/* ==========================================================================
   Retune Labs — Design System & Styles
   ========================================================================== */

/* --- 1. Design Tokens --- */
:root {
    --rt-bg-primary: #0A0B0E;
    --rt-bg-card: #0E0F13;
    --rt-text-title: #E8E4DA;
    --rt-text-body: #A6A69E;
    --rt-text-dim: #595F6B;
    --rt-accent-blue: #6FA8C7;
    --rt-line-divider: #282A30;

    --rt-font-serif: 'Instrument Serif', serif;
    --rt-font-body: 'IBM Plex Serif', serif;
    --rt-font-mono: 'IBM Plex Mono', monospace;
    --rt-font-sans: 'Work Sans', sans-serif;

    --rt-nav-height: 72px;
    --rt-pad: 170px;
    --rt-pad-desktop: 170px;
    --rt-pad-tablet: 48px;
    --rt-pad-mobile: 24px;
}

/* --- 2. Reset & Base --- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

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

body.rt-page {
    background: var(--rt-bg-primary);
    color: var(--rt-text-body);
    font-family: var(--rt-font-body);
    font-weight: 300;
    font-size: 15px;
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

/* --- 3. Typography --- */
.rt-font-serif { font-family: var(--rt-font-serif); font-weight: 400; }
.rt-font-serif-italic { font-family: var(--rt-font-serif); font-style: italic; font-weight: 400; }
.rt-font-mono { font-family: var(--rt-font-mono); font-weight: 400; }
.rt-font-sans { font-family: var(--rt-font-sans); font-weight: 500; }

/* --- 4. Layout --- */
.rt-container {
    width: 100%;
    max-width: 1440px;
    margin: 0 auto;
    padding-left: var(--rt-pad-desktop);
    padding-right: var(--rt-pad-desktop);
}

/* --- 5. Navigation --- */
.rt-nav {
    position: sticky;
    top: 0;
    z-index: 100;
    background: var(--rt-bg-primary);
}

.rt-nav-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: 20px;
    padding-bottom: 20px;
}

.rt-nav-brand {
    display: flex;
    align-items: center;
    color: var(--rt-text-title);
}

.rt-nav-crown {
    width: auto;
    height: 54px;
}

.rt-nav-compact {
    display: none;
    height: 56px;
    width: auto;
    color: var(--rt-text-title);
}

.rt-nav-brand .rt-crown-dot { fill: var(--rt-accent-blue); }
.rt-nav-brand .rt-crown-staff { fill: var(--rt-text-title); }

.rt-nav-links {
    display: flex;
    align-items: center;
    gap: 32px;
}

.rt-nav-links a {
    font-family: var(--rt-font-mono);
    font-size: 10px;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--rt-text-dim);
    transition: color 0.2s;
}

.rt-nav-links a:hover { color: var(--rt-text-title); }

.rt-nav-contact {
    border: 1px solid var(--rt-text-dim);
    padding: 8px 16px;
    transition: border-color 0.2s, color 0.2s;
}

.rt-nav-contact:hover {
    border-color: var(--rt-text-title);
}

.rt-hamburger {
    display: none;
    background: none;
    border: none;
    color: var(--rt-text-dim);
    cursor: pointer;
    padding: 8px;
    font-size: 22px;
    line-height: 1;
}

.rt-mobile-menu {
    display: none;
    position: fixed;
    inset: 0;
    z-index: 101;
    background: var(--rt-bg-primary);
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 40px;
    overscroll-behavior: none;
}

.rt-mobile-menu.is-open { display: flex; }

.rt-mobile-menu a {
    font-family: var(--rt-font-mono);
    font-size: 14px;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--rt-text-dim);
    transition: color 0.2s;
}

.rt-mobile-menu a:hover { color: var(--rt-text-title); }

/* --- 6. Footer --- */
.rt-cta {
    text-align: center;
    padding-top: 120px;
    padding-bottom: 60px;
}

.rt-cta-text {
    font-family: var(--rt-font-serif);
    font-style: italic;
    font-size: 36px;
    line-height: 1.3;
    color: var(--rt-text-title);
    margin-bottom: 40px;
}

.rt-footer {
    padding: 32px 0 40px;
}

.rt-footer-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: relative;
}

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

.rt-footer-lockup {
    height: 48px;
    width: auto;
    color: var(--rt-text-dim);
    margin-left: -11px;
}

.rt-footer-copy {
    font-family: var(--rt-font-mono);
    font-size: 11px;
    color: var(--rt-text-dim);
    letter-spacing: 0.05em;
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
}

