2px;
}

.cat-tab.is-on {
    color: var(--tech);
    border-bottom-color: var(--tech);
}

.cat-panel {
    display: none;
}

.cat-panel.is-on {
    display: block;
}

.cat-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 14px;
}

.cat-card {
    display: flex;
    flex-direction: column;
    background: #fff;
    border: 1px solid var(--line);
    padding: 18px 16px 16px;
    min-height: 168px;
}

.cat-card .icon {
    color: var(--tech);
}

.cat-card h3 {
    margin: 12px 0 0;
    color: var(--ink);
    font-size: 16px;
    font-weight: 700;
}

.cat-card p {
    margin: 6px 0 0;
    font-size: 13px;
    flex: 1;
}

.more {
    margin-top: 12px;
    color: var(--tech);
    font-size: 13px;
    font-weight: 700;
}

.cat-card:hover {
    border-color: #93c5fd;
}

.scale-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 14px;
}

.scale-card {
    background: #fff;
    border: 1px solid var(--line);
    padding: 20px;
}

.scale-card.is-on {
    border-color: var(--tech);
    box-shadow: inset 0 3px 0 var(--tech);
}

.scale-card h3 {
    margin: 0;
    color: var(--ink);
    font-size: 20px;
}

.scale-card .tag {
    margin: 6px 0 0;
    font-size: 13px;
    color: #6b7280;
}

.scale-card p {
    margin: 12px 0 0;
}

.scale-card ul {
    margin: 12px 0 0;
    padding: 0 0 0 18px;
    font-size: 13px;
}

.scale-actions {
    display: flex;
    gap: 8px;
    margin-top: 16px;
}

.page-head {
    padding: 28px 0 18px;
}

.crumbs {
    margin: 0 0 10px;
    font-size: 13px;
    color: #6b7280;
}

.crumbs a:hover {
    color: var(--tech);
}

.page-head .kicker {
    margin: 0 0 6px;
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--tech);
}

.page-head h1 {
    margin: 0;
    color: var(--ink);
    font-size: clamp(1.6rem, 2.6vw, 2.1rem);
    line-height: 1.25;
}

.page-head .lede {
    margin: 10px 0 0;
    max-width: 40rem;
}

.page-body {
    padding: 0 0 56px;
}

.stack {
    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
    background: #fff;
}

.stack-row {
    display: grid;
    grid-template-columns: 180px 1fr auto;
    gap: 20px;
    align-items: start;
    padding: 22px 20px;
    border-top: 1px solid var(--line);
}

.stack-row:first-child {
    border-top: 0;
}

.stack-row h2,
.stack-row h3 {
    margin: 0;
    color: var(--ink);
    font-size: 18px;
}

.stack-row .meta {
    margin: 4px 0 0;
    font-size: 13px;
    color: #6b7280;
}

.stack-row .actions {
    display: flex;
    gap: 8px;
    flex-direction: column;
}

.photo-row {
    display: grid;
    grid-template-columns: 200px 1fr auto;
    gap: 20px;
}

.thumb {
    width: 100%;
    height: 96px;
    object-fit: cover;
}

.credit {
    margin: 4px 0 0;
    font-size: 11px;
    color: #9ca3af;
}

.mod-list {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 18px 32px;
    margin: 0;
    padding: 0;
    list-style: none;
}

.mod-list li {
    display: grid;
    grid-template-columns: 2rem 1fr;
    gap: 8px;
}

.mod-list em {
    color: #9ca3af;
    font-style: normal;
    font-size: 13px;
}

.mod-list h3 {
    margin: 0;
    color: var(--ink);
    font-size: 16px;
}

.mod-list p {
    margin: 4px 0 0;
    font-size: 14px;
}

.compare {
    width: 100%;
    border-collapse: collapse;
    background: #fff;
}

.compare th,
.compare td {
    border: 1px solid var(--line);
    padding: 10px 12px;
    text-align: left;
    font-size: 14px;
}

