/* ============================================================
   wattli — design system
   Hand-written static site, no build step. Everything below is
   plain CSS with custom properties; re-tinting the brand is a
   matter of editing the :root block.
   ============================================================ */

:root {
    /* --- surfaces --- */
    --paper:            #FFFFFF;
    --tint:             #F4F6F8;
    --tint-2:           #E8ECF1;
    --ink:              #12181F;
    --ink-soft:         #1B242E;
    --border:           #DCE3EA;
    --border-on-ink:    #2C3844;

    /* --- text --- */
    --text:             #12181F;
    --text-muted:       #5A6875;   /* 5.7:1 on paper, 5.2:1 on tint */
    --text-on-ink:      #FFFFFF;
    --text-on-ink-muted:#98A6B4;   /* 7.1:1 on ink */

    /* --- accent ---
       `accent` is for graphics and large type; `accent-strong` is the
       text-safe variant on light backgrounds (5.7:1); `accent-on-ink`
       is the variant for dark sections (7.7:1). */
    --accent:           #0B8F8C;
    --accent-strong:    #077370;
    --accent-on-ink:    #2FBDB5;
    --accent-wash:      #E6F4F3;

    /* --- type --- */
    --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;

    /* --- geometry --- */
    --container: 1180px;
    --radius:    10px;
    --radius-lg: 18px;
    --header-h:  72px;

    /* --- elevation --- */
    --shadow-sm: 0 1px 2px rgb(18 24 31 / .06);
    --shadow-md: 0 4px 14px -4px rgb(18 24 31 / .10), 0 2px 5px -2px rgb(18 24 31 / .06);
    --shadow-lg: 0 18px 40px -16px rgb(18 24 31 / .22);

    --transition: .2s ease;
}

/* ============================================================
   Reset & base
   ============================================================ */

*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }

html {
    scroll-behavior: smooth;
    scroll-padding-top: calc(var(--header-h) + 16px);
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: var(--font);
    font-size: 1.0625rem;
    line-height: 1.65;
    color: var(--text);
    background: var(--paper);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    padding-top: var(--header-h);
}

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

a { color: var(--accent-strong); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { color: var(--accent); }

h1, h2, h3, h4 { line-height: 1.15; letter-spacing: -.022em; font-weight: 650; }
h1 { font-size: clamp(2.25rem, 1.35rem + 3.4vw, 3.9rem); letter-spacing: -.032em; }
h2 { font-size: clamp(1.75rem, 1.25rem + 1.8vw, 2.6rem); letter-spacing: -.028em; }
h3 { font-size: clamp(1.15rem, 1.02rem + .45vw, 1.4rem); }
h4 { font-size: 1.0625rem; }

:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 3px;
    border-radius: 3px;
}

.container {
    width: 100%;
    max-width: var(--container);
    margin: 0 auto;
    padding: 0 1.5rem;
}

/* Small utility set — deliberately tiny. It exists so that no HTML file
   needs a style="" attribute, which in turn lets the CSP ship without
   'unsafe-inline' for styles. */
.mt-s { margin-top: 1rem; }
.mt-m { margin-top: 1.5rem; }
.mt-l { margin-top: 2.5rem; }
.text-sm { font-size: .875rem; }

.bullets {
    margin-top: 1rem;
    display: grid;
    gap: .7rem;
    padding-left: 1.1rem;
}
.bullets li { color: var(--text-muted); }

.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;
}

/* ============================================================
   Logo wordmark
   "watt" is the power, "li" is the diminutive — same size, same
   baseline, set apart by the accent colour alone.
   ============================================================ */

.logo {
    display: inline-flex;
    align-items: baseline;
    font-weight: 650;
    font-size: 1.5rem;
    line-height: 1;
    letter-spacing: -.035em;
    color: var(--text);
    text-decoration: none;
    white-space: nowrap;
}
.logo__li {
    letter-spacing: -.01em;
    margin-left: .02em;
    color: var(--accent);
}
.logo:hover { color: var(--text); }

/* on dark backgrounds */
.on-ink .logo,
.footer .logo { color: var(--text-on-ink); }
.on-ink .logo__li,
.footer .logo__li { color: var(--accent-on-ink); }

