/* ============================================================
   IMMUTABLE QUALITY CONTROL — LANDING PAGE STYLES
   Color Palette: Deep Navy, Crisp White, Slate Gray, Blue Accent
   (Revised per Opus 4.8 review — unified cards, fixed pipeline, status strip, research section)
   ============================================================ */

/* ---------- CSS Custom Properties ---------- */
:root {
    --color-navy-900: #060e1a;
    --color-navy-800: #0b1929;
    --color-navy-700: #102a43;
    --color-navy-600: #1a3a5c;
    --color-blue-600: #1a56db;
    --color-blue-500: #2563eb;
    --color-blue-400: #3b82f6;
    --color-blue-300: #60a5fa;
    --color-slate-600: #475569;
    --color-slate-500: #64748b;
    --color-slate-400: #94a3b8;
    --color-slate-300: #cbd5e1;
    --color-slate-200: #e2e8f0;
    --color-slate-100: #f1f5f9;
    --color-slate-50: #f8fafc;
    --color-white: #ffffff;
    --color-emerald-500: #10b981;
    --color-amber-500: #f59e0b;

    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;

    --max-width: 1200px;
    --nav-height: 72px;

    --transition-fast: 0.2s ease;
    --transition-medium: 0.35s ease;
    --transition-slow: 0.5s ease;

    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.15);
    --shadow-glow: 0 0 30px rgba(37, 99, 235, 0.15);
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-primary);
    color: var(--color-slate-600);
    background-color: var(--color-white);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

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

ul, ol {
    list-style: none;
}

strong {
    color: var(--color-navy-800);
}

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

/* ---------- Section Labels & Titles ---------- */
.section__label {
    display: inline-block;
    font-size: 0.8rem;
    font-weight: 700;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--color-blue-600);
    margin-bottom: 12px;
}

.section__label--light {
    color: var(--color-blue-300);
}

.section__title {
    font-size: clamp(1.75rem, 4vw, 2.75rem);
    font-weight: 800;
    color: var(--color-navy-800);
    letter-spacing: -0.03em;
    line-height: 1.2;
    margin-bottom: 48px;
}

.section__title--light {
    color: var(--color-white);
}

/* ---------- Buttons ---------- */
.btn {
    display: inline-block;
    font-family: var(--font-primary);
    font-size: 0.95rem;
    font-weight: 600;
    padding: 14px 32px;
    border-radius: 8px;
    cursor: pointer;
    transition: all var(--transition-fast);
    border: 2px solid transparent;
    text-align: center;
    letter-spacing: -0.01em;
}

.btn--primary {
    background-color: var(--color-blue-500);
    color: var(--color-white);
    box-shadow: 0 4px 14px rgba(37, 99, 235, 0.3);
}

.btn--primary:hover {
    background-color: var(--color-blue-600);
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(37, 99, 235, 0.4);
}

.btn--secondary {
    background-color: transparent;
    color: var(--color-white);
    border-color: rgba(255, 255, 255, 0.35);
}

.btn--secondary:hover {
    background-color: rgba(255, 255, 255, 0.08);
    border-color: rgba(255, 255, 255, 0.6);
}

.btn--large {
    font-size: 1.05rem;
    padding: 18px 44px;
    border-radius: 10px;
}

/* ============================================================
   NAVIGATION
   ============================================================ */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--nav-height);
    z-index: 1000;
    background-color: transparent;
    transition: background-color var(--transition-medium), box-shadow var(--transition-medium);
}

.nav--scrolled {
    background-color: rgba(6, 14, 26, 0.95);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.3);
}

.nav__container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav__logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-white);
    letter-spacing: -0.02em;
    z-index: 1001;
}

.nav__logo-icon {
    font-size: 1.4rem;
    color: var(--color-blue-400);
    transition: transform var(--transition-fast);
}

.nav__logo:hover .nav__logo-icon {
    transform: rotate(90deg);
}

.nav__logo-accent {
    color: var(--color-blue-400);
}

.nav__links {
    display: flex;
    align-items: center;
    gap: 36px;
}

.nav__link {
    font-size: 0.9rem;
    font-weight: 500;
    color: rgba(255, 255, 255, 0.8);
    transition: color var(--transition-fast);
    position: relative;
}

