/* Roommate Albert, built on the pattern of pdf-archiver.io: paper throughout, one dark card, and one
   signature object. Here that object is the roller counter of a water meter, rolling in the hero
   and at rest in the dark card. */

:root {
    color-scheme: light dark;

    /* Brand: the two ends of the app icon's gradient, and the red of a meter's decimal rollers. */
    --ink: #0e1a2b;
    --paper: #f3f6fa;
    --paper-sunk: #e6ecf4;
    --blue: #2a62d4;
    --blue-bright: #6aa6ff;
    --sky: #74c7fb;
    --roller-red: #c42a38;

    --text: #1b2533;
    --text-soft: #56606e;
    --rule: #d7dfea;
    --card: #fff;
    --ok: #1f8a4c;

    --accent: var(--blue);
    /* White on --blue-bright is under 3:1, so filled buttons keep the dark blue in both modes. */
    --accent-fill: var(--blue);

    --wrap: 72rem;
    /* Charter ships with macOS and iOS; everyone else gets Source Serif. */
    --font-heading: Charter, "Bitstream Charter", "Source Serif 4", Georgia, serif;
    --font-body: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    --font-digits: "Barlow Semi Condensed", "DIN Condensed", "Arial Narrow", sans-serif;
}

@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
        --paper: #111a26;
        --paper-sunk: #18222f;
        --card: #1a2533;
        --text: #e6ebf2;
        --text-soft: #a2adbc;
        --rule: #3b4a60;
        --accent: var(--blue-bright);
        --ok: #4fc98a;
    }
}

:root[data-theme="dark"] {
    --paper: #111a26;
    --paper-sunk: #18222f;
    --card: #1a2533;
    --text: #e6ebf2;
    --text-soft: #a2adbc;
    --rule: #3b4a60;
    --accent: var(--blue-bright);
    --ok: #4fc98a;
}

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

html { scroll-behavior: smooth; }

body {
    margin: 0;
    background: var(--paper);
    color: var(--text);
    font-family: var(--font-body);
    font-size: 1.0625rem;
    line-height: 1.65;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
}

h1, h2, h3 {
    margin: 0;
    font-family: var(--font-heading);
    line-height: 1.08;
    letter-spacing: -0.02em;
    text-wrap: balance;
}

p { margin: 0 0 1.1em; }

a { color: var(--accent); text-underline-offset: 0.18em; }

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

:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 3px;
    border-radius: 4px;
}

.skip-link {
    position: fixed;
    top: -100%;
    left: 1rem;
    z-index: 40;
    padding: 0.7rem 1.1rem;
    border: 1px solid var(--rule);
    border-radius: 0.7rem;
    background: var(--card);
    color: var(--text);
    font-weight: 600;
    text-decoration: none;
}

.skip-link:focus { top: 1rem; }

.wrap {
    width: 100%;
    max-width: var(--wrap);
    margin-inline: auto;
    padding-inline: clamp(1rem, 5vw, 3rem);
}

.section-title {
    font-size: clamp(1.7rem, 3.2vw, 2.3rem);
    font-weight: 700;
    text-align: center;
}

.section-lead {
    margin: 0.6rem auto 0;
    max-width: 32em;
    color: var(--text-soft);
    text-align: center;
}

#so-gehts, #fragen, #laden,
#how-it-works, #questions, #download { scroll-margin-top: 5rem; }

/* ---------- Buttons ---------- */

.button {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.85rem 1.6rem;
    border-radius: 999px;
    background: var(--accent-fill);
    color: #fff;
    font-weight: 600;
    text-decoration: none;
    box-shadow: 0 12px 24px -12px color-mix(in srgb, var(--blue) 80%, transparent);
    transition: transform 0.15s ease;
}

.button:hover { transform: translateY(-2px); color: #fff; }

.button-ghost {
    background: transparent;
    color: var(--text);
    box-shadow: inset 0 0 0 1.5px var(--rule);
}

.button-ghost:hover { background: var(--paper-sunk); color: var(--text); }

.button svg { width: 1.1em; height: 1.1em; flex: none; }

/* ---------- Header: transparent at rest, a floating pill once scrolled (from pdf-archiver.io) ---------- */

.site-header {
    padding-block: 1.3rem;
    position: sticky;
    top: 0;
    z-index: 30;
    background: transparent;
    transition: padding-block 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.site-header-inner {
    display: flex;
    align-items: center;
    gap: clamp(1rem, 4vw, 2.5rem);
    border: 1px solid transparent;
    border-radius: 999px;
    background: transparent;
    transition:
        border-color 0.4s ease,
        max-width 0.4s cubic-bezier(0.4, 0, 0.2, 1),
        padding-block 0.4s cubic-bezier(0.4, 0, 0.2, 1),
        padding-inline 0.4s cubic-bezier(0.4, 0, 0.2, 1),
        gap 0.4s cubic-bezier(0.4, 0, 0.2, 1),
        background-color 0.4s ease,
        box-shadow 0.4s ease;
}