.rt-footer-social {
    display: flex;
    gap: 24px;
}

.rt-footer-social a {
    font-family: var(--rt-font-mono);
    font-size: 11px;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--rt-text-dim);
    transition: color 0.2s;
}

.rt-footer-social a:hover { color: var(--rt-text-title); }

/* --- 7. Components --- */
.rt-badge {
    display: inline-block;
    font-family: var(--rt-font-mono);
    font-size: 11px;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--rt-accent-blue);
}

.rt-btn-outline {
    display: inline-block;
    font-family: var(--rt-font-mono);
    font-size: 11px;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--rt-text-title);
    border: 1px solid var(--rt-text-dim);
    padding: 14px 28px;
    transition: border-color 0.2s, background 0.2s;
}

.rt-btn-outline:hover {
    border-color: var(--rt-text-title);
    background: rgba(232, 228, 218, 0.04); /* --rt-text-title at 4% */
}


.rt-section-label {
    font-family: var(--rt-font-mono);
    font-size: 11px;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--rt-text-dim);
    margin-bottom: 48px;
}

/* --- 8. Landing Page: Hero --- */
.rt-hero {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    padding-top: 80px;
    padding-bottom: 80px;
    min-height: 90vh;
    justify-content: center;
}

.rt-hero-lockup {
    width: 380px;
    height: auto;
    margin-bottom: 48px;
}

.rt-hero-title {
    font-family: var(--rt-font-serif);
    font-size: 56px;
    font-weight: 400;
    line-height: 1.15;
    color: var(--rt-text-title);
    margin-bottom: 24px;
}

.rt-hero-sub {
    font-family: var(--rt-font-body);
    font-size: 16px;
    font-weight: 300;
    color: var(--rt-text-body);
    max-width: 480px;
    margin-bottom: 32px;
}

.rt-hero-location {
    font-family: var(--rt-font-mono);
    font-size: 13px;
    letter-spacing: 0.15em;
    text-transform: uppercase;
    color: var(--rt-text-dim);
    margin-bottom: 48px;
}

.rt-hero-scroll {
    font-family: var(--rt-font-mono);
    font-size: 10px;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--rt-text-dim);
    opacity: 0.5;
}

/* --- Shared: Content-width divider pseudo-element --- */
.rt-divider-top,
.rt-divider-bottom { position: relative; }

.rt-divider-top::before,
.rt-divider-bottom::after {
    content: '';
    position: absolute;
    left: var(--rt-pad);
    right: var(--rt-pad);
    height: 1px;
    background: var(--rt-line-divider);
}

.rt-divider-top::before { top: 0; }
.rt-divider-bottom::after { bottom: 0; }

/* --- 9. Landing Page: Portfolio --- */
.rt-portfolio {
    padding-top: 80px;
    padding-bottom: 80px;
}

.rt-card {
    display: grid;
    grid-template-columns: 32px 1fr auto;
    gap: 0 20px;
    align-items: start;
    padding: 48px 0;
    border-bottom: 1px solid var(--rt-line-divider);
}

.rt-card:first-of-type { padding-top: 0; }

.rt-card-numeral {
    font-family: var(--rt-font-serif);
    font-style: italic;
    font-size: 24px;
    color: var(--rt-text-dim);
    padding-top: 4px;
}

.rt-card-content {}

.rt-card-title {
    font-family: var(--rt-font-serif);
    font-size: 28px;
    font-weight: 400;
    color: var(--rt-text-title);
    margin-bottom: 12px;
}

.rt-card-desc {
    font-family: var(--rt-font-body);
    font-size: 14px;
    font-weight: 300;
    color: var(--rt-text-body);
    line-height: 1.7;
    max-width: 540px;
}

.rt-card-meta {
    text-align: right;
    padding-top: 4px;
}

.rt-card-meta .rt-badge { margin-bottom: 8px; }

.rt-card-link {
    font-family: var(--rt-font-mono);
    font-size: 11px;
    letter-spacing: 0.05em;
    color: var(--rt-accent-blue);
    transition: opacity 0.2s;
    display: block;
}

.rt-card-link:hover { opacity: 0.7; }


/* --- 10. Landing Page: Consulting --- */
.rt-consulting {
    padding-top: 80px;
    padding-bottom: 80px;
}

.rt-consulting-layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 80px;
    margin-top: 48px;
}

.rt-consulting-title {
    font-family: var(--rt-font-serif);
    font-size: 36px;
    font-weight: 400;
    line-height: 1.25;
    color: var(--rt-text-title);
    margin-bottom: 24px;
}

