/* =============================================================================
   University of Toronto — Machine Learning Group
   Shared stylesheet for all pages.

   Design decisions (locked in after design-previewer feedback):
     • Palette ........ Sand (warm off-white surfaces)
     • Type ........... Headers = Bembo (serif), Body = Trade Gothic Next (sans)
     • Accent ......... U of T Blue #1E3765 ONLY. All "variations" are opacity
                        steps of the same hue — no off-brand blues anywhere.
     • Width .......... Responsive in-between: fluid up to a 1360px cap so large
                        screens don't read as empty, but it still breathes.
   The standalone design previewer is preserved under /design-options/.
   ============================================================================= */

/* -----------------------------------------------------------------------------
   1. Web fonts
   - Trade Gothic Next (body) via Adobe Typekit — U of T's designated sans.
   - Bembo (headlines) via Adobe Typekit — U of T's designated serif.
   Both load through licensed kit CSS in each page's <head>:
       <link rel="preconnect" href="https://use.typekit.net" crossorigin>
       <link rel="stylesheet" href="https://use.typekit.net/rwd3ahf.css">  (trade-gothic-next)
       <link rel="stylesheet" href="https://use.typekit.net/kpp6qjy.css">  (bembo)
   NOTE: do not add local @font-face rules named "Bembo" — family matching is
   case-insensitive, so they'd override the kit's "bembo" faces and break it.
   - EB Garamond remains as a fallback serif behind Bembo; final fallback is
     Times New Roman (U of T's stated digital substitute for Bembo).
   -------------------------------------------------------------------------- */
@import url('https://fonts.googleapis.com/css2?family=EB+Garamond:ital,wght@0,400;0,500;0,600;0,700;1,400;1,500&display=swap');

/* -----------------------------------------------------------------------------
   2. Design tokens
   -------------------------------------------------------------------------- */
:root {
    /* ---- U of T Blue: one hue, opacity-only variations -------------------- */
    --uoft-blue: #1E3765;            /* official #1E3765 = rgb(30,55,101)      */
    --uoft-blue-rgb: 30, 55, 101;
    --blue-90: rgba(30, 55, 101, 0.90);
    --blue-70: rgba(30, 55, 101, 0.70);
    --blue-55: rgba(30, 55, 101, 0.55);
    --blue-40: rgba(30, 55, 101, 0.40);
    --blue-25: rgba(30, 55, 101, 0.25);
    --blue-15: rgba(30, 55, 101, 0.15);
    --blue-08: rgba(30, 55, 101, 0.08);
    --blue-04: rgba(30, 55, 101, 0.04);

    /* ---- Semantic colour roles (Sand palette) ----------------------------- */
    --color-primary:        var(--uoft-blue);
    --color-primary-hover:  var(--blue-90);   /* subtle opacity step on hover  */
    --color-link:           var(--uoft-blue);
    --color-text:           #1a1a2e;          /* near-black for body copy       */
    --color-text-light:     #44485a;
    --color-text-muted:     #5f6373;          /* ≥4.5:1 on sand and white (WCAG AA) */
    --color-background:     #f0efee;          /* sand                           */
    --color-background-alt: #ffffff;
    --color-surface-tint:   var(--blue-08);
    --color-border:         #e2ddd3;
    --color-white:          #ffffff;

    /* ---- Type ------------------------------------------------------------- */
    --font-serif: 'bembo', 'EB Garamond', Georgia, 'Times New Roman', serif;
    --font-sans:  'trade-gothic-next', 'Trade Gothic Next', 'Helvetica Neue', Arial, sans-serif;

    --font-size-xs:  0.75rem;
    --font-size-sm:  0.875rem;
    --font-size-base:1rem;
    --font-size-lg:  1.125rem;
    --font-size-xl:  1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 2rem;
    --font-size-4xl: 2.75rem;

    /* ---- Spacing ---------------------------------------------------------- */
    --spacing-xs:  0.25rem;
    --spacing-sm:  0.5rem;
    --spacing-md:  1rem;
    --spacing-lg:  1.5rem;
    --spacing-xl:  2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
    --spacing-4xl: 6rem;
    --spacing-5xl: 8rem;
    /* Vertical rhythm: space at the top and bottom of every section, and
       between a section's header and its content. */
    --section-space: 4rem;
    --block-gap: 2.5rem;

    /* ---- Layout ----------------------------------------------------------- */
    /* Responsive in-between width: fluid (uses the viewport) but capped at
       1360px so wide monitors never feel sparse the way the 1600px full-width
       option did, while still reading much wider than the 1100px "regular". */
    --container-max: 1360px;
    --container-padding: clamp(1.25rem, 4vw, 3rem);
    --header-h: 103px;   /* height of .site-header; the sticky hero graphic sits below it */

    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --radius: 2px;
}

/* -----------------------------------------------------------------------------
   3. Reset & base elements
   -------------------------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
    font-size: 100%;   /* respect the reader's browser font-size setting */
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
}

/* Body copy — Trade Gothic Light. (The loaded kit ships 400/700/800; 300
   gracefully renders at the nearest available weight until a Light face is
   added.) */
body {
    font-family: var(--font-sans);
    font-size: var(--font-size-base);
    font-weight: 300;
    line-height: 1.7;
    color: var(--color-text);
    background-color: var(--color-background);
}

