/* Design Tokens */
:root {
    /* Colors - Endfield Palette */
    --color-bg-primary: #101110;
    --color-bg-secondary: #181a18;
    --color-bg-tertiary: #1e201d;
    --color-text-primary: #f5f5f0;
    --color-text-secondary: #898d89;
    --color-text-muted: #5a5d59;
    --color-accent: #fff500;
    --color-accent-deep: #e8e000;
    --color-accent-subtle: rgba(255, 245, 0, 0.08);
    --color-border: #343633;
    --color-border-strong: #4a4d49;
    --color-signal-pink: #DF52AC;
    --color-signal-blue: #5A7EFD;
    --color-signal-red: #FA294B;
    --color-signal-green: #7ADDB5;
    --color-signal-orange: #FF8C42;
    --color-signal-cyan: #00E5FF;
    --color-signal-purple: #B287F8;
    --color-signal-steel: #8E959E;

    /* Geometry */
    --radius-none: 0px;
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;

    /* Typography */
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", "PingFang SC", sans-serif;
    --font-mono: "Cascadia Code", "SF Mono", Consolas, monospace;

    /* Layout */
    --nav-height: 56px;
    --grid-size: 72px;

    /* Transitions */
    --ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);
    --ease-in-out-cubic: cubic-bezier(0.76, 0, 0.24, 1);
}

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

html {
    scroll-behavior: smooth;
    font-variant-numeric: tabular-nums;
}

body {
    font-family: var(--font-sans);
    background: var(--color-bg-primary);
    color: var(--color-text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    position: relative;
}

body::before {
    content: '';
    position: fixed;
    inset: 0;
    background-image:
        repeating-linear-gradient(0deg, transparent, transparent calc(var(--grid-size) - 1px), var(--color-border) calc(var(--grid-size) - 1px), var(--color-border) var(--grid-size)),
        repeating-linear-gradient(90deg, transparent, transparent calc(var(--grid-size) - 1px), var(--color-border) calc(var(--grid-size) - 1px), var(--color-border) var(--grid-size));
    opacity: 0.03;
    pointer-events: none;
    z-index: 1;
}

body.is-loading {
    overflow: hidden;
}

::selection {
    background: var(--color-accent);
    color: var(--color-bg-primary);
}

::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: transparent;
}

::-webkit-scrollbar-thumb {
    background: var(--color-border);
    border-radius: 0;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--color-accent);
}

a {
    color: inherit;
    text-decoration: none;
    transition: color 200ms;
}

a:hover {
    color: var(--color-accent);
}

/* Links within content */
.about__bio a,
.section__intro a,
.card__desc a,
.thanks-item__desc a,
.sponsor-note a {
    color: var(--color-accent);
}

.about__bio a:hover,
.section__intro a:hover,
.card__desc a:hover,
.thanks-item__desc a:hover,
.sponsor-note a:hover {
    color: var(--color-accent-deep);
}

/* Loading Screen */
.loader {
    position: fixed;
    inset: 0;
    z-index: 9999;
    background: var(--color-bg-primary);
    display: flex;
}

.loader__bar {
    position: absolute;
    left: 0;
    top: 0;
    width: 8px;
    height: 100%;
    background: var(--color-accent);
    transform: scaleY(0);
    transform-origin: top;
    transition: transform 1900ms linear;
}

.loader__overlay {
    position: absolute;
    inset: 0;
    background: var(--color-bg-primary);
    border-left: 3px solid var(--color-accent);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 780ms var(--ease-in-out-cubic);
}

.loader__hud {
    width: 100%;
    height: 100%;
    position: relative;
    padding: var(--spacing-xl);
}

.loader__brand {
    position: absolute;
    top: var(--spacing-xl);
    left: var(--spacing-xl);
    font-family: var(--font-mono);
    font-size: 0.875rem;
    letter-spacing: 0.1em;
    color: var(--color-text-secondary);
}