/* ============================================================
   Header & navigation
   ============================================================ */

.header {
    position: fixed;
    inset: 0 0 auto 0;
    height: var(--header-h);
    background: rgb(255 255 255 / .88);
    backdrop-filter: saturate(180%) blur(12px);
    -webkit-backdrop-filter: saturate(180%) blur(12px);
    border-bottom: 1px solid transparent;
    z-index: 1000;
    transition: border-color var(--transition), box-shadow var(--transition);
}
.header.is-scrolled {
    border-bottom-color: var(--border);
    box-shadow: 0 1px 14px -6px rgb(18 24 31 / .18);
}

.nav {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    height: var(--header-h);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 2rem;
    list-style: none;
    margin-left: auto;
}
.nav-links a {
    color: var(--text);
    text-decoration: none;
    font-weight: 500;
    font-size: .975rem;
    white-space: nowrap;
    transition: color var(--transition);
}
.nav-links a:hover,
.nav-links a[aria-current="page"] { color: var(--accent-strong); }
.nav-links a[aria-current="page"] { font-weight: 600; }

.nav-toggle {
    display: none;
    width: 42px; height: 42px;
    border: 0; background: none; cursor: pointer;
    padding: 10px 9px;
    border-radius: 8px;
}
.nav-toggle span {
    display: block; height: 2px; border-radius: 2px;
    background: var(--text);
    transition: transform var(--transition), opacity var(--transition);
}
.nav-toggle span + span { margin-top: 5px; }

/* ============================================================
   Buttons
   ============================================================ */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: .5rem;
    padding: .8rem 1.5rem;
    border: 1px solid transparent;
    border-radius: var(--radius);
    font-size: .975rem;
    font-weight: 600;
    line-height: 1.2;
    text-decoration: none;
    cursor: pointer;
    transition: background var(--transition), color var(--transition),
                border-color var(--transition), transform var(--transition);
}
.btn:active { transform: translateY(1px); }

.btn--primary { background: var(--accent); color: #fff; }
.btn--primary:hover { background: var(--accent-strong); color: #fff; }

.btn--outline {
    background: transparent;
    color: var(--text);
    border-color: var(--border);
}
.btn--outline:hover { border-color: var(--text); color: var(--text); }

.btn--sm { padding: .55rem 1rem; font-size: .9rem; }

.on-ink .btn--primary { background: var(--accent-on-ink); color: var(--ink); }
.on-ink .btn--primary:hover { background: #4ACFC7; color: var(--ink); }
.on-ink .btn--outline { color: var(--text-on-ink); border-color: var(--border-on-ink); }
.on-ink .btn--outline:hover { border-color: var(--text-on-ink); color: var(--text-on-ink); }

/* Text link with a trailing arrow */
.link-arrow {
    display: inline-flex;
    align-items: center;
    gap: .4rem;
    font-weight: 600;
    font-size: .975rem;
    text-decoration: none;
    color: var(--accent-strong);
}
.link-arrow::after {
    content: "→";
    transition: transform var(--transition);
}
.link-arrow:hover::after { transform: translateX(3px); }
.on-ink .link-arrow { color: var(--accent-on-ink); }

/* ============================================================
   Section system
   ============================================================ */

.wl-section { padding: clamp(4rem, 2.4rem + 6vw, 7.5rem) 0; }
.wl-section--tint { background: var(--tint); }
.wl-section--ink  { background: var(--ink); color: var(--text-on-ink); }
.wl-section--tight { padding-top: clamp(2.5rem, 1.6rem + 3.4vw, 4rem); }

.wl-section--ink h1, .wl-section--ink h2, .wl-section--ink h3 { color: var(--text-on-ink); }
.wl-section--ink p { color: var(--text-on-ink-muted); }
.wl-section--ink a:not(.btn) { color: var(--accent-on-ink); }

.eyebrow {
    display: block;
    font-size: .78rem;
    font-weight: 650;
    letter-spacing: .16em;
    text-transform: uppercase;
    color: var(--accent-strong);
    margin-bottom: 1rem;
}
.on-ink .eyebrow, .wl-section--ink .eyebrow { color: var(--accent-on-ink); }

