:root {
    --bg: #050711;
    --bg-2: #0c1220;
    --surface: rgba(255, 255, 255, 0.06);
    --surface-strong: rgba(255, 255, 255, 0.1);
    --line: rgba(255, 255, 255, 0.14);
    --text: #f8fbff;
    --muted: #a9b4c2;
    --cyan: #34d5ff;
    --orange: #ff7a3d;
    --green: #7ddc9b;
    --shadow: 0 28px 80px rgba(0, 0, 0, 0.38);
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    color: var(--text);
    background: var(--bg);
    font-family: Inter, "Microsoft YaHei", "PingFang SC", "Segoe UI", Arial, sans-serif;
    overflow-x: hidden;
}

body.is-locked {
    overflow: hidden;
}

a {
    color: inherit;
}

button,
a {
    -webkit-tap-highlight-color: transparent;
}

.container {
    width: min(1180px, calc(100% - 40px));
    margin: 0 auto;
}

.site-header {
    position: fixed;
    inset: 0 0 auto;
    z-index: 50;
    background: rgba(5, 7, 17, 0.78);
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    backdrop-filter: blur(18px);
}

.nav {
    width: min(1180px, calc(100% - 40px));
    min-height: 72px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    color: var(--text);
    font-size: 1.4rem;
    font-weight: 900;
    letter-spacing: 0;
    text-decoration: none;
}

.brand-mark {
    width: 30px;
    height: 30px;
    border: 2px solid var(--cyan);
    border-radius: 50%;
    position: relative;
    box-shadow: 0 0 28px rgba(52, 213, 255, 0.35);
}

.brand-mark::after {
    content: "";
    position: absolute;
    width: 34px;
    height: 2px;
    left: -2px;
    top: 13px;
    background: var(--orange);
    transform: rotate(-24deg);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 28px;
    margin: 0;
    padding: 0;
    list-style: none;
}

.nav-links a {
    color: var(--muted);
    font-size: 0.95rem;
    font-weight: 800;
    text-decoration: none;
    transition: color 0.2s ease;
}

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

.nav-toggle {
    display: none;
    width: 42px;
    height: 42px;
    padding: 0;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: transparent;
    color: var(--text);
    cursor: pointer;
}

.nav-toggle span {
    display: block;
    width: 18px;
    height: 2px;
    margin: 4px auto;
    background: currentColor;
}

.hero {
    min-height: 100vh;
    position: relative;
    display: flex;
    align-items: center;
    padding: 130px 0 88px;
    overflow: hidden;
}

.hero-media {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: 62% center;
}

.hero-overlay {
    position: absolute;
    inset: 0;
    background:
        radial-gradient(circle at 78% 34%, rgba(52, 213, 255, 0.18), transparent 28%),
        linear-gradient(90deg, rgba(5, 7, 17, 0.96) 0%, rgba(5, 7, 17, 0.74) 46%, rgba(5, 7, 17, 0.18) 100%),
        linear-gradient(180deg, rgba(5, 7, 17, 0) 68%, var(--bg) 100%);
}

.hero-content {
    position: relative;
    z-index: 1;
    width: min(1180px, calc(100% - 40px));
    margin: 0 auto;
    max-width: 860px;
}

.eyebrow {
    margin: 0 0 12px;
    color: var(--green);
    font-size: 0.78rem;
    font-weight: 900;
    letter-spacing: 0;
    text-transform: uppercase;
}

.hero h1 {
    margin: 0;
    max-width: 920px;
    font-size: clamp(3.8rem, 9vw, 8rem);
    line-height: 0.96;
    letter-spacing: 0;
    text-wrap: balance;
}

.hero-copy {
    max-width: 760px;
    margin: 28px 0 34px;
    color: #d8e0eb;
    font-size: clamp(1.08rem, 2vw, 1.34rem);
    line-height: 1.8;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
}

.hero-metrics {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1px;
    width: min(760px, 100%);
    margin-top: 42px;
    border: 1px solid rgba(255, 255, 255, 0.16);
    border-radius: 8px;
    overflow: hidden;
    background: rgba(255, 255, 255, 0.14);
    box-shadow: 0 24px 70px rgba(0, 0, 0, 0.28);
}