.loader__rec {
    position: absolute;
    top: var(--spacing-xl);
    right: var(--spacing-xl);
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--color-signal-red);
    animation: blink 1.5s infinite;
}

@keyframes blink {
    0%, 50% { opacity: 1; }
    51%, 100% { opacity: 0.3; }
}

.loader__stats {
    position: absolute;
    bottom: calc(var(--spacing-xl) + 4px);
    left: var(--spacing-xl);
}

.loader__percent {
    font-family: var(--font-mono);
    font-size: 4rem;
    font-weight: 700;
    line-height: 1;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-xs);
}

.loader__status {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--color-text-secondary);
    letter-spacing: 0.05em;
    margin-bottom: 0.25rem;
}

.loader__version {
    font-family: var(--font-mono);
    font-size: 0.625rem;
    color: var(--color-text-muted);
}

.loader__progress {
    position: absolute;
    bottom: var(--spacing-xl);
    left: var(--spacing-xl);
    right: var(--spacing-xl);
    height: 2px;
    background: var(--color-border);
}

.loader__progress::after {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    height: 100%;
    width: 0%;
    background: var(--color-accent);
    transition: width 1900ms linear;
}

/* Main Content */
.main-content {
    opacity: 0;
    position: relative;
    z-index: 2;
}

/* Navigation */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    background: rgba(16, 17, 16, 0.78);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--color-border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 var(--spacing-xl);
    z-index: 100;
    opacity: 0;
    transform: translateY(-100%);
    transition: opacity 600ms var(--ease-out-expo), transform 600ms var(--ease-out-expo);
}

.nav__brand {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    letter-spacing: 0.1em;
    font-weight: 600;
}

.nav__links {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
}

.nav__link {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    letter-spacing: 0.05em;
    color: var(--color-text-secondary);
    transition: color 200ms;
    position: relative;
}

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

.nav__link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--color-accent);
    transform: scaleX(0);
    transition: transform 200ms;
}

.nav__link:hover::after {
    transform: scaleX(1);
}

.nav__lang-toggle {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    background: none;
    border: 1px solid var(--color-border);
    color: var(--color-text-secondary);
    padding: 0.25rem 0.75rem;
    cursor: pointer;
    transition: border-color 200ms;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav__lang-toggle:hover {
    border-color: var(--color-accent);
}

.nav__lang-option {
    transition: color 200ms;
}

.nav__lang-option--active {
    color: var(--color-accent);
}

.nav__lang-divider {
    color: var(--color-border);
}

/* Side Navigation */
.side-nav {
    position: fixed;
    right: var(--spacing-lg);
    top: 50%;
    transform: translateY(-50%);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    z-index: 99;
    opacity: 0;
    transition: opacity 600ms var(--ease-out-expo) 300ms;
}

.side-nav__item {
    width: 20px;
    height: 2px;
    background: var(--color-border);
    transition: all 200ms;
}

.side-nav__item--active,
.side-nav__item:hover {
    width: 32px;
    background: var(--color-accent);
}

/* HUD Elements */
.hud {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 98;
    opacity: 0;
    transition: opacity 600ms var(--ease-out-expo) 400ms;
}

.hud__coords {
    position: absolute;
    bottom: var(--spacing-xl);
    left: var(--spacing-xl);
    font-family: var(--font-mono);
    font-size: 0.625rem;
    color: var(--color-text-muted);
}

.hud__label {
    margin-bottom: 0.125rem;
}

.hud__value {
    color: var(--color-accent);
}

.hud__scroll-hint {
    position: absolute;
    bottom: var(--spacing-2xl);
    left: 50%;
    transform: translateX(-50%);
    width: 1px;
    height: 60px;
}

.hud__scroll-line {
    position: absolute;
    top: 0;
    left: 0;
    width: 1px;
    height: 100%;
    background: var(--color-border);
}

.hud__scroll-dot {
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 4px;
    height: 4px;
    background: var(--color-accent);
    border-radius: 50%;
    animation: scrollHint 2s ease-in-out infinite;
}

