/* AIurelius — single-page site
   Brand: warm dark gray + disciplined purple, classical serif + clean sans.
*/

:root {
    --bg: #FAFAF7;
    --surface: #FFFFFF;
    --border: #E5E5E0;
    --accent: #6B2FD9;
    --accent-hover: #7B3FE9;
    --text: #0F0F11;
    --text-muted: #5A5A63;
    --text-dim: #8A8A93;

    --font-serif: 'Fraunces', Georgia, 'Times New Roman', serif;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;

    --max-w: 1120px;
    --max-w-narrow: 720px;
}

::selection {
    background-color: rgba(107, 47, 217, 0.2);
    color: var(--text);
}
::-moz-selection {
    background-color: rgba(107, 47, 217, 0.2);
    color: var(--text);
}

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

html {
    scroll-behavior: smooth;
}

body {
    background-color: var(--bg);
    color: var(--text);
    font-family: var(--font-sans);
    font-size: 16px;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
}

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

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

ul { list-style: none; }

/* ── Layout containers ─────────────────────────────────────────────── */
.container {
    width: 100%;
    max-width: var(--max-w);
    margin: 0 auto;
    padding: 0 32px;
}
.container-narrow { max-width: var(--max-w-narrow); }

/* ── Nav ───────────────────────────────────────────────────────────── */
.nav {
    position: fixed;
    top: 0; left: 0; right: 0;
    z-index: 100;
    background: transparent;
    border-bottom: 1px solid transparent;
    transition: background-color 220ms ease, border-color 220ms ease, backdrop-filter 220ms ease;
}
.nav.scrolled {
    background: rgba(250, 250, 247, 0.85);
    backdrop-filter: saturate(140%) blur(12px);
    -webkit-backdrop-filter: saturate(140%) blur(12px);
    border-bottom-color: var(--border);
}
.nav-inner {
    max-width: var(--max-w);
    margin: 0 auto;
    padding: 16px 32px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
}
.nav-logo img {
    height: 32px;
    width: auto;
}

/* ── Buttons ───────────────────────────────────────────────────────── */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-family: var(--font-sans);
    font-weight: 500;
    font-size: 15px;
    line-height: 1;
    padding: 11px 20px;
    border-radius: 6px;
    border: 1px solid transparent;
    cursor: pointer;
    transition: background-color 160ms ease, border-color 160ms ease, color 160ms ease, box-shadow 200ms ease;
    white-space: nowrap;
}
.btn-primary {
    background-color: var(--accent);
    color: #FFFFFF;
    box-shadow: 0 1px 2px rgba(15, 15, 17, 0.04);
}
.btn-primary:hover {
    background-color: var(--accent-hover);
    box-shadow: 0 6px 16px rgba(107, 47, 217, 0.22);
}
.btn-lg {
    font-size: 16px;
    padding: 14px 26px;
    border-radius: 7px;
}

/* ── Hero ──────────────────────────────────────────────────────────── */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 120px 0 96px;
}
.hero-inner {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}
.hero-logo {
    height: 80px;
    width: auto;
    margin-bottom: 56px;
}
.hero-headline {
    font-family: var(--font-serif);
    font-weight: 500;
    font-size: clamp(40px, 5.6vw, 64px);
    line-height: 1.08;
    letter-spacing: -0.015em;
    max-width: 880px;
    margin-bottom: 24px;
}
.hero-sub {
    font-size: 18px;
    line-height: 1.6;
    color: var(--text-muted);
    max-width: 640px;
    margin-bottom: 40px;
}

/* ── Sections ──────────────────────────────────────────────────────── */
.section {
    padding: 120px 0;
    border-top: 1px solid var(--border);
}
.section-cta {
    text-align: center;
}
.section-cta .section-heading {
    margin-bottom: 16px;
}
.section-cta .section-sub {
    margin-bottom: 36px;
}
.eyebrow {
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--accent);
    margin-bottom: 20px;
}
.section-heading {
    font-family: var(--font-serif);
    font-weight: 500;
    font-size: clamp(32px, 4.2vw, 48px);
    line-height: 1.12;
    letter-spacing: -0.012em;
    max-width: 780px;
    margin-bottom: 20px;
}
.section-sub {
    font-size: 17px;
    line-height: 1.6;
    color: var(--text-muted);
    max-width: 640px;
    margin-bottom: 64px;
}