.site-header.is-scrolled { padding-block: 0.7rem; }

.site-header.is-scrolled .site-header-inner {
    max-width: min(54rem, 94vw);
    padding-block: 0.55rem;
    padding-inline: 1.2rem 0.55rem;
    gap: clamp(0.75rem, 3vw, 1.75rem);
    border-color: var(--rule);
    background: color-mix(in srgb, var(--card) 97%, transparent);
    backdrop-filter: blur(24px) saturate(1.6);
    -webkit-backdrop-filter: blur(24px) saturate(1.6);
    box-shadow:
        0 10px 20px -8px rgba(14, 26, 43, 0.22),
        0 28px 55px -22px rgba(14, 26, 43, 0.4);
}

.site-name {
    display: inline-flex;
    align-items: center;
    gap: 0.6rem;
    font-weight: 800;
    font-size: 1.05rem;
    letter-spacing: -0.01em;
    color: var(--text);
    text-decoration: none;
}

.site-icon { width: 28px; height: 28px; border-radius: 7px; flex: none; }

.site-nav { margin-inline-start: auto; }

.site-nav ul {
    display: flex;
    align-items: center;
    gap: clamp(1rem, 3vw, 2rem);
    list-style: none;
    margin: 0;
    padding: 0;
}

.site-nav a {
    color: var(--text-soft);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.95rem;
}

.site-nav a:hover { color: var(--accent); }

/* Scoped under `.site-nav` so it outweighs `.site-nav a`, which would paint the label in the pill's colour. */
.site-nav .nav-cta {
    display: inline-flex;
    align-items: center;
    line-height: 1;
    background: var(--accent-fill);
    color: #fff;
    padding: 0.55rem 1.2rem;
    border-radius: 999px;
}

.site-nav .nav-cta:hover { background: color-mix(in srgb, var(--accent-fill) 85%, var(--ink)); color: #fff; }

.language-toggle { display: inline-flex; align-items: baseline; gap: 0.3rem; font-size: 0.85rem; }

/* SC 2.5.8 asks for 24 × 24 CSS px; the bare 0.85rem label is about 17 × 22. */
.language-toggle a {
    display: inline-flex;
    align-items: center;
    min-height: 24px;
    padding-inline: 0.4rem;
    color: var(--text-soft);
    text-decoration: none;
    font-weight: 500;
    opacity: 0.75;
}

.language-toggle a:hover { color: var(--accent); opacity: 1; }

.language-toggle [aria-current="page"] { color: var(--text); font-weight: 700; opacity: 1; }

.language-sep { color: var(--rule); }

@media (max-width: 720px) {
    /* Without the toggle there is no way to the other language: nothing redirects by Accept-Language. */
    .site-nav ul li:not(:has(.nav-cta)):not(.language-toggle) { display: none; }

    .site-header-inner { flex-wrap: wrap; row-gap: 0.5rem; }

    .site-nav .nav-cta { padding-inline: 0.9rem; }
}

@media (prefers-reduced-motion: reduce) {
    .site-header, .site-header-inner { transition: none; }
}

/* ---------- Hero ---------- */

.hero { padding-block: clamp(2.5rem, 7vw, 5.5rem) clamp(3rem, 7vw, 5rem); }

.hero .wrap {
    display: grid;
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
    gap: clamp(2rem, 5vw, 4.5rem);
    align-items: center;
}

@media (max-width: 56rem) {
    .hero .wrap { grid-template-columns: minmax(0, 1fr); }
}

.hero-kicker {
    margin-bottom: 1.1rem;
    color: var(--text-soft);
    font-weight: 500;
}

.hero h1 {
    font-size: clamp(2.6rem, 6.4vw, 4.6rem);
    font-weight: 700;
}

.hero h1 span { display: block; }

.hero-lead {
    margin-top: 1.4rem;
    max-width: 30em;
    color: var(--text-soft);
    font-size: 1.15rem;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.8rem;
    margin-top: 1.8rem;
}

.hero-note {
    margin: 1.1rem 0 0;
    color: var(--text-soft);
    font-size: 0.95rem;
}

/* ---------- The meter, drawn in the app icon's line style ---------- */

.scene { position: relative; max-width: 30rem; margin-inline: auto; width: 100%; }

.tile {
    position: relative;
    padding: clamp(3rem, 7vw, 3.8rem) clamp(1.2rem, 4vw, 2.4rem) clamp(2.4rem, 6vw, 3.2rem);
    border-radius: 1.8rem;
    background: linear-gradient(180deg, #3b82f6, var(--sky));
    box-shadow: 0 30px 60px -30px rgba(14, 26, 43, 0.55);
}

