/* ---------------------------------------------------------
   Reset
--------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body { margin: 0; }
img { max-width: 100%; height: auto; display: block; }
a { color: inherit; }
table { border-collapse: collapse; }

/* ---------------------------------------------------------
   Design tokens
   Editorial ice palette: dark navy header/footer, white page
   background, ice-blue accent, serif headings / sans body.
--------------------------------------------------------- */
:root {
  --color-bg: #ffffff;
  --color-bg-subtle: #f0f7fc;
  --color-border: #dbe7ef;
  --color-text: #16232f;
  --color-text-muted: #55697a;
  --color-panel: #f0f7fc;
  --color-panel-border: #bfe0f0;
  --color-accent: #4a9eca;
  --color-accent-ink: #2b7ba0;
  --color-dark-bg: #0d1b2e;
  --color-dark-bg-alt: #16273d;
  --color-dark-text: #f2f7fb;
  --color-dark-text-muted: #b9c9d6;
  --color-dark-border: rgba(242, 247, 251, 0.14);
  --font-serif: Georgia, "Playfair Display", "Times New Roman", serif;
  --font-sans: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, system-ui, sans-serif;
  --radius: 10px;
  --container: 800px;
}

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.65;
  font-size: 17px;
}

.container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

h1, h2, h3 {
  font-family: var(--font-serif);
  font-weight: 700;
  letter-spacing: -0.01em;
  line-height: 1.25;
  color: var(--color-text);
}

h1 { font-size: 2.2rem; margin: 0 0 14px; }
h2 { font-size: 1.55rem; margin: 48px 0 16px; }
h3 { font-size: 1.15rem; margin: 30px 0 10px; }

p { margin: 0 0 16px; color: var(--color-text); }
ul, ol { margin: 0 0 16px; padding-left: 22px; }
li { margin-bottom: 6px; }

.lede {
  font-size: 1.08rem;
  color: var(--color-text-muted);
  font-family: var(--font-sans);
}

/* ---------------------------------------------------------
   Header / Footer (identical markup on all 4 pages)
--------------------------------------------------------- */
.site-header {
  background: var(--color-dark-bg);
  border-bottom: 1px solid var(--color-dark-border);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
  flex-wrap: wrap;
}

.site-logo {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-family: var(--font-serif);
  font-size: 1.15rem;
  text-decoration: none;
  color: var(--color-dark-text);
  font-weight: 700;
}

.site-logo__mark {
  display: inline-block;
  width: 20px;
  height: 20px;
  flex: 0 0 auto;
  background: var(--color-accent);
  border-radius: 50%;
  position: relative;
}

.site-logo__mark::after {
  content: "";
  position: absolute;
  inset: 6px;
  background: var(--color-dark-bg);
  border-radius: 50%;
}

.site-nav {
  display: flex;
  gap: 24px;
  list-style: none;
  margin: 0;
  padding: 12px 0;
  flex-wrap: wrap;
}

.site-nav a {
  text-decoration: none;
  color: var(--color-dark-text-muted);
  font-size: 0.92rem;
  font-weight: 600;
}

.site-nav a:hover,
.site-nav a[aria-current="page"] {
  color: var(--color-dark-text);
}

.site-footer {
  margin-top: 64px;
  background: var(--color-dark-bg);
  color: var(--color-dark-text-muted);
}

.footer-cta {
  padding: 28px 0;
  border-bottom: 1px solid var(--color-dark-border);
}

.footer-cta p {
  margin: 0;
  font-size: 0.95rem;
  color: var(--color-dark-text);
}

.footer-cta a {
  color: #7fc4e6;
  text-decoration: underline;
}

.footer-bottom {
  padding: 20px 0 32px;
}

.footer-bottom .container {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.site-footer nav {
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
}

.site-footer a {
  text-decoration: none;
  color: var(--color-dark-text-muted);
  font-size: 0.9rem;
}

.site-footer a:hover { color: var(--color-dark-text); }

.footer-note {
  font-size: 0.85rem;
  color: var(--color-dark-text-muted);
  max-width: 640px;
  margin: 16px 0 0;
}

/* ---------------------------------------------------------
   Topics bar (sitewide guide links, sits under the header)
--------------------------------------------------------- */
.topics-bar {
  background: var(--color-dark-bg-alt);
  border-bottom: 1px solid var(--color-dark-border);
}

.topics-bar .container {
  padding-top: 10px;
  padding-bottom: 10px;
}

.topics-bar nav {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.topics-bar a {
  flex: 0 0 auto;
  text-decoration: none;
  color: var(--color-dark-text-muted);
  font-size: 0.83rem;
  font-weight: 600;
  padding: 6px 13px;
  border-radius: 999px;
  border: 1px solid var(--color-dark-border);
}