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

a {
    color: var(--color-link);
    text-decoration: none;
    text-underline-offset: 0.15em;
    transition: color var(--transition-fast), opacity var(--transition-fast);
}
a:hover { color: var(--color-primary-hover); }
/* Plain text links (contact details, footer credit, photo credits): U of T
   Blue, underlined on hover and keyboard focus. Cards and buttons style
   their own hover. */
a:not([class]):hover, a:not([class]):focus-visible,
a.tl-credit:hover, a.tl-credit:focus-visible { text-decoration: underline; }
/* One clear keyboard focus ring everywhere (white on the dark timeline captions). */
:focus-visible { outline: 2px solid var(--color-primary); outline-offset: 2px; }
.tl-cap :focus-visible { outline-color: var(--color-white); }

/* "Skip to main content": off-screen until focused with the keyboard. */
.skip-link {
    position: absolute;
    top: var(--spacing-sm);
    left: var(--spacing-sm);
    z-index: 1001;   /* above the sticky header */
    padding: var(--spacing-sm) var(--spacing-md);
    font-family: var(--font-sans);
    font-size: var(--font-size-sm);
    font-weight: 700;
    color: var(--color-white);
    background-color: var(--color-primary);
    border-radius: var(--radius);
    transform: translateY(-200%);
}
.skip-link:focus { transform: none; color: var(--color-white); }

/* Headlines & subheads — Bembo (serif), per the locked-in type direction.
   Weight 600 targets the Semibold cut; serif normal gets -0.5px tracking to
   match the quote/stat voice. Sans labels (.section-label, .where-aside h3,
   .contact-info h3) override this locally and stay Trade Gothic. */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-serif);
    font-weight: 600;
    letter-spacing: -0.03em;
    line-height: 1.2;
    color: var(--color-primary);
}

/* Deck — page intros above the fold and short one-line subheadings, in
   Trade Gothic Bold. Longer section descriptions stay at body weight. */
.deck, .page-hero > .container > p { font-weight: 700; }

/* Quote & Stats — the serif voice (Bembo, falling back to EB Garamond).
   Tracking: serif italic → 0; serif normal/bold → -0.5px. */
.quote, blockquote, .stat {
    font-family: var(--font-serif);
    font-weight: 400;
}
.stat { letter-spacing: -0.03em; }            /* serif normal */
.quote, blockquote { font-style: italic; letter-spacing: 0; }  /* serif italic */
h1 { font-size: var(--font-size-4xl); }
h2 { font-size: var(--font-size-3xl); }
h3 { font-size: var(--font-size-xl); }

ul, ol { list-style: none; }

/* -----------------------------------------------------------------------------
   4. Layout helpers
   -------------------------------------------------------------------------- */
.container {
    width: 100%;
    max-width: min(92vw, var(--container-max));
    margin-inline: auto;
    padding-inline: var(--container-padding);
}

.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;
}

.section-label {
    font-family: var(--font-sans);
    font-size: var(--font-size-xs);
    font-weight: 700;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    line-height: 1.2;   /* tight, so a section's first ink sits on its padding */
    margin-bottom: var(--spacing-sm);
}

.section-header { margin-bottom: var(--block-gap); }
.section-header.center { text-align: center; }
.section-header h2 { margin-bottom: var(--spacing-md); }

.section-description {
    max-width: 640px;
    color: var(--color-text-light);
    font-size: var(--font-size-lg);
}
.section-header.center .section-description { margin-inline: auto; }

/* -----------------------------------------------------------------------------
   5. Buttons
   -------------------------------------------------------------------------- */
.btn {
    display: inline-block;
    padding: 0.7rem 1.6rem;
    font-family: var(--font-sans);
    font-size: var(--font-size-sm);
    font-weight: 700;
    letter-spacing: 0.02em;
    text-align: center;
    border-radius: var(--radius);
    border: 1px solid transparent;
    cursor: pointer;
    transition: all var(--transition-fast);
}
.btn-primary {
    background-color: var(--color-primary);
    color: var(--color-white);
    border-color: var(--color-primary);
}
.btn-primary:hover {
    background-color: var(--blue-90);
    border-color: var(--blue-90);
    color: var(--color-white);
    transform: translateY(-2px);
}
.btn-secondary {
    background-color: transparent;
    color: var(--color-primary);
    border-color: var(--blue-40);
}
.btn-secondary:hover {
    background-color: var(--blue-08);
    border-color: var(--color-primary);
    color: var(--color-primary);
    transform: translateY(-2px);
}

/* -----------------------------------------------------------------------------
   6. Header & navigation
   -------------------------------------------------------------------------- */
.site-header {
    /* Scrolls away with the page, then re-reveals when the user scrolls up.
       JS toggles .site-header--hidden; sticky keeps it pinned while visible. */
    position: sticky;
    top: 0;
    z-index: 1000;
    background-color: var(--color-background);
    border-bottom: 1px solid var(--color-border);
    backdrop-filter: saturate(180%) blur(6px);
    transition: transform var(--transition-base);
    will-change: transform;
}
.site-header--hidden { transform: translateY(-100%); }

.main-nav {
    width: 100%;
    max-width: min(92vw, var(--container-max));
    margin-inline: auto;
    padding: var(--spacing-md) var(--container-padding);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--spacing-xl);
}

/* Logo — black-on-white source recoloured to U of T Blue via SVG filter.
   Rendered as a real <img> at 70px tall so it isn't shrunk to fit a box;
   width follows the image's ~7.2:1 aspect ratio. */
/* Logo never shrinks (keeps its true aspect ratio); SVGs are pre-coloured. */
.brand { display: inline-flex; align-items: center; flex-shrink: 0; }
.logo {
    display: block;
    height: 70px;
    width: auto;
    flex-shrink: 0;
}
.logo--simple { display: none; }   /* swapped in when space is tight */