.hero-metrics div {
    padding: 18px;
    background: rgba(5, 7, 17, 0.64);
    backdrop-filter: blur(12px);
}

.hero-metrics strong {
    display: block;
    margin-bottom: 6px;
    color: var(--text);
    font-size: 1.45rem;
}

.hero-metrics span {
    color: var(--muted);
    line-height: 1.5;
}

.primary-action,
.secondary-action,
.vehicle-body button {
    min-height: 46px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 8px;
    font-weight: 900;
    text-decoration: none;
    cursor: pointer;
    transition: transform 0.2s ease, border-color 0.2s ease, background 0.2s ease;
}

.primary-action {
    padding: 0 18px;
    background: linear-gradient(135deg, var(--cyan), var(--orange));
    color: #071018;
}

.secondary-action {
    padding: 0 18px;
    border: 1px solid rgba(255, 255, 255, 0.25);
    color: var(--text);
    background: rgba(255, 255, 255, 0.06);
}

.primary-action:hover,
.secondary-action:hover,
.vehicle-body button:hover {
    transform: translateY(-2px);
}

.section {
    padding: 92px 0;
}

.why-section {
    position: relative;
    overflow: hidden;
    background:
        radial-gradient(circle at 18% 22%, rgba(255, 122, 61, 0.16), transparent 28%),
        radial-gradient(circle at 78% 52%, rgba(52, 213, 255, 0.1), transparent 30%),
        linear-gradient(180deg, var(--bg) 0%, #080d18 100%);
}

.why-section::before {
    content: "";
    position: absolute;
    inset: 0;
    pointer-events: none;
    opacity: 0.28;
    background-image:
        linear-gradient(rgba(255, 255, 255, 0.06) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.06) 1px, transparent 1px);
    background-size: 72px 72px;
    mask-image: linear-gradient(90deg, transparent, #000 18%, #000 78%, transparent);
}

.concepts-section {
    background: #080d18;
}

.journey-section {
    background: #0b1120;
}

.vehicles-section {
    position: relative;
    overflow: hidden;
    background: linear-gradient(180deg, var(--bg) 0%, #0b1120 100%);
}

.vehicles-section::before {
    content: "";
    position: absolute;
    inset: 0;
    pointer-events: none;
    background:
        linear-gradient(180deg, rgba(5, 7, 17, 0.72) 0%, rgba(11, 17, 32, 0.9) 100%),
        url("../assets/starship-real.jpg") center 28% / cover no-repeat;
    opacity: 0.18;
}

.vehicles-section .container {
    position: relative;
    z-index: 1;
}

.system-section {
    background: #0b1120;
}

.milestones-section {
    background: linear-gradient(180deg, #0b1120 0%, #080b14 100%);
}

.mission-section {
    background:
        radial-gradient(circle at 22% 42%, rgba(52, 213, 255, 0.14), transparent 32%),
        radial-gradient(circle at 82% 48%, rgba(255, 122, 61, 0.14), transparent 30%),
        #060811;
}

.section-heading {
    max-width: 780px;
    margin-bottom: 34px;
}

.section-heading h2,
.system-copy h2,
.mission-layout h2 {
    margin: 0;
    font-size: clamp(2.2rem, 5vw, 4.4rem);
    line-height: 1.05;
    letter-spacing: 0;
}

.section-heading p:not(.eyebrow),
.system-copy > p,
.mission-layout > p {
    color: var(--muted);
    font-size: 1.05rem;
    line-height: 1.8;
}

.vehicle-intro {
    max-width: 950px;
    text-wrap: pretty;
}

.vehicle-name {
    display: inline-block;
    color: #d8f3ff;
    font-weight: 900;
    white-space: nowrap;
    text-shadow: 0 0 24px rgba(52, 213, 255, 0.28);
}

.split-layout,
.journey-layout {
    display: grid;
    gap: 48px;
    align-items: start;
}

.split-layout {
    position: relative;
    z-index: 1;
    grid-template-columns: minmax(0, 0.92fr) minmax(420px, 1.08fr);
    align-items: stretch;
}

.journey-layout {
    grid-template-columns: minmax(360px, 1.04fr) minmax(0, 0.96fr);
    align-items: center;
}

