/* ============================================================
   ACID BEAST - Furface Landing Page
   FurryFans Design System
   ============================================================ */

:root {
    /* Acid Beast Palette */
    --acid: #BEFA00;
    --acid-dim: #9ed100;
    --acid-glow: rgba(190, 250, 0, 0.5);
    --acid-muted: rgba(190, 250, 0, 0.12);

    --hot: #FF2E63;
    --hot-glow: rgba(255, 46, 99, 0.4);

    --void: #0a0a0f;
    --void-light: #12121a;
    --surface: #1a1a25;
    --surface-light: #242433;

    --text: #f0f0f5;
    --text-dim: #8888a0;
    --text-muted: #5a5a70;

    --success: #10b981;
    --error: #FF2E63;

    /* Typography */
    --font-display: 'Archivo Black', Impact, sans-serif;
    --font-body: 'DM Sans', system-ui, sans-serif;
    --font-mono: 'JetBrains Mono', monospace;

    /* Animation */
    --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
    --ease-smooth: cubic-bezier(0.4, 0, 0.2, 1);
}

*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    scroll-behavior: smooth;
    overflow-x: hidden;
}

body {
    font-family: var(--font-body);
    background: var(--void);
    color: var(--text);
    min-height: 100vh;
    overflow-x: hidden;
    line-height: 1.6;
    width: 100%;
    max-width: 100vw;
}

::selection {
    background: var(--acid);
    color: var(--void);
}

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

/* ============================================================
   Background Effects
   ============================================================ */

.bg {
    position: fixed;
    inset: 0;
    z-index: 0;
    overflow: hidden;
    pointer-events: none;
}

.bg-grid {
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(rgba(190, 250, 0, 0.03) 1px, transparent 1px),
        linear-gradient(90deg, rgba(190, 250, 0, 0.03) 1px, transparent 1px);
    background-size: 60px 60px;
}

.bg-glow {
    position: absolute;
    border-radius: 50%;
    filter: blur(150px);
    opacity: 0.25;
}

.bg-glow--1 {
    width: 600px;
    height: 600px;
    background: var(--acid);
    top: -200px;
    right: -100px;
}

.bg-glow--2 {
    width: 500px;
    height: 500px;
    background: var(--hot);
    bottom: 20%;
    left: -150px;
}

.bg-glow--3 {
    width: 400px;
    height: 400px;
    background: var(--acid);
    bottom: -100px;
    right: 20%;
    opacity: 0.15;
}

/* ============================================================
   Navigation
   ============================================================ */

.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(10, 10, 15, 0.85);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
    transition: all 0.3s var(--ease-smooth);
}

.nav.scrolled {
    background: rgba(10, 10, 15, 0.95);
}

.nav.menu-open {
    background: #0A0A0F;
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 16px 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 40px;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.nav-link-back {
    font-size: 14px;
    font-weight: 500;
    color: var(--text-dim);
    transition: all 0.2s ease;
    white-space: nowrap;
    padding: 6px 12px;
    border: 1px solid rgba(255, 255, 255, 0.15);
}

.nav-link-back:hover {
    color: var(--acid);
    border-color: var(--acid);
}

.nav-logo-text {
    font-family: var(--font-display);
    font-size: 20px;
    letter-spacing: 0.02em;
    color: var(--acid);
    text-shadow: 0 0 20px var(--acid-glow);
}

.nav-logo-badge {
    padding: 4px 10px;
    background: var(--acid-muted);
    border: 1px solid var(--acid);
    color: var(--acid);
    font-size: 9px;
    font-weight: 700;
    letter-spacing: 0.15em;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 32px;
    flex: 1;
    justify-content: flex-start;
}

.nav-link {
    font-size: 14px;
    font-weight: 500;
    color: var(--text-dim);
    transition: color 0.2s ease;
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--acid);
    transition: width 0.3s var(--ease-out);
}

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

.nav-link:hover::after {
    width: 100%;
}

.nav-link--active {
    color: var(--acid);
}

.nav-link--active::after {
    width: 100%;
}

.nav-mobile-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.nav-mobile-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text);
    transition: all 0.3s ease;
}

.nav-mobile-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(6px, 4px);
}

.nav-mobile-toggle.active span:nth-child(2) {
    opacity: 0;
}

.nav-mobile-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(6px, -4px);
}

/* Nav Actions (Login/Register) */
.nav-actions {
    display: flex;
    align-items: center;
    gap: 12px;
}

.nav-mobile-actions {
    display: none;
}

/* 移动端头部用户头像 */
.nav-mobile-user-header {
    display: none;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: 0;
    overflow: hidden;
    border: 2px solid var(--acid);
    cursor: pointer;
    transition: all 0.2s ease;
}

.nav-mobile-user-header:hover {
    border-color: var(--text);
    box-shadow: 0 0 20px var(--acid-glow);
}

.nav-mobile-user-header img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.btn-nav-outline {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 20px;
    font-family: var(--font-body);
    font-size: 16px;
    font-weight: 700;
    background: transparent;
    color: var(--text);
    border: none;
    cursor: pointer;
    transition: all 0.3s var(--ease-out);
    clip-path: polygon(
        0 0,
        calc(100% - 8px) 0,
        100% 8px,
        100% 100%,
        8px 100%,
        0 calc(100% - 8px)
    );
}

.btn-nav-outline:hover {
    color: var(--acid);
    background: rgba(190, 250, 0, 0.1);
}

.btn-nav-primary {
    padding: 10px 20px;
    font-size: 13px;
}

/* ============================================================
   Mobile Menu
   ============================================================ */

.mobile-menu {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--void);
    z-index: 999;
    display: none;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.mobile-menu.show {
    display: flex;
    opacity: 1;
}

.mobile-menu-content {
    width: 100%;
    padding: 100px 24px 40px;
    display: flex;
    flex-direction: column;
    gap: 24px;
    align-items: center;
}

.mobile-link {
    font-family: var(--font-display);
    font-size: 24px;
    color: var(--text);
    transition: color 0.2s ease;
}

.mobile-link:hover {
    color: var(--acid);
}

/* ============================================================
   Buttons
   ============================================================ */

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 24px;
    background: var(--acid);
    color: var(--void);
    border: none;
    font-family: var(--font-body);
    font-size: 14px;
    font-weight: 700;
    letter-spacing: 0.03em;
    cursor: pointer;
    transition: all 0.3s var(--ease-out);
    clip-path: polygon(
        0 0,
        calc(100% - 10px) 0,
        100% 10px,
        100% 100%,
        10px 100%,
        0 calc(100% - 10px)
    );
}

.btn:hover {
    background: var(--acid-dim);
    box-shadow: 0 0 32px var(--acid-glow);
}