.nav-list {
    display: flex;
    align-items: center;
    gap: clamp(0.85rem, 1.9vw, 2rem);
}
.nav-link {
    display: inline-block;
    font-family: var(--font-sans);
    font-size: var(--font-size-base);
    font-weight: 500;
    color: var(--color-text-light);
    /* Horizontal padding gives the hover tint block breathing room around
       the text; the matching negative margin cancels it out of the layout,
       so link spacing and header edge alignment stay exactly as before. */
    padding: var(--spacing-sm) 0.75rem;
    margin: 0 -0.75rem;
    border-radius: var(--radius);
    white-space: nowrap;
    transition: color var(--transition-base), background-color var(--transition-base);
}

/* Hover — the link's block softly tints blue (an opacity step of the one
   brand blue), mirroring the mobile menu's hover treatment. */
.nav-link:hover,
.nav-link:focus-visible {
    color: var(--color-primary);
    background-color: var(--blue-08);
}

.nav-link.active {
    color: var(--color-primary);
    font-weight: 700;   /* bold the current page */
    /* background-color: var(--blue-04); */
}
.nav-link.active:hover,
.nav-link.active:focus-visible {
    background-color: var(--blue-08);
}

@media (prefers-reduced-motion: reduce) {
    .nav-link { transition: none; }
}

/* Mobile menu toggle */
.nav-toggle {
    display: none;
    width: 40px; height: 40px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    background: transparent;
    cursor: pointer;
    align-items: center;
    justify-content: center;
    color: var(--color-primary);
}
.nav-toggle svg { width: 20px; height: 20px; }

/* -----------------------------------------------------------------------------
   7. Hero
   -------------------------------------------------------------------------- */
/* Desktop hero: text in a wide column, the graphic in a narrow one beside it.
   The graphic is sized to fit on screen below the header and stays put
   (sticky) while longer text scrolls past; the section then scrolls away. */
.hero {
    min-height: calc(100svh - var(--header-h));
    padding: var(--section-space) 0;
    overflow: clip;   /* clip the graphic's overhang without breaking sticky */
    background-color: var(--color-background);
}
.hero .container {
    display: grid;
    grid-template-columns: minmax(0, 3fr) minmax(0, 2fr);   /* graphic ~40% of the row */
    column-gap: var(--spacing-3xl);
    align-items: center;
}

.hero-tagline {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-family: var(--font-sans);
    font-size: var(--font-size-sm);
    color: var(--color-text-light);
    margin-bottom: var(--spacing-xl);
    padding: 0.4rem 0.7rem 0.4rem 0.4rem;
    border-radius: 9999px;
    background-color: var(--blue-08);
    border: 1px solid var(--blue-15);
    transition: background-color var(--transition-fast);
}
.hero-tagline:hover { background-color: var(--blue-15); color: var(--color-primary); }
.hero-tagline .tag {
    padding: 0.25rem 0.75rem;
    border-radius: 9999px;
    background-color: var(--color-primary);
    color: var(--color-white);
    font-size: var(--font-size-xs);
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}
.hero-tagline svg { width: 1rem; height: 1rem; flex-shrink: 0; }

.hero h1 {
    font-size: clamp(2.4rem, 5.2vw, 3.5rem);
    font-weight: 600;
    /* letter-spacing: -0.03em; */
    line-height: 1.08;
    margin-bottom: var(--spacing-xl);
}
.hero-description {
    font-size: var(--font-size-base);
    line-height: 1.75;
    color: var(--color-text-light);
    margin-bottom: var(--spacing-md);
}
.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-md);
    margin-top: var(--spacing-xl);
}

/* Hero graphic shell. The SVG stack is injected by JS and sized to this box:
   as wide as the column, compressed (then shrunk) to fit its height. */
.hero-graphic {
    position: sticky;
    top: var(--header-h);
    align-self: start;
    /* Span the hero's full height: bleed through its top/bottom padding and
       fill the screen below the header. */
    height: calc(100svh - var(--header-h));
    margin-block: calc(-1 * var(--section-space));
    display: flex;
    align-items: center;
    justify-content: center;
    pointer-events: none;
    overflow: visible;
}
.hero-graphic svg { display: block; }

/* -----------------------------------------------------------------------------
   8. Generic page sections
   -------------------------------------------------------------------------- */
/* One vertical rhythm: 96px between a section's edge and its content (64px on
   phones), 48px between a section header and what follows, and no stray
   bottom margin on a section's last block. */
.section { padding: var(--section-space) 0; }
.section > .container > :last-child { margin-bottom: 0; }
.section--tint { background-color: var(--color-background-alt); }
.section--sand { background-color: var(--color-background); }
/* Divider line between two same-coloured sections. */
.section--divider-top { border-top: 1px solid var(--color-border); }

.page-hero {
    padding: var(--section-space) 0;   /* same rhythm as .section */
    border-bottom: 1px solid var(--color-border);
}
.page-hero h1 {
    font-size: clamp(2.2rem, 4.5vw, 3rem);
    margin-bottom: var(--spacing-md);
}
.page-hero p {
    max-width: 60ch;
    font-size: var(--font-size-lg);
    color: var(--color-text-light);
}
/* Keep the eyebrow label at the standard .section-label size, not the
   enlarged page-hero paragraph size. */
.page-hero p.section-label {
    font-size: var(--font-size-xs);
    color: var(--color-text-muted);
}