.nav__link::after {
    content: '';
    position: absolute;
    bottom: -6px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--color-blue-400);
    transition: width var(--transition-fast);
}

.nav__link:hover {
    color: var(--color-white);
}

.nav__link:hover::after {
    width: 100%;
}

/* Mobile nav (from previous version) */
.nav__toggle {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 24px;
    height: 18px;
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0;
    z-index: 1001;
}

.nav__toggle-bar {
    display: block;
    height: 2px;
    width: 100%;
    background-color: var(--color-white);
    transition: all var(--transition-fast);
}

@media (max-width: 768px) {
    .nav__toggle { display: flex; }
    .nav__links {
        position: fixed; top: 0; right: -100%; width: 280px; height: 100vh;
        flex-direction: column; background-color: rgba(6,14,26,0.98);
        backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
        padding: 100px 32px 40px; gap: 28px;
        transition: right var(--transition-medium);
        box-shadow: -10px 0 40px rgba(0,0,0,0.4);
    }
    .nav__links--open { right: 0; }
    .nav__link { font-size: 1.05rem; }
}

/* ============================================================
   HERO
   ============================================================ */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    background-color: var(--color-navy-900);
    color: var(--color-white);
    overflow: hidden;
}

.hero__bg-pattern {
    position: absolute;
    inset: 0;
    background-image: 
        linear-gradient(rgba(255,255,255,0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255,255,255,0.03) 1px, transparent 1px);
    background-size: 40px 40px;
    pointer-events: none;
}

.hero__container {
    position: relative;
    z-index: 2;
    max-width: 1200px;
    margin: 0 auto;
    padding: 140px 40px 100px;
    text-align: center;
}

.hero__badge {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-size: 0.78rem;
    font-weight: 600;
    letter-spacing: 0.08em;
    color: var(--color-blue-300);
    background: rgba(37, 99, 235, 0.12);
    border: 1px solid rgba(37, 99, 235, 0.3);
    padding: 8px 18px;
    border-radius: 100px;
    margin-bottom: 28px;
}

.hero__badge-dot {
    width: 8px; height: 8px; border-radius: 50%;
    background: var(--color-emerald-500);
    box-shadow: 0 0 10px rgba(16, 185, 129, 0.7);
}

.hero__headline {
    font-size: clamp(2.7rem, 5.8vw, 4.05rem);
    font-weight: 800;
    letter-spacing: -0.05em;
    line-height: 1.05;
    margin-bottom: 28px;
}

.hero__subheadline {
    font-size: 1.25rem;
    font-weight: 500;
    color: var(--color-blue-300);
    margin-bottom: 32px;
    line-height: 1.4;
}

.hero__description {
    font-size: 1.05rem;
    line-height: 1.75;
    color: rgba(255,255,255,0.75);
    max-width: 1000px;
    margin: 0 auto 48px;
}

.hero__actions {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
    justify-content: center;
}

/* ============================================================
   STATUS STRIP
   ============================================================ */
.status-strip {
    background: var(--color-navy-900);
    border-bottom: 1px solid rgba(255,255,255,0.06);
    padding: 20px 0;
}
.status-strip__list {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}
.status-strip__item { display: flex; align-items: center; gap: 10px; }
.status-strip__state {
    font-size: 0.7rem; font-weight: 700; letter-spacing: 0.08em;
    text-transform: uppercase; padding: 3px 10px; border-radius: 100px;
    flex-shrink: 0;
}
.status-strip__state--live { background: rgba(16,185,129,0.15); color: var(--color-emerald-500); }
.status-strip__state--progress { background: rgba(245,158,11,0.15); color: var(--color-amber-500); }
.status-strip__state--planned { background: rgba(148,163,184,0.12); color: var(--color-slate-400); }
.status-strip__label { font-size: 0.82rem; color: rgba(255,255,255,0.6); line-height: 1.4; }

/* ============================================================
   UNIFIED CARD SYSTEM
   ============================================================ */
.card-grid { display: grid; gap: 24px; align-items: stretch; }
.card-grid--2 { grid-template-columns: repeat(2, 1fr); }
.card-grid--3 { grid-template-columns: repeat(3, 1fr); }
.card-grid--tight { gap: 16px; }

