/* ============================================================
   AURISUS — main.css (shared)
   ============================================================ */

:root {
    --void: #050608;
    --ivory: #F5F5F2;
    --silver: #C0C7D1;

    --font-display: "Oxanium", system-ui, sans-serif;

    --space-1: 0.5rem;
    --space-2: 1rem;
    --space-3: 1.5rem;
    --space-4: 2rem;
    --space-5: 3rem;
    --space-6: 4.5rem;
    --space-7: 7rem;
    --space-8: 10rem;

    --maxw: 76rem;
    --gutter: clamp(1.25rem, 5vw, 3rem);

    --ease: cubic-bezier(0.16, 1, 0.3, 1);
    --dur: 400ms;
}

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

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
    margin: 0;
    background: var(--void);
    color: var(--ivory);
    font-family: var(--font-display);
    font-weight: 400;
    line-height: 1.6;
    font-size: 1.125rem; 
    letter-spacing: 0.01em;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
}

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

a { color: inherit; text-decoration: none; }

h1, h2, h3, h4 {
    font-family: var(--font-display);
    font-weight: 600;
    line-height: 1.05;
    margin: 0 0 var(--space-3);
    letter-spacing: -0.01em;
}

p { margin: 0 0 var(--space-3); color: var(--silver); }

/* Skip link */
.skip-link {
    position: absolute;
    left: -9999px;
    top: 0;
    background: var(--ivory);
    color: var(--void);
    padding: 0.75rem 1rem;
    z-index: 1000;
}
.skip-link:focus { left: 1rem; top: 1rem; }

/* Focus visibility */
:focus-visible {
    outline: 1px solid var(--silver);
    outline-offset: 4px;
}

/* ---------------- Header / Nav ---------------- */

.site-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 100;
    background: linear-gradient(to bottom, rgba(5, 6, 8, 0.9) 0%, rgba(5, 6, 8, 0) 100%);
    padding-top: 0.5rem;
}

.nav {
    max-width: var(--maxw);
    margin: 0 auto;
    padding: 1rem var(--gutter);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-3);
}

.nav-home {
    font-family: var(--font-display);
    font-weight: 700;
    font-size: 1.25rem;
    letter-spacing: 0.05em;
    color: var(--ivory);
}

.nav-list {
    display: none;
    list-style: none;
    margin: 0;
    padding: 0;
    gap: var(--space-4);
}

.nav-list a {
    color: var(--silver);
    font-size: 0.9375rem;
    font-weight: 500;
    letter-spacing: 0.05em;
    transition: color var(--dur) var(--ease);
}
.nav-list a:hover { color: var(--ivory); }
.nav-list a[aria-current="page"] { color: var(--ivory); }

/* ---------------- Mobile toggle (Corner Mark) ---------------- */

.nav-toggle {
    --mark-size: 22px;
    --stroke: var(--silver);
    appearance: none;
    background: none;
    border: 0;
    padding: 0.6rem;
    min-width: 44px;
    min-height: 44px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--ivory);
    z-index: 101;
}

.nav-toggle:hover .mark span { background: var(--ivory); }

.mark { position: relative; width: var(--mark-size); height: var(--mark-size); display: block; }
.mark span { position: absolute; background: var(--stroke); transition: all var(--dur) var(--ease); }
.mark-h { top: 0; left: 0; width: 100%; height: 1px; }
.mark-v-left { top: 0; left: 0; width: 1px; height: 100%; opacity: 1; }
.mark-v-right { top: 0; right: 0; width: 1px; height: 0%; opacity: 0; }

.nav-toggle[aria-expanded="true"] .mark-v-left { height: 0%; opacity: 0; }
.nav-toggle[aria-expanded="true"] .mark-v-right { height: 100%; opacity: 1; }

/* ---------------- Mobile menu ---------------- */

.mobile-menu {
    position: fixed;
    inset: 0;
    z-index: 90;
    background: var(--void);
    padding: calc(5rem + 2rem) var(--gutter) var(--gutter);
    display: flex;
    flex-direction: column;
    opacity: 0;
    transform: translateY(-10px);
    transition: opacity var(--dur) var(--ease), transform var(--dur) var(--ease);
    pointer-events: none;
    overflow-y: auto;
}

.mobile-menu.is-open { opacity: 1; transform: translateY(0); pointer-events: auto; }

.mobile-menu-list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
    border-top: 1px solid color-mix(in srgb, var(--silver) 20%, transparent);
    padding-top: var(--space-4);
}

.mobile-menu-list a {
    font-family: var(--font-display);
    font-size: clamp(2.5rem, 12vw, 4rem);
    font-weight: 500;
    color: var(--silver);
    letter-spacing: -0.01em;
    display: inline-block;
    padding: 0.25rem 0;
    transition: color var(--dur) var(--ease);
}
.mobile-menu-list a:hover,
.mobile-menu-list a[aria-current="page"] { color: var(--ivory); }

body.nav-open { overflow: hidden; }

@media (min-width: 900px) {
    .nav-list { display: flex; }
    .nav-toggle { display: none; }
    .mobile-menu { display: none !important; }
}