/* Vertical timeline (adapted from the originui-vue timeline pattern):
   a marker rail down the left with dot + connector, content to the right. */
.timeline { position: relative; max-width: 760px; }
.timeline-item {
    position: relative;
    padding-left: 2.75rem;
    padding-bottom: var(--spacing-2xl);
}
.timeline-item:last-child { padding-bottom: 0; }
/* connector line */
.timeline-item::before {
    content: "";
    position: absolute;
    left: 9px;
    top: 1.7rem;
    bottom: -0.4rem;
    width: 2px;
    background-color: var(--blue-15);
    transition: background-color 350ms ease;
}
.timeline-item:last-child::before { display: none; }
/* dot marker */
.timeline-item::after {
    content: "";
    position: absolute;
    left: 0;
    top: 0.4rem;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background-color: var(--color-background);
    border: 2px solid var(--color-primary);
    box-shadow: 0 0 0 4px var(--color-background);
    transition: background-color 350ms ease, box-shadow 350ms ease;
}
.timeline--tint .timeline-item::after { box-shadow: 0 0 0 4px var(--color-background-alt); }

/* Active state (set by JS as you scroll, or on click): the rail fills up to
   the active event, its dot fills in, and a tinted highlight slides behind it. */
.timeline--interactive .timeline-item { cursor: pointer; }
.timeline-item.is-past::before { background-color: var(--color-primary); }
.timeline-item.is-past::after,
.timeline-item.is-active::after { background-color: var(--color-primary); }
.timeline-item.is-active::after { box-shadow: 0 0 0 4px var(--blue-25); }
.timeline-indicator {
    position: absolute;
    top: 0;
    left: -0.75rem;
    right: 0;
    height: 0;
    border-radius: var(--radius);
    background-color: var(--blue-08);
    pointer-events: none;
    transition: transform 400ms cubic-bezier(0.22, 1, 0.36, 1),
                height 400ms cubic-bezier(0.22, 1, 0.36, 1);
}
.timeline-indicator.is-instant { transition: none; }
.timeline-date {
    font-family: var(--font-sans);
    font-size: var(--font-size-sm);
    font-weight: 700;
    letter-spacing: 0.04em;
    color: var(--color-primary);
}
.timeline-title {
    font-size: var(--font-size-xl);
    color: var(--color-text-light);
    margin: 0.15rem 0 0.45rem;
    transition: color 350ms ease;
}
/* The title's button looks exactly like the heading text. */
.timeline-trigger {
    font: inherit;
    letter-spacing: inherit;
    color: inherit;
    text-align: left;
    background: none;
    border: 0;
    padding: 0;
    cursor: pointer;
}
.timeline-item.is-active .timeline-title,
.timeline--interactive .timeline-item:hover .timeline-title { color: var(--color-primary); }
@media (prefers-reduced-motion: reduce) {
    .timeline-item::before, .timeline-item::after,
    .timeline-title, .timeline-indicator, .tl-media { transition: none; }
}
.timeline-body {
    color: var(--color-text-light);
    font-size: var(--font-size-base);
    max-width: 60ch;
}

/* Two-column timeline: events on the left, a sticky image stage on the right
   that swaps as you scroll. On mobile the stage is hidden and each event
   carries its own image inline (see .tl-inline below). */
.timeline-layout {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: var(--spacing-3xl);
    align-items: start;
}
.timeline-media-sticky {
    position: sticky;
    top: 120px;
}
.timeline-stage {
    position: relative;
    width: 100%;
    aspect-ratio: 4 / 3;
    border-radius: var(--radius);
    overflow: hidden;
    background-color: var(--blue-08);
}
/* A media panel: either an <img> or a styled placeholder. Stacked and
   cross-faded inside the stage; shown inline (static) on mobile. */
.tl-media {
    position: absolute;
    inset: 0;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    padding: var(--spacing-lg);
    /* Solid U of T blue — a per-event shade is applied inline by JS (no gradients). */
    background-color: var(--uoft-blue);
    opacity: 0;
    visibility: hidden;
    transition: opacity 450ms ease, visibility 0s linear 450ms;
}
.timeline-stage .tl-media.is-active { opacity: 1; visibility: visible; transition-delay: 0s; }
/* With a photo: the image fills the panel above a solid caption band. */
.tl-media--photo { padding: 0; }
.tl-media--photo::before { display: none; }
.tl-media img {
    flex: 1 1 0;
    min-height: 0;
    width: 100%;
    object-fit: cover;
}
/* Diagrams and logos: shown whole on white rather than cropped. */
.tl-media--contain img {
    object-fit: contain;
    padding: var(--spacing-lg);
    background-color: var(--color-white);
}
/* Graphics with their own text: shown whole, letterboxed on the panel colour. */
.tl-media--letterbox img { object-fit: contain; }
.tl-media--photo .tl-cap {
    display: grid;
    grid-template-columns: auto 1fr;
    column-gap: var(--spacing-md);
    align-items: baseline;
    padding: var(--spacing-md) var(--spacing-lg);
    text-shadow: none;
}
.tl-media--photo .tl-year { font-size: var(--font-size-2xl); }
.tl-media--photo .tl-caption { margin-top: 0; }
.tl-credit {
    grid-column: 1 / -1;
    margin-top: var(--spacing-xs);
    font-family: var(--font-sans);
    font-size: 0.7rem;
    color: rgba(255, 255, 255, 0.72);
}
a.tl-credit:hover { color: var(--color-white); }
.tl-cap { position: relative; z-index: 1; text-shadow: 0 1px 6px rgba(0, 0, 0, 0.28); }

