/* =====================================================================
   Alpha Blue Technologies — One-Page Business Card
   Self-contained, dependency-free stylesheet.
   No external fonts, no trackers, no cookies.
   ===================================================================== */

:root {
    --ab-blue: #0078c8;
    --ab-blue-600: #0069b0;
    --ab-cyan: #00b4e6;
    --ab-navy: #063856;
    --ab-navy-800: #052b42;
    --ab-ink: #16232e;
    --ab-muted: #5b6b78;
    --ab-line: #e4e9ef;
    --ab-bg: #ffffff;
    --ab-bg-alt: #f4f7fa;
    --ab-white: #ffffff;

    --ab-radius: 16px;
    --ab-radius-sm: 10px;
    --ab-shadow: 0 10px 30px -12px rgba(6, 56, 86, 0.25);
    --ab-shadow-lg: 0 24px 60px -20px rgba(6, 56, 86, 0.35);
    --ab-container: 1180px;
    --ab-header-h: 76px;

    --ab-font: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial,
        "Apple Color Emoji", "Segoe UI Emoji", sans-serif;
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: calc(var(--ab-header-h) + 12px);
    -webkit-text-size-adjust: 100%;
}

body {
    margin: 0;
    font-family: var(--ab-font);
    font-size: 17px;
    line-height: 1.65;
    color: var(--ab-ink);
    background: var(--ab-bg);
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
}

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

a {
    color: var(--ab-blue-600);
    text-decoration: none;
    transition: color 0.2s ease;
}

a:hover {
    color: var(--ab-navy);
}

h1,
h2,
h3 {
    line-height: 1.15;
    color: var(--ab-navy);
    margin: 0 0 0.5em;
    font-weight: 800;
    letter-spacing: -0.01em;
}

p {
    margin: 0 0 1rem;
}

/* ---------- Language visibility (DE default) ---------- */
html[lang="en"] .lang-de {
    display: none !important;
}

html[lang="de"] .lang-en {
    display: none !important;
}

/* ---------- Accessibility helpers ---------- */
.skip-link {
    position: absolute;
    left: -999px;
    top: 0;
    z-index: 1000;
    background: var(--ab-navy);
    color: #fff;
    padding: 12px 18px;
    border-radius: 0 0 var(--ab-radius-sm) 0;
}

.skip-link:focus {
    left: 0;
    color: #fff;
}

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

.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;
}

/* ---------- Layout ---------- */
.container {
    width: 100%;
    max-width: var(--ab-container);
    margin: 0 auto;
    padding: 0 24px;
}

.section {
    padding: clamp(56px, 8vw, 104px) 0;
}

.section--alt {
    background: var(--ab-bg-alt);
}

.section__head {
    max-width: 760px;
    margin: 0 auto clamp(36px, 5vw, 56px);
    text-align: center;
}

.section__eyebrow {
    display: inline-block;
    font-size: 0.8rem;
    font-weight: 700;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--ab-blue);
    margin-bottom: 12px;
}

.section__title {
    font-size: clamp(1.8rem, 4vw, 2.6rem);
}

.section__lead {
    color: var(--ab-muted);
    font-size: 1.1rem;
    margin: 0;
}

/* ---------- Buttons ---------- */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 14px 26px;
    border-radius: 999px;
    font-weight: 700;
    font-size: 1rem;
    line-height: 1;
    cursor: pointer;
    border: 2px solid transparent;
    transition: transform 0.15s ease, box-shadow 0.2s ease,
        background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
    white-space: nowrap;
}

.btn:hover {
    transform: translateY(-2px);
}

.btn--primary {
    background: linear-gradient(135deg, var(--ab-blue), var(--ab-cyan));
    color: #fff;
    box-shadow: var(--ab-shadow);
}

.btn--primary:hover {
    color: #fff;
    box-shadow: var(--ab-shadow-lg);
}

.btn--ghost {
    background: transparent;
    border-color: rgba(255, 255, 255, 0.5);
    color: #fff;
}

.btn--ghost:hover {
    color: var(--ab-navy);
    background: #fff;
    border-color: #fff;
}

.btn--outline {
    background: transparent;
    border-color: var(--ab-blue);
    color: var(--ab-blue-600);
}

