/* ===========================================
RAIL.CSS — Desktop left rail (≥900px)
===========================================
Spec: docs/superpowers/specs/2026-04-20-desktop-left-rail-design.md
Structure:
State model (data-rail-state on ):
mobile — hide rail (also handled by media query)
expanded — full-width labelled rail (default at ≥1200px)
collapsed — narrow icon-only rail (default at 900-1199px)
The toggle is ALWAYS visible at ≥900px and click flips between
expanded/collapsed. There is no hover-peek; manual toggle only.
=========================================== */
.rail-spacer {
display: none;
}
.rail {
display: none;
}
/* Backdrop — declared at all widths so opacity:0 is the computed value
even outside the midrange tier. If these rules lived only inside the
midrange media query, crossing 1200px would jump opacity from the
default 1 to 0 with a transition, fading a fullscreen black overlay
for 220ms (the "screen flash" on resize). The element is invisible at
wide because pointer-events:none and opacity:0; the midrange media
query just adds the [expanded] override. */
.rail-backdrop {
position: fixed;
inset: 0;
background: var(--overlay-dark);
opacity: 0;
pointer-events: none;
z-index: 1000;
transition: opacity var(--rail-transition);
}
@media (min-width: 900px) {
.rail {
display: flex;
flex-direction: column;
flex: 0 0 var(--rail-width-expanded);
/* Allow flex item to honour flex-basis below children's intrinsic
min-content (the heading text's white-space:nowrap would otherwise
floor-lock the rail at ~95px and prevent it collapsing to 56px). */
min-width: 0;
position: sticky;
top: 0;
align-self: flex-start;
height: 100vh;
background: var(--bg-secondary);
border-right: 1px solid var(--border-color);
color: var(--text-primary);
font-family: var(--font-sans);
z-index: 150;
-webkit-font-smoothing: antialiased;
transition: flex-basis var(--rail-transition);
}
[data-theme="dark"] .rail {
background: var(--bg-secondary);
}
/* ---------- Brand ---------- */
/* Two-track grid: logo (1fr) + toggle (auto). At collapsed the logo
track shrinks to 0fr and the toggle drifts into the centred slot. */
.rail-brand {
display: grid;
grid-template-columns: 1fr auto;
align-items: center;
gap: 0.5rem;
padding: 0 0.75rem;
height: var(--topbar-height);
box-sizing: border-box;
border-bottom: 1px solid var(--border-subtle);
flex-shrink: 0;
transition: grid-template-columns var(--rail-transition),
padding var(--rail-transition);
}
.rail-brand-logo {
display: flex;
align-items: center;
gap: 0.625rem;
min-width: 0;
overflow: hidden;
}
.rail-brand-mark {
width: 30px;
height: 30px;
border-radius: var(--radius-md);
display: block;
color: var(--theme-primary, var(--nhs-blue));
box-shadow: 0 1px 2px color-mix(in srgb, currentColor 25%, transparent);
flex-shrink: 0;
transition: color 200ms ease, box-shadow 200ms ease;
}
/* Drug-theme mask: on DMARD/Biologics pages with a drug selected, recolor
the logo square to the active drug color. Compass rose stays white. */
body[data-page="dmard"][data-active-drug] .rail-brand-mark,
body[data-page="biologics"][data-active-class] .rail-brand-mark {
color: var(--active-color);
}
.rail-brand-mark svg {
width: 100%;
height: 100%;
display: block;
}
.rail-brand-name {
font-size: 0.875rem;
font-weight: 700;
letter-spacing: -0.01em;
color: var(--text-primary);
white-space: nowrap;
}
/* Toggle — always visible at ≥900px (manual click is the only trigger).
