:root { --ink: #19324a; --muted: #5f6f7d; --line: #c8d1d8; --surface: #f8fafb; --accent: #0c5a85; --good: #1e6a45; --warn: #835c00; --error: #922b21; }
* { box-sizing: border-box; }
body { margin: 0; background: var(--surface); color: var(--ink); font-family: "Segoe UI", Arial, sans-serif; line-height: 1.45; }
.site-header { background: var(--ink); color: white; padding: 1.1rem max(1rem, calc((100% - 1120px) / 2)); }
.site-header p { margin: .15rem 0 0; color: #d8e3ea; font-size: .92rem; }
.brand { color: white; font-size: 1.35rem; font-weight: 700; text-decoration: none; }
.page { max-width: 1120px; margin: 0 auto; padding: 1.5rem 1rem 3rem; }
.page.chronology-comparison-page { max-width: 1840px; }
h1 { margin-top: 0; } h2 { font-size: 1.1rem; margin-top: 0; } h3 { font-size: 1rem; }
.panel { background: white; border: 1px solid var(--line); border-radius: 6px; padding: 1rem; margin: 1rem 0; }
.grid { display: grid; gap: 1rem; } .grid.two { grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); }
.form-grid { display: grid; gap: 1rem; } .form-grid fieldset { border: 1px solid var(--line); border-radius: 4px; padding: .9rem; }
.form-grid label { display: grid; gap: .25rem; margin: .55rem 0; font-weight: 600; }
input, select, textarea { border: 1px solid #8c9aa6; border-radius: 4px; padding: .5rem; font: inherit; }
button, .button { display: inline-block; border: 1px solid var(--accent); border-radius: 4px; padding: .55rem .8rem; background: white; color: var(--accent); font: inherit; font-weight: 600; cursor: pointer; text-decoration: none; }
button.primary, .primary { background: var(--accent); color: white; } button:disabled { opacity: .65; cursor: wait; }
.actions { display: flex; flex-wrap: wrap; gap: .6rem; margin-bottom: 1rem; } .actions form { display: inline; }
.help, small { color: var(--muted); font-size: .9rem; }
.alert { border-left: 4px solid; padding: .8rem; margin: 1rem 0; background: white; } .alert.error { border-color: var(--error); } .alert.caution { border-color: var(--warn); }
.badge, .status { display: inline-block; border-radius: 999px; padding: .1rem .5rem; background: #e8eef2; font-size: .82rem; } .badge.good { background: #e1f2e8; color: var(--good); } .badge.warn { background: #fff0ce; color: var(--warn); }
dl { margin: 0; } dt { font-weight: 700; } dd { margin: 0 0 .55rem; } .facts { display: grid; grid-template-columns: minmax(130px, 210px) 1fr; gap: .3rem .8rem; } .facts dd { margin: 0; }
details summary { cursor: pointer; } .candidate-list { margin-top: .8rem; } .candidate { display: flex; gap: .65rem; padding: .65rem 0; border-top: 1px solid #e1e7eb; }
code { overflow-wrap: anywhere; }
@media (max-width: 640px) { .facts { grid-template-columns: 1fr; gap: .1rem; } .facts dd { margin-bottom: .55rem; } }.reach-map { min-height: 420px; border: 1px solid var(--line); border-radius: 4px; background: #e8eef2; margin-bottom: .7rem; z-index: 0; }
.reach-map.map-unavailable { display: grid; place-items: center; min-height: 160px; padding: 1rem; color: var(--muted); text-align: center; }
@media (max-width: 640px) { .reach-map { min-height: 320px; } }
.button.disabled { border-color: #9aa7b1; background: #eef2f4; color: #667784; cursor: not-allowed; }
.alert.success { border-color: var(--good); background: #f1faf4; }
.compact-facts { margin-top: .65rem; }
.map-legend { display: flex; align-items: center; gap: .45rem; margin: .4rem 0 .7rem; font-weight: 600; }
.legend-swatch { width: 1rem; height: 1rem; display: inline-block; border-radius: 2px; }
.legend-swatch.corridor { background: rgba(111, 169, 197, .5); border: 2px solid #0c5a85; }
.section-heading { display: flex; justify-content: space-between; align-items: flex-start; gap: 1rem; }
.section-heading .button { flex: 0 0 auto; }
@media (max-width: 640px) { .section-heading { display: grid; } }
.extent-map-panel { border-color: #8fb4c8; box-shadow: 0 1px 0 rgba(12, 90, 133, .08); }
.extent-controls { display: grid; grid-template-columns: repeat(4, minmax(140px, 1fr)); gap: .8rem; }
.extent-controls label { margin: 0; }
.unit-input { display: grid; grid-template-columns: 1fr auto; align-items: stretch; }
.unit-input input { border-radius: 4px 0 0 4px; min-width: 0; }
.unit-input span { display: grid; place-items: center; min-width: 2.8rem; border: 1px solid #8c9aa6; border-left: 0; border-radius: 0 4px 4px 0; background: #eef2f4; color: var(--muted); font-weight: 600; }
.extent-handle { display: grid !important; place-items: center; width: 36px !important; height: 36px !important; margin: 0 !important; border: 3px solid white; border-radius: 50%; background: var(--accent); color: white; box-shadow: 0 1px 6px rgba(0, 0, 0, .45); font: 700 14px/1 "Segoe UI", Arial, sans-serif; cursor: grab; touch-action: none; }