.impact-grid,
.concept-grid {
    display: grid;
    gap: 16px;
}

.impact-grid {
    position: relative;
    align-content: stretch;
    gap: 18px;
}

.impact-grid::before {
    content: "";
    position: absolute;
    top: 40px;
    bottom: 40px;
    left: 27px;
    width: 1px;
    background: linear-gradient(180deg, rgba(255, 122, 61, 0), rgba(255, 122, 61, 0.65), rgba(52, 213, 255, 0.38), rgba(255, 122, 61, 0));
}

.why-copy {
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    min-height: 620px;
    margin-bottom: 0;
    padding: 22px 0;
}

.why-copy h2 {
    max-width: 620px;
    font-size: clamp(3.2rem, 5.8vw, 6.1rem);
    line-height: 0.96;
    text-wrap: balance;
}

.why-copy > p:not(.eyebrow) {
    max-width: 610px;
    margin-top: 24px;
    font-size: 1.08rem;
}

.why-stats {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1px;
    width: min(610px, 100%);
    margin-top: auto;
    border: 1px solid rgba(255, 255, 255, 0.16);
    border-radius: 8px;
    overflow: hidden;
    background: rgba(255, 255, 255, 0.14);
    box-shadow: var(--shadow);
}

.why-stats div {
    padding: 20px;
    background: rgba(255, 255, 255, 0.055);
    backdrop-filter: blur(14px);
}

.why-stats strong {
    display: block;
    margin-bottom: 8px;
    color: var(--text);
    font-size: 1.55rem;
}

.why-stats span {
    color: var(--muted);
    line-height: 1.6;
}

.concept-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
}

.impact-grid article,
.concept-grid article {
    border: 1px solid var(--line);
    border-radius: 8px;
    background: linear-gradient(145deg, rgba(255, 255, 255, 0.1), rgba(255, 255, 255, 0.045));
    box-shadow: var(--shadow);
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 0.5s ease, transform 0.5s ease, border-color 0.2s ease;
}

.impact-grid article {
    position: relative;
    min-height: 188px;
    display: grid;
    grid-template-columns: 62px 1fr;
    align-items: center;
    column-gap: 26px;
    padding: 28px 30px 28px 26px;
}

.impact-grid article:nth-child(2) {
    margin-left: 44px;
}

.impact-grid article:nth-child(3) {
    margin-left: 88px;
}

.concept-grid article {
    min-height: 290px;
    padding: 24px;
}

.impact-grid article.is-visible,
.concept-grid article.is-visible {
    opacity: 1;
    transform: translateY(0);
}

.impact-grid article:hover,
.concept-grid article:hover {
    border-color: rgba(255, 122, 61, 0.42);
}

.impact-grid span {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 54px;
    height: 54px;
    margin-bottom: 0;
    border: 1px solid rgba(255, 122, 61, 0.52);
    border-radius: 50%;
    color: var(--orange);
    font-weight: 900;
    background: rgba(255, 122, 61, 0.08);
    box-shadow: 0 0 34px rgba(255, 122, 61, 0.14);
}

.impact-grid h3,
.impact-grid p {
    grid-column: 2;
}

.impact-grid h3,
.concept-grid h3 {
    margin: 0 0 12px;
    font-size: 1.35rem;
}

.impact-grid p,
.concept-grid p {
    margin: 0;
    color: var(--muted);
    line-height: 1.78;
}

.journey-copy h2 {
    margin: 0;
    font-size: clamp(2.2rem, 5vw, 4.4rem);
    line-height: 1.05;
}

.step-list {
    display: grid;
    gap: 1px;
    margin-top: 30px;
    border: 1px solid var(--line);
    border-radius: 8px;
    overflow: hidden;
    background: var(--line);
}

.step-list div {
    display: grid;
    grid-template-columns: 112px 1fr;
    gap: 18px;
    padding: 18px;
    background: #0c1220;
}

.step-list strong {
    color: var(--text);
}

.step-list span {
    color: var(--muted);
    line-height: 1.68;
}

.vehicle-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 18px;
}

.vehicle-card {
    min-height: 610px;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: var(--surface);
    box-shadow: var(--shadow);
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 0.5s ease, transform 0.5s ease, border-color 0.2s ease;
}