.btn--outline:hover {
    background: var(--ab-blue);
    color: #fff;
}

/* ---------- Header ---------- */
.site-header {
    position: fixed;
    inset: 0 0 auto 0;
    height: var(--ab-header-h);
    z-index: 100;
    display: flex;
    align-items: center;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: saturate(180%) blur(12px);
    -webkit-backdrop-filter: saturate(180%) blur(12px);
    border-bottom: 1px solid transparent;
    transition: box-shadow 0.25s ease, border-color 0.25s ease;
}

.site-header.is-scrolled {
    box-shadow: 0 6px 24px -14px rgba(6, 56, 86, 0.4);
    border-bottom-color: var(--ab-line);
}

.site-header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
}

.brand {
    display: inline-flex;
    align-items: center;
}

.brand img {
    height: 46px;
    width: auto;
}

/* ---------- Primary nav ---------- */
.nav {
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav__list {
    display: flex;
    align-items: center;
    gap: 4px;
    list-style: none;
    margin: 0;
    padding: 0;
}

.nav__list a {
    display: block;
    padding: 10px 14px;
    border-radius: var(--ab-radius-sm);
    color: var(--ab-navy);
    font-weight: 600;
    font-size: 0.98rem;
}

.nav__list a:hover {
    background: var(--ab-bg-alt);
    color: var(--ab-blue-600);
}

.nav__cta {
    margin-left: 6px;
    padding: 10px 20px;
    font-size: 0.95rem;
}

/* Language switch */
.lang-switch {
    display: inline-flex;
    align-items: center;
    border: 1px solid var(--ab-line);
    border-radius: 999px;
    overflow: hidden;
    margin-left: 8px;
    background: #fff;
}

.lang-switch button {
    appearance: none;
    border: 0;
    background: transparent;
    padding: 7px 12px;
    font: inherit;
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--ab-muted);
    cursor: pointer;
    transition: background 0.2s ease, color 0.2s ease;
}

.lang-switch button[aria-pressed="true"] {
    background: var(--ab-blue);
    color: #fff;
}

/* Hamburger */
.nav-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 44px;
    height: 44px;
    padding: 0;
    border: 0;
    background: transparent;
    cursor: pointer;
}

.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    margin: 0 auto;
    background: var(--ab-navy);
    border-radius: 2px;
    transition: transform 0.25s ease, opacity 0.2s ease;
}

.nav-toggle[aria-expanded="true"] span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

.nav-toggle[aria-expanded="true"] span:nth-child(2) {
    opacity: 0;
}

.nav-toggle[aria-expanded="true"] span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

/* ---------- Hero ---------- */
.hero {
    position: relative;
    padding: calc(var(--ab-header-h) + clamp(60px, 12vw, 130px)) 0
        clamp(70px, 12vw, 140px);
    background: radial-gradient(
            120% 120% at 85% 10%,
            rgba(0, 180, 230, 0.35) 0%,
            rgba(0, 120, 200, 0) 45%
        ),
        linear-gradient(135deg, var(--ab-navy) 0%, var(--ab-blue-600) 100%);
    color: #fff;
    overflow: hidden;
}

.hero::after {
    content: "";
    position: absolute;
    inset: auto -10% -40% auto;
    width: 60%;
    height: 80%;
    background: radial-gradient(
        circle,
        rgba(0, 180, 230, 0.25),
        transparent 60%
    );
    pointer-events: none;
}

.hero__inner {
    position: relative;
    max-width: 760px;
}

.hero__badge {
    display: inline-block;
    padding: 7px 16px;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.12);
    border: 1px solid rgba(255, 255, 255, 0.25);
    font-size: 0.82rem;
    font-weight: 600;
    letter-spacing: 0.05em;
    margin-bottom: 22px;
    backdrop-filter: blur(4px);
}

.hero h1 {
    color: #fff;
    font-size: clamp(2.3rem, 6vw, 4rem);
    margin-bottom: 20px;
}

.hero h1 .accent {
    background: linear-gradient(90deg, #7fe9de 0%, var(--ab-cyan) 60%);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.hero__lead {
    font-size: clamp(1.05rem, 2.4vw, 1.35rem);
    color: rgba(255, 255, 255, 0.9);
    max-width: 640px;
    margin-bottom: 34px;
}

.hero__actions {
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
}

/* ---------- Service cards ---------- */
.cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 26px;
}

.card {
    position: relative;
    background: var(--ab-white);
    border: 1px solid var(--ab-line);
    border-radius: var(--ab-radius);
    padding: 34px 30px;
    box-shadow: 0 1px 2px rgba(6, 56, 86, 0.04);
    transition: transform 0.2s ease, box-shadow 0.25s ease,
        border-color 0.25s ease;
    overflow: hidden;
}