@keyframes scrollHint {
    0%, 100% { transform: translate(-50%, 0); opacity: 1; }
    80% { transform: translate(-50%, 56px); opacity: 0; }
}

.hud__corner {
    position: absolute;
    width: 20px;
    height: 20px;
}

.hud__corner::before,
.hud__corner::after {
    content: '';
    position: absolute;
    background: var(--color-accent);
}

.hud__corner--tl {
    top: calc(var(--nav-height) + var(--spacing-md));
    left: var(--spacing-xl);
}

.hud__corner--tl::before {
    top: 0;
    left: 0;
    width: 2px;
    height: 100%;
}

.hud__corner--tl::after {
    top: 0;
    left: 0;
    width: 100%;
    height: 2px;
}

.hud__corner--tr {
    top: calc(var(--nav-height) + var(--spacing-md));
    right: var(--spacing-xl);
}

.hud__corner--tr::before {
    top: 0;
    right: 0;
    width: 2px;
    height: 100%;
}

.hud__corner--tr::after {
    top: 0;
    right: 0;
    width: 100%;
    height: 2px;
}

.hud__corner--bl {
    bottom: var(--spacing-xl);
    left: var(--spacing-xl);
}

.hud__corner--bl::before {
    bottom: 0;
    left: 0;
    width: 2px;
    height: 100%;
}

.hud__corner--bl::after {
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
}

.hud__corner--br {
    bottom: var(--spacing-xl);
    right: var(--spacing-xl);
}

.hud__corner--br::before {
    bottom: 0;
    right: 0;
    width: 2px;
    height: 100%;
}

.hud__corner--br::after {
    bottom: 0;
    right: 0;
    width: 100%;
    height: 2px;
}

/* Sections */
.section {
    min-height: 100vh;
    padding: calc(var(--nav-height) + var(--spacing-2xl)) var(--spacing-xl) var(--spacing-2xl);
    position: relative;
    display: flex;
    flex-direction: column;
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 600ms var(--ease-out-expo), transform 600ms var(--ease-out-expo);
}

.section--hero {
    justify-content: center;
}

.section__number {
    font-family: var(--font-mono);
    font-size: clamp(4rem, 8vw, 6rem);
    font-weight: 900;
    color: transparent;
    -webkit-text-stroke: 1px var(--color-border);
    text-stroke: 1px var(--color-border);
    line-height: 1;
    margin-bottom: var(--spacing-sm);
}

.section__label {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--color-text-muted);
    letter-spacing: 0.1em;
    margin-bottom: var(--spacing-xs);
}

.section__underline {
    width: 72px;
    height: 3px;
    background: var(--color-accent);
    margin-bottom: var(--spacing-xl);
}

.section__content {
    max-width: 1200px;
    width: 100%;
}

.section__intro {
    font-size: 1.125rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xl);
    max-width: 600px;
}

/* Hero Section */
.hero__title {
    font-size: clamp(3rem, 9vw, 6.5rem);
    font-weight: 900;
    line-height: 1.1;
    margin-bottom: var(--spacing-md);
    letter-spacing: -0.02em;
}

.hero__subtitle {
    font-size: clamp(1.25rem, 3vw, 2rem);
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xl);
    font-weight: 300;
}

.about__bio {
    max-width: 700px;
    margin-bottom: var(--spacing-xl);
}

.about__bio p {
    font-size: 1.125rem;
    line-height: 1.8;
    margin-bottom: var(--spacing-md);
    color: var(--color-text-secondary);
}

/* Specs */
.specs {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    max-width: 600px;
}

.specs__item {
    display: flex;
    align-items: center;
    padding: var(--spacing-sm) 0;
    border-bottom: 1px dashed var(--color-border);
}

.specs__label {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--color-text-muted);
    min-width: 120px;
    letter-spacing: 0.05em;
}

.specs__value {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--color-text-primary);
}