.rt-consulting-desc {
    font-family: var(--rt-font-body);
    font-size: 14px;
    font-weight: 300;
    color: var(--rt-text-body);
    line-height: 1.7;
}

.rt-service-list { display: flex; flex-direction: column; }

.rt-service-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 0;
    border-bottom: 1px solid var(--rt-line-divider);
    font-family: var(--rt-font-sans);
    font-size: 15px;
    font-weight: 500;
    color: var(--rt-text-title);
}

.rt-service-item:first-child { border-top: 1px solid var(--rt-line-divider); }

.rt-service-arrow {
    color: var(--rt-text-dim);
    font-size: 18px;
    transition: transform 0.2s;
}

.rt-service-item:hover .rt-service-arrow { transform: translateX(4px); }

/* --- 11. Product Pages --- */
.rt-product-hero {
    padding-top: 80px;
    padding-bottom: 60px;
}

.rt-product-hero .rt-badge { margin-bottom: 16px; }

.rt-product-title {
    font-family: var(--rt-font-serif);
    font-size: 56px;
    font-weight: 400;
    line-height: 1.1;
    color: var(--rt-text-title);
    margin-bottom: 16px;
}

.rt-product-tagline {
    font-family: var(--rt-font-serif);
    font-size: 22px;
    font-weight: 400;
    color: var(--rt-text-body);
    margin-bottom: 20px;
}

.rt-product-body {
    font-family: var(--rt-font-body);
    font-size: 15px;
    font-weight: 300;
    color: var(--rt-text-body);
    line-height: 1.7;
    max-width: 620px;
    margin-bottom: 24px;
}

.rt-product-link {
    font-family: var(--rt-font-mono);
    font-size: 11px;
    color: var(--rt-accent-blue);
    letter-spacing: 0.03em;
    transition: opacity 0.2s;
}

.rt-product-link:hover { opacity: 0.7; }

.rt-section {
    padding-top: 80px;
    padding-bottom: 80px;
}

.rt-section-heading {
    font-family: var(--rt-font-serif);
    font-size: 28px;
    font-weight: 400;
    color: var(--rt-text-title);
    line-height: 1.3;
    margin-bottom: 20px;
}

.rt-section-body {
    font-family: var(--rt-font-body);
    font-size: 15px;
    font-weight: 300;
    color: var(--rt-text-body);
    line-height: 1.7;
    max-width: 620px;
}

.rt-ascii-diagram {
    font-family: var(--rt-font-mono);
    font-size: 12px;
    color: var(--rt-text-dim);
    line-height: 1.6;
    margin-top: 32px;
    overflow-x: auto;
    white-space: pre;
    padding: 20px;
    border: 1px solid var(--rt-line-divider);
    border-radius: 4px;
}

.rt-feature-list { margin-top: 32px; }

.rt-feature-block {
    padding: 28px 0;
    border-bottom: 1px solid var(--rt-line-divider);
}

.rt-feature-block:first-child { border-top: 1px solid var(--rt-line-divider); }

.rt-feature-title {
    font-family: var(--rt-font-sans);
    font-size: 15px;
    font-weight: 500;
    color: var(--rt-text-title);
    margin-bottom: 8px;
}

.rt-feature-desc {
    font-family: var(--rt-font-body);
    font-size: 14px;
    font-weight: 300;
    color: var(--rt-text-body);
    line-height: 1.7;
}

/* Capability grid (2x3 on desktop/tablet, 1 col on mobile) */
.rt-capability-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 48px 64px;
    margin-top: 32px;
}

.rt-capability-title {
    font-family: var(--rt-font-sans);
    font-size: 15px;
    font-weight: 500;
    color: var(--rt-text-title);
    margin-bottom: 8px;
}

.rt-capability-desc {
    font-family: var(--rt-font-body);
    font-size: 14px;
    font-weight: 300;
    color: var(--rt-text-body);
    line-height: 1.7;
}

/* Use cases grid */
.rt-usecase-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
    margin-top: 32px;
}

.rt-section-body + .rt-usecase-grid { margin-top: 32px; }

.rt-usecase-title {
    font-family: var(--rt-font-sans);
    font-size: 15px;
    font-weight: 500;
    color: var(--rt-text-title);
    margin-bottom: 8px;
}

.rt-usecase-desc {
    font-family: var(--rt-font-body);
    font-size: 14px;
    font-weight: 300;
    color: var(--rt-text-body);
    line-height: 1.6;
}

/* Product CTA (different from landing footer CTA) */
.rt-product-cta {
    text-align: center;
    padding-top: 100px;
    padding-bottom: 60px;
}

