/* ====================================================================
   MGNA Oy — site styles
   Design system: tokens, reset, base, layout primitives, components.
   ==================================================================== */

/* --- Design tokens -------------------------------------------------- */
:root {
    /* Color */
    --color-bg:          #ffffff;
    --color-bg-alt:      #f4f6f9;
    --color-surface:     #ffffff;
    --color-text:        #1f2733;
    --color-text-muted:  #5c6675;
    --color-heading:     #11192a;
    --color-accent:      #1a5fa8;
    --color-accent-dark: #134a85;
    --color-accent-soft: #e9f1f9;
    --color-border:      #e3e7ed;
    --color-footer-bg:   #11192a;
    --color-footer-text: #aab3c0;
    --color-footer-head: #ffffff;

    /* Typography */
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    --line-body: 1.65;
    --line-tight: 1.2;

    /* Spacing & layout */
    --container: 1120px;
    --gutter: 1.5rem;
    --section-y: clamp(3.5rem, 8vw, 6.5rem);
    --radius: 10px;
    --radius-sm: 6px;

    /* Effects */
    --shadow-sm: 0 1px 2px rgba(17, 25, 42, .06), 0 1px 3px rgba(17, 25, 42, .08);
    --shadow-md: 0 4px 14px rgba(17, 25, 42, .10), 0 2px 4px rgba(17, 25, 42, .06);
    --transition: 160ms ease;
}

/* --- Reset ---------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
    font-family: var(--font-sans);
    font-size: 1rem;
    line-height: var(--line-body);
    color: var(--color-text);
    background: var(--color-bg);
    -webkit-font-smoothing: antialiased;
}

img, picture, svg, iframe { display: block; max-width: 100%; }
a { color: var(--color-accent); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--color-accent-dark); }
ul { list-style: none; padding: 0; }
h1, h2, h3 { color: var(--color-heading); line-height: var(--line-tight); font-weight: 700; }
p { max-width: 70ch; }

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

/* anchor offset so sticky header does not cover section tops */
[id] { scroll-margin-top: 5rem; }

/* --- Skip link (accessibility) -------------------------------------- */
.skip-link {
    position: absolute;
    left: .5rem;
    top: -3.5rem;
    z-index: 100;
    background: var(--color-accent);
    color: #fff;
    padding: .6rem 1rem;
    border-radius: var(--radius-sm);
    transition: top var(--transition);
}
.skip-link:focus { top: .5rem; color: #fff; }

/* --- Layout primitives ---------------------------------------------- */
.container {
    width: 100%;
    max-width: var(--container);
    margin-inline: auto;
    padding-inline: var(--gutter);
}

.section { padding-block: var(--section-y); }
.section--alt { background: var(--color-bg-alt); }

.section__head { max-width: 62ch; margin-bottom: 2.5rem; }
.section__eyebrow {
    display: inline-block;
    font-size: .8rem;
    font-weight: 700;
    letter-spacing: .08em;
    text-transform: uppercase;
    color: var(--color-accent);
    margin-bottom: .6rem;
}
.section h2 { font-size: clamp(1.6rem, 3.5vw, 2.25rem); }
.section__lead { margin-top: .9rem; color: var(--color-text-muted); font-size: 1.075rem; }

/* --- Header / nav --------------------------------------------------- */
.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(255, 255, 255, .92);
    -webkit-backdrop-filter: blur(8px);
    backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--color-border);
}
.site-header__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    min-height: 4rem;
    flex-wrap: wrap;
}
.brand {
    display: inline-flex;
    align-items: baseline;
    gap: .3rem;
    font-weight: 800;
    font-size: 1.25rem;
    letter-spacing: -.01em;
    color: var(--color-heading);
}
.brand:hover { color: var(--color-heading); }
.brand__mark { color: var(--color-accent); }

.nav { display: flex; flex-wrap: wrap; gap: .25rem 1.4rem; }
.nav a {
    color: var(--color-text-muted);
    font-size: .95rem;
    font-weight: 500;
    padding: .35rem 0;
}
.nav a:hover { color: var(--color-accent); }

/* --- Hero ----------------------------------------------------------- */
.hero { padding-block: clamp(3.5rem, 9vw, 7rem); }
.hero h1 {
    font-size: clamp(2.2rem, 6vw, 3.6rem);
    letter-spacing: -.02em;
    max-width: 20ch;
}
.hero__lead {
    margin-top: 1.25rem;
    font-size: clamp(1.05rem, 2.2vw, 1.3rem);
    color: var(--color-text-muted);
    max-width: 54ch;
}
.hero__actions { margin-top: 2rem; display: flex; flex-wrap: wrap; gap: .85rem; }