.btn:active {
}

.btn-nav {
    padding: 10px 20px;
    font-size: 13px;
}

.btn-hero {
    padding: 16px 32px;
    font-size: 15px;
}

.btn-hero-secondary {
    background: transparent;
    color: var(--text);
    border: 1px solid rgba(255, 255, 255, 0.2);
    clip-path: none;
    padding: 16px 32px;
}

.btn-hero-secondary:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: var(--acid);
    color: var(--acid);
    box-shadow: none;
}

.btn-mobile-cta {
    width: 100%;
    max-width: 300px;
    padding: 16px;
    margin-top: 16px;
}

.btn-cta-submit {
    padding: 18px 40px;
    font-size: 16px;
}

/* ============================================================
   Hero Section
   ============================================================ */

.hero {
    position: relative;
    width: 100%;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 120px 24px 80px;
    z-index: 1;
}

.hero-content {
    text-align: center;
    max-width: 800px;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    background: var(--surface);
    border: 1px solid rgba(255, 255, 255, 0.06);
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 0.05em;
    color: var(--text-dim);
    margin-bottom: 24px;
    animation: fade-in-up 0.6s var(--ease-out) 0.1s both;
}

.hero-badge-dot {
    width: 8px;
    height: 8px;
    background: var(--acid);
    border-radius: 50%;
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

.hero-title {
    font-family: var(--font-display);
    font-size: clamp(64px, 12vw, 120px);
    line-height: 1;
    margin-bottom: 16px;
    background: linear-gradient(135deg, var(--text) 0%, var(--acid) 50%, var(--text) 100%);
    background-size: 200% 200%;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: fade-in-up 0.6s var(--ease-out) 0.2s both, gradient-shift 8s ease infinite;
}

.hero-title::selection {
    background: var(--acid);
    color: var(--void);
    -webkit-text-fill-color: var(--void);
}

@keyframes gradient-shift {
    0%, 100% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
}

.hero-subtitle {
    font-family: var(--font-display);
    font-size: clamp(20px, 4vw, 32px);
    color: var(--acid);
    text-shadow: 0 0 40px var(--acid-glow);
    margin-bottom: 16px;
    animation: fade-in-up 0.6s var(--ease-out) 0.3s both;
}

.hero-desc {
    font-size: 16px;
    color: var(--text-dim);
    line-height: 1.8;
    margin-bottom: 40px;
    animation: fade-in-up 0.6s var(--ease-out) 0.4s both;
}

.hero-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 60px;
    animation: fade-in-up 0.6s var(--ease-out) 0.5s both;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 40px;
    flex-wrap: wrap;
    animation: fade-in-up 0.6s var(--ease-out) 0.6s both;
}

.hero-stat {
    text-align: center;
}

.hero-stat-value {
    font-family: var(--font-display);
    font-size: 28px;
    color: var(--acid);
    text-shadow: 0 0 20px var(--acid-glow);
    display: block;
}

.hero-stat-label {
    font-size: 12px;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.hero-stat-divider {
    width: 1px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
}

.hero-visual {
    position: absolute;
    right: 10%;
    top: 50%;
    transform: translateY(-50%);
    width: 300px;
    height: 300px;
    display: none;
}

.hero-visual-ring {
    position: absolute;
    border: 1px solid rgba(190, 250, 0, 0.2);
    border-radius: 50%;
}

.hero-visual-ring--1 {
    inset: 0;
    animation: rotate 20s linear infinite;
}

.hero-visual-ring--2 {
    inset: 30px;
    animation: rotate 15s linear infinite reverse;
}

.hero-visual-ring--3 {
    inset: 60px;
    animation: rotate 10s linear infinite;
}

@keyframes rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.hero-visual-center {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: var(--acid);
}

@keyframes fade-in-up {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ============================================================
   Section Common Styles
   ============================================================ */

.section {
    position: relative;
    z-index: 1;
    padding: 100px 0;
    width: 100%;
}

.section-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-tag {
    display: inline-block;
    padding: 6px 16px;
    background: var(--acid-muted);
    border: 1px solid var(--acid);
    color: var(--acid);
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.15em;
    margin-bottom: 16px;
}

.section-title {
    font-family: var(--font-display);
    font-size: clamp(32px, 5vw, 48px);
    margin-bottom: 16px;
}

.section-subtitle {
    font-size: 16px;
    color: var(--text-dim);
    max-width: 600px;
    margin: 0 auto;
}

/* ============================================================
   About Section - Architecture
   ============================================================ */

.section-about {
    background: linear-gradient(180deg,
        transparent 0%,
        var(--void-light) 15%,
        var(--void-light) 85%,
        transparent 100%
    );
}

/* About Intro */
.about-intro {
    max-width: 720px;
    margin: -20px auto 80px;
    padding: 40px 48px;
    background: var(--surface);
    border: 1px solid rgba(255, 255, 255, 0.06);
    position: relative;
    clip-path: polygon(
        0 0,
        calc(100% - 16px) 0,
        100% 16px,
        100% 100%,
        16px 100%,
        0 calc(100% - 16px)
    );
}

.about-intro::before {
    content: '';
    position: absolute;
    top: 8px;
    right: 0;
    width: 24px;
    height: 2px;
    background: var(--acid);
    transform: rotate(-45deg);
    transform-origin: right;
}

.about-intro::after {
    content: '"';
    position: absolute;
    top: 20px;
    left: 24px;
    font-family: var(--font-display);
    font-size: 64px;
    color: var(--acid);
    opacity: 0.15;
    line-height: 1;
}

.about-intro p {
    font-size: 15px;
    line-height: 2;
    color: var(--text-dim);
    text-align: justify;
    position: relative;
    z-index: 1;
}

.about-architecture {
    display: flex;
    align-items: stretch;
    gap: 24px;
    margin-bottom: 60px;
}

.arch-card {
    flex: 1;
    background: var(--surface);
    border: 1px solid rgba(255, 255, 255, 0.06);
    padding: 32px;
    position: relative;
    clip-path: polygon(
        0 0,
        calc(100% - 16px) 0,
        100% 16px,
        100% 100%,
        16px 100%,
        0 calc(100% - 16px)
    );
    transition: all 0.3s var(--ease-out);
}

.arch-card::before {
    content: '';
    position: absolute;
    top: 8px;
    right: 0;
    width: 24px;
    height: 2px;
    background: var(--acid);
    transform: rotate(-45deg);
    transform-origin: right;
}

.arch-card:hover {
    border-color: var(--acid);
}

.arch-card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 20px;
}

.arch-card-icon {
    color: var(--acid);
}

.arch-card-stage {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--acid);
    background: var(--acid-muted);
    padding: 4px 12px;
    letter-spacing: 0.1em;
}