.card {
    display: flex;
    flex-direction: column;
    background-color: var(--color-white);
    border: 1px solid var(--color-slate-200);
    border-radius: 12px;
    padding: 28px 24px;
    height: 100%;
    transition: transform var(--transition-medium), box-shadow var(--transition-medium), border-color var(--transition-medium);
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); border-color: var(--color-slate-300); }
.card--feature { background-color: var(--color-slate-50); }
.card--feature:hover { border-color: var(--color-blue-400); }
.card--dark {
    background: rgba(255,255,255,0.04);
    border-color: rgba(255,255,255,0.08);
}
.card--dark:hover { background: rgba(255,255,255,0.07); border-color: rgba(96,165,250,0.3); transform: translateY(-4px); }

.card__icon { color: var(--color-blue-500); margin-bottom: 20px; }
.card__title { font-size: 1.1rem; font-weight: 700; color: var(--color-navy-800); margin-bottom: 12px; }
.card__title--accent { color: var(--color-blue-300); }
.card__text { font-size: 0.95rem; line-height: 1.65; color: var(--color-slate-600); }
.card__text--muted { color: rgba(255,255,255,0.65); }
.card__link { margin-top: auto; padding-top: 14px; font-size: 0.85rem; font-weight: 600; color: var(--color-blue-400); }

/* ============================================================
   PROBLEM
   ============================================================ */
.problem { padding: 100px 0; background-color: var(--color-slate-50); }
.problem .card-grid { margin-bottom: 48px; }
.problem__stat { background-color: var(--color-navy-800); color: var(--color-white); padding: 28px 32px; border-radius: 12px; text-align: center; }
.problem__stat-text { font-size: 1.05rem; line-height: 1.6; max-width: 720px; margin: 0 auto; }
.problem__stat-text strong { color: var(--color-white); }

/* ============================================================
   SOLUTION
   ============================================================ */
.solution { padding: 100px 0; background-color: var(--color-white); }

/* ============================================================
   HOW IT WORKS — PIPELINE (alignment fixed)
   ============================================================ */
.how-it-works { padding: 100px 0; background-color: var(--color-white); }
.pipeline {
    display: flex;
    align-items: flex-start;
    gap: 0;
    list-style: none;
    padding: 0;
    margin: 0;
}
.pipeline__step { flex: 1 1 0; min-width: 200px; text-align: center; padding: 0 8px; }
.pipeline__step-number {
    display: flex; align-items: center; justify-content: center;
    width: 56px; height: 56px; border-radius: 50%;
    background: linear-gradient(135deg, var(--color-blue-500), var(--color-blue-600));
    color: var(--color-white); font-size: 1.3rem; font-weight: 800;
    margin: 0 auto 20px; box-shadow: 0 6px 20px rgba(37,99,235,0.3);
}
.pipeline__step-title { font-size: 1.1rem; font-weight: 700; color: var(--color-navy-800); margin-bottom: 8px; }
.pipeline__step-text { font-size: 0.9rem; color: var(--color-slate-500); line-height: 1.6; max-width: 240px; margin: 0 auto; }
.pipeline__connector {
    flex: 0 0 40px;
    display: flex; align-items: flex-start; justify-content: center;
    padding-top: 27px;
}
.pipeline__connector-line {
    display: block; width: 100%; height: 2px;
    background: linear-gradient(90deg, var(--color-blue-400), var(--color-slate-300));
    border-radius: 2px;
}

/* ============================================================
   TECHNICAL
   ============================================================ */
.technical { padding: 100px 0; background: linear-gradient(170deg, var(--color-navy-800) 0%, var(--color-navy-900) 100%); color: var(--color-white); }
.technical__subhead { font-size: 1.1rem; font-weight: 600; color: var(--color-blue-300); margin-bottom: 24px; letter-spacing: 0.02em; }
.technical__subhead--spaced { margin-top: 56px; }
.stack__item {
    background: rgba(255,255,255,0.03); border: 1px solid rgba(255,255,255,0.06);
    border-radius: 12px; padding: 18px 20px;
}
.stack__name { display: block; font-weight: 700; color: var(--color-white); font-size: 0.95rem; margin-bottom: 4px; }
.stack__desc { font-size: 0.85rem; color: rgba(255,255,255,0.55); line-height: 1.5; }