.vehicle-card.is-visible,
.timeline article.is-visible {
    opacity: 1;
    transform: translateY(0);
}

.vehicle-card:hover {
    border-color: rgba(52, 213, 255, 0.42);
    transform: translateY(-4px);
}

.vehicle-card img {
    width: 100%;
    aspect-ratio: 1.38;
    object-fit: cover;
    object-position: center;
    background: #0d1422;
    filter: saturate(1.08) contrast(1.03);
}

.vehicle-body {
    flex: 1;
    display: flex;
    flex-direction: column;
    padding: 22px;
}

.vehicle-type {
    margin: 0 0 10px;
    color: var(--green);
    font-size: 0.72rem;
    font-weight: 900;
    text-transform: uppercase;
}

.vehicle-body h3 {
    margin: 0 0 12px;
    font-size: 1.45rem;
}

.vehicle-body p:not(.vehicle-type) {
    margin: 0 0 18px;
    color: var(--muted);
    line-height: 1.72;
}

.vehicle-body dl {
    margin: auto 0 18px;
}

.vehicle-body dl div {
    display: flex;
    justify-content: space-between;
    gap: 18px;
    padding: 10px 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.09);
}

.vehicle-body dt {
    color: var(--muted);
    font-weight: 800;
}

.vehicle-body dd {
    margin: 0;
    color: var(--cyan);
    font-weight: 900;
    text-align: right;
}

.vehicle-body button {
    width: 100%;
    border: 1px solid rgba(52, 213, 255, 0.44);
    background: rgba(52, 213, 255, 0.12);
    color: var(--text);
}

.system-layout {
    display: grid;
    grid-template-columns: minmax(0, 0.92fr) minmax(360px, 1.08fr);
    gap: 48px;
    align-items: center;
}

.system-points {
    display: grid;
    gap: 14px;
    margin-top: 28px;
}

.system-points div {
    display: grid;
    grid-template-columns: 88px 1fr;
    gap: 18px;
    padding: 18px 0;
    border-top: 1px solid var(--line);
}

.system-points strong {
    color: var(--text);
    font-size: 1.1rem;
}

.system-points span {
    color: var(--muted);
    line-height: 1.72;
}

.system-visual {
    width: 100%;
    border-radius: 8px;
    border: 1px solid var(--line);
    box-shadow: var(--shadow);
}

.timeline {
    display: grid;
    grid-template-columns: repeat(5, minmax(0, 1fr));
    gap: 1px;
    border: 1px solid var(--line);
    border-radius: 8px;
    overflow: hidden;
    background: var(--line);
}

.timeline article {
    min-height: 260px;
    padding: 24px;
    background: #0c1220;
    opacity: 0;
    transform: translateY(24px);
    transition: opacity 0.5s ease, transform 0.5s ease;
}

.timeline span {
    display: inline-block;
    margin-bottom: 52px;
    color: var(--orange);
    font-weight: 900;
    font-size: 1.5rem;
}

.timeline h3 {
    margin: 0 0 12px;
}

.timeline p {
    margin: 0;
    color: var(--muted);
    line-height: 1.7;
}

.mission-layout {
    display: grid;
    grid-template-columns: minmax(0, 0.86fr) minmax(320px, 1fr);
    gap: 48px;
    align-items: end;
    min-height: 420px;
}

.mission-layout > p {
    margin: 0;
    font-size: 1.12rem;
}

.detail-dialog {
    width: min(860px, calc(100% - 32px));
    max-height: min(820px, calc(100vh - 32px));
    padding: 0;
    border: 1px solid rgba(52, 213, 255, 0.32);
    border-radius: 8px;
    background: #101827;
    color: var(--text);
    box-shadow: var(--shadow);
}

.detail-dialog::backdrop {
    background: rgba(0, 0, 0, 0.76);
    backdrop-filter: blur(10px);
}

.dialog-close {
    position: absolute;
    top: 14px;
    right: 14px;
    width: 42px;
    height: 42px;
    border: 1px solid rgba(255, 255, 255, 0.22);
    border-radius: 8px;
    background: rgba(5, 7, 17, 0.56);
    color: var(--text);
    cursor: pointer;
    font-size: 1.7rem;
}