.arch-card-title {
    font-family: var(--font-display);
    font-size: 20px;
    margin-bottom: 12px;
}

.arch-card-desc {
    font-size: 14px;
    color: var(--text-dim);
    line-height: 1.6;
    margin-bottom: 20px;
}

.arch-card-features {
    list-style: none;
}

.arch-card-features li {
    font-size: 13px;
    color: var(--text-muted);
    padding: 8px 0;
    border-top: 1px solid rgba(255, 255, 255, 0.06);
    display: flex;
    align-items: center;
    gap: 8px;
}

.arch-card-features li::before {
    content: '';
    width: 6px;
    height: 6px;
    background: var(--acid);
    border-radius: 50%;
}

.arch-connector {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 80px;
    flex-shrink: 0;
    position: relative;
}

.arch-connector-line {
    position: absolute;
    width: 100%;
    height: 2px;
    background: linear-gradient(90deg, var(--acid), var(--acid-dim));
}

.arch-connector-arrow {
    position: relative;
    color: var(--acid);
    background: var(--void-light);
    padding: 8px;
    border-radius: 50%;
    animation: arrow-pulse 2s ease-in-out infinite;
}

@keyframes arrow-pulse {
    0%, 100% { transform: translateX(0); }
    50% { transform: translateX(5px); }
}

/* Metrics Grid */
.about-metrics {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.metric-card {
    background: var(--surface);
    border: 1px solid rgba(255, 255, 255, 0.06);
    padding: 32px 24px;
    text-align: center;
    position: relative;
    transition: all 0.3s var(--ease-out);
}

.metric-card::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: linear-gradient(90deg, transparent, var(--acid), transparent);
    opacity: 0;
    transition: opacity 0.3s ease;
}

.metric-card:hover::before {
    opacity: 1;
}

.metric-value {
    font-family: var(--font-display);
    font-size: 36px;
    color: var(--acid);
    text-shadow: 0 0 30px var(--acid-glow);
    margin-bottom: 8px;
}

.metric-label {
    font-family: var(--font-mono);
    font-size: 12px;
    color: var(--text-muted);
    margin-bottom: 4px;
}

.metric-desc {
    font-size: 14px;
    color: var(--text-dim);
}

/* ============================================================
   Showcase Section
   ============================================================ */

.section-showcase {
    background: var(--void);
    position: relative;
}

.section-showcase::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(190, 250, 0, 0.1), transparent);
}

.section-showcase::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(190, 250, 0, 0.1), transparent);
}

.showcase-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 24px;
}

.showcase-card {
    background: var(--surface);
    border: 1px solid rgba(255, 255, 255, 0.06);
    overflow: hidden;
    cursor: pointer;
    transition: all 0.3s var(--ease-out);
    clip-path: polygon(
        0 0,
        calc(100% - 12px) 0,
        100% 12px,
        100% 100%,
        12px 100%,
        0 calc(100% - 12px)
    );
}

.showcase-card:hover {
    border-color: var(--acid);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.4), 0 0 40px var(--acid-glow);
}

.showcase-card-img-wrapper {
    position: relative;
    width: 100%;
    height: 200px;
    overflow: hidden;
    background: var(--void-light);
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.showcase-card-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.detection-points {
    position: absolute;
    inset: 0;
    pointer-events: none;
}

.detection-point {
    position: absolute;
    width: 6px;
    height: 6px;
    transform: translate(-50%, -50%);
}

.showcase-card-body {
    padding: 20px;
}

.showcase-card-title {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 8px;
}

.showcase-card-meta {
    font-size: 13px;
    color: var(--text-muted);
    margin-bottom: 16px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.showcase-card-meta svg {
    color: var(--acid);
}

.showcase-card-results {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.result-tag {
    padding: 6px 12px;
    border: 1px solid;
    font-size: 12px;
    font-weight: 600;
}

.showcase-empty {
    text-align: center;
    padding: 80px 24px;
    color: var(--text-muted);
}

.showcase-empty-icon {
    margin-bottom: 16px;
    opacity: 0.5;
}

/* ============================================================
   Features Section
   ============================================================ */

.section-features {
    background: linear-gradient(180deg,
        transparent 0%,
        var(--void-light) 15%,
        var(--void-light) 85%,
        transparent 100%
    );
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.feature-card {
    background: var(--surface);
    border: 1px solid rgba(255, 255, 255, 0.06);
    padding: 32px;
    text-align: center;
    position: relative;
    transition: all 0.3s var(--ease-out);
    clip-path: polygon(
        0 0,
        calc(100% - 12px) 0,
        100% 12px,
        100% 100%,
        12px 100%,
        0 calc(100% - 12px)
    );
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 6px;
    right: 0;
    width: 18px;
    height: 2px;
    background: var(--acid);
    transform: rotate(-45deg);
    transform-origin: right;
}

.feature-card:hover {
    border-color: var(--acid);
}

.feature-icon {
    color: var(--acid);
    margin-bottom: 20px;
}

.feature-title {
    font-family: var(--font-display);
    font-size: 18px;
    margin-bottom: 12px;
}

.feature-desc {
    font-size: 14px;
    color: var(--text-dim);
    line-height: 1.6;
}

/* ============================================================
   Use Cases Section
   ============================================================ */

.section-usecases {
    background: var(--void);
    position: relative;
}

.section-usecases::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(190, 250, 0, 0.1), transparent);
}

.usecases-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
}

.usecase-card {
    background: var(--surface);
    border: 1px solid rgba(255, 255, 255, 0.06);
    padding: 40px 32px;
    position: relative;
    overflow: hidden;
    transition: all 0.3s var(--ease-out);
}

.usecase-card:hover {
    border-color: var(--acid);
}

.usecase-number {
    font-family: var(--font-display);
    font-size: 72px;
    color: rgba(190, 250, 0, 0.1);
    position: absolute;
    top: -10px;
    right: 20px;
    line-height: 1;
}

.usecase-content {
    position: relative;
}

.usecase-title {
    font-family: var(--font-display);
    font-size: 20px;
    margin-bottom: 12px;
}

.usecase-desc {
    font-size: 14px;
    color: var(--text-dim);
    line-height: 1.6;
    margin-bottom: 20px;
}

.usecase-features {
    list-style: none;
}

.usecase-features li {
    font-size: 13px;
    color: var(--text-muted);
    padding: 8px 0;
    display: flex;
    align-items: center;
    gap: 8px;
}

.usecase-features li::before {
    content: '';
    width: 4px;
    height: 4px;
    background: var(--acid);
}

.usecases-footer {
    text-align: center;
    margin-top: 48px;
    font-size: 14px;
    color: var(--text-muted);
    letter-spacing: 0.1em;
}