.specs__value--active {
    color: var(--color-accent);
}

/* Card Grid */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.card {
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    padding: var(--spacing-lg);
    position: relative;
    transition: border-color 300ms, transform 300ms;
}

.card:hover {
    border-color: var(--color-accent);
    transform: translate(2px, -2px);
}

.card__corner {
    position: absolute;
    width: 16px;
    height: 16px;
    transition: all 300ms;
}

.card__corner::before,
.card__corner::after {
    content: '';
    position: absolute;
    background: var(--color-accent);
}

.card__corner--tl {
    top: -1px;
    left: -1px;
}

.card__corner--tl::before {
    top: 0;
    left: 0;
    width: 2px;
    height: 100%;
}

.card__corner--tl::after {
    top: 0;
    left: 0;
    width: 100%;
    height: 2px;
}

.card__corner--br {
    bottom: -1px;
    right: -1px;
}

.card__corner--br::before {
    bottom: 0;
    right: 0;
    width: 2px;
    height: 100%;
}

.card__corner--br::after {
    bottom: 0;
    right: 0;
    width: 100%;
    height: 2px;
}

.card__index {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--color-accent);
    margin-bottom: var(--spacing-xs);
}

.card__date {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-sm);
}

.card__title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    line-height: 1.3;
}

.card__desc {
    font-size: 0.9375rem;
    line-height: 1.6;
    color: var(--color-text-secondary);
}

/* Thanks Grid */
.thanks-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-xl);
}

.thanks-item {
    text-align: center;
}

.thanks-item__icon {
    width: 64px;
    height: 64px;
    margin: 0 auto var(--spacing-md);
    padding: var(--spacing-md);
    border: 2px solid var(--color-border);
    color: var(--color-accent);
    transition: all 300ms;
}

.thanks-item:hover .thanks-item__icon {
    border-color: var(--color-accent);
    transform: translateY(-4px);
}

.thanks-item__title {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: var(--spacing-xs);
}

.thanks-item__desc {
    font-size: 0.9375rem;
    color: var(--color-text-secondary);
}

/* Sponsor QR Code */
.sponsor-qr {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin-top: var(--spacing-lg);
    gap: var(--spacing-sm);
}

.sponsor-qr__frame {
    position: relative;
    padding: var(--spacing-md);
    background: var(--color-bg-primary);
    border: 1px solid var(--color-border);
}

.sponsor-qr__frame::before {
    content: '';
    position: absolute;
    inset: 0;
    background: var(--color-accent-subtle);
}

.sponsor-qr__corner {
    position: absolute;
    width: 20px;
    height: 20px;
}

.sponsor-qr__corner::before,
.sponsor-qr__corner::after {
    content: '';
    position: absolute;
    background: var(--color-accent);
}

.sponsor-qr__corner--tl { top: -1px; left: -1px; }
.sponsor-qr__corner--tl::before { top: 0; left: 0; width: 2px; height: 100%; }
.sponsor-qr__corner--tl::after  { top: 0; left: 0; width: 100%; height: 2px; }

.sponsor-qr__corner--tr { top: -1px; right: -1px; }
.sponsor-qr__corner--tr::before { top: 0; right: 0; width: 2px; height: 100%; }
.sponsor-qr__corner--tr::after  { top: 0; right: 0; width: 100%; height: 2px; }

.sponsor-qr__corner--bl { bottom: -1px; left: -1px; }
.sponsor-qr__corner--bl::before { bottom: 0; left: 0; width: 2px; height: 100%; }
.sponsor-qr__corner--bl::after  { bottom: 0; left: 0; width: 100%; height: 2px; }

.sponsor-qr__corner--br { bottom: -1px; right: -1px; }
.sponsor-qr__corner--br::before { bottom: 0; right: 0; width: 2px; height: 100%; }
.sponsor-qr__corner--br::after  { bottom: 0; right: 0; width: 100%; height: 2px; }