.section-head { max-width: 46rem; margin-bottom: clamp(2.25rem, 1.6rem + 2.4vw, 3.5rem); }
.section-head p { color: var(--text-muted); font-size: 1.125rem; margin-top: 1.1rem; }
.wl-section--ink .section-head p { color: var(--text-on-ink-muted); }

.lead { font-size: clamp(1.075rem, 1rem + .35vw, 1.25rem); color: var(--text-muted); }

/* ============================================================
   Hero
   ============================================================ */

.hero {
    position: relative;
    padding: clamp(3.5rem, 2rem + 6vw, 7rem) 0 clamp(3.5rem, 2rem + 5vw, 6rem);
    background: var(--ink);
    color: var(--text-on-ink);
    overflow: hidden;
}
.hero__inner { position: relative; z-index: 1; max-width: 54rem; }
.hero h1 { color: var(--text-on-ink); }
.hero h1 em { font-style: normal; color: var(--accent-on-ink); }
.hero__sub {
    margin-top: 1.5rem;
    max-width: 42rem;
    font-size: clamp(1.075rem, 1rem + .4vw, 1.3rem);
    color: var(--text-on-ink-muted);
}
.hero__ctas { display: flex; flex-wrap: wrap; gap: .875rem; margin-top: 2.25rem; }

/* decorative waveform, purely presentational */
.hero__wave {
    position: absolute;
    right: -6%;
    bottom: -18%;
    width: min(760px, 74%);
    opacity: .30;
    pointer-events: none;
}

.hero__meta {
    display: flex;
    flex-wrap: wrap;
    gap: .6rem 1.4rem;
    margin-top: 2.5rem;
    font-size: .9rem;
    color: var(--text-on-ink-muted);
}
.hero__meta span { display: inline-flex; align-items: center; gap: .5rem; }
.hero__meta span::before {
    content: "";
    width: 5px; height: 5px; border-radius: 50%;
    background: var(--accent-on-ink);
    flex: none;
}

/* ============================================================
   Grids & cards
   ============================================================ */

.grid { display: grid; gap: 1.5rem; }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }

.card {
    display: flex;
    flex-direction: column;
    padding: 1.85rem;
    background: var(--paper);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    transition: border-color var(--transition), box-shadow var(--transition),
                transform var(--transition);
}
.card h3 { margin-bottom: .7rem; }
.card p { color: var(--text-muted); font-size: 1rem; }
.card__foot { margin-top: auto; padding-top: 1.5rem; }

a.card { text-decoration: none; color: inherit; }
a.card:hover {
    border-color: var(--accent);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.card__num {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 2.25rem; height: 2.25rem;
    margin-bottom: 1.1rem;
    border-radius: 8px;
    background: var(--accent-wash);
    color: var(--accent-strong);
    font-size: .875rem;
    font-weight: 700;
    font-variant-numeric: tabular-nums;
}

.wl-section--ink .card {
    background: var(--ink-soft);
    border-color: var(--border-on-ink);
}
.wl-section--ink .card p { color: var(--text-on-ink-muted); }
.wl-section--ink .card__num { background: rgb(47 189 181 / .14); color: var(--accent-on-ink); }

/* ============================================================
   Feature rows — alternating text + image
   ============================================================ */

.feature {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: clamp(2rem, 1rem + 4vw, 4.5rem);
    align-items: center;
}
.feature + .feature { margin-top: clamp(3.5rem, 2rem + 5vw, 6rem); }
.feature--flip .feature__media { order: -1; }
.feature h2 { margin-bottom: 1.1rem; }
.feature p { color: var(--text-muted); }
.feature p + p { margin-top: 1rem; }
.feature__cta { margin-top: 1.75rem; }

.feature__media {
    border-radius: var(--radius-lg);
    overflow: hidden;
    background: var(--tint);
    border: 1px solid var(--border);
}
.feature__media img { width: 100%; }
.wl-section--ink .feature__media { border-color: var(--border-on-ink); background: var(--ink-soft); }