/* ============================================================
   Developer Section
   ============================================================ */

.section-developer {
    background: linear-gradient(180deg,
        transparent 0%,
        var(--void-light) 15%,
        var(--void-light) 85%,
        transparent 100%
    );
}

.developer-content {
    max-width: 800px;
    margin: 0 auto;
    background: var(--surface);
    border: 1px solid rgba(255, 255, 255, 0.06);
    padding: 48px 48px 24px 48px;
    position: relative;
    clip-path: polygon(
        0 0,
        calc(100% - 20px) 0,
        100% 20px,
        100% 100%,
        20px 100%,
        0 calc(100% - 20px)
    );
}

.developer-content::before {
    content: '';
    position: absolute;
    top: 10px;
    right: 0;
    width: 32px;
    height: 2px;
    background: var(--acid);
    transform: rotate(-45deg);
    transform-origin: right;
}

.developer-info p {
    font-size: 15px;
    line-height: 1.8;
    color: var(--text-dim);
    margin-bottom: 32px;
    text-align: center;
}

.developer-features {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    margin-bottom: 24px;
}

.developer-features li {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 16px 20px;
    background: var(--void-light);
    border: 1px solid rgba(255, 255, 255, 0.06);
    font-size: 14px;
    color: var(--text);
    transition: all 0.3s var(--ease-out);
}

.developer-features li:hover {
    border-color: var(--acid);
}

.developer-feature-icon {
    color: var(--acid);
    display: flex;
    align-items: center;
    justify-content: center;
}

.developer-cta {
    text-align: center;
    padding-top: 24px;
    border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.developer-cta-badge {
    display: inline-block;
    padding: 8px 20px;
    background: rgba(90, 90, 112, 0.12);
    border: 1px solid var(--text-muted);
    color: var(--text-muted);
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 0.1em;
    margin-bottom: 12px;
    clip-path: polygon(
        0 0,
        calc(100% - 8px) 0,
        100% 8px,
        100% 100%,
        8px 100%,
        0 calc(100% - 8px)
    );
}

.developer-cta p {
    font-size: 14px;
    color: var(--text-muted);
}

/* ============================================================
   Thanks Section
   ============================================================ */

.section-thanks {
    background: var(--void);
    position: relative;
}

.section-thanks::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(190, 250, 0, 0.1), transparent);
}

.thanks-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.thanks-card {
    background: var(--surface);
    border: 1px solid rgba(255, 255, 255, 0.06);
    padding: 40px 32px;
    text-align: center;
    position: relative;
    transition: all 0.3s var(--ease-out);
    clip-path: polygon(
        0 0,
        calc(100% - 12px) 0,
        100% 12px,
        100% 100%,
        12px 100%,
        0 calc(100% - 12px)
    );
}

.thanks-card::before {
    content: '';
    position: absolute;
    top: 6px;
    right: 0;
    width: 18px;
    height: 2px;
    background: var(--acid);
    transform: rotate(-45deg);
    transform-origin: right;
}

.thanks-card:hover {
    border-color: var(--acid);
}

.thanks-card-icon {
    color: var(--acid);
    margin-bottom: 20px;
}

.thanks-card-title {
    font-family: var(--font-display);
    font-size: 18px;
    margin-bottom: 12px;
}

.thanks-card-desc {
    font-size: 14px;
    color: var(--text-dim);
    line-height: 1.6;
}

.thanks-footer {
    text-align: center;
    margin-top: 48px;
}

.btn-thanks-more {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 28px;
    background: transparent;
    border: 1px solid rgba(255, 255, 255, 0.15);
    color: var(--text-dim);
    font-size: 14px;
    font-weight: 600;
    transition: all 0.3s var(--ease-out);
    clip-path: polygon(
        0 0,
        calc(100% - 10px) 0,
        100% 10px,
        100% 100%,
        10px 100%,
        0 calc(100% - 10px)
    );
}

.btn-thanks-more:hover {
    border-color: var(--acid);
    color: var(--acid);
    background: var(--acid-muted);
}

.btn-thanks-more svg {
    transition: transform 0.3s var(--ease-out);
}

.btn-thanks-more:hover svg {
    transform: translateX(4px);
}

/* ============================================================
   CTA Section
   ============================================================ */

.section-cta {
    background: linear-gradient(180deg, var(--void), var(--surface) 50%, var(--void));
    padding: 120px 0;
}

.section-cta .section-container {
    position: relative;
}

.cta-content {
    text-align: center;
    position: relative;
    z-index: 1;
}

.cta-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    background: var(--surface);
    border: 1px solid rgba(255, 255, 255, 0.06);
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 0.05em;
    color: var(--acid);
    margin-bottom: 24px;
}

.cta-badge-dot {
    width: 8px;
    height: 8px;
    background: var(--acid);
    border-radius: 50%;
    animation: pulse 2s ease-in-out infinite;
}

.cta-title {
    font-family: var(--font-display);
    font-size: clamp(32px, 5vw, 48px);
    margin-bottom: 16px;
    background: linear-gradient(135deg, var(--text), var(--acid));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.cta-desc {
    font-size: 16px;
    color: var(--text-dim);
    line-height: 1.8;
    margin-bottom: 40px;
}

.cta-status {
    margin-top: 24px;
    font-size: 14px;
    min-height: 24px;
}

.cta-status--info {
    color: var(--acid);
}

.cta-status--success {
    color: var(--success);
}

.cta-status--error {
    color: var(--error);
}

.cta-decoration {
    position: absolute;
    inset: -100px;
    pointer-events: none;
    overflow: hidden;
}

.cta-ring {
    position: absolute;
    border: 1px solid rgba(190, 250, 0, 0.1);
    border-radius: 50%;
}

.cta-ring--1 {
    width: 400px;
    height: 400px;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    animation: cta-ring-pulse 4s ease-in-out infinite;
}

.cta-ring--2 {
    width: 600px;
    height: 600px;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    animation: cta-ring-pulse 4s ease-in-out 1s infinite;
}

@keyframes cta-ring-pulse {
    0%, 100% {
        opacity: 0.3;
        transform: translate(-50%, -50%) scale(1);
    }
    50% {
        opacity: 0.1;
        transform: translate(-50%, -50%) scale(1.1);
    }
}

/* ============================================================
   Footer
   ============================================================ */

.footer {
    position: relative;
    z-index: 1;
    width: 100%;
    background: var(--surface);
    border-top: 1px solid rgba(255, 255, 255, 0.06);
    padding: 60px 0;
}

.footer-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 24px;
}

.footer-logo {
    font-family: var(--font-display);
    font-size: 20px;
    color: var(--acid);
    margin-bottom: 8px;
}