.extent-handle:focus { outline: 3px solid #f4b942; outline-offset: 2px; }
.extent-handle-upstream { background: #1f6b45; }
.extent-handle-downstream { background: #8a5b00; }
.extent-handle-left-bank, .extent-handle-right-bank { background: #0c5a85; }
.input-error { color: var(--error); font-weight: 600; }
.advanced-recovery summary { padding: .25rem 0; }
.advanced-recovery[open] summary { margin-bottom: .8rem; }
.advanced-coordinate-form { grid-template-columns: repeat(2, minmax(220px, 1fr)); }
@media (max-width: 820px) {
  .extent-controls { grid-template-columns: repeat(2, minmax(150px, 1fr)); }
  .extent-handle { width: 42px !important; height: 42px !important; font-size: 15px; }
}
@media (max-width: 520px) {
  .extent-controls, .advanced-coordinate-form { grid-template-columns: 1fr; }
}
.searching-notice { display: flex; align-items: center; gap: .7rem; margin: .8rem 0; padding: .8rem; border-left: 4px solid var(--accent); background: #edf6fa; }
.searching-notice[hidden] { display: none; }
.search-spinner { width: 1.25rem; height: 1.25rem; flex: 0 0 auto; border: 3px solid #a9cbdc; border-top-color: var(--accent); border-radius: 50%; animation: h2flo-spin .8s linear infinite; }
.search-panel { max-width: 760px; }
.review-subheading { margin: 1rem 0 .45rem; font-size: .95rem; color: var(--muted); }
.show-all-candidates { margin: .6rem 0 0; padding: .5rem .7rem; border: 1px solid #d5e0e6; border-radius: 4px; background: #f8fafb; }
.year-candidate-group > h2 { margin-bottom: .2rem; }
.processed-image-preview { display: block; max-width: 100%; max-height: 80vh; margin: 0 auto; background: #eef2f4; border: 1px solid var(--line); }
.chronology-frame-canvas { display: grid; place-items: center; width: 100%; overflow: hidden; background: #eef2f4; border: 1px solid var(--line); }
.chronology-frame-preview { display: block; width: 100%; height: 100%; object-fit: contain; }
.chronology-comparison-viewport { cursor: grab; touch-action: none; user-select: none; }
.chronology-comparison-viewport.is-panning { cursor: grabbing; }
.chronology-zoomable { transform-origin: center center; will-change: transform; -webkit-user-drag: none; }
.chronology-frame-meta { margin-top: .7rem; }
.chronology-flicker-canvas { position: relative; }
.chronology-flicker-image { position: absolute; inset: 0; opacity: 0; visibility: hidden; z-index: 0; pointer-events: none; }
.chronology-flicker-image.is-active { opacity: 1; visibility: visible; z-index: 1; }
.chronology-pair-definition { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: .75rem; margin-top: .8rem; }
.chronology-pair-definition article { border: 1px solid var(--line); border-radius: 4px; padding: .65rem; }
.chronology-pair-definition h3, .chronology-pair-definition p { margin: 0; }
.chronology-pair-definition p { margin-top: .25rem; }
.chronology-comparison:focus { outline: 3px solid #f4b942; outline-offset: 3px; }
@keyframes h2flo-spin { to { transform: rotate(360deg); } }.historical-aerial-viewport { position: relative; display: grid; place-items: center; width: 100%; max-height: 80vh; overflow: hidden; background: #eef2f4; border: 1px solid var(--line); cursor: grab; touch-action: none; user-select: none; }
.historical-aerial-viewport.is-panning { cursor: grabbing; }
.historical-aerial-viewport img { display: block; max-width: 100%; max-height: 78vh; transform-origin: center center; will-change: transform; -webkit-user-drag: none; }

.terrain-display-controls { display: flex; flex-wrap: wrap; align-items: end; gap: .75rem 1rem; margin: .7rem 0; padding: .75rem; border: 1px solid #d5e0e6; border-radius: 4px; background: #f8fafb; }
.terrain-display-controls fieldset { display: flex; flex-wrap: wrap; gap: .35rem .7rem; margin: 0; padding: .45rem .65rem; border: 1px solid var(--line); border-radius: 4px; }
.terrain-display-controls label { display: grid; gap: .25rem; color: var(--ink); font-weight: 600; }
.terrain-display-controls fieldset label { display: inline-flex; align-items: center; gap: .2rem; font-weight: 400; }
.terrain-display-controls input[type="range"] { min-width: 150px; padding: 0; }
.terrain-map { min-height: 520px; }
.terrain-elevation-legend { display: flex; flex-wrap: wrap; align-items: center; gap: .55rem; margin: .4rem 0 .7rem; color: var(--muted); font-size: .9rem; }
.terrain-elevation-gradient { display: inline-block; width: 160px; height: .85rem; border: 1px solid #6d7b84; border-radius: 2px; background: linear-gradient(90deg, rgb(47,102,91), rgb(105,142,92), rgb(177,166,104), rgb(174,132,91), rgb(226,215,190)); }
@media (max-width: 640px) { .terrain-map { min-height: 360px; } .terrain-display-controls { display: grid; } .terrain-display-controls fieldset { display: grid; } }