Compact (20px) so the brand row fits "RheumTools" without clipping. */
.rail-toggle {
display: grid;
place-items: center;
width: 20px;
height: 20px;
padding: 0;
appearance: none;
border: none;
background: transparent;
color: var(--text-muted);
cursor: pointer;
border-radius: var(--radius-sm);
transition: background 0.12s ease, color 0.12s ease;
}
.rail-toggle:focus-visible {
outline: none;
box-shadow: var(--focus-ring-nhs-green);
}
@media (hover: hover) {
.rail-toggle:hover {
background: var(--bg-tertiary);
color: var(--text-primary);
}
}
.rail-toggle-icon {
display: grid;
place-items: center;
transition: transform var(--rail-transition);
}
.rail-toggle svg {
width: 14px;
height: 14px;
display: block;
}
/* Chevron flips to point outward (right) when the rail is collapsed,
matching the user's expand intent. */
[data-rail-state="collapsed"] .rail-toggle-icon {
transform: rotate(180deg);
}
/* ---------- Nav ---------- */
.rail-nav {
flex: 1;
min-height: 0;
overflow-y: auto;
padding: 0.25rem 0 0.5rem;
}
.rail-group {
display: flex;
flex-direction: column;
}
.rail-group[hidden],
.rail-group.rail-group-hidden {
display: none;
}
.rail-group > [role="group"] {
display: flex;
flex-direction: column;
}
/* Heading uses max-height collapse — bulletproof across browsers
(the grid-template-rows: 0fr trick is flaky in some engines). 3rem
generously covers 1rem top padding + ~12px text + 0.375rem bottom. */
.rail-group-heading {
overflow: hidden;
max-height: 3rem;
transition: max-height var(--rail-transition);
}
.rail-group-heading-text {
display: block;
font-size: 0.625rem;
font-weight: 600;
letter-spacing: 0.08em;
text-transform: uppercase;
color: var(--text-muted);
padding: 1rem 1.125rem 0.375rem;
white-space: nowrap;
}
/* ---------- Rail item ---------- */
.rail-item {
appearance: none;
border: none;
background: transparent;
text-align: left;
cursor: pointer;
position: relative;
display: flex;
align-items: center;
gap: 0.625rem;
padding: 0.4375rem 0.625rem;
margin: 0 0.5rem;
border-radius: var(--radius-md);
color: var(--text-secondary);
font-family: var(--font-sans);
font-size: 0.8125rem;
font-weight: 500;
transition: background 0.12s ease, color 0.12s ease,
margin var(--rail-transition),
padding var(--rail-transition),
gap var(--rail-transition);
}
.rail-item:focus-visible {
outline: none;
box-shadow: var(--focus-ring-nhs-green);
}
.rail-item-icon {
width: 22px;
height: 22px;
border-radius: var(--radius-sm);
display: grid;
place-items: center;
color: var(--text-muted);
flex-shrink: 0;
transition: background 0.12s ease, color 0.12s ease;
}
.rail-item-icon svg {
width: 14px;
height: 14px;
stroke-width: 1.9;
}
.rail-item-label {
flex: 1;
min-width: 0;
white-space: nowrap;
overflow: hidden;
text-overflow: ellipsis;
transition: opacity 180ms 40ms var(--ease-out-quint),
transform 180ms 40ms var(--ease-out-quint);
}
@media (hover: hover) {
.rail-item:hover {
background: var(--bg-tertiary);
color: var(--text-primary);
}
.rail-item:hover .rail-item-icon {
color: var(--text-primary);
}
}
/* Per-module rail accent defaults — one source of truth in CSS so the
drug/class-theme cascade below can override cleanly (no inline style,
no !important). Must stay in sync with pageColors in js/core/data.js. */
.rail-item[data-module="dmard"] { --rail-accent: var(--nhs-blue); }
.rail-item[data-module="biologics"] { --rail-accent: var(--biologics-base); }
.rail-item[data-module="prednisolone"] { --rail-accent: var(--steroid-amber); }
.rail-item[data-module="monitoring"] { --rail-accent: var(--monitoring-primary); }
.rail-item[data-module="osteoanabolic"] { --rail-accent: var(--osteo-primary); }
.rail-item[data-module="das28"] { --rail-accent: var(--das28-primary); }
.rail-item[data-module="axspa"] { --rail-accent: var(--axspa-primary); }
.rail-item[data-module="gcaps"] { --rail-accent: var(--emerald-primary); }
.rail-item[data-module="sledai"] { --rail-accent: var(--sledai-primary); }
.rail-item[data-module="bvas"] { --rail-accent: var(--bvas-purple); }
/* Active state — uses --rail-accent set per-module above */
.rail-item[aria-current="page"] {
background: color-mix(in srgb, var(--rail-accent, var(--nhs-blue)) 8%, transparent);
color: var(--rail-accent, var(--nhs-blue));
font-weight: 600;
}
[data-theme="dark"] .rail-item[aria-current="page"] {
background: var(--bg-tertiary);
color: var(--text-primary);
}
.rail-item[aria-current="page"] .rail-item-icon {
background: color-mix(in srgb, var(--rail-accent, var(--nhs-blue)) 24%, transparent);
color: var(--rail-accent, var(--nhs-blue));
}
.rail-item[aria-current="page"]::before {
content: "";
position: absolute;
left: -1px;
top: 7px;
bottom: 7px;
width: 3px;
border-radius: 2px;
background: var(--rail-accent, var(--nhs-blue));
}
/* Drug-theme mask: on DMARD/Biologics pages with a drug/class selected,
recolor the active rail item's accent to match. Wins over the
per-module default via higher specificity (0,5,0 vs 0,2,0). */
body[data-page="dmard"][data-active-drug] .rail-item[data-module="dmard"][aria-current="page"],
body[data-page="biologics"][data-active-class] .rail-item[data-module="biologics"][aria-current="page"] {
--rail-accent: var(--active-color);
}
/* ---------- Collapsed state ---------- */
[data-rail-state="collapsed"] .rail {
flex-basis: var(--rail-width-collapsed);
}
[data-rail-state="collapsed"] .rail-brand {
grid-template-columns: 0fr auto;
padding: 0;
justify-content: center;
}
[data-rail-state="collapsed"] .rail-group-heading {
max-height: 0;
}
/* Labels fade AND stop occupying flex space so the icon truly centres.