.footer-tagline {
    font-size: 13px;
    color: var(--text-muted);
}

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

.footer-links a {
    font-size: 14px;
    color: var(--text-dim);
    transition: color 0.2s ease;
}

.footer-links a:hover {
    color: var(--acid);
}

.footer-copyright {
    text-align: right;
}

.footer-copyright p {
    font-size: 13px;
    color: var(--text-muted);
}

.footer-powered {
    font-size: 12px;
    color: var(--text-muted);
    margin-top: 4px;
}

/* ============================================================
   Modal
   ============================================================ */

.modal {
    position: fixed;
    inset: 0;
    z-index: 2000;
    display: none;
    align-items: center;
    justify-content: center;
}

.modal.show {
    display: flex;
}

.modal-backdrop {
    position: absolute;
    inset: 0;
    background: rgba(10, 10, 15, 0.92);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}

.modal-box {
    position: relative;
    background: var(--surface);
    border: 1px solid rgba(255, 255, 255, 0.06);
    width: 90%;
    max-width: 800px;
    max-height: 90vh;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    clip-path: polygon(
        0 0,
        calc(100% - 20px) 0,
        100% 20px,
        100% 100%,
        20px 100%,
        0 calc(100% - 20px)
    );
    box-shadow: 0 8px 40px rgba(0, 0, 0, 0.6), 0 0 60px var(--acid-glow);
}

.modal-box::before {
    content: '';
    position: absolute;
    top: 10px;
    right: 0;
    width: 32px;
    height: 2px;
    background: var(--acid);
    transform: rotate(-45deg);
    transform-origin: right;
}

.modal-header {
    padding: 20px 24px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.modal-title {
    font-family: var(--font-display);
    font-size: 18px;
}

.modal-close {
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 8px;
    transition: color 0.2s ease;
}

.modal-close:hover {
    color: var(--text);
}

.modal-body {
    padding: 24px;
    overflow-y: auto;
}

.modal-img-wrapper {
    position: relative;
    width: 100%;
    margin-bottom: 20px;
}

.modal-img {
    width: 100%;
    border-radius: 4px;
}

.modal-results {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.modal-result {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 16px;
    background: var(--void-light);
    border: 1px solid rgba(255, 255, 255, 0.06);
}

.modal-result-name {
    font-weight: 600;
}

.modal-result-conf {
    font-family: var(--font-mono);
}

/* ============================================================
   Toast
   ============================================================ */

.toast {
    position: fixed;
    bottom: 24px;
    right: 24px;
    background: var(--surface);
    border: 1px solid rgba(255, 255, 255, 0.06);
    padding: 16px 24px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
    transform: translateY(100px);
    opacity: 0;
    transition: all 0.3s var(--ease-out);
    z-index: 3000;
    font-size: 14px;
    font-weight: 500;
    clip-path: polygon(
        0 0,
        calc(100% - 8px) 0,
        100% 8px,
        100% 100%,
        8px 100%,
        0 calc(100% - 8px)
    );
}

.toast.show {
    transform: translateY(0);
    opacity: 1;
}

.toast.success {
    border-color: var(--success);
}

.toast.error {
    border-color: var(--error);
}

.toast.info {
    border-color: var(--acid);
}

/* ============================================================
   Responsive Design
   ============================================================ */

@media (max-width: 1024px) {
    .hero-visual {
        display: none;
    }

    .nav-container {
        gap: 20px;
    }

    .nav-links {
        gap: 20px;
    }

    .nav-link {
        font-size: 13px;
    }

    .about-architecture {
        flex-direction: column;
    }

    .arch-connector {
        width: auto;
        height: 60px;
        transform: rotate(90deg);
    }

    .about-metrics {
        grid-template-columns: repeat(2, 1fr);
    }

    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .thanks-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

@media (max-width: 900px) {
    .nav-container {
        gap: 16px;
    }

    .nav-link-back {
        font-size: 13px;
    }

    .nav-links {
        gap: 16px;
    }

    .nav-link {
        font-size: 12px;
    }

    .nav-logo-text {
        font-size: 18px;
    }

    .btn-nav-outline,
    .btn-nav-primary {
        padding: 8px 16px;
        font-size: 14px;
    }
}

@media (max-width: 768px) {
    .nav-container {
        padding: 12px 16px;
        gap: 12px;
        justify-content: center;
        position: relative;
        height: 60px;
    }

    .nav-link-back {
        display: none;
    }

    .nav-logo-text {
        font-size: 18px;
    }

    .nav-logo-badge {
        font-size: 8px;
        padding: 3px 8px;
    }

    .nav-links {
        position: fixed;
        top: 60px;
        left: 0;
        right: 0;
        background: var(--void);
        border-top: solid rgba(190, 250, 0, 0.5) 1px;
        flex-direction: column;
        justify-content: flex-start;
        align-items: center;
        gap: 32px;
        padding-top: 10px;
        padding-bottom: 60px;
        overflow-y: auto;
        z-index: 1001;
        opacity: 0;
        pointer-events: none;
        transition: opacity 0.3s ease;
    }

    .nav-links.show {
        opacity: 1;
        pointer-events: auto;
    }

    .nav-link {
        font-size: 24px;
        font-weight: 600;
    }

    /* 移动端 toggle 按钮放在左边 */
    .nav-mobile-toggle {
        display: flex;
        z-index: 1002;
        position: absolute;
        left: 16px;
    }

    /* 隐藏桌面端按钮和用户菜单 */
    .nav-actions {
        display: none !important;
    }

    .nav-user {
        display: none !important;
    }

    /* 显示移动端登录按钮 */
    .nav-mobile-actions {
        display: flex;
        align-items: center;
        gap: 12px;
        margin-top: 20px;
    }

    .nav-mobile-actions .btn-nav-outline {
        padding: 12px 24px;
        font-size: 16px;
    }

    .nav-mobile-actions .btn-nav-primary {
        padding: 12px 24px;
        font-size: 16px;
    }

    /* 移动端用户头像（在导航栏右边）- 只有 .visible 时显示 */
    .nav-mobile-user-header.visible {
        display: flex;
        position: absolute;
        right: 16px;
        z-index: 1002;
    }

    /* 移动端用户下拉菜单 - 只有 .visible 时显示 */
    .nav-mobile-user.visible {
        display: flex;
    }

    /* 移动端登录按钮 - 只有 .visible 时显示 */
    .nav-mobile-actions.visible {
        display: flex;
    }

    .nav-mobile-actions .btn-nav-primary {
        padding: 12px 24px;
        font-size: 16px;
    }

    .hero {
        width: 100%;
        padding: 100px 16px 60px;
        text-align: center;
        min-height: auto;
    }