.topics-bar a:hover,
.topics-bar a[aria-current="page"] {
  color: var(--color-dark-text);
  border-color: var(--color-accent);
  background: rgba(74, 158, 202, 0.16);
}

/* ---------------------------------------------------------
   Footer guides column
--------------------------------------------------------- */
.footer-guides {
  padding: 22px 0;
  border-bottom: 1px solid var(--color-dark-border);
}

.footer-guides__label {
  display: block;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-dark-text-muted);
  margin-bottom: 12px;
}

.footer-guides nav {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 24px;
}

.footer-guides a {
  color: var(--color-dark-text-muted);
  text-decoration: none;
  font-size: 0.9rem;
}

.footer-guides a:hover { color: var(--color-dark-text); }

/* ---------------------------------------------------------
   Hero band - illustrated ice scene + breadcrumbs
--------------------------------------------------------- */
.hero-band {
  position: relative;
  background: var(--color-dark-bg);
  padding-bottom: 40px;
  overflow: hidden;
  isolation: isolate;
}

.hero-scene {
  position: absolute;
  inset: 0;
  z-index: -1;
}

.hero-scene svg {
  width: 100%;
  height: 100%;
  display: block;
}

.hero-band .container { position: relative; }

.breadcrumbs {
  font-size: 0.85rem;
  color: var(--color-dark-text-muted);
  margin: 0;
  padding: 22px 0 18px;
  list-style: none;
  display: flex;
  gap: 6px;
}
.breadcrumbs a { color: var(--color-dark-text-muted); text-decoration: none; }
.breadcrumbs a:hover { color: var(--color-dark-text); text-decoration: underline; }
.breadcrumbs li:not(:last-child)::after { content: "/"; margin-left: 6px; color: rgba(242, 247, 251, 0.3); }

.eyebrow {
  display: inline-block;
  font-family: var(--font-sans);
  font-size: 0.74rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: #9bd4ee;
  background: rgba(74, 158, 202, 0.18);
  border: 1px solid rgba(127, 196, 230, 0.4);
  padding: 5px 13px;
  border-radius: 999px;
  margin-bottom: 16px;
}

/* ---------------------------------------------------------
   Article shell
--------------------------------------------------------- */
main { padding-bottom: 24px; }

.article-header { padding: 8px 0 0; }
.hero-band > .container > .article-header:first-child { padding-top: 12px; }

.article-header h1 { color: var(--color-dark-text); }

.hero-band .lede { color: var(--color-dark-text-muted); }

.article-meta {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  font-size: 0.85rem;
  color: var(--color-dark-text-muted);
  margin: 4px 0 0;
  font-family: var(--font-sans);
}

/* ---------------------------------------------------------
   Table of contents (standard article-style numbered list
   of on-page sections, floats over the hero bottom edge)
--------------------------------------------------------- */
.toc-wrap { position: relative; z-index: 2; }

.toc {
  background: var(--color-panel);
  border: 1px solid var(--color-panel-border);
  border-radius: var(--radius);
  padding: 24px 28px 22px;
  margin: -34px 0 36px;
  box-shadow: 0 16px 32px rgba(13, 27, 46, 0.14);
}

.toc__label {
  display: block;
  font-family: var(--font-sans);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-accent-ink);
  margin-bottom: 14px;
}

.toc__list {
  margin: 0;
  padding-left: 22px;
  columns: 1;
  column-gap: 36px;
}

@media (min-width: 640px) {
  .toc__list { columns: 2; }
}

.toc__list li {
  margin-bottom: 9px;
  font-size: 0.94rem;
  break-inside: avoid;
}

.toc__list a {
  color: var(--color-accent-ink);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}

.toc__list a:hover {
  color: var(--color-text);
  border-bottom-color: var(--color-accent);
}

/* ---------------------------------------------------------
   Section groups - rotated kicker labels
--------------------------------------------------------- */
.section-group { position: relative; margin: 8px 0; }

.section-kicker {
  display: block;
  color: var(--color-accent-ink);
  font-weight: 700;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin: 0 0 6px;
  font-family: var(--font-sans);
}

@media (min-width: 768px) {
  .section-group { padding-left: 46px; }
  .section-kicker {
    position: absolute;
    left: -4px;
    top: 6px;
    writing-mode: vertical-rl;
    transform: rotate(180deg);
    font-size: 0.9rem;
    margin: 0;
  }
}

