:root {
    color-scheme: light dark;
    --bg-color: #050a16;
    --text-color: #f8fafc;
    --muted-color: rgba(226, 232, 240, 0.78);
    --accent-color: #38bdf8;
    --accent-color-2: #2563eb;
    --header-height: 96px;
    --stage-margin: clamp(1.5rem, 4vw, 4rem);
    --slide-padding: clamp(2.5rem, 6vw, 6rem);
    --road-gap: clamp(12px, 2vh, 20px);
    --vehicle-bob-amplitude: 6px;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    background: radial-gradient(circle at top right, rgba(56, 189, 248, 0.18), transparent 55%),
        radial-gradient(circle at bottom left, rgba(37, 99, 235, 0.2), transparent 60%),
        var(--bg-color);
    color: var(--text-color);
    min-height: 100vh;
    overflow-x: hidden;
    overscroll-behavior-y: none;
    scroll-snap-type: y mandatory;
    scroll-padding-top: var(--header-height);
    scroll-behavior: smooth;
}

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

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

.hero-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    display: grid;
    grid-template-columns: auto 1fr auto;
    align-items: center;
    gap: clamp(1rem, 3vw, 2rem);
    padding: clamp(1rem, 2vw, 1.6rem) clamp(1.5rem, 4vw, 3rem);
    backdrop-filter: blur(14px);
    background: rgba(4, 10, 22, 0.72);
    border-bottom: 1px solid rgba(148, 163, 184, 0.22);
    z-index: 40;
}

.hero-brand {
    display: inline-flex;
    align-items: center;
    gap: 0.8rem;
    font-weight: 600;
    color: var(--text-color);
}

.hero-brand__logo {
    width: clamp(42px, 4vw, 56px);
    height: clamp(42px, 4vw, 56px);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 16px;
    background: rgba(15, 23, 42, 0.8);
    padding: 0.4rem;
    box-shadow: 0 12px 26px rgba(15, 23, 42, 0.45);
}

.hero-brand__text {
    display: grid;
    gap: 0.1rem;
}

.hero-brand__title {
    font-size: clamp(1.1rem, 2vw, 1.35rem);
    letter-spacing: 0.01em;
}

.hero-brand__subtitle {
    font-size: clamp(0.75rem, 1.6vw, 0.95rem);
    color: rgba(226, 232, 240, 0.72);
}

.hero-nav {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: clamp(1.2rem, 3vw, 2rem);
    font-weight: 500;
}

.hero-nav__link {
    position: relative;
    padding: 0.4rem 0.2rem;
    color: rgba(226, 232, 240, 0.85);
    transition: color 0.2s ease;
}

.hero-nav__link::after {
    content: '';
    position: absolute;
    left: 0;
    right: 0;
    bottom: -0.2rem;
    height: 2px;
    background: linear-gradient(90deg, var(--accent-color), var(--accent-color-2));
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.25s ease;
    opacity: 0.7;
}

.hero-nav__link:hover,
.hero-nav__link:focus-visible {
    color: var(--text-color);
}

.hero-nav__link:hover::after,
.hero-nav__link:focus-visible::after {
    transform: scaleX(1);
}

.hero-actions {
    display: inline-flex;
    align-items: center;
    gap: 0.8rem;
}

.hero-login {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.6rem 1.1rem;
    font-weight: 600;
    border-radius: 999px;
    background: linear-gradient(135deg, var(--accent-color), var(--accent-color-2));
    color: #0f172a;
    box-shadow: 0 14px 36px rgba(37, 99, 235, 0.28);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.hero-login:hover,
.hero-login:focus-visible {
    transform: translateY(-1px);
    box-shadow: 0 16px 42px rgba(37, 99, 235, 0.32);
}

.hero-track {
    position: relative;
    padding-top: var(--header-height);
    overflow: visible;
}

.hero-overlay {
    position: sticky;
    top: var(--header-height);
    height: calc(100vh - var(--header-height));
    min-height: clamp(440px, 80vh, 680px);
    pointer-events: none;
    overflow: hidden;
    isolation: isolate;
    z-index: 0;
    --background-shift: 0;
    --road-shift: 0;
    --vehicle-shift: 0;
    --vehicle-bob: 0;
    --vehicle-center-offset: 0px;
    --vehicle-vertical-offset: 0px;
    --road-vertical-offset: 0px;
}

.hero-bg,
.hero-road,
.hero-van {
    position: absolute;
    left: 0;
    right: 0;
}

.hero-bg {
    inset: 0;
    background: radial-gradient(circle at top, rgba(44, 82, 130, 0.45), transparent 70%);
    background-size: cover;
    background-position: calc(var(--background-shift) * -1px) center;
    background-repeat: no-repeat;
    opacity: 1;
    transition: opacity 0.4s ease, background-image 0.3s ease;
    will-change: background-position, opacity;
    z-index: 0;
}

