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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
    background: #000000;
    color: #ffffff;
    overflow-x: hidden;
    line-height: 1.6;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Language Switching System */
body.lang-en {
    font-family: 'Space Grotesk', -apple-system, BlinkMacSystemFont, sans-serif;
}

body .zh {
    display: inline;
}

body .en {
    display: none;
}

body.lang-en .zh {
    display: none;
}

body.lang-en .en {
    display: inline;
}

/* Navigation */
.nav {
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    background: rgba(0, 0, 0, 0.85);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    transition: all 0.3s ease;
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 80px;
}

.nav-logo a {
    font-size: 1.3rem;
    font-weight: 600;
    color: #ffffff;
    text-decoration: none;
    letter-spacing: 0.05em;
}

.nav-menu {
    display: flex;
    gap: 3rem;
}

.nav-link {
    color: #ffffff;
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    letter-spacing: 0.05em;
    transition: color 0.3s ease;
    position: relative;
}

.nav-link:hover {
    color: #cccccc;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 1px;
    background: #ffffff;
    transition: width 0.3s ease;
}

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

.nav-right {
    display: flex;
    align-items: center;
    gap: 2rem;
}

/* Elegant Language Toggle */
.language-toggle {
    position: relative;
}

.lang-toggle-btn {
    position: relative;
    width: 60px;
    height: 30px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 15px;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    backdrop-filter: blur(10px);
    overflow: hidden;
}

.lang-toggle-btn:hover {
    border-color: rgba(255, 255, 255, 0.4);
    background: rgba(255, 255, 255, 0.08);
}

.lang-text {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 0.75rem;
    font-weight: 500;
    color: #ffffff;
    z-index: 3;
    transition: all 0.3s ease;
    pointer-events: none;
}

.toggle-slider {
    position: absolute;
    top: 2px;
    left: 2px;
    width: 26px;
    height: 26px;
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.3), rgba(255, 255, 255, 0.1));
    border-radius: 50%;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    backdrop-filter: blur(5px);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.lang-toggle-btn.active .toggle-slider {
    transform: translateX(30px);
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.4), rgba(255, 255, 255, 0.2));
}

.nav-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.nav-toggle span {
    width: 25px;
    height: 2px;
    background: #ffffff;
    margin: 3px 0;
    transition: 0.3s;
}

/* Hero Section */
.hero {
    height: 100vh;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
}

#cube-canvas {
    width: 100%;
    height: 100%;
}

.hero-content {
    text-align: center;
    z-index: 2;
}

.hero-title {
    font-size: clamp(3rem, 8vw, 8rem);
    font-weight: 300;
    line-height: 0.9;
    margin-bottom: 2rem;
    opacity: 0;
    transform: translateY(50px);
}

.hero-title .line {
    display: block;
    overflow: hidden;
}

.hero-subtitle {
    font-size: clamp(1rem, 2vw, 1.5rem);
    font-weight: 300;
    letter-spacing: 0.1em;
    margin-bottom: 3rem;
    opacity: 0;
    transform: translateY(30px);
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.hero-tags {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin-bottom: 4rem;
    opacity: 0;
    transform: translateY(30px);
    flex-wrap: wrap;
}

.tag {
    padding: 0.5rem 1rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    font-size: 0.9rem;
    font-weight: 500;
    letter-spacing: 0.05em;
    transition: all 0.3s ease;
}

.tag:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.4);
}

.hero-scroll {
    position: absolute;
    bottom: 3rem;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    font-size: 0.8rem;
    letter-spacing: 0.1em;
}

.scroll-indicator {
    width: 1px;
    height: 40px;
    background: linear-gradient(to bottom, transparent, #ffffff, transparent);
    animation: scroll-pulse 2s infinite;
}

/* Animations */
.fade-in {
    animation: fadeInUp 1s ease forwards;
    animation-delay: 0.5s;
}

.fade-in-delay {
    animation: fadeInUp 1s ease forwards;
    animation-delay: 1s;
}

.fade-in-delay-2 {
    animation: fadeInUp 1s ease forwards;
    animation-delay: 1.5s;
}

@keyframes fadeInUp {
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes scroll-pulse {
    0%, 100% { opacity: 0.3; }
    50% { opacity: 1; }
}

/* Section Titles */
.section-title {
    font-size: clamp(2rem, 5vw, 4rem);
    font-weight: 300;
    letter-spacing: 0.05em;
    margin-bottom: 4rem;
    text-align: center;
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.8s ease;
}

.section-title.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Platform Section */
.platform-section {
    padding: 8rem 0;
    background: linear-gradient(180deg, #000000 0%, #0a0a0a 100%);
}

.platform-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 3rem;
    max-width: 1000px;
    margin: 0 auto;
}

.platform-card {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(20px);
    padding: 3rem;
    transition: all 0.5s ease;
    opacity: 0;
    transform: translateY(30px);
}

.platform-card.visible {
    opacity: 1;
    transform: translateY(0);
}

.platform-card:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: rgba(255, 255, 255, 0.3);
    transform: translateY(-5px);
}