/* Uniform crop — used where several photos of different native aspect
   ratios sit side by side and a ragged grid would read as sloppy. */
.feature__media--crop { aspect-ratio: 4 / 3; }
.feature__media--crop img { width: 100%; height: 100%; object-fit: cover; object-position: center; }

/* Column of stacked figures next to a block of text */
.feature__media-stack { display: block; min-width: 0; }

figure { margin: 0; }
figcaption {
    margin-top: .75rem;
    font-size: .8125rem;
    line-height: 1.5;
    color: var(--text-muted);
}
.wl-section--ink figcaption { color: var(--text-on-ink-muted); }

/* Concept diagram — scrolls inside its own box rather than widening the
   page when the viewport is narrower than the drawing needs to be. */
.diagram {
    overflow-x: auto;
    margin: clamp(2rem, 1.2rem + 2.6vw, 3rem) 0 0;
}
.diagram svg {
    display: block;
    width: 100%;
    min-width: 660px;
    height: auto;
}

/* Attribution line under a project block */
.credit {
    margin-top: 2.25rem;
    padding-top: 1.25rem;
    border-top: 1px solid var(--border);
    font-size: .8125rem;
    color: var(--text-muted);
}
.wl-section--ink .credit { border-top-color: var(--border-on-ink); color: var(--text-on-ink-muted); }

/* ============================================================
   Competence strip
   ============================================================ */

.strip {
    display: flex;
    flex-wrap: wrap;
    gap: .625rem;
}
.strip li {
    list-style: none;
    padding: .5rem 1rem;
    border: 1px solid var(--border);
    border-radius: 999px;
    font-size: .9rem;
    font-weight: 500;
    color: var(--text-muted);
    background: var(--paper);
}
.wl-section--ink .strip li {
    border-color: var(--border-on-ink);
    background: transparent;
    color: var(--text-on-ink-muted);
}

/* ============================================================
   Steps — numbered process
   ============================================================ */

.steps { counter-reset: step; display: grid; gap: 1.5rem; }
.steps > li {
    list-style: none;
    counter-increment: step;
    position: relative;
    padding-left: 3.25rem;
}
.steps > li::before {
    content: counter(step);
    position: absolute;
    left: 0; top: -.15rem;
    width: 2.25rem; height: 2.25rem;
    display: grid; place-items: center;
    border-radius: 50%;
    background: var(--accent-wash);
    color: var(--accent-strong);
    font-size: .875rem;
    font-weight: 700;
    font-variant-numeric: tabular-nums;
}
.steps h3 { margin-bottom: .4rem; }
.steps p { color: var(--text-muted); }
.wl-section--ink .steps > li::before { background: rgb(47 189 181 / .14); color: var(--accent-on-ink); }

/* ============================================================
   Contact block
   ============================================================ */

.contact { text-align: center; max-width: 40rem; margin: 0 auto; }
.contact h2 { margin-bottom: 1rem; }
.contact p { margin-bottom: 2rem; }
.contact__mail {
    display: inline-block;
    font-size: clamp(1.25rem, 1rem + 1.1vw, 1.75rem);
    font-weight: 650;
    letter-spacing: -.02em;
    text-decoration: none;
    color: var(--accent-on-ink);
    border-bottom: 2px solid rgb(47 189 181 / .35);
    padding-bottom: .1rem;
    transition: border-color var(--transition);
}
.contact__mail:hover { border-bottom-color: var(--accent-on-ink); }

/* Same link on a light background — the on-ink accent would fall to
   roughly 2:1 there, so switch to the text-safe variant. */
.contact__mail--light {
    color: var(--accent-strong);
    border-bottom-color: rgb(7 115 112 / .3);
}
.contact__mail--light:hover { border-bottom-color: var(--accent-strong); }

/* ============================================================
   Footer
   ============================================================ */