/* ============================================================
   RESEARCH / METHODOLOGY
   ============================================================ */
.research { padding: 100px 0; background-color: var(--color-slate-50); }
.research__cta { text-align: center; margin-top: 40px; }
.btn--outline {
    background: transparent; color: var(--color-blue-600);
    border-color: var(--color-slate-300);
}
.btn--outline:hover { border-color: var(--color-blue-500); background: var(--color-white); transform: translateY(-2px); }

/* ============================================================
   CTA
   ============================================================ */
.cta { padding: 120px 0; background-color: var(--color-white); text-align: center; }
.cta__title { font-size: clamp(1.75rem, 4vw, 2.5rem); font-weight: 800; color: var(--color-navy-800); letter-spacing: -0.03em; margin-bottom: 20px; }
.cta__text { font-size: 1.05rem; color: var(--color-slate-500); max-width: 1000px; margin: 0 auto 48px; line-height: 1.85; }
.cta__actions { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; }
.btn--secondary-dark { background: transparent; color: var(--color-navy-800); border-color: var(--color-slate-300); }
.btn--secondary-dark:hover { border-color: var(--color-navy-700); background: var(--color-slate-50); }

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 1024px) {
    .card-grid--3 { grid-template-columns: repeat(2, 1fr); }
    .status-strip__list { grid-template-columns: repeat(2, 1fr); }
    .pipeline { flex-wrap: wrap; justify-content: center; gap: 32px; }
    .pipeline__connector { display: none; }
    .pipeline__step { flex: 0 0 calc(50% - 32px); }
}

@media (max-width: 768px) {
    :root { --nav-height: 64px; }
    .nav__links {
        position: fixed; top: 0; right: -100%; width: 280px; height: 100vh;
        flex-direction: column; background-color: rgba(6,14,26,0.98);
        backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
        padding: 100px 32px 40px; gap: 28px;
        transition: right var(--transition-medium);
        box-shadow: -10px 0 40px rgba(0,0,0,0.4);
    }
    .nav__links--open { right: 0; }
    .nav__link { font-size: 1.05rem; }
    .nav__toggle { display: flex; }

    .hero__container { padding: 100px 20px 70px; }
    .hero__actions { flex-direction: column; align-items: center; }
    .hero__actions .btn { width: 100%; max-width: 300px; }

    .card-grid--2, .card-grid--3 { grid-template-columns: 1fr; }
    .status-strip__list { grid-template-columns: 1fr; }
    .pipeline__step { flex: 0 0 100%; min-width: unset; }

    .section__title { margin-bottom: 32px; }
    .section__lead { margin-bottom: 40px; }

    .problem, .solution, .how-it-works,
    .technical, .research, .cta { padding: 64px 0; }
    .status-strip { padding: 16px 0; }
}

@media (max-width: 480px) {
    .hero__headline { font-size: 2.4rem; }
    .hero__subheadline { font-size: 1rem; }
    .btn--large { padding: 16px 28px; font-size: 0.95rem; }
    .footer__links { gap: 32px; }
}
/* ============================================================
   FOOTER - Centered container + columns
   ============================================================ */
.footer {
    background: var(--color-navy-900);
    color: rgba(255, 255, 255, 0.6);
    padding: 60px 0 30px;
    font-size: 0.9rem;
}

.footer__container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 48px;
}

.footer__brand {
    flex: 0 0 auto;
}

.footer__logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--color-white);
    margin-bottom: 8px;
}

.footer__logo-icon {
    color: var(--color-blue-400);
}

.footer__logo-accent {
    color: var(--color-blue-400);
}

.footer__tagline {
    font-size: 0.85rem;
    color: rgba(255, 255, 255, 0.5);
}

.footer__links {
    display: flex;
    gap: 48px;
    flex-wrap: wrap;
}

.footer__col h4 {
    font-size: 0.8rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--color-blue-300);
    margin-bottom: 12px;
}

.footer__col ul li {
    margin-bottom: 8px;
}

.footer__col a {
    color: rgba(255, 255, 255, 0.6);
    transition: color 0.2s ease;
}

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

.footer__bottom {
    width: 100%;
    margin-top: 48px;
    padding-top: 24px;
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    text-align: center;
    font-size: 0.8rem;
    color: rgba(255, 255, 255, 0.4);
}

@media (max-width: 768px) {
    .footer__container {
        flex-direction: column;
        gap: 40px;
    }
    .footer__links {
        gap: 32px;
    }
}