/* "placeholder" corner badge — shown on every placeholder image (not avatars). */
.tl-media::before,
.photo-fallback::before,
.placeholder-box::before {
    content: "placeholder";
    position: absolute;
    top: var(--spacing-sm);
    left: var(--spacing-sm);
    z-index: 3;
    font-family: var(--font-sans);
    font-size: 0.65rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--uoft-blue);
    background-color: rgba(255, 255, 255, 0.9);
    padding: 0.12rem 0.45rem;
    border-radius: 2px;
}
.photo-fallback, .placeholder-box { position: relative; }
.tl-year {
    font-family: var(--font-sans);
    font-size: var(--font-size-4xl);
    line-height: 1;
    color: var(--color-white);
}
.tl-caption {
    font-family: var(--font-sans);
    font-size: var(--font-size-sm);
    font-weight: 700;
    color: rgba(255, 255, 255, 0.92);
    margin-top: var(--spacing-xs);
}
/* Inline media wrapper inside each event — desktop hides it (the sticky
   stage handles imagery); mobile shows it grouped with its event. */
.tl-inline {
    display: none;
    margin-top: var(--spacing-md);
}
.tl-inline .tl-media {
    position: relative;
    aspect-ratio: 16 / 9;
    border-radius: var(--radius);
    overflow: hidden;
    opacity: 1;
    visibility: visible;
}
.tl-inline .tl-media--photo { aspect-ratio: 4 / 3; }

@media (max-width: 48em) {
    .timeline-layout { grid-template-columns: 1fr; gap: 0; }
    .timeline-media-sticky { display: none; }
    .tl-inline { display: block; }
}

/* Research-areas / feature columns */
.feature-columns {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-2xl);
    margin-bottom: var(--block-gap);
}
/* About (Mission / History / Excellence): serif headings. */
.feature-card h2 { font-size: var(--font-size-2xl); margin-bottom: var(--spacing-md); }
/* Research areas: small sans labels. */
.feature-card h3 {
    font-family: var(--font-sans);
    font-size: var(--font-size-sm);
    font-weight: 700;
    color: var(--color-primary);
    text-transform: uppercase;
    letter-spacing: 0.03em;
    margin-bottom: var(--spacing-md);
}
.feature-card p {
    color: var(--color-text-light);
    font-size: var(--font-size-base);
}

/* Large feature image / team photo */
.feature-image img,
.feature-image .photo-fallback {
    width: 100%;
    height: clamp(320px, 42vw, 520px);
    object-fit: cover;
    background-color: var(--blue-08);
    border-radius: var(--radius);
}
/* Caption matches the .section-label eyebrow style. */
.feature-image figcaption {
    padding-top: var(--spacing-md);
    font-family: var(--font-sans);
    font-size: var(--font-size-xs);
    font-weight: 700;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

/* Reusable placeholder image block (solid U of T blue, badge via ::before). */
.placeholder-box {
    background-color: var(--blue-15);
    border-radius: var(--radius);
}

/* Section header with a placeholder image at the top-right. */
.section-with-media {
    display: flex;
    gap: var(--spacing-2xl);
    align-items: flex-start;
    justify-content: space-between;
    margin-bottom: var(--spacing-2xl);
}
.section-with-media .section-header { flex: 1; margin-bottom: 0; }
.section-corner-media {
    flex-shrink: 0;
    width: clamp(200px, 26vw, 320px);
    aspect-ratio: 4 / 3;
}
@media (max-width: 48em) {
    .section-with-media { flex-direction: column; }
    .section-corner-media { width: 100%; aspect-ratio: 16 / 9; }
}

/* -----------------------------------------------------------------------------
   9. People grid (faculty / students)
   -------------------------------------------------------------------------- */
/* ---- Tile variant (home page): square cards, à la design-options -------- */
/* Flex rather than grid so a short last row sits centred under the others. */
.people-grid--tile {
    --cols: 5;
    --gap: var(--spacing-4xl);
    max-width: 66rem;
    margin: var(--spacing-3xl) auto 0;   /* more air under the section intro than the usual header gap */
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--spacing-3xl) var(--gap);
}
.people-grid--tile > * { flex: 0 0 calc((100% - (var(--cols) - 1) * var(--gap)) / var(--cols)); }
@media (max-width: 64em) { .people-grid--tile { --cols: 4; --gap: var(--spacing-2xl); row-gap: var(--spacing-2xl); } }
.person-tile {
    display: flex;
    flex-direction: column;
}
.person-tile .tile-img { margin-bottom: var(--spacing-md); }
/* Linked people (home tiles, People cards) lift and underline the name on
   hover; the card opens their homepage. */
.person-tile, .person-profile { transition: transform var(--transition-fast); }
.person-tile[href]:hover, .person-profile.is-linked:hover { transform: translateY(-3px); }
.person-tile[href]:hover .person-name,
.person-profile.is-linked:hover .pp-name { text-decoration: underline; }
.tile-img {
    width: 100%;
    aspect-ratio: 1;
    border-radius: var(--radius);          /* essentially square */
    background-color: var(--blue-08);
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: var(--font-serif);
    font-size: var(--font-size-4xl);
    color: var(--blue-40);
    transition: background-color var(--transition-base), color var(--transition-base);
}
.person-tile:hover .tile-img { background-color: var(--blue-15); color: var(--blue-55); }
/* Faculty photos: shown as a uniform U of T Blue monotone (grayscale under a
   blue "color" blend), switching to full colour on hover. */
.tile-img,
.person-profile .avatar { position: relative; overflow: hidden; }
.tile-img img,
.person-profile .avatar img {
    width: 100%; height: 100%;
    object-fit: cover;
    filter: grayscale(1) contrast(0.92) brightness(1.06);
    transition: filter var(--transition-base);
}
.tile-img:has(img)::after,
.person-profile .avatar:has(img)::after {
    content: "";
    position: absolute;
    inset: 0;
    background-color: var(--uoft-blue);
    mix-blend-mode: color;
    opacity: 0.55;
    pointer-events: none;
    transition: opacity var(--transition-base);
}
.person-tile:hover .tile-img img,
.person-tile:focus-visible .tile-img img,
.person-profile:hover .avatar img { filter: none; }
.person-tile:hover .tile-img::after,
.person-tile:focus-visible .tile-img::after,
.person-profile:hover .avatar::after { opacity: 0; }
.person-tile .person-name {
    line-height: 1.3;   /* name sits right on its role, as on the People page */
    font-family: var(--font-sans);
    font-size: var(--font-size-sm);
    font-weight: 700;
    color: var(--color-primary);
    text-align: center;
}
.person-tile .person-role {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
    text-align: center;
}