.rt-product-cta-text {
    font-family: var(--rt-font-serif);
    font-style: italic;
    font-size: 28px;
    line-height: 1.4;
    color: var(--rt-text-title);
    margin-bottom: 40px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* --- 12. Responsive: Tablet (max-width: 1024px) --- */
@media (max-width: 1024px) {
    :root { --rt-pad: var(--rt-pad-tablet); }
    .rt-container {
        padding-left: var(--rt-pad-tablet);
        padding-right: var(--rt-pad-tablet);
    }

    .rt-hero-title { font-size: 44px; }
    .rt-hero { min-height: calc(100dvh - 100px); padding-top: 60px; padding-bottom: 60px; }

    .rt-card { display: grid; grid-template-columns: 32px 1fr; position: relative; gap: 0 12px; }
    .rt-card-numeral { font-size: 20px; padding-top: 4px; }
    .rt-card-title { font-size: 24px; }
    .rt-card-content { grid-column: 2; }
    .rt-card-meta { grid-column: 2; text-align: left; }
    .rt-card-meta .rt-badge {
        position: absolute;
        top: 48px;
        right: 0;
    }
    .rt-card:first-of-type .rt-badge { top: 0; }
    .rt-card-link { display: block; margin-top: 12px; }

    .rt-consulting-title { font-size: 28px; }
    .rt-consulting-layout { gap: 48px; }

    .rt-cta-text { font-size: 28px; }

    .rt-product-title { font-size: 44px; }
    .rt-product-tagline { font-size: 20px; }

    .rt-nav-crown { display: none; }
    .rt-nav-compact { display: block; margin-left: -16px; }
    .rt-nav-contact { border: none; padding: 0; }
    .rt-footer-lockup { margin-left: -16px; }
}

/* --- 13. Responsive: Mobile (max-width: 768px) --- */
@media (max-width: 768px) {
    :root { --rt-pad: var(--rt-pad-mobile); }
    .rt-container {
        padding-left: var(--rt-pad-mobile);
        padding-right: var(--rt-pad-mobile);
    }


    .rt-hero { min-height: auto; padding-top: 48px; padding-bottom: 48px; }
    .rt-hero-lockup { width: 220px; }
    .rt-hero-title { font-size: 36px; }
    .rt-hero-sub { font-size: 15px; }
    .rt-hero-scroll { display: none; }

    .rt-portfolio { padding-top: 48px; padding-bottom: 48px; }
    .rt-card { padding: 32px 0; grid-template-columns: 32px 1fr; gap: 4px 12px; }
    .rt-card-numeral { font-size: 18px; padding-top: 4px; }
    .rt-card-title { font-size: 22px; }
    .rt-card-content { grid-column: 2; }
    .rt-card-meta { grid-column: 2; text-align: left; margin-top: 8px; }

    .rt-consulting { padding-top: 48px; padding-bottom: 48px; }
    .rt-consulting-layout { grid-template-columns: 1fr; gap: 40px; }
    .rt-consulting-title { font-size: 28px; }

    .rt-cta { padding-top: 80px; padding-bottom: 40px; }
    .rt-cta-text { font-size: 24px; }


    .rt-product-hero { padding-top: 48px; padding-bottom: 40px; }
    .rt-product-title { font-size: 36px; }
    .rt-product-tagline { font-size: 18px; }

    .rt-section { padding-top: 48px; padding-bottom: 48px; }
    .rt-section-label { margin-bottom: 32px; }
    .rt-section-heading { font-size: 24px; }

    .rt-product-cta { padding: 64px 0 40px; }
    .rt-product-cta-text { font-size: 22px; }

    .rt-capability-grid { grid-template-columns: 1fr; gap: 32px; }
    .rt-usecase-grid { grid-template-columns: 1fr; gap: 24px; }

    .rt-ascii-diagram { padding: 16px; }

    .rt-ascii-diagram { font-size: 10px; }
}

/* --- 14. Responsive: Mobile nav (max-width: 767px) --- */
@media (max-width: 767px) {
    .rt-nav-links { display: none; }
    .rt-hamburger { display: block; }
    .rt-nav-compact { margin-left: -16px; }

    .rt-footer-inner { flex-direction: column; align-items: center; gap: 20px; text-align: center; }
    .rt-footer-copy { position: static; transform: none; order: 3; }
    .rt-footer-brand { order: 1; }
    .rt-footer-social { justify-content: center; order: 2; }
    .rt-footer-lockup { height: 56px; margin-left: -16px; }
}