/* ── What We Build cards ──────────────────────────────────────────── */
.cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}
.card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 32px;
    box-shadow: 0 1px 2px rgba(0, 0, 0, 0.04);
    transition: border-color 200ms ease, box-shadow 200ms ease;
}
.card:hover {
    border-color: rgba(107, 47, 217, 0.3);
    box-shadow: 0 4px 12px rgba(107, 47, 217, 0.08);
}
.card-title {
    font-family: var(--font-serif);
    font-weight: 500;
    font-size: 22px;
    line-height: 1.25;
    letter-spacing: -0.005em;
    margin-bottom: 14px;
}
.card-body {
    font-size: 15px;
    line-height: 1.65;
    color: var(--text-muted);
}

/* ── How We Work steps ────────────────────────────────────────────── */
.steps {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 56px;
}
.step-num {
    font-family: var(--font-serif);
    font-weight: 500;
    font-size: 56px;
    line-height: 1;
    color: var(--accent);
    margin-bottom: 24px;
}
.step-title {
    font-family: var(--font-serif);
    font-weight: 500;
    font-size: 22px;
    line-height: 1.25;
    margin-bottom: 12px;
}
.step-body {
    font-size: 15px;
    line-height: 1.65;
    color: var(--text-muted);
}

/* ── Built For chips ──────────────────────────────────────────────── */
.chips {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}
.chip {
    display: inline-flex;
    align-items: center;
    padding: 10px 18px;
    background-color: var(--surface);
    border: 1px solid var(--border);
    border-radius: 999px;
    font-size: 14px;
    font-weight: 500;
    color: var(--text);
    letter-spacing: 0.005em;
}

/* ── Footer ───────────────────────────────────────────────────────── */
.footer {
    border-top: 1px solid var(--border);
    padding: 32px 0;
}
.footer-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
    flex-wrap: wrap;
}
.footer-left {
    display: flex;
    align-items: center;
    gap: 20px;
    flex-wrap: wrap;
}
.footer-logo {
    height: 24px;
    width: auto;
}
.footer-email {
    font-size: 14px;
    color: var(--text-muted);
    transition: color 160ms ease;
}
.footer-email:hover {
    color: var(--text);
}
.footer-right {
    font-size: 13px;
    color: var(--text-dim);
}

/* ── Reveal animation ─────────────────────────────────────────────── */
.reveal {
    opacity: 0;
    transform: translateY(16px);
    transition: opacity 600ms ease, transform 600ms ease;
}
.reveal.is-visible {
    opacity: 1;
    transform: none;
}

@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    .reveal {
        opacity: 1;
        transform: none;
        transition: none;
    }
    * { transition-duration: 0ms !important; animation-duration: 0ms !important; }
}

/* ── Responsive (768px) ───────────────────────────────────────────── */
@media (max-width: 768px) {
    .container { padding: 0 20px; }
    .nav-inner { padding: 12px 20px; }
    .nav-logo img { height: 28px; }

    .hero { padding: 96px 0 72px; }
    .hero-logo { height: 56px; margin-bottom: 40px; }
    .hero-headline { font-size: 34px; }
    .hero-sub { font-size: 16px; margin-bottom: 32px; }

    .section { padding: 80px 0; }
    .section-heading { font-size: 30px; }
    .section-sub { font-size: 16px; margin-bottom: 48px; }

    .cards { grid-template-columns: 1fr; gap: 16px; }
    .card { padding: 28px; }
    .card-title { font-size: 20px; }

    .steps { grid-template-columns: 1fr; gap: 40px; }
    .step-num { font-size: 48px; margin-bottom: 16px; }

    .footer-inner { flex-direction: column; align-items: flex-start; gap: 16px; }
}

@media (max-width: 480px) {
    .btn-lg { width: 100%; }
    .nav-cta { padding: 9px 16px; font-size: 14px; }
}