.compare th {
    background: var(--ink);
    color: #fff;
    font-weight: 700;
}

.compare td:not(:first-child) {
    text-align: center;
    width: 18%;
}

.compare .yes {
    color: var(--tech);
    font-weight: 700;
}

.compare .no {
    color: #9ca3af;
}

.prose {
    font-size: 1.05rem;
}

.prose p,
.prose li {
    margin: 0 0 14px;
}

.prose a {
    color: var(--tech);
}

.form-split {
    display: grid;
    grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.15fr);
    gap: 40px;
    align-items: start;
}

.form-box {
    background: #fff;
    border: 1px solid var(--line);
    padding: 24px;
}

.form-box h2,
.topic h2 {
    margin: 0 0 10px;
    color: var(--ink);
    font-size: 18px;
}

.form-box label {
    display: block;
}

.form-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 14px;
}

.field {
    width: 100%;
    border: 1px solid #c5ced8;
    background: #fff;
    color: var(--ink);
    padding: 9px 11px;
}

.field:focus {
    outline: 2px solid rgba(37, 99, 235, 0.25);
    border-color: var(--tech);
}

label .lbl {
    display: block;
    margin-bottom: 5px;
    color: var(--ink);
    font-size: 13px;
    font-weight: 700;
}

.choice {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 8px;
}

.choice label {
    border: 1px solid var(--line);
    padding: 10px;
    text-align: center;
    font-weight: 600;
    cursor: pointer;
}

.choice input {
    position: absolute;
    opacity: 0;
}

.choice label:has(:checked) {
    border-color: var(--tech);
    color: var(--tech);
    background: #eff6ff;
}

.alert {
    padding: 10px 12px;
    border: 1px solid #fecaca;
    background: #fef2f2;
    color: #b91c1c;
    font-size: 14px;
}

.ok {
    text-align: center;
}

.err {
    margin: 4px 0 0;
    color: #b91c1c;
    font-size: 13px;
}

.check {
    display: flex;
    gap: 8px;
    align-items: flex-start;
    font-size: 14px;
}

.site-foot {
    background: var(--ink);
    color: #94a3b8;
    font-size: 14px;
}

.foot-in {
    display: grid;
    grid-template-columns: 1.3fr 1fr 1fr 1fr;
    gap: 32px;
    padding: 40px 0;
}

.site-foot a:hover {
    color: #fff;
}

.site-foot h2 {
    margin: 0 0 10px;
    color: #fff;
    font-size: 13px;
    letter-spacing: 0.06em;
    text-transform: uppercase;
}

.site-foot ul {
    margin: 0;
    padding: 0;
    list-style: none;
}

.site-foot li {
    margin: 0 0 7px;
}

.foot-logo {
    display: inline-block;
    background: #fff;
    padding: 8px 10px;
}

.foot-copy {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding: 14px 0;
    text-align: center;
    font-size: 12px;
}

.faq details {
    border-bottom: 1px solid var(--line);
    padding: 14px 0;
}

.faq summary {
    cursor: pointer;
    color: var(--ink);
    font-weight: 700;
}

.faq p {
    margin: 8px 0 0;
}

.topic {
    border-top: 1px solid var(--line);
    padding: 16px 0;
}

:focus-visible {
    outline: 2px solid var(--tech);
    outline-offset: 2px;
}

@media (max-width: 980px) {
    .nav,
    .mast-cta {
        display: none;
    }

    .burger {
        display: block;
        position: relative;
    }

    .cat-grid,
    .scale-grid {
        grid-template-columns: 1fr 1fr;
    }

    .stack-row,
    .photo-row,
    .form-split,
    .foot-in {
        grid-template-columns: 1fr;
    }

    .stack-row .actions {
        flex-direction: row;
    }

    .mod-list,
    .form-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 640px) {
    .cat-grid,
    .scale-grid {
        grid-template-columns: 1fr;
    }

    .hero {
        min-height: 360px;
    }

    .compare {
        display: block;
        overflow-x: auto;
    }
}

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }
}