/* --- Buttons -------------------------------------------------------- */
.btn {
    display: inline-flex;
    align-items: center;
    gap: .5rem;
    padding: .7rem 1.4rem;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: .975rem;
    border: 1px solid transparent;
    cursor: pointer;
    transition: background var(--transition), color var(--transition), border-color var(--transition);
}
.btn--primary { background: var(--color-accent); color: #fff; }
.btn--primary:hover { background: var(--color-accent-dark); color: #fff; }
.btn--ghost { background: transparent; color: var(--color-accent); border-color: var(--color-border); }
.btn--ghost:hover { border-color: var(--color-accent); background: var(--color-accent-soft); }

/* --- About / card grid --------------------------------------------- */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 1.5rem;
}
.card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: 1.75rem;
    box-shadow: var(--shadow-sm);
}
.card h3 { font-size: 1.2rem; margin-bottom: .6rem; }
.card p { color: var(--color-text-muted); }

/* --- Demo sections -------------------------------------------------- */
.demo__desc { margin-top: .9rem; color: var(--color-text-muted); max-width: 65ch; }

.demo-frame {
    margin-top: 2rem;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    overflow: hidden;
    background: var(--color-bg-alt);
    box-shadow: var(--shadow-sm);
}
.demo-frame iframe { width: 100%; height: 100%; border: 0; display: block; }

/* live demo slot — gives the embedded app room; the iframe fills it */
.demo-frame--live { height: clamp(520px, 80vh, 860px); }

/* placeholder slot — replaced by a real iframe in Phase 4 */
.demo-frame--placeholder {
    aspect-ratio: 16 / 9;
    display: grid;
    place-items: center;
    text-align: center;
    padding: 1.5rem;
    color: var(--color-text-muted);
    background:
        repeating-linear-gradient(45deg, transparent, transparent 14px,
            rgba(26, 95, 168, .04) 14px, rgba(26, 95, 168, .04) 28px),
        var(--color-bg-alt);
}
.demo-frame__label { font-weight: 600; color: var(--color-heading); }
.demo-frame__hint { font-size: .9rem; margin-top: .35rem; }

.badge {
    display: inline-block;
    font-size: .7rem;
    font-weight: 700;
    letter-spacing: .06em;
    text-transform: uppercase;
    color: var(--color-accent);
    background: var(--color-accent-soft);
    padding: .3rem .65rem;
    border-radius: 999px;
    margin-left: .5rem;
    vertical-align: middle;
}
.demo--coming .demo-frame--placeholder { opacity: .9; }

/* --- Accordion (native <details>/<summary>) ------------------------- */
.accordion {
    margin-top: 2rem;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    background: var(--color-surface);
    box-shadow: var(--shadow-sm);
    overflow: hidden;
}
.accordion__summary {
    list-style: none;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    padding: 1.1rem 1.5rem;
    font-weight: 600;
    font-size: 1.05rem;
    color: var(--color-heading);
}
.accordion__summary::-webkit-details-marker { display: none; }
.accordion__summary:hover { color: var(--color-accent); }
.accordion__summary:focus-visible { outline: 3px solid var(--color-accent); outline-offset: -3px; }
.accordion__summary::after {
    content: "";
    flex: none;
    width: .55rem;
    height: .55rem;
    border-right: 2px solid currentColor;
    border-bottom: 2px solid currentColor;
    transform: rotate(45deg);
    transition: transform var(--transition);
}
.accordion[open] .accordion__summary { border-bottom: 1px solid var(--color-border); }
.accordion[open] .accordion__summary::after { transform: rotate(-135deg); }
.accordion__body { padding: 1.5rem; }

/* --- Contact -------------------------------------------------------- */
.contact__grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1.5rem;
    margin-top: 1.5rem;
}
.contact__item h3 {
    font-size: .82rem;
    text-transform: uppercase;
    letter-spacing: .07em;
    color: var(--color-text-muted);
    margin-bottom: .35rem;
}
.contact__item p { font-size: 1.05rem; }

/* --- Footer --------------------------------------------------------- */
.site-footer {
    background: var(--color-footer-bg);
    color: var(--color-footer-text);
    padding-block: 3rem;
}
.site-footer h3 { color: var(--color-footer-head); }
.site-footer p { color: var(--color-footer-text); }
.site-footer a { color: var(--color-footer-text); }
.site-footer a:hover { color: #fff; }

.footer__grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 2rem;
}
.footer__brand {
    font-weight: 800;
    font-size: 1.2rem;
    color: var(--color-footer-head);
    margin-bottom: .5rem;
}
.footer__legal {
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px solid rgba(255, 255, 255, .1);
    font-size: .9rem;
}

/* --- Responsive ----------------------------------------------------- */
@media (max-width: 560px) {
    .site-header__inner { min-height: auto; padding-block: .7rem; }
    .nav { width: 100%; }
}

@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    *, *::before, *::after { transition: none !important; }
}