/* ---------------- Footer (Differentiated) ---------------- */

.site-footer {
    border-top: 1px solid color-mix(in srgb, var(--silver) 30%, transparent);
    background: color-mix(in srgb, var(--void) 95%, var(--silver) 5%);
    padding: var(--space-6) var(--gutter) var(--space-4);
    margin-top: var(--space-7);
}

.footer-inner {
    max-width: var(--maxw);
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: var(--space-5);
}

.footer-top {
    display: flex;
    flex-direction: column;
    gap: var(--space-4);
}

.footer-brand {
    max-width: 32ch;
}

.footer-name {
    font-family: var(--font-display);
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--ivory);
    margin: 0 0 0.5rem;
    letter-spacing: 0.05em;
}

.footer-mission {
    color: var(--silver);
    font-size: 0.875rem;
    margin: 0;
    line-height: 1.6;
}

.footer-nav {
    display: flex;
    gap: var(--space-5);
}

.footer-col h4 {
    font-family: var(--font-display);
    font-size: 0.6875rem;
    font-weight: 700;
    color: var(--silver);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin: 0 0 1rem;
    opacity: 0.6;
}

.footer-col ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
}

.footer-col a {
    color: var(--ivory);
    font-size: 0.8125rem;
    font-weight: 500;
    transition: color var(--dur) var(--ease);
}
.footer-col a:hover { color: var(--silver); }

.footer-bottom {
    border-top: 1px solid color-mix(in srgb, var(--silver) 15%, transparent);
    padding-top: var(--space-3);
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.footer-copy {
    color: color-mix(in srgb, var(--silver) 50%, transparent);
    font-size: 0.75rem;
    margin: 0;
}

@media (min-width: 720px) {
    .footer-top {
        flex-direction: row;
        justify-content: space-between;
        align-items: flex-start;
    }
    
    .footer-brand {
        flex: 1;
        padding-right: var(--space-5);
        border-right: 1px solid color-mix(in srgb, var(--silver) 15%, transparent);
    }

    .footer-nav {
        flex: 1;
        justify-content: flex-end;
        gap: var(--space-6);
    }

    .footer-bottom {
        flex-direction: row;
        justify-content: space-between;
        align-items: center;
    }
}

/* ---------------- Utilities & Animations ---------------- */

.section {
    max-width: var(--maxw);
    margin: 0 auto;
    padding: var(--space-8) var(--gutter);
}

.section-title {
    font-size: clamp(2rem, 4.5vw, 3rem);
    color: var(--ivory);
    margin-bottom: var(--space-5);
    font-weight: 600;
}

.link-arrow {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    margin-top: var(--space-4);
    color: var(--ivory);
    font-family: var(--font-display);
    font-size: 1.125rem;
    font-weight: 500;
    letter-spacing: 0.02em;
    border-bottom: 1px solid color-mix(in srgb, var(--silver) 30%, transparent);
    padding-bottom: 4px;
    transition: border-color var(--dur) var(--ease);
}
.link-arrow svg {
    width: 18px;
    height: 18px;
    transition: transform var(--dur) var(--ease);
}
.link-arrow:hover { border-color: var(--ivory); }
.link-arrow:hover svg { transform: translateX(4px); }

/* Text Reveal */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 1.2s var(--ease), transform 1.2s var(--ease);
    will-change: opacity, transform;
}
.reveal.is-visible {
    opacity: 1;
    transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.001ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.001ms !important;
        scroll-behavior: auto !important;
    }
    .mobile-menu { transform: none; }
    .mark span { transition: none; }
    .reveal { opacity: 1; transform: none; transition: none; }
}

/* ============================================================
   AURORA & STARS KEYFRAMES
   ============================================================ */

.aurora-blob {
    transform-origin: center;
    animation: floatAurora 24s ease-in-out infinite alternate;
}
.aurora-blob:nth-child(2) { animation-duration: 32s; animation-direction: alternate-reverse; }
.aurora-blob:nth-child(3) { animation-duration: 28s; animation-delay: -5s; }

@keyframes floatAurora {
    0%   { transform: translate(0, 0) scale(1); }
    50%  { transform: translate(4%, 2%) scale(1.1); }
    100% { transform: translate(-2%, -2%) scale(0.95); }
}

.star { animation: twinkle 4s ease-in-out infinite alternate; }

@keyframes twinkle {
    0% { opacity: 0.2; transform: scale(0.8); }
    100% { opacity: 1; transform: scale(1.2); }
}
/* ============================================================
   TEXT SELECTION
   ============================================================ */

::selection {
    background-color: var(--silver);
    color: var(--void);
}

::-moz-selection {
    background-color: var(--silver);
    color: var(--void);
}