/* ---------------------------------------------------------
   Key Takeaways / callout
--------------------------------------------------------- */
.callout {
  border-left: 4px solid var(--color-accent);
  background: var(--color-panel);
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 20px 24px;
  margin: 20px 0 28px;
  box-shadow: 0 1px 2px rgba(13, 27, 46, 0.04);
}

.callout__label {
  display: block;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-accent-ink);
  margin-bottom: 10px;
  font-family: var(--font-sans);
}

.callout ul { margin: 0; padding-left: 20px; }
.callout li { margin-bottom: 8px; }
.callout li:last-child { margin-bottom: 0; }

/* ---------------------------------------------------------
   Pull quote / field note (dark accent band)
--------------------------------------------------------- */
.pull-quote {
  background: var(--color-dark-bg);
  border-radius: var(--radius);
  padding: 36px 40px 32px;
  margin: 28px 0 32px;
}

.pull-quote::before {
  content: "\201C";
  display: block;
  font-family: var(--font-serif);
  font-size: 3.6rem;
  line-height: 1;
  color: var(--color-accent);
  margin-bottom: -8px;
}

.pull-quote p {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 1.2rem;
  line-height: 1.55;
  color: var(--color-dark-text);
  margin: 0 0 12px;
}

.pull-quote__label {
  display: block;
  font-family: var(--font-sans);
  font-size: 0.78rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: #7fc4e6;
}

/* ---------------------------------------------------------
   Guide card grid (cross-links to sibling guides)
--------------------------------------------------------- */
.guide-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
  gap: 16px;
  margin: 20px 0 32px;
}

.guide-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 22px;
  background: var(--color-bg);
  text-decoration: none;
  color: var(--color-text);
  box-shadow: 0 1px 2px rgba(13, 27, 46, 0.04);
  transition: box-shadow 0.15s ease, transform 0.15s ease, border-color 0.15s ease;
}

.guide-card:hover {
  box-shadow: 0 14px 28px rgba(13, 27, 46, 0.12);
  transform: translateY(-2px);
  border-color: var(--color-panel-border);
}

.guide-card__icon {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--color-panel);
  border: 1px solid var(--color-panel-border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  flex: 0 0 auto;
}

.guide-card__title {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  font-weight: 700;
  margin: 0;
  color: var(--color-text);
}

.guide-card__desc {
  font-size: 0.88rem;
  color: var(--color-text-muted);
  margin: 0;
  flex: 1 0 auto;
}

.guide-card__cta {
  font-family: var(--font-sans);
  font-size: 0.83rem;
  font-weight: 700;
  color: var(--color-accent-ink);
}

/* ---------------------------------------------------------
   Operator ranking list (top-operators section)
--------------------------------------------------------- */
.operator-list {
  list-style: none;
  margin: 20px 0 28px;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.operator-item {
  display: flex;
  gap: 18px;
  align-items: flex-start;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 20px 24px;
  background: var(--color-bg);
  box-shadow: 0 1px 2px rgba(13, 27, 46, 0.04);
}

.operator-item--featured {
  border-color: var(--color-panel-border);
  border-left: 4px solid var(--color-accent);
  background: var(--color-panel);
}

.operator-rank {
  flex: 0 0 auto;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--color-bg-subtle);
  border: 1px solid var(--color-panel-border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: 1rem;
  color: var(--color-accent-ink);
}

.operator-item--featured .operator-rank {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: #fff;
}

.operator-item__body { flex: 1 1 auto; min-width: 0; }

.operator-item__top {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 6px;
}

.operator-item__name {
  font-family: var(--font-serif);
  font-size: 1.1rem;
  font-weight: 700;
  margin: 0;
  color: var(--color-text);
}

.operator-item__badge {
  display: inline-block;
  font-family: var(--font-sans);
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-accent-ink);
  background: rgba(74, 158, 202, 0.14);
  border: 1px solid var(--color-panel-border);
  padding: 3px 9px;
  border-radius: 999px;
}

.operator-item__desc {
  margin: 0 0 10px;
  color: var(--color-text-muted);
  font-size: 0.94rem;
}

.operator-item__link {
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--color-accent-ink);
  text-decoration: none;
}

.operator-item__link:hover { text-decoration: underline; }

/* ---------------------------------------------------------
   Tables
--------------------------------------------------------- */
.table-wrap {
  overflow-x: auto;
  margin: 20px 0 28px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: 0 1px 2px rgba(13, 27, 46, 0.04);
}

table.data-table {
  width: 100%;
  min-width: 560px;
  font-size: 0.9rem;
}

.data-table caption {
  text-align: left;
  font-size: 0.85rem;
  color: var(--color-text-muted);
  padding: 12px 16px 0;
}