.card::before {
    content: "";
    position: absolute;
    inset: 0 0 auto 0;
    height: 4px;
    background: linear-gradient(90deg, var(--ab-blue), var(--ab-cyan));
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.3s ease;
}

.card:hover {
    transform: translateY(-6px);
    box-shadow: var(--ab-shadow-lg);
    border-color: transparent;
}

.card:hover::before {
    transform: scaleX(1);
}

.card__icon {
    width: 58px;
    height: 58px;
    display: grid;
    place-items: center;
    border-radius: 14px;
    background: linear-gradient(135deg, rgba(0, 120, 200, 0.12), rgba(0, 180, 230, 0.12));
    color: var(--ab-blue-600);
    margin-bottom: 20px;
}

.card__icon svg {
    width: 30px;
    height: 30px;
}

.card h3 {
    font-size: 1.3rem;
    margin-bottom: 10px;
}

.card p {
    color: var(--ab-muted);
    margin: 0;
    font-size: 1rem;
}

/* ---------- About ---------- */
.about {
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    gap: clamp(32px, 6vw, 72px);
    align-items: center;
}

.about__text h2 {
    font-size: clamp(1.8rem, 4vw, 2.5rem);
}

.about__text p {
    color: var(--ab-muted);
    font-size: 1.08rem;
}

.about__facts {
    list-style: none;
    margin: 0;
    padding: 0;
    display: grid;
    gap: 16px;
}

.about__facts li {
    display: flex;
    gap: 14px;
    align-items: flex-start;
    background: #fff;
    border: 1px solid var(--ab-line);
    border-radius: var(--ab-radius-sm);
    padding: 18px 20px;
    box-shadow: 0 1px 2px rgba(6, 56, 86, 0.04);
}

.about__facts .tick {
    flex: 0 0 auto;
    width: 26px;
    height: 26px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--ab-blue), var(--ab-cyan));
    color: #fff;
    display: grid;
    place-items: center;
    font-size: 0.8rem;
    margin-top: 2px;
}

.about__facts strong {
    display: block;
    color: var(--ab-navy);
}

.about__facts span.desc {
    color: var(--ab-muted);
    font-size: 0.96rem;
}

/* ---------- Contact ---------- */
.contact {
    background: linear-gradient(135deg, var(--ab-navy) 0%, var(--ab-blue-600) 100%);
    color: #fff;
    border-radius: clamp(18px, 3vw, 28px);
    padding: clamp(40px, 7vw, 72px);
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: clamp(32px, 6vw, 64px);
    align-items: center;
    box-shadow: var(--ab-shadow-lg);
}

.contact h2 {
    color: #fff;
    font-size: clamp(1.8rem, 4vw, 2.5rem);
}

.contact p {
    color: rgba(255, 255, 255, 0.88);
}

.contact__list {
    list-style: none;
    margin: 22px 0 0;
    padding: 0;
    display: grid;
    gap: 16px;
}

.contact__list li {
    display: flex;
    gap: 14px;
    align-items: flex-start;
}

.contact__list .ci {
    flex: 0 0 auto;
    width: 42px;
    height: 42px;
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.12);
    display: grid;
    place-items: center;
    color: #fff;
}

.contact__list .ci svg {
    width: 20px;
    height: 20px;
}

.contact__list a {
    color: #fff;
    font-weight: 600;
}

.contact__list a:hover {
    color: var(--ab-cyan);
}

.contact__list .label {
    display: block;
    font-size: 0.8rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: rgba(255, 255, 255, 0.6);
}

.contact__card address {
    font-style: normal;
    color: rgba(255, 255, 255, 0.9);
    line-height: 1.8;
}

/* ---------- Legal sections ---------- */
.legal h2 {
    font-size: clamp(1.6rem, 3.5vw, 2.2rem);
}

.legal h3 {
    font-size: 1.15rem;
    margin-top: 1.8em;
    color: var(--ab-navy);
}

.legal {
    color: var(--ab-ink);
    max-width: 860px;
    margin: 0 auto;
}

.legal p,
.legal address {
    color: var(--ab-muted);
    font-style: normal;
    font-size: 1rem;
}