/* ---- Profile variant (people.html): photo + tags + social links --------- */
.people-grid--profile {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: var(--spacing-2xl);
}
.person-profile {
    position: relative;
    display: flex;
    gap: var(--spacing-lg);
    align-items: flex-start;
}
/* The name is the card's link; its ::after stretches over the whole card so
   the card is clickable, while the social icons sit above it. */
.pp-name::after { content: ""; position: absolute; inset: 0; }
.pp-name:focus-visible { outline: none; }
.person-profile:has(.pp-name:focus-visible) { outline: 2px solid var(--color-primary); outline-offset: 4px; }
/* Square image, matching the home-page people tiles (not a circle). */
.person-profile .avatar {
    width: 92px; height: 92px;
    flex-shrink: 0;
    border-radius: var(--radius);
    overflow: hidden;
    background-color: var(--blue-08);
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: var(--font-serif);
    font-size: var(--font-size-3xl);
    color: var(--blue-40);
}
.pp-body { min-width: 0; }
.pp-body > :last-child { margin-bottom: 0; }
.pp-name {
    display: block;
    width: fit-content;
    margin-top: -0.1875em;   /* cancel the line's leading so the name's ink starts level with the photo */
    font-family: var(--font-sans);
    font-size: var(--font-size-base);
    font-weight: 700;
    color: var(--color-primary);
    line-height: 1.3;
}
.pp-role {
    font-size: var(--font-size-sm);
    color: var(--color-text-light);
    margin-bottom: var(--spacing-sm);
}
.pp-tags {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-sm);
}
.pp-social { position: relative; z-index: 1; display: flex; gap: var(--spacing-md); }
.pp-social a { display: inline-flex; color: var(--color-text-muted); }
.pp-social a:hover { color: var(--color-primary); }
.pp-social svg { width: 18px; height: 18px; }

/* -----------------------------------------------------------------------------
   10. Research / publication cards
   -------------------------------------------------------------------------- */
.work-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-lg);
}
/* Each publication is a bordered block, matching .link-card (Contact quick
   links, Join Us CTAs). The article stretches so cards in a row match height. */
.work-card { display: flex; }
.work-type {
    display: inline-block;
    font-family: var(--font-sans);
    font-size: var(--font-size-xs);
    font-weight: 700;
    color: var(--color-primary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: var(--spacing-sm);
}
.work-card h3 {
    font-size: var(--font-size-lg);
    line-height: 1.35;
    margin-bottom: var(--spacing-xs);
}
/* Bordered link cards — publications here, the Join Us / Contact call-outs
   (.link-card) below. The whole card is one link: hover or focus lifts it
   and underlines its arrow. */
.work-card-link, .link-card {
    display: flex;
    flex-direction: column;
    padding: var(--spacing-lg);
    background-color: var(--color-background-alt);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    color: inherit;
    transition: border-color var(--transition-fast), transform var(--transition-fast);
}
.work-card-link { flex: 1; }
:is(.work-card-link, .link-card):is(:hover, :focus-visible) { border-color: var(--blue-40); transform: translateY(-2px); }
.work-card-link h3 { color: var(--color-text); transition: color 0.2s ease; }
.work-card-link:hover h3, .work-card-link:focus-visible h3 { color: var(--color-primary); }
.work-meta {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-md);
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-sm);
}
.work-meta .publication { font-weight: 700; color: var(--color-primary); }
.work-excerpt {
    font-size: var(--font-size-sm);
    color: var(--color-text-light);
    margin-bottom: var(--spacing-sm);
    flex: 1;
}
/* "Read paper →", "Visit →", "Contact us →" */
.read-more, .link-arrow {
    font-family: var(--font-sans);
    font-size: var(--font-size-sm);
    font-weight: 700;
    color: var(--color-primary);
}
.read-more { display: inline-block; }
.work-card-link .read-more, .link-arrow { margin-top: var(--spacing-sm); }
.read-more:hover,
:is(.work-card-link, .link-card):is(:hover, :focus-visible) :is(.read-more, .link-arrow) { text-decoration: underline; }

/* -----------------------------------------------------------------------------
   11. Courses
   -------------------------------------------------------------------------- */
.course-list {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-md);
}
.course-card {
    display: grid;
    grid-template-columns: 130px 1fr auto;
    gap: var(--spacing-lg);
    align-items: baseline;
    padding: var(--spacing-lg) var(--spacing-xl);
    background-color: var(--color-background-alt);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    transition: border-color var(--transition-fast), transform var(--transition-fast);
}
.course-card:hover {
    border-color: var(--blue-40);
    transform: translateY(-2px);
}
.course-code {
    font-family: var(--font-sans);
    font-weight: 700;
    color: var(--color-primary);
    letter-spacing: 0.03em;
}
.course-body h3 {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-xs);
}
.course-body p {
    font-size: var(--font-size-sm);
    color: var(--color-text-light);
}
.course-term {
    font-size: var(--font-size-xs);
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-muted);
    white-space: nowrap;
}

/* -----------------------------------------------------------------------------
   12. Open positions / Join us
   -------------------------------------------------------------------------- */
.positions-list {
    display: grid;
    gap: var(--spacing-lg);
}
.position-card {
    padding: var(--spacing-xl);
    background-color: var(--color-background-alt);
    border: 1px solid var(--color-border);
    border-left: 3px solid var(--color-primary);
    border-radius: var(--radius);
}
.position-card h3 { font-size: var(--font-size-xl); margin-bottom: var(--spacing-sm); }
.position-card .position-meta {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-md);
}
.position-card p { color: var(--color-text-light); }

/* -----------------------------------------------------------------------------
   13. Contact & forms
   -------------------------------------------------------------------------- */
/* Map — light, minimal basemap (Carto Positron) that stays in the background. */
.map-embed {
    position: relative;
    width: 100%;
    aspect-ratio: 24 / 9;
    margin-bottom: var(--spacing-2xl);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    overflow: hidden;
    background-color: var(--blue-08);
}
.map-embed #contact-map,
.map-embed iframe { width: 100%; height: 100%; border: 0; display: block; }
@media (max-width: 48em) { .map-embed { aspect-ratio: 4 / 3; } }
/* When the map sits below the details, move its spacing above it. */
.map-embed--below { margin-top: var(--spacing-2xl); margin-bottom: 0; }

/* Balanced contact details (3 columns, no form). */
.contact-details {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-2xl);
}
@media (max-width: 48em) { .contact-details { grid-template-columns: 1fr; gap: var(--spacing-lg); } }

/* Quick links to U of T offices. */
.links-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg);
}
/* Two-up (2x2) variant — used on the Join Us and Contact pages. */
.links-grid--2col { grid-template-columns: repeat(2, 1fr); }
.link-card { gap: var(--spacing-xs); }
.link-card h3 { font-size: var(--font-size-lg); margin-bottom: var(--spacing-xs); }
.link-card p { font-size: var(--font-size-sm); color: var(--color-text-light); flex: 1; }
@media (max-width: 48em) { .links-grid { grid-template-columns: 1fr; } }

/* Join Us — prose sections (DGP-style), each closing with one clear CTA. */
.join-prose { max-width: 70ch; }
.join-prose p {
    color: var(--color-text-light);
    margin-bottom: var(--spacing-md);
}
.join-prose ul {
    list-style: disc;
    padding-left: 1.4rem;
    color: var(--color-text-light);
    margin-bottom: var(--spacing-md);
}
.join-prose li { margin-bottom: var(--spacing-xs); }
.join-prose > :last-child { margin-bottom: 0; }
.cta-single {
    display: grid;
    max-width: 520px;
    margin-top: var(--block-gap);
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-3xl);
}
.contact-info h3 { font-family: var(--font-sans); font-size: var(--font-size-sm); font-weight: 700; text-transform: uppercase; letter-spacing: 0.05em; color: var(--color-primary); margin-bottom: var(--spacing-xs); }
/* Links in these paragraphs aren't underlined, so they're told apart by
   colour alone: text a shade lighter (#707484, 4.65:1 on white) and links a
   deeper U of T navy (#132548), 3.26:1 against the text (WCAG 1.4.1). */
.contact-info p { color: #707484; margin-bottom: var(--spacing-lg); }
.contact-info p a { color: #132548; }

.form-field { margin-bottom: var(--spacing-lg); }
.form-field label {
    display: block;
    font-family: var(--font-sans);
    font-size: var(--font-size-sm);
    font-weight: 700;
    color: var(--color-text);
    margin-bottom: var(--spacing-xs);
}
.form-field input,
.form-field textarea {
    width: 100%;
    padding: 0.7rem var(--spacing-md);
    font-family: var(--font-sans);
    font-size: var(--font-size-base);
    color: var(--color-text);
    background-color: var(--color-white);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
}
.form-field input:focus,
.form-field textarea:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px var(--blue-15);
}
.form-field textarea { resize: vertical; min-height: 140px; }

/* -----------------------------------------------------------------------------
   14. Newsletter & footer
   -------------------------------------------------------------------------- */
.newsletter {
    text-align: center;
    padding: var(--spacing-4xl) 0;
    border-top: 1px solid var(--color-border);
}
.newsletter h2 { font-size: var(--font-size-2xl); margin-bottom: var(--spacing-lg); }
.newsletter-form {
    display: flex;
    gap: var(--spacing-sm);
    max-width: 480px;
    margin: 0 auto;
}
.newsletter-form input[type="email"] {
    flex: 1;
    padding: 0.7rem var(--spacing-md);
    font-family: var(--font-sans);
    font-size: var(--font-size-base);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    background-color: var(--color-white);
}
.newsletter-form input[type="email"]:focus { outline: none; border-color: var(--color-primary); }

/* "Where we are" — shared across index.html and about.html.
   Two columns: 2/3 intro text, 1/3 address + contact link. */
.where-grid {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: var(--spacing-3xl);
    align-items: start;
}
.where-grid .where-text .section-description { margin-top: var(--spacing-md); font-size: var(--font-size-base); }
.where-aside h3 {
    font-family: var(--font-sans);
    font-size: var(--font-size-sm);
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-primary);
    margin-bottom: var(--spacing-xs);
}
.where-aside p { color: var(--color-text-light); }
.where-aside .where-contact { margin-top: var(--spacing-md); }
@media (max-width: 48em) {
    .where-grid { grid-template-columns: 1fr; gap: var(--spacing-xl); }
}

.site-footer {
    background-color: var(--color-background);
    border-top: 1px solid var(--color-border);
    padding: var(--spacing-2xl) 0;
    font-family: var(--font-sans);
    font-weight: 400;
}
/* Three-part footer: copyright (left) · version (middle) · credit (right) */
.footer-inner {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    align-items: center;
    gap: var(--spacing-md) var(--spacing-lg);
}
.footer-inner .copyright {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
}
.footer-inner .credit {
    font-size: var(--font-size-sm);
    color: var(--color-text-muted);
    text-align: right;
    margin-left: auto;
}
.footer-inner .build-timestamp {
    font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
    font-size: var(--font-size-xs);
    color: var(--blue-55);
    background-color: var(--blue-08);
    padding: 0.15rem 0.55rem;
    border-radius: var(--radius);
}

/* -----------------------------------------------------------------------------
   15. Responsive
   -------------------------------------------------------------------------- */
/* Swap to the narrower logo when the full wordmark + nav no longer fit. */
@media (max-width: 68.75em) {
    .logo--full { display: none; }
    .logo--simple { display: block; }
}
@media (max-width: 37.5em) {
    .logo { height: 50px; }
}

@media (max-width: 64em) {
    .feature-columns { grid-template-columns: 1fr; gap: var(--spacing-xl); }
    .work-grid { grid-template-columns: 1fr; }

    /* Below laptop size, the hero stacks (text first) so the graphic gets a
       full-width, short band — which the horizontal stack variant fills.
       The JS swaps the vertical stack for the horizontal one at this width. */
    .hero { min-height: 0; }
    .hero .container { display: flex; flex-direction: column; }
    .hero-content { max-width: 100%; order: 1; }
    /* Graphic sits ABOVE the hero text on stacked layouts, and matches the
       container so it lines up with the section content. */
    .hero-graphic {
        position: relative;
        top: auto;
        order: -1;
        width: 100%;
        height: auto;
        margin: 0 auto var(--spacing-2xl);
        justify-content: center;
    }
    .hero-graphic svg { width: 100%; height: auto; }
    /* No tagline on tablet and below. */
    .hero-tagline { display: none; }
}

@media (max-width: 48em) {
    /* Breathing room before and after the graphic, in the hero's paragraph rhythm. */
    .hero { padding: var(--spacing-lg) 0 var(--section-space); }
    .hero-graphic { margin-top: var(--spacing-md); margin-bottom: var(--spacing-lg); }
    /* Text runs a step smaller on phones (xs stays at 12px for legibility). */
    :root {
        --section-space:  3rem;
        --font-size-sm:   0.8125rem;
        --font-size-base: 0.9375rem;
        --font-size-lg:   1.0625rem;
        --font-size-xl:   1.125rem;
        --font-size-2xl:  1.375rem;
        --font-size-3xl:  1.6rem;
        --font-size-4xl:  2rem;
    }
    .nav-toggle { display: inline-flex; }
    .nav-list {
        position: absolute;
        top: 100%; left: 0; right: 0;
        flex-direction: column;
        align-items: stretch;
        gap: 0;
        background-color: var(--color-background-alt);
        border-bottom: 1px solid var(--color-border);
        box-shadow: 0 8px 20px var(--blue-15);
        padding: var(--spacing-sm) 0;
        display: none;
    }
    .nav-list.open { display: flex; }
    /* The links must be block-level here: as inline <a>, their vertical padding
       and borders bled into neighbouring rows, which read as stray sand-coloured
       lines striking through the text. Block layout gives each its own row. */
    .nav-list li { width: 100%; }
    /* Same tint treatment as desktop, but on full-width rows: reset the
       desktop's negative margin and radius so the tint spans edge to edge. */
    .nav-list .nav-link {
        display: block;
        width: 100%;
        padding: var(--spacing-md) var(--container-padding);
        margin: 0;
        border-radius: 0;
    }
    .nav-list li + li .nav-link { border-top: 1px solid var(--color-border); }

    /* Dropdown children are always visible in the mobile menu, as indented
       rows beneath their parent link. */

    .contact-grid { grid-template-columns: 1fr; gap: var(--spacing-xl); }
    .course-card { grid-template-columns: 1fr; gap: var(--spacing-xs); }
    .course-term { order: -1; }
    .footer-inner { flex-direction: column; align-items: flex-start; }
    .footer-inner .credit { text-align: left; margin-left: 0; }
    .newsletter-form { flex-direction: column; }
    /* Home tiles stay two-up; People profiles go single-column on mobile. */
    .people-grid--tile { --cols: 2; --gap: var(--spacing-xl); row-gap: var(--spacing-xl); }
    .people-grid--profile { grid-template-columns: 1fr; }
}

@media (max-width: 28.75em) {
    .feature-columns { grid-template-columns: 1fr; }
}

/* Respect reduced-motion preferences for the hero reveal & transitions */
@media (prefers-reduced-motion: reduce) {
    * { scroll-behavior: auto !important; }
}