    .hero-content {
        text-align: center;
        width: 100%;
    }

    .hero-title {
        font-size: 48px;
    }

    .hero-subtitle {
        font-size: 18px;
    }

    .hero-desc {
        font-size: 14px;
    }

    .hero-stats {
        flex-direction: column;
        gap: 20px;
        align-items: center;
    }

    .hero-stat-divider {
        display: none;
    }

    .section {
        width: 100%;
        padding: 60px 0;
    }

    .section-container {
        width: 100%;
        padding: 0 16px;
        text-align: center;
    }

    .section-header {
        text-align: center;
    }

    .section-title {
        font-size: 28px;
    }

    .section-subtitle {
        font-size: 14px;
    }

    .about-intro {
        margin: -10px auto 40px;
        padding: 24px 20px;
        text-align: left;
    }

    .about-intro::after {
        font-size: 40px;
        top: 8px;
        left: 12px;
    }

    .about-intro p {
        font-size: 14px;
        text-align: left;
        line-height: 1.8;
    }

    .about-metrics {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .metric-card {
        padding: 24px 20px;
        text-align: center;
    }

    .metric-value {
        font-size: 28px;
    }

    .features-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .feature-card {
        padding: 24px;
        text-align: center;
    }

    .showcase-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .usecases-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .usecase-card {
        padding: 32px 24px;
        text-align: left;
    }

    .usecase-content {
        text-align: left;
    }

    .usecase-number {
        font-size: 48px;
    }

    .usecases-footer {
        margin-top: 32px;
        font-size: 12px;
    }

    .developer-content {
        padding: 24px 20px;
    }

    .developer-info p {
        font-size: 14px;
    }

    .developer-features {
        grid-template-columns: 1fr;
        gap: 12px;
    }

    .developer-features li {
        padding: 12px 16px;
        font-size: 13px;
    }

    .thanks-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .thanks-card {
        padding: 32px 24px;
    }

    .thanks-footer {
        margin-top: 32px;
    }

    .section-cta {
        padding: 80px 0;
    }

    .cta-content {
        text-align: center;
    }

    .cta-title {
        font-size: 28px;
    }

    .cta-desc {
        font-size: 14px;
    }

    .btn-cta-submit {
        padding: 14px 32px;
        font-size: 14px;
    }

    .footer {
        width: 100%;
        padding: 40px 0;
    }

    .footer-container {
        width: 100%;
        padding: 0 16px;
        flex-direction: column;
        text-align: center;
        gap: 20px;
    }

    .footer-brand {
        text-align: center;
    }

    .footer-links {
        flex-wrap: wrap;
        justify-content: center;
        gap: 16px;
    }

    .footer-copyright {
        text-align: center;
    }

    .modal-box {
        width: 100%;
        max-width: 100%;
        max-height: 100%;
        clip-path: none;
    }

    .toast {
        left: 16px;
        right: 16px;
        bottom: 16px;
    }
}

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

/* ============================================================
   Features Section - Charts
   ============================================================ */

.features-charts {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
    margin-top: 48px;
}

.chart-card {
    background: var(--surface);
    border: 1px solid rgba(255, 255, 255, 0.06);
    padding: 24px;
    position: relative;
    transition: all 0.3s var(--ease-smooth);
    clip-path: polygon(
        0 0,
        calc(100% - 16px) 0,
        100% 16px,
        100% 100%,
        16px 100%,
        0 calc(100% - 16px)
    );
}

.chart-card::before {
    content: '';
    position: absolute;
    top: 8px;
    right: 0;
    width: 24px;
    height: 2px;
    background: var(--acid);
    transform: rotate(-45deg);
    transform-origin: right;
}

.chart-card:hover {
    border-color: var(--acid);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.4), 0 0 40px var(--acid-glow);
}

.chart-title {
    font-family: var(--font-body);
    font-size: 18px;
    font-weight: 600;
    color: var(--text);
    margin-bottom: 4px;
}

.chart-desc {
    font-size: 13px;
    color: var(--text-dim);
    margin-bottom: 20px;
}

.chart-container {
    height: 300px;
    position: relative;
}

@media (max-width: 768px) {
    .features-charts {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .chart-card {
        padding: 20px;
    }

    .chart-container {
        height: 180px;
    }
}

/* ============================================================
   Auth Modal
   ============================================================ */

.auth-modal {
    position: fixed;
    inset: 0;
    z-index: 3000;
    display: none;
    align-items: center;
    justify-content: center;
    padding: 24px;
}

.auth-modal.show {
    display: flex;
}

.auth-modal-backdrop {
    position: absolute;
    inset: 0;
    background: rgba(10, 10, 15, 0.92);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
}

.auth-modal-box {
    position: relative;
    background: var(--surface);
    border: 1px solid rgba(255, 255, 255, 0.06);
    width: 100%;
    max-width: 420px;
    max-height: 90vh;
    overflow-y: auto;
    padding: 32px;
    clip-path: polygon(
        0 0,
        calc(100% - 20px) 0,
        100% 20px,
        100% 100%,
        20px 100%,
        0 calc(100% - 20px)
    );
    box-shadow: 0 8px 40px rgba(0, 0, 0, 0.6), 0 0 60px var(--acid-glow);
    animation: auth-modal-in 0.3s var(--ease-out);
}

.auth-modal-box::before {
    content: '';
    position: absolute;
    top: 10px;
    right: 0;
    width: 32px;
    height: 2px;
    background: var(--acid);
    transform: rotate(-45deg);
    transform-origin: right;
}

@keyframes auth-modal-in {
    from {
        opacity: 0;
        transform: translateY(20px) scale(0.95);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

.auth-modal-close {
    position: absolute;
    top: 16px;
    right: 16px;
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 8px;
    transition: color 0.2s ease;
    z-index: 10;
}

.auth-modal-close:hover {
    color: var(--text);
}

/* Auth Tabs */
.auth-tabs {
    display: flex;
    gap: 8px;
    margin-bottom: 24px;
    padding: 4px;
    background: var(--void-light);
    border: 1px solid rgba(255, 255, 255, 0.06);
}

.auth-tab {
    flex: 1;
    padding: 12px 16px;
    background: transparent;
    border: none;
    color: var(--text-dim);
    font-family: var(--font-body);
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}

.auth-tab:hover {
    color: var(--text);
}

.auth-tab.active {
    background: var(--acid);
    color: var(--void);
}

/* Auth Panels */
.auth-panel {
    display: none;
}

.auth-panel.active {
    display: block;
    animation: auth-panel-in 0.3s var(--ease-out);
}

@keyframes auth-panel-in {
    from {
        opacity: 0;
        transform: translateX(10px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.auth-form-panel {
    display: none;
}

.auth-form-panel.active {
    display: block;
    animation: auth-panel-in 0.3s var(--ease-out);
}