.detail-header {
    padding: 32px 76px 26px 30px;
    background: linear-gradient(135deg, rgba(52, 213, 255, 0.22), rgba(255, 122, 61, 0.18));
}

.detail-header p {
    margin: 0 0 8px;
    color: var(--green);
    font-size: 0.78rem;
    font-weight: 900;
    text-transform: uppercase;
}

.detail-header h2 {
    margin: 0;
    font-size: clamp(1.9rem, 4vw, 3rem);
}

.detail-body {
    padding: 30px;
}

.detail-body > p {
    margin: 0 0 26px;
    color: var(--muted);
    line-height: 1.82;
}

.detail-columns {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 22px;
}

.detail-columns h3 {
    margin: 0 0 12px;
}

.detail-columns ul {
    margin: 0;
    padding: 0;
    list-style: none;
}

.detail-columns li {
    padding: 12px 0;
    border-top: 1px solid rgba(255, 255, 255, 0.09);
    color: var(--muted);
}

.footer {
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    background: #050711;
}

.footer-inner {
    min-height: 78px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    color: var(--muted);
    font-size: 0.92rem;
}

@media (max-width: 1080px) {
    .vehicle-grid,
    .concept-grid,
    .timeline {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .system-layout,
    .mission-layout,
    .split-layout,
    .journey-layout {
        grid-template-columns: 1fr;
    }

    .why-copy {
        min-height: auto;
        padding: 0;
    }

    .why-stats {
        margin-top: 28px;
    }

    .impact-grid article,
    .impact-grid article:nth-child(2),
    .impact-grid article:nth-child(3) {
        margin-left: 0;
    }
}

@media (max-width: 720px) {
    .nav-toggle {
        display: block;
    }

    .nav-links {
        position: absolute;
        top: 72px;
        left: 0;
        right: 0;
        display: none;
        flex-direction: column;
        align-items: stretch;
        gap: 0;
        padding: 10px 20px 18px;
        background: rgba(5, 7, 17, 0.98);
        border-bottom: 1px solid var(--line);
    }

    .nav-links.is-open {
        display: flex;
    }

    .nav-links a {
        display: block;
        padding: 14px 0;
    }

    .hero {
        min-height: 86vh;
        padding-top: 118px;
    }

    .hero-overlay {
        background:
            linear-gradient(180deg, rgba(5, 7, 17, 0.72) 0%, rgba(5, 7, 17, 0.9) 72%, var(--bg) 100%),
            linear-gradient(90deg, rgba(5, 7, 17, 0.55), rgba(5, 7, 17, 0.3));
    }

    .vehicles-section::before {
        background:
            linear-gradient(180deg, rgba(5, 7, 17, 0.86) 0%, rgba(11, 17, 32, 0.78) 46%, rgba(11, 17, 32, 0.94) 100%),
            url("../assets/starship-real.jpg") 58% top / auto 520px no-repeat;
        opacity: 0.26;
    }

    .hero-actions {
        flex-direction: column;
    }

    .hero-metrics {
        grid-template-columns: 1fr;
    }

    .why-stats {
        grid-template-columns: 1fr;
    }

    .primary-action,
    .secondary-action {
        width: 100%;
    }

    .section {
        padding: 66px 0;
    }

    .vehicle-grid,
    .concept-grid,
    .timeline,
    .detail-columns {
        grid-template-columns: 1fr;
    }

    .vehicle-card {
        min-height: auto;
    }

    .timeline article {
        min-height: auto;
    }

    .timeline span {
        margin-bottom: 28px;
    }

    .system-points div {
        grid-template-columns: 1fr;
        gap: 8px;
    }

    .step-list div {
        grid-template-columns: 1fr;
        gap: 8px;
    }

    .impact-grid::before {
        display: none;
    }

    .impact-grid article {
        grid-template-columns: 1fr;
        align-items: start;
    }

    .impact-grid h3,
    .impact-grid p {
        grid-column: auto;
    }

    .impact-grid span {
        margin-bottom: 24px;
    }

    .footer-inner {
        flex-direction: column;
        align-items: flex-start;
        justify-content: center;
    }
}

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        scroll-behavior: auto !important;
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}