Without width:0 + flex:0 the label's flex:1 keeps the icon left-aligned
inside the pill and inside the active highlight box. */
[data-rail-state="collapsed"] .rail-item-label {
opacity: 0;
width: 0;
flex: 0 0 0;
transform: translateX(-4px);
pointer-events: none;
}
[data-rail-state="collapsed"] .rail-item {
justify-content: center;
margin: 0 0.375rem;
padding-left: 0;
padding-right: 0;
gap: 0;
}
}
/* Single shared tooltip — rail.js appends one
to and retargets it on hover/focus of any collapsed rail item.
Replaces per-item ::after pseudo-elements: those promoted one
compositing layer per item in WebKit and flashed at stale --tt-top/
--tt-left coordinates during the rail's collapse reflow. One layer
outside .rail can't be touched by the rail's reflow. JS sets inline
top/left from the hovered button's rect and toggles data-visible.
Lives outside the @media (min-width: 900px) wrapper so the baseline
visibility:hidden + position:fixed apply at <900px too — without them
the tooltip element (still in body from a prior desktop hover) falls
back to default block styles and lands at bottom-left of the viewport
on every module. */
.rail-tooltip {
position: fixed;
top: 0;
left: 0;
transform: translate(-4px, -50%);
background: var(--text-primary);
color: var(--bg-primary);
font-size: 0.75rem;
font-weight: 500;
line-height: 1.2;
padding: 0.3125rem 0.5rem;
border-radius: var(--radius-sm);
white-space: nowrap;
box-shadow: 0 2px 8px rgba(0, 0, 0, 0.18);
visibility: hidden;
opacity: 0;
pointer-events: none;
z-index: 1100;
transition: opacity 0.08s ease,
transform 0.08s ease,
visibility 0s 0.08s;
}
.rail-tooltip[data-visible="true"] {
visibility: visible;
opacity: 1;
transform: translate(0, -50%);
transition: opacity 0.08s ease,
transform 0.08s ease,
visibility 0s;
}
/* Midrange (900–1199): rail becomes a fixed-position overlay. Content
doesn't have room for an expanded rail at this width, so peek-expand
floats the rail above main content rather than pushing it. The
.rail-spacer flex item reserves the 56px slot so layout never
reflows when the rail widens or narrows.
Default-collapsed visuals are applied at CSS-paint time (keyed on
:root:not([data-rail-state="expanded"])) so there's no flash before
JS writes data-rail-state. Peek-expand wins via specificity. */
@media (min-width: 900px) and (max-width: 1199.98px) {
.rail {
position: fixed;
left: 0;
top: 0;
width: var(--rail-width-collapsed);
flex-basis: var(--rail-width-collapsed);
transition: width var(--rail-transition),
box-shadow var(--rail-transition);
}
.rail-spacer {
display: block;
flex: 0 0 var(--rail-width-collapsed);
align-self: stretch;
}
[data-rail-state="expanded"] .rail {
width: var(--rail-width-expanded);
box-shadow: 0 8px 32px rgba(0, 0, 0, 0.18);
z-index: 1001;
}
[data-rail-state="expanded"] .rail-backdrop {
opacity: 1;
pointer-events: auto;
}
:root:not([data-rail-state="expanded"]) .rail-brand {
grid-template-columns: 0fr auto;
padding: 0;
justify-content: center;
}
:root:not([data-rail-state="expanded"]) .rail-group-heading {
max-height: 0;
}
:root:not([data-rail-state="expanded"]) .rail-item-label {
opacity: 0;
width: 0;
flex: 0 0 0;
transform: translateX(-4px);
pointer-events: none;
}
:root:not([data-rail-state="expanded"]) .rail-item {
justify-content: center;
margin: 0 0.375rem;
padding-left: 0;
padding-right: 0;
gap: 0;
}
:root:not([data-rail-state="expanded"]) .rail-toggle-icon {
transform: rotate(180deg);
}
}
/* Reduced motion: strip all rail transitions. Driven by rail-state.js
reading matchMedia and writing . */
[data-rail-motion="reduced"] .rail,
[data-rail-motion="reduced"] .rail-brand,
[data-rail-motion="reduced"] .rail-group-heading,
[data-rail-motion="reduced"] .rail-item,
[data-rail-motion="reduced"] .rail-item-label {
transition: none !important;
}