/* Auth Fields */
.auth-field {
    margin-bottom: 20px;
}

.auth-field-label {
    display: block;
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 0.15em;
    color: var(--text-dim);
    margin-bottom: 8px;
}

.auth-field-input-wrap {
    position: relative;
}

.auth-field-input-wrap--grow {
    flex: 1;
}

.auth-field-row {
    display: flex;
    gap: 12px;
}

.auth-field-input {
    width: 100%;
    height: 48px;
    padding: 0 16px;
    font-family: var(--font-body);
    font-size: 15px;
    color: var(--text);
    background: var(--void-light);
    border: 1px solid rgba(255, 255, 255, 0.08);
    outline: none;
    transition: all 0.2s ease;
}

.auth-field-input::placeholder {
    color: var(--text-muted);
}

.auth-field-input:focus {
    border-color: var(--acid);
    background: var(--void);
    box-shadow: 0 0 0 3px var(--acid-muted);
}

.auth-field-toggle {
    position: absolute;
    right: 12px;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    padding: 4px;
    transition: color 0.2s ease;
}

.auth-field-toggle:hover {
    color: var(--text);
}

.auth-field-error {
    display: flex;
    align-items: center;
    gap: 6px;
    margin-top: 8px;
    font-size: 13px;
    color: var(--hot);
}

.auth-field-error[hidden] {
    display: none;
}

/* Auth Options */
.auth-options {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

/* Auth Checkbox */
.auth-checkbox {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    cursor: pointer;
    margin-bottom: 20px;
}

.auth-checkbox input {
    display: none;
}

.auth-checkbox-box {
    width: 18px;
    height: 18px;
    border: 2px solid var(--text-muted);
    position: relative;
    transition: all 0.2s ease;
    flex-shrink: 0;
    margin-top: 2px;
}

.auth-checkbox input:checked + .auth-checkbox-box {
    background: var(--acid);
    border-color: var(--acid);
}

.auth-checkbox input:checked + .auth-checkbox-box::after {
    content: '';
    position: absolute;
    left: 5px;
    top: 1px;
    width: 4px;
    height: 9px;
    border: solid var(--void);
    border-width: 0 2px 2px 0;
    transform: rotate(45deg);
}

.auth-checkbox-text {
    font-size: 13px;
    color: var(--text-dim);
    line-height: 1.5;
}

/* Auth Buttons */
.auth-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    height: 48px;
    padding: 0 24px;
    font-family: var(--font-body);
    font-size: 14px;
    font-weight: 700;
    border: none;
    cursor: pointer;
    transition: all 0.3s var(--ease-out);
}

.auth-btn--primary {
    width: 100%;
    background: var(--acid);
    color: var(--void);
    clip-path: polygon(
        0 0,
        calc(100% - 10px) 0,
        100% 10px,
        100% 100%,
        10px 100%,
        0 calc(100% - 10px)
    );
}

.auth-btn--primary:hover {
    background: var(--acid-dim);
    box-shadow: 0 0 32px var(--acid-glow);
}

.auth-btn--primary:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.auth-btn--ghost {
    width: 100%;
    background: transparent;
    color: var(--text-dim);
    margin-top: 12px;
}

.auth-btn--ghost:hover {
    color: var(--text);
    background: var(--surface-light);
}

.auth-btn--outline {
    background: transparent;
    border: 1px solid var(--acid);
    color: var(--acid);
    font-size: 12px;
    padding: 0 16px;
    white-space: nowrap;
}

.auth-btn--outline:hover {
    background: var(--acid-muted);
}

.auth-btn--outline:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.auth-btn-icon {
    transition: transform 0.3s var(--ease-out);
}

.auth-btn--primary:hover .auth-btn-icon {
    transform: translateX(4px);
}

/* Loading State */
.auth-btn--loading {
    pointer-events: none;
}

.auth-btn--loading .auth-btn-text,
.auth-btn--loading .auth-btn-icon {
    visibility: hidden;
}

.auth-btn--loading::after {
    content: '';
    position: absolute;
    width: 20px;
    height: 20px;
    border: 2px solid transparent;
    border-top-color: currentColor;
    border-radius: 50%;
    animation: auth-spin 0.6s linear infinite;
}

@keyframes auth-spin {
    to { transform: rotate(360deg); }
}

/* Auth Link */
.auth-link {
    color: var(--text-dim);
    text-decoration: none;
    font-size: 13px;
    transition: color 0.2s ease;
}

.auth-link:hover {
    color: var(--acid);
}

/* Auth Divider */
.auth-divider {
    display: flex;
    align-items: center;
    gap: 16px;
    margin: 24px 0;
}

.auth-divider::before,
.auth-divider::after {
    content: '';
    flex: 1;
    height: 1px;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.1), transparent);
}

.auth-divider span {
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 0.1em;
    color: var(--text-muted);
    white-space: nowrap;
}

/* Auth OAuth */
.auth-oauth {
    display: flex;
    justify-content: center;
    gap: 12px;
}

.auth-oauth-btn {
    width: 52px;
    height: 52px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--void-light);
    border: 1px solid rgba(255, 255, 255, 0.06);
    color: var(--text-dim);
    cursor: pointer;
    transition: all 0.3s var(--ease-out);
    clip-path: polygon(
        0 0,
        calc(100% - 8px) 0,
        100% 8px,
        100% 100%,
        8px 100%,
        0 calc(100% - 8px)
    );
}

.auth-oauth-btn:hover {
    border-color: var(--acid);
    color: var(--text);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.3);
}

.auth-oauth-btn[data-provider="qq"]:hover {
    color: #12b7f5;
    border-color: #12b7f5;
}

.auth-oauth-btn[data-provider="wechat"]:hover {
    color: #07c160;
    border-color: #07c160;
}

.auth-oauth-btn[data-provider="google"]:hover {
    color: #ea4335;
    border-color: #ea4335;
}

/* Auth Steps */
.auth-steps {
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 24px;
}

.auth-step {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
}

.auth-step-num {
    width: 28px;
    height: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--surface-light);
    border: 2px solid var(--text-muted);
    font-size: 12px;
    font-weight: 700;
    color: var(--text-muted);
    transition: all 0.3s ease;
}

.auth-step-label {
    font-size: 10px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--text-muted);
    transition: color 0.3s ease;
}

.auth-step.active .auth-step-num {
    background: var(--acid);
    border-color: var(--acid);
    color: var(--void);
    box-shadow: 0 0 12px var(--acid-glow);
}

.auth-step.active .auth-step-label {
    color: var(--acid);
}

.auth-step.completed .auth-step-num {
    background: var(--acid);
    border-color: var(--acid);
    color: var(--void);
}