.photo-exif {
    position: absolute;
    top: 0.9rem;
    right: 1rem;
    padding: 0.2rem 0.65rem;
    border-radius: 999px;
    background: rgba(14, 26, 43, 0.35);
    color: #fff;
    font-size: 0.78rem;
    font-weight: 500;
}

.meter {
    padding: 1.4rem 1.3rem 1.2rem;
    border: 3px solid #fff;
    border-radius: 1.4rem;
    color: #fff;
}

.serial {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-family: var(--font-digits);
    font-size: 1.05rem;
    font-weight: 600;
    letter-spacing: 0.05em;
}

/* Dashed like a text-recognition box: the serial number is what identifies the meter. */
.serial b { padding: 0.05rem 0.45rem; border: 2px dashed #fff; border-radius: 0.3rem; font-weight: 600; }

.meter .counter { margin-top: 1.1rem; }

.meter-foot {
    display: flex;
    justify-content: space-between;
    margin-top: 1rem;
    font-size: 0.9rem;
    font-weight: 600;
}

/* ---------- Roller counter ---------- */

.counter {
    --size: clamp(1.7rem, 5.8vw, 2.5rem);
    display: flex;
    gap: 0.26rem;
    font-family: var(--font-digits);
    font-size: var(--size);
    font-weight: 600;
    line-height: 1;
}

.roller {
    flex: 1 1 0;
    height: 1.35em;
    overflow: hidden;
    border-radius: 0.25em;
    box-shadow: inset 0 0 0 2.5px #fff;
    color: #fff;
    text-align: center;
}

/* The litre rollers behind the comma, red on a real meter, are filled here. */
.roller.red { background: rgba(255, 255, 255, 0.22); }

.comma {
    flex: none;
    align-self: flex-end;
    width: 0.2em;
    color: #fff;
}

.strip {
    display: flex;
    flex-direction: column;
    /* Each digit cell is 1.35em tall; --to is the index of the resting digit in a 0–9 ×3 strip. */
    transform: translateY(calc(var(--to) * -1.35em));
    transition: transform var(--dur, 1.6s) cubic-bezier(0.22, 0.8, 0.26, 1) var(--delay, 0s);
}

.strip span { display: block; height: 1.35em; line-height: 1.35em; }

.counter.is-idle .strip { transform: translateY(0); transition: none; }

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

/* ---------- Suggestion card (as in the app's Review tab) ---------- */

.suggestion {
    position: relative;
    margin: -1.4rem 0.4rem 0 auto;
    width: min(21rem, 92%);
    padding: 1rem 1.1rem 1.1rem;
    border: 1px solid var(--rule);
    border-radius: 1.2rem;
    background: var(--card);
    box-shadow: 0 24px 40px -24px rgba(14, 26, 43, 0.45);
    transform: rotate(0.8deg);
}

.suggestion-head { display: flex; gap: 0.7rem; align-items: center; }

.kind-icon {
    display: grid;
    place-items: center;
    width: 2.3rem;
    height: 2.3rem;
    border-radius: 0.6rem;
    background: linear-gradient(180deg, var(--sky), #3b8df0);
    color: #fff;
    flex: none;
}

.kind-icon svg { width: 1.2rem; height: 1.2rem; }

.suggestion-head strong { display: block; font-size: 1rem; }

.recognized { color: var(--ok); font-size: 0.85rem; }

.suggestion-value {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    margin-top: 0.8rem;
    color: var(--text-soft);
}

.suggestion-value b { color: var(--text); font-size: 1.45rem; font-variant-numeric: tabular-nums; }

.suggestion-foot {
    display: flex;
    justify-content: space-between;
    margin-top: 0.3rem;
    color: var(--text-soft);
    font-size: 0.85rem;
}

.suggestion-foot span:last-child { color: #d0342c; }

.suggestion-confirm {
    margin-top: 0.9rem;
    padding: 0.6rem;
    border-radius: 999px;
    background: var(--accent-fill);
    color: #fff;
    font-weight: 600;
    text-align: center;
}

/* ---------- Steps ---------- */

.steps { padding-block: clamp(3.5rem, 8vw, 6rem); background: var(--paper-sunk); }

.step-list {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: clamp(1.5rem, 3.5vw, 3rem);
    margin: clamp(2.2rem, 5vw, 3.5rem) 0 0;
    padding: 0;
    list-style: none;
    counter-reset: step;
}

@media (max-width: 52rem) {
    .step-list { grid-template-columns: minmax(0, 1fr); max-width: 34rem; margin-inline: auto; }
}