.card-icon {
    width: 60px;
    height: 60px;
    margin-bottom: 2rem;
    color: #ffffff;
    opacity: 0.8;
}

.icon-svg {
    width: 100%;
    height: 100%;
}

.card-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
    letter-spacing: 0.05em;
}

.card-desc {
    font-size: 1rem;
    line-height: 1.7;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.card-features {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.feature {
    padding: 0.3rem 0.8rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    font-size: 0.8rem;
    font-weight: 500;
    letter-spacing: 0.05em;
}

/* Community Section */
.community-section {
    padding: 8rem 0;
    background: linear-gradient(180deg, #0a0a0a 0%, #111111 100%);
}

.community-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.vision-timeline {
    margin-top: 2rem;
}

.vision-item {
    display: flex;
    margin-bottom: 3rem;
    opacity: 0;
    transform: translateX(-30px);
    transition: all 0.6s ease;
}

.vision-item.visible {
    opacity: 1;
    transform: translateX(0);
}

.vision-year {
    flex-shrink: 0;
    width: 80px;
    font-size: 1.2rem;
    font-weight: 600;
    color: #888888;
}

.vision-content {
    padding-left: 2rem;
    border-left: 1px solid rgba(255, 255, 255, 0.2);
    margin-left: 1rem;
}

.vision-content h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    letter-spacing: 0.05em;
}

.vision-content p {
    font-size: 0.9rem;
    line-height: 1.6;
    opacity: 0.8;
}

.network-visualization {
    display: flex;
    justify-content: center;
    align-items: center;
}

.network-svg {
    width: 100%;
    max-width: 400px;
    height: auto;
}

.central-node {
    animation: pulse-center 3s ease-in-out infinite;
}

.network-node {
    animation: float-node 6s ease-in-out infinite;
}

.network-node:nth-child(3) { animation-delay: -1s; }
.network-node:nth-child(4) { animation-delay: -2s; }
.network-node:nth-child(5) { animation-delay: -3s; }
.network-node:nth-child(6) { animation-delay: -4s; }
.network-node:nth-child(7) { animation-delay: -5s; }

.connection-line {
    animation: pulse-connection 4s ease-in-out infinite;
}

@keyframes pulse-center {
    0%, 100% { opacity: 0.8; transform: scale(1); }
    50% { opacity: 1; transform: scale(1.1); }
}

@keyframes float-node {
    0%, 100% { transform: translateY(0px); opacity: 0.6; }
    50% { transform: translateY(-5px); opacity: 1; }
}

@keyframes pulse-connection {
    0%, 100% { opacity: 0.3; }
    50% { opacity: 0.8; }
}

/* Contact Section */
.contact-section {
    padding: 8rem 0;
    background: #000000;
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
}

.contact-form-container {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(20px);
    padding: 3rem;
}

.contact-intro {
    margin-bottom: 2rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.contact-intro h3 {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 1rem;
    letter-spacing: 0.05em;
}

.contact-intro p {
    font-size: 0.9rem;
    line-height: 1.6;
    opacity: 0.8;
}

.form-group {
    position: relative;
    margin-bottom: 2rem;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    background: transparent;
    border: none;
    border-bottom: 1px solid rgba(255, 255, 255, 0.3);
    padding: 1rem 0;
    font-size: 1rem;
    color: #ffffff;
    font-family: inherit;
    outline: none;
    transition: border-color 0.3s ease;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    border-bottom-color: #ffffff;
}

.form-group select {
    cursor: pointer;
}

.form-group select option {
    background: #000000;
    color: #ffffff;
}

.form-group label {
    position: absolute;
    top: 1rem;
    left: 0;
    font-size: 0.9rem;
    color: #888888;
    pointer-events: none;
    transition: all 0.3s ease;
    letter-spacing: 0.05em;
}

.form-group input:focus + label,
.form-group input:valid + label,
.form-group textarea:focus + label,
.form-group textarea:valid + label,
.form-group select:focus + label,
.form-group select:valid + label {
    top: -0.5rem;
    font-size: 0.8rem;
    color: #ffffff;
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

.submit-btn {
    position: relative;
    background: transparent;
    border: 1px solid rgba(255, 255, 255, 0.3);
    color: #ffffff;
    padding: 1rem 2rem;
    font-size: 0.9rem;
    font-weight: 500;
    letter-spacing: 0.05em;
    cursor: pointer;
    overflow: hidden;
    transition: all 0.3s ease;
    font-family: inherit;
    width: 100%;
}

.submit-btn:hover {
    border-color: #ffffff;
    color: #000000;
}

.btn-bg {
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: #ffffff;
    transition: left 0.3s ease;
    z-index: -1;
}

.submit-btn:hover .btn-bg {
    left: 0;
}

.contact-channels {
    margin-bottom: 3rem;
}

.contact-channels h3,
.location-info h3 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    letter-spacing: 0.05em;
}

.contact-links {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.contact-link {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1rem 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    color: #ffffff;
    text-decoration: none;
    font-size: 1rem;
    font-weight: 500;
    transition: all 0.3s ease;
}

.contact-link:hover {
    color: #cccccc