.auth-step.completed .auth-step-label {
    color: var(--text-dim);
}

.auth-step-line {
    width: 32px;
    height: 2px;
    background: var(--surface-light);
    margin: 0 8px;
    margin-bottom: 16px;
    transition: background 0.3s ease;
}

.auth-step.completed + .auth-step-line {
    background: var(--acid);
}

/* Auth Password Strength */
.auth-password-strength {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-top: 10px;
}

.auth-strength-bars {
    display: flex;
    gap: 4px;
}

.auth-strength-bar {
    width: 28px;
    height: 4px;
    background: var(--surface-light);
    transition: background 0.2s ease;
}

.auth-strength-text {
    font-size: 11px;
    color: var(--text-muted);
}

.auth-password-strength[data-strength="1"] .auth-strength-bar:nth-child(1) {
    background: var(--hot);
}

.auth-password-strength[data-strength="2"] .auth-strength-bar:nth-child(-n+2) {
    background: #f59e0b;
}

.auth-password-strength[data-strength="3"] .auth-strength-bar:nth-child(-n+3) {
    background: #22d3ee;
}

.auth-password-strength[data-strength="4"] .auth-strength-bar {
    background: var(--acid);
}

/* Auth Success */
.auth-success {
    text-align: center;
    padding: 24px 0;
}

.auth-success-icon {
    color: var(--acid);
    margin-bottom: 20px;
    animation: auth-success-pop 0.5s var(--ease-out);
}

@keyframes auth-success-pop {
    0% { transform: scale(0); opacity: 0; }
    50% { transform: scale(1.2); }
    100% { transform: scale(1); opacity: 1; }
}

.auth-success-title {
    font-family: var(--font-display);
    font-size: 22px;
    color: var(--acid);
    margin-bottom: 8px;
}

.auth-success-desc {
    font-size: 14px;
    color: var(--text-dim);
    margin-bottom: 24px;
}

/* Auth Message */
.auth-message {
    padding: 12px 16px;
    margin-bottom: 16px;
    font-size: 13px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.auth-message--success {
    background: rgba(16, 185, 129, 0.1);
    border-left: 3px solid #10b981;
    color: #10b981;
}

.auth-message--error {
    background: rgba(255, 46, 99, 0.1);
    border-left: 3px solid var(--hot);
    color: var(--hot);
}

/* Auth Modal Responsive */
@media (max-width: 480px) {
    .auth-modal {
        padding: 16px;
    }

    .auth-modal-box {
        padding: 24px;
        clip-path: none;
    }

    .auth-modal-box::before {
        display: none;
    }

    .auth-field-row {
        flex-direction: column;
    }

    .auth-btn--outline {
        width: 100%;
    }
}

/* ============================================================
   Nav User (Logged-in State)
   ============================================================ */

.nav-user {
    position: relative;
}

.nav-user-trigger {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 6px 12px 6px 6px;
    background: transparent;
    border: 1px solid rgba(255, 255, 255, 0.1);
    cursor: pointer;
    transition: all 0.2s ease;
    clip-path: polygon(
        0 0,
        calc(100% - 8px) 0,
        100% 8px,
        100% 100%,
        8px 100%,
        0 calc(100% - 8px)
    );
}

.nav-user-trigger:hover {
    border-color: var(--acid);
    background: rgba(190, 250, 0, 0.05);
}

.nav-user-avatar {
    width: 32px;
    height: 32px;
    object-fit: cover;
    border: 2px solid var(--acid);
}

.nav-user-caret {
    color: var(--text-dim);
    transition: transform 0.2s ease;
}

.nav-user.open .nav-user-caret {
    transform: rotate(180deg);
}

.nav-user-dropdown {
    position: absolute;
    top: calc(100% + 12px);
    right: 0;
    width: 220px;
    background: var(--surface);
    border: 1px solid rgba(255, 255, 255, 0.08);
    padding: 8px 0;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-8px);
    transition: all 0.2s var(--ease-out);
    z-index: 1000;
    clip-path: polygon(
        0 0,
        calc(100% - 12px) 0,
        100% 12px,
        100% 100%,
        12px 100%,
        0 calc(100% - 12px)
    );
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4), 0 0 20px rgba(190, 250, 0, 0.1);
}

.nav-user.open .nav-user-dropdown {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.nav-user-info {
    padding: 12px 16px;
}

.nav-user-name {
    font-size: 14px;
    font-weight: 600;
    color: var(--text);
}

.nav-user-divider {
    height: 1px;
    background: rgba(255, 255, 255, 0.06);
    margin: 4px 0;
}

.nav-user-item {
    display: flex;
    align-items: center;
    gap: 12px;
    width: 100%;
    padding: 12px 16px;
    background: none;
    border: none;
    color: var(--text-dim);
    font-family: var(--font-body);
    font-size: 14px;
    text-align: left;
    cursor: pointer;
    transition: all 0.2s ease;
}

.nav-user-item:hover {
    background: rgba(255, 255, 255, 0.04);
    color: var(--text);
}

.nav-user-item svg {
    color: var(--text-muted);
    transition: color 0.2s ease;
}

.nav-user-item:hover svg {
    color: var(--acid);
}

.nav-user-item--danger {
    color: var(--hot);
}

.nav-user-item--danger:hover {
    background: rgba(255, 46, 99, 0.1);
    color: var(--hot);
}

.nav-user-item--danger svg {
    color: var(--hot);
}

/* ============================================================
   Nav Mobile User (Logged-in State)
   ============================================================ */

/* 移动端按钮和用户菜单默认在桌面端隐藏 */
.nav-mobile-actions,
.nav-mobile-user,
.nav-mobile-user-header {
    display: none;
}

.nav-mobile-user {
    flex-direction: column;
    gap: 16px;
    margin-top: 24px;
    padding-top: 24px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    width: 100%;
    max-width: 280px;
}

.nav-mobile-user-info {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 0 8px;
}

.nav-mobile-user-avatar {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid var(--acid);
}

.nav-mobile-user-name {
    font-size: 18px;
    font-weight: 600;
    color: var(--text);
}

.nav-mobile-user-item {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    padding: 14px 24px;
    background: var(--surface);
    border: 1px solid rgba(255, 255, 255, 0.08);
    color: var(--text);
    font-family: var(--font-body);
    font-size: 16px;
    font-weight: 500;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s ease;
    text-decoration: none;
}

.nav-mobile-user-item:hover {
    border-color: var(--acid);
    color: var(--acid);
}

.nav-mobile-user-item--danger {
    color: var(--hot);
    border-color: rgba(255, 46, 99, 0.3);
}

.nav-mobile-user-item--danger:hover {
    background: rgba(255, 46, 99, 0.1);
    border-color: var(--hot);
    color: var(--hot);
}