.sponsor-qr__img {
    display: block;
    width: 200px;
    height: 200px;
    object-fit: contain;
    position: relative;
    /* 黑色模块 → 黄色，白色背景 → 透明 */
    filter: invert(1) sepia(1) saturate(10) hue-rotate(1deg) brightness(1.1);
    mix-blend-mode: screen;
}

.sponsor-qr__label {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    letter-spacing: 0.1em;
    color: var(--color-text-muted);
}
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.sponsor-card {
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-top: 3px solid var(--color-accent);
    padding: var(--spacing-xl);
}

.sponsor-card__header {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.sponsor-card__icon {
    width: 32px;
    height: 32px;
    color: var(--color-accent);
}

.sponsor-card__title {
    font-size: 1.25rem;
    font-weight: 700;
}

.sponsor-card__desc {
    font-size: 0.9375rem;
    line-height: 1.6;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-lg);
}

.sponsor-note {
    padding: var(--spacing-lg);
    background: var(--color-accent-subtle);
    border-left: 3px solid var(--color-accent);
}

.sponsor-note p {
    font-size: 0.9375rem;
    line-height: 1.6;
    color: var(--color-text-secondary);
}

/* Button */
.btn {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    padding: 0.75rem 1.5rem;
    background: none;
    border: 1px solid var(--color-border);
    color: var(--color-text-primary);
    cursor: pointer;
    transition: all 200ms;
    letter-spacing: 0.05em;
}

.btn:hover {
    border-color: var(--color-accent);
    color: var(--color-accent);
}

.btn--clip {
    background: var(--color-accent);
    border-color: var(--color-accent);
    color: var(--color-bg-primary);
    clip-path: polygon(0 0, calc(100% - 14px) 0, 100% 14px, 100% 100%, 0 100%);
}

.btn--clip:hover {
    background: var(--color-accent-deep);
    border-color: var(--color-accent-deep);
}

/* Contact Grid */
.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
}

.contact-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: var(--spacing-xl);
    border: 1px solid var(--color-border);
    transition: all 300ms;
    text-align: center;
}

.contact-item:hover {
    border-color: var(--color-accent);
    transform: translateY(-4px);
}

.contact-item__icon {
    width: 48px;
    height: 48px;
    margin-bottom: var(--spacing-md);
    color: var(--color-accent);
}

.contact-item__label {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-xs);
    letter-spacing: 0.1em;
}

.contact-item__value {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--color-text-primary);
}

/* Footer */
.footer {
    padding: var(--spacing-xl) var(--spacing-xl) var(--spacing-lg);
    position: relative;
}

.footer__stripe {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 8px;
    background: repeating-linear-gradient(
        -45deg,
        var(--color-accent) 0,
        var(--color-accent) 12px,
        var(--color-bg-primary) 12px,
        var(--color-bg-primary) 24px
    );
}

.footer__content {
    text-align: center;
    padding-top: var(--spacing-lg);
}

.footer__text {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: var(--color-text-muted);
}

.footer__divider {
    margin: 0 var(--spacing-sm);
}

/* Responsive */
@media (max-width: 768px) {
    :root {
        --spacing-xl: 2rem;
        --spacing-2xl: 3rem;
    }

    .nav {
        padding: 0 var(--spacing-md);
    }

    .nav__links {
        gap: var(--spacing-sm);
    }

    .nav__link {
        font-size: 0.625rem;
    }

    .side-nav {
        display: none;
    }

    .section {
        padding: calc(var(--nav-height) + var(--spacing-xl)) var(--spacing-md) var(--spacing-xl);
    }

    .card-grid {
        grid-template-columns: 1fr;
    }

    .thanks-grid {
        grid-template-columns: 1fr;
    }

    .sponsor-options {
        grid-template-columns: 1fr;
    }

    .contact-grid {
        grid-template-columns: 1fr;
    }

    .hud__coords,
    .hud__corner {
        display: none;
    }
}

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