.step-list li { counter-increment: step; }

/* The step number sits on a single roller: the sequence is real, so it gets the counter's look. */
.step-list li::before {
    content: counter(step);
    display: grid;
    place-items: center;
    width: 2.4rem;
    height: 3rem;
    margin-bottom: 1.1rem;
    border-radius: 0.5rem;
    box-shadow: inset 0 0 0 2.5px var(--accent);
    color: var(--accent);
    font-family: var(--font-digits);
    font-size: 1.7rem;
    font-weight: 600;
}

.step-list h3 { font-size: 1.55rem; margin-bottom: 0.6rem; }

.step-list p { color: var(--text-soft); }

.ui { color: var(--text); font-weight: 600; white-space: nowrap; }

.steps-note {
    max-width: 44rem;
    margin: clamp(2rem, 4vw, 3rem) auto 0;
    padding-top: 1.6rem;
    border-top: 1px solid var(--rule);
    color: var(--text-soft);
    text-align: center;
}

/* ---------- The dark card ---------- */

.reading { padding-block: clamp(3.5rem, 8vw, 6rem); }

.dark-card {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: clamp(2rem, 5vw, 4rem);
    align-items: center;
    padding: clamp(1.6rem, 5vw, 4rem);
    border-radius: 2rem;
    background: var(--ink);
    color: #e6ebf2;
}

:root:not([data-theme="light"]) .dark-card { box-shadow: inset 0 0 0 1px transparent; }

@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) .dark-card { box-shadow: inset 0 0 0 1px var(--rule); background: #0a121d; }
}

@media (max-width: 56rem) {
    .dark-card { grid-template-columns: minmax(0, 1fr); }
}

.dark-card h2 { font-size: clamp(1.8rem, 3.6vw, 2.6rem); font-weight: 700; color: #fff; }

.dark-card p { color: #b5c0cf; }

.dark-card p:first-of-type { margin-top: 1.2rem; }

.dark-card a { color: var(--blue-bright); }

.at-rest { margin: 0; }

.at-rest .counter { --size: clamp(1.7rem, 4.6vw, 2.4rem); }

.at-rest figcaption { margin-top: 0.8rem; font-size: 0.85rem; color: #b5c0cf; }

.pipeline {
    margin: 1.8rem 0 0;
    padding: 0;
    list-style: none;
    counter-reset: stage;
}

.pipeline li {
    counter-increment: stage;
    display: grid;
    grid-template-columns: 1.8rem minmax(0, 1fr);
    gap: 0.8rem;
    padding-block: 0.7rem;
    border-top: 1px solid rgba(255, 255, 255, 0.12);
    color: #b5c0cf;
    font-size: 0.97rem;
}

.pipeline li::before {
    content: counter(stage);
    color: var(--sky);
    font-family: var(--font-digits);
    font-size: 1.2rem;
    font-weight: 600;
    line-height: 1.4;
}

.pipeline b { color: #fff; font-weight: 600; }

/* ---------- Practice ---------- */

.practice { padding-block: 0 clamp(3.5rem, 8vw, 6rem); }

.checks {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.8rem clamp(1.5rem, 3.5vw, 3rem);
    margin: clamp(2rem, 4vw, 3rem) 0 0;
    padding: 0;
    list-style: none;
}

@media (max-width: 60rem) { .checks { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
@media (max-width: 38rem) { .checks { grid-template-columns: minmax(0, 1fr); } }

.checks li { display: grid; grid-template-columns: 1.6rem minmax(0, 1fr); gap: 0.6rem; }

.checks svg { width: 1.3rem; height: 1.3rem; margin-top: 0.2rem; color: var(--accent); }

.checks b { display: block; color: var(--text); }

.checks span { color: var(--text-soft); }

/* ---------- Status and questions ---------- */

.status, .questions {
    padding-block: clamp(3rem, 7vw, 5rem);
    border-top: 1px solid var(--rule);
    text-align: center;
}

.status { background: var(--paper-sunk); }

.status .wrap, .questions .wrap { max-width: 42rem; }

.status h2, .questions h2 { font-size: clamp(1.7rem, 3.2vw, 2.3rem); font-weight: 700; }

.status p, .questions p { margin-top: 1rem; color: var(--text-soft); }

.status .hero-actions, .questions .hero-actions { justify-content: center; }

/* ---------- Footer ---------- */

.site-footer { padding-block: 2rem 2.6rem; border-top: 1px solid var(--rule); font-size: 0.95rem; }

.site-footer .wrap {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    gap: 1rem;
    color: var(--text-soft);
}

.site-footer nav { display: flex; flex-wrap: wrap; gap: 1.2rem; }

.site-footer a { color: var(--text-soft); text-decoration: none; }

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