.data-table th,
.data-table td {
  text-align: left;
  padding: 12px 16px;
  border-bottom: 1px solid var(--color-border);
  vertical-align: top;
}

.data-table thead th {
  background: var(--color-bg-subtle);
  font-weight: 700;
  color: var(--color-text-muted);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.data-table tbody tr:last-child td { border-bottom: none; }
.data-table a { color: var(--color-accent-ink); text-decoration: none; }
.data-table a:hover { text-decoration: underline; }

/* ---------------------------------------------------------
   Camera gear checklist grid
--------------------------------------------------------- */
.checklist-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
  margin: 20px 0 28px;
  padding: 22px;
  background: var(--color-bg-subtle);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  list-style: none;
  box-shadow: 0 1px 2px rgba(13, 27, 46, 0.04);
}

@media (min-width: 640px) {
  .checklist-grid { grid-template-columns: repeat(3, 1fr); }
}

.checklist-grid li {
  display: flex;
  align-items: center;
  gap: 11px;
  font-size: 0.92rem;
  margin: 0;
}

.checklist-grid .icon {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--color-bg);
  border: 1px solid var(--color-panel-border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  line-height: 1;
  flex: 0 0 auto;
}

/* ---------------------------------------------------------
   CSS landscape diagram (composition rules)
--------------------------------------------------------- */
.diagram {
  display: grid;
  gap: 14px;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  margin: 20px 0 28px;
  padding: 22px;
  background: var(--color-dark-bg);
  border-radius: var(--radius);
}

.diagram__card {
  background: var(--color-dark-bg-alt);
  border: 1px solid var(--color-dark-border);
  border-top: 3px solid var(--color-accent);
  border-radius: 8px;
  padding: 16px;
  color: var(--color-dark-text);
}

.diagram__card h3 {
  margin: 0 0 8px;
  font-size: 0.95rem;
  color: #7fc4e6;
  font-family: var(--font-sans);
}

.diagram__card p {
  margin: 0;
  font-size: 0.85rem;
  color: var(--color-dark-text-muted);
}

/* ---------------------------------------------------------
   Figures
--------------------------------------------------------- */
.figure {
  margin: 24px 0 28px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--color-bg-subtle);
}
.figure img,
.figure svg { width: 100%; height: auto; display: block; }
.figure figcaption {
  padding: 12px 18px;
  font-size: 0.85rem;
  color: var(--color-text-muted);
  border-top: 1px solid var(--color-border);
  background: var(--color-bg);
}

/* ---------------------------------------------------------
   FAQ (always-visible Q&A, not a collapsed accordion -
   keeps answers directly readable and citable)
--------------------------------------------------------- */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin: 20px 0 8px;
}

.faq-item {
  border: 1px solid var(--color-border);
  border-left: 3px solid var(--color-accent);
  border-radius: var(--radius);
  padding: 20px 24px;
  background: var(--color-bg);
  box-shadow: 0 1px 2px rgba(13, 27, 46, 0.04);
}

.faq-item__q {
  font-family: var(--font-serif);
  font-size: 1.05rem;
  margin: 0 0 8px;
  color: var(--color-text);
}

.faq-item__a { margin: 0; color: var(--color-text-muted); }

/* ---------------------------------------------------------
   Dark band (full-bleed contrast section)
--------------------------------------------------------- */
.dark-band {
  background: var(--color-dark-bg);
  color: var(--color-dark-text-muted);
  padding: 48px 0;
  margin: 8px 0;
}
.dark-band h2 { color: var(--color-dark-text); }
.dark-band p { color: var(--color-dark-text-muted); }

/* ---------------------------------------------------------
   Misc content blocks
--------------------------------------------------------- */
.notice {
  background: var(--color-bg-subtle);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 16px 20px;
  font-size: 0.9rem;
  color: var(--color-text-muted);
  margin: 20px 0 28px;
}

.sources-list {
  list-style: none;
  margin: 0 0 28px;
  padding: 0;
}

.sources-list li {
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 16px 20px;
  margin-bottom: 12px;
}

.sources-list h2 { margin: 0 0 4px; font-size: 1rem; }
.sources-list p { margin: 0; font-size: 0.9rem; color: var(--color-text-muted); }
.sources-list a { color: var(--color-accent-ink); text-decoration: none; font-size: 0.9rem; }
.sources-list a:hover { text-decoration: underline; }