.legal address {
    line-height: 1.8;
    margin-bottom: 1rem;
}

.legal__note {
    margin-top: 12px;
    padding: 16px 18px;
    background: var(--ab-bg-alt);
    border-left: 4px solid var(--ab-blue);
    border-radius: 0 var(--ab-radius-sm) var(--ab-radius-sm) 0;
    font-size: 0.95rem;
}

/* ---------- Footer ---------- */
.site-footer {
    background: var(--ab-navy-800);
    color: rgba(255, 255, 255, 0.75);
    padding: 56px 0 28px;
}

.site-footer .container {
    display: grid;
    grid-template-columns: 1.4fr 1fr 1fr;
    gap: 36px;
}

.site-footer img {
    height: 42px;
    width: auto;
    margin-bottom: 16px;
    background: #fff;
    padding: 8px 12px;
    border-radius: 10px;
    box-sizing: content-box;
}

.footer__about {
    max-width: 340px;
    font-size: 0.95rem;
    color: rgba(255, 255, 255, 0.65);
}

.footer__col h4 {
    color: #fff;
    font-size: 0.85rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    margin: 0 0 16px;
}

.footer__col ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: grid;
    gap: 10px;
}

.footer__col a {
    color: rgba(255, 255, 255, 0.75);
    font-size: 0.96rem;
}

.footer__col a:hover {
    color: var(--ab-cyan);
}

.footer__bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.12);
    margin-top: 44px;
    padding-top: 22px;
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    justify-content: space-between;
    align-items: center;
    font-size: 0.9rem;
    color: rgba(255, 255, 255, 0.55);
}

.footer__bottom a {
    color: rgba(255, 255, 255, 0.7);
}

/* ---------- Scroll-to-top ---------- */
.to-top {
    position: fixed;
    right: 22px;
    bottom: 22px;
    width: 46px;
    height: 46px;
    border-radius: 50%;
    border: 0;
    background: var(--ab-blue);
    color: #fff;
    display: grid;
    place-items: center;
    cursor: pointer;
    box-shadow: var(--ab-shadow);
    opacity: 0;
    visibility: hidden;
    transform: translateY(12px);
    transition: opacity 0.25s ease, transform 0.25s ease, visibility 0.25s;
    z-index: 90;
}

.to-top.is-visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.to-top:hover {
    background: var(--ab-navy);
}

/* ---------- Reveal on scroll ---------- */
.reveal {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.is-in {
    opacity: 1;
    transform: none;
}

/* ---------- Responsive ---------- */
@media (max-width: 940px) {
    .cards {
        grid-template-columns: 1fr;
        max-width: 460px;
        margin: 0 auto;
    }

    .about,
    .contact {
        grid-template-columns: 1fr;
    }

    .site-footer .container {
        grid-template-columns: 1fr 1fr;
    }

    .footer__brand {
        grid-column: 1 / -1;
    }
}

@media (max-width: 760px) {
    .nav-toggle {
        display: flex;
        order: 3;
    }

    .nav {
        position: fixed;
        inset: var(--ab-header-h) 0 auto 0;
        flex-direction: column;
        align-items: stretch;
        gap: 0;
        background: #fff;
        border-bottom: 1px solid var(--ab-line);
        box-shadow: var(--ab-shadow);
        padding: 12px 20px 20px;
        transform: translateY(-120%);
        transition: transform 0.3s ease;
        max-height: calc(100dvh - var(--ab-header-h));
        overflow-y: auto;
    }

    .nav.is-open {
        transform: translateY(0);
    }

    .nav__list {
        flex-direction: column;
        align-items: stretch;
        gap: 2px;
        width: 100%;
    }

    .nav__list a {
        padding: 14px 12px;
        border-radius: var(--ab-radius-sm);
    }

    .nav__cta {
        margin: 10px 0 0;
        justify-content: center;
    }

    .lang-switch {
        margin: 14px 0 0;
        align-self: flex-start;
    }
}

@media (max-width: 480px) {
    body {
        font-size: 16px;
    }

    .site-footer .container {
        grid-template-columns: 1fr;
    }

    .hero__actions .btn {
        width: 100%;
        justify-content: center;
    }
}

/* ---------- Motion preference ---------- */
@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    *,
    *::before,
    *::after {
        animation-duration: 0.001ms !important;
        transition-duration: 0.001ms !important;
    }

    .reveal {
        opacity: 1;
        transform: none;
    }
}

/* ---------- Print ---------- */
@media print {
    .site-header,
    .to-top,
    .hero__actions,
    .nav-toggle {
        display: none !important;
    }

    body {
        color: #000;
    }
}