.hero-overlay--fallback .hero-bg {
    background: radial-gradient(circle at top, rgba(30, 58, 138, 0.62), rgba(8, 47, 73, 0.92));
}

.hero-road {
    bottom: clamp(8%, 10vh, 14%);
    left: 50%;
    width: 200%;
    height: clamp(140px, 16vh, 220px);
    transform: translate3d(calc(-50% + var(--vehicle-center-offset)), var(--road-vertical-offset), 0);
    background-image: url('../images/hero-road.svg');
    background-repeat: repeat-x;
    background-size: auto 100%;
    background-position-x: calc(50% - (var(--road-shift) * 1px));
    background-position-y: center;
    filter: drop-shadow(0 22px 48px rgba(9, 15, 30, 0.45));
    will-change: transform, background-position;
    z-index: 1;
}

.hero-van {
    position: absolute;
    left: 0;
    top: var(--van-top, 0px);
    width: clamp(210px, 28vw, 360px);
    transform: translate3d(0, 0, 0);
    filter: drop-shadow(0 28px 60px rgba(8, 12, 28, 0.5));
    will-change: transform;
    pointer-events: none;
    z-index: 2;
}

.hero-van img {
    pointer-events: none;
}

.slide {
    position: relative;
    z-index: 2;
    scroll-snap-align: start;
    scroll-snap-stop: always;
    min-height: calc(100vh - var(--header-height));
    padding: max(var(--stage-margin), 6vh) var(--stage-margin);
    display: flex;
    align-items: center;
    justify-content: flex-start;
    transition: transform 0.4s ease, opacity 0.4s ease;
}

.slide__content {
    display: grid;
    gap: 1.2rem;
    max-width: min(620px, 92vw);
    padding: clamp(2rem, 4vw, 3rem);
    background: rgba(8, 15, 30, 0.78);
    border: 1px solid rgba(148, 163, 184, 0.18);
    border-radius: clamp(1.6rem, 3vw, 2.4rem);
    backdrop-filter: blur(14px);
    box-shadow: 0 24px 70px -48px rgba(6, 11, 24, 0.9);
}

.slide__eyebrow {
    font-weight: 600;
    color: var(--accent-color);
    letter-spacing: 0.18em;
    text-transform: uppercase;
    margin: 0;
}

.slide__title {
    font-size: clamp(2.4rem, 4.5vw, 3.6rem);
    margin: 0;
}

.slide__text {
    margin: 0;
    line-height: 1.65;
    color: var(--muted-color);
}

.slide__list {
    margin: 0;
    padding-left: 1.2rem;
    display: grid;
    gap: 0.4rem;
    color: var(--muted-color);
}

.slide__actions {
    display: inline-flex;
    gap: 1rem;
    flex-wrap: wrap;
    align-items: center;
}

.slide.is-active .slide__content {
    border-color: rgba(148, 163, 184, 0.32);
    box-shadow: 0 32px 90px -52px rgba(37, 99, 235, 0.45);
}

.scroll-progress {
    position: fixed;
    top: 0;
    left: 0;
    height: 4px;
    width: 100%;
    background: rgba(148, 163, 184, 0.22);
    z-index: 50;
}

.scroll-progress__bar {
    height: 100%;
    width: 0;
    background: linear-gradient(90deg, var(--accent-color), var(--accent-color-2));
    transition: width 0.1s ease-out;
}

@media (max-width: 992px) {
    :root {
        --header-height: 104px;
        --vehicle-bob-amplitude: 4px;
    }

    .hero-header {
        grid-template-columns: 1fr;
        justify-items: center;
        text-align: center;
        gap: 0.8rem;
    }

    .hero-nav {
        flex-wrap: wrap;
    }

    .slide {
        justify-content: center;
        text-align: center;
    }

    .slide__content {
        justify-items: center;
    }

    .slide__actions {
        justify-content: center;
    }

    .hero-van {
        width: clamp(190px, 52vw, 300px);
    }
}

@media (max-width: 600px) {
    :root {
        --header-height: 120px;
        --vehicle-bob-amplitude: 3px;
    }

    body {
        scroll-snap-type: y proximity;
    }

    .hero-header {
        padding-inline: clamp(1rem, 5vw, 1.4rem);
    }

    .hero-nav {
        gap: 1rem;
    }

    .slide {
        padding: clamp(2rem, 7vw, 2.8rem);
    }

    .hero-van {
        width: clamp(170px, 60vw, 230px);
    }
}

@media (prefers-reduced-motion: reduce) {
    .hero-login,
    .slide,
    .hero-bg,
    .scroll-progress__bar {
        transition: none !important;
    }
}