.footer {
    background: var(--ink);
    color: var(--text-on-ink-muted);
    padding: 3.5rem 0 2rem;
    font-size: .9375rem;
}
.footer__grid {
    display: grid;
    grid-template-columns: 1.4fr 1fr 1fr;
    gap: 2.5rem;
    padding-bottom: 2.5rem;
    border-bottom: 1px solid var(--border-on-ink);
}
.footer__tagline { margin-top: 1rem; max-width: 22rem; }
.footer h4 {
    color: var(--text-on-ink);
    font-size: .8rem;
    font-weight: 650;
    letter-spacing: .14em;
    text-transform: uppercase;
    margin-bottom: 1rem;
}
.footer ul { list-style: none; display: grid; gap: .6rem; }
.footer a { color: var(--text-on-ink-muted); text-decoration: none; transition: color var(--transition); }
.footer a:hover { color: var(--text-on-ink); }

.footer__bottom {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    gap: 1rem;
    padding-top: 1.75rem;
    font-size: .875rem;
}
.footer__legal { display: flex; gap: 1.5rem; list-style: none; }

/* ============================================================
   Prose — legal pages
   ============================================================ */

.prose { max-width: 46rem; }
.prose h2 {
    font-size: clamp(1.3rem, 1.15rem + .6vw, 1.6rem);
    margin: 2.75rem 0 .9rem;
}
.prose h3 { margin: 1.9rem 0 .6rem; font-size: 1.075rem; }
.prose p, .prose li { color: var(--text-muted); }
.prose p + p { margin-top: 1rem; }
.prose ul, .prose ol { margin: 1rem 0 1rem 1.25rem; display: grid; gap: .5rem; }
.prose > :first-child { margin-top: 0; }

.page-head {
    padding: clamp(2.5rem, 1.8rem + 3vw, 4rem) 0 clamp(1.5rem, 1rem + 2vw, 2.5rem);
    border-bottom: 1px solid var(--border);
}
.page-head p { color: var(--text-muted); margin-top: .9rem; max-width: 42rem; }

.note {
    padding: 1.15rem 1.35rem;
    background: var(--tint);
    border-left: 3px solid var(--accent);
    border-radius: 0 var(--radius) var(--radius) 0;
    font-size: .9375rem;
    margin: 1.5rem 0;
}
.note p { color: var(--text); }

/* ============================================================
   Reveal on scroll
   ============================================================ */

[data-reveal] {
    opacity: 0;
    transform: translateY(14px);
    transition: opacity .55s ease, transform .55s ease;
}
[data-reveal].is-revealed { opacity: 1; transform: none; }

/* ============================================================
   Responsive
   ============================================================ */

@media (max-width: 900px) {
    .grid--3 { grid-template-columns: 1fr; }
    .grid--2 { grid-template-columns: 1fr; }
    .feature { grid-template-columns: 1fr; }
    .feature--flip .feature__media { order: 0; }
    .footer__grid { grid-template-columns: 1fr 1fr; }
    .footer__brand { grid-column: 1 / -1; }
}

@media (max-width: 780px) {
    .nav-toggle { display: block; margin-left: auto; }

    .nav-links {
        position: fixed;
        inset: var(--header-h) 0 auto 0;
        flex-direction: column;
        align-items: stretch;
        gap: 0;
        margin: 0;
        padding: .5rem 1.5rem 1.5rem;
        background: var(--paper);
        border-bottom: 1px solid var(--border);
        box-shadow: var(--shadow-lg);
        display: none;
    }
    .nav-links.active { display: flex; }
    .nav-links li { border-top: 1px solid var(--border); }
    .nav-links a { display: block; padding: .95rem 0; font-size: 1.0625rem; }

    .hero__wave { opacity: .18; right: -22%; bottom: -12%; width: 105%; }
}

@media (max-width: 560px) {
    .footer__grid { grid-template-columns: 1fr; gap: 2rem; }
    .hero__ctas .btn { width: 100%; }
}

/* ============================================================
   Motion & print
   ============================================================ */

@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    *, *::before, *::after {
        animation-duration: .01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: .01ms !important;
    }
    [data-reveal] { opacity: 1; transform: none; }
}

@media print {
    .header, .footer, .hero__wave, .nav-toggle { display: none; }
    body { padding-top: 0; }
    .wl-section--ink, .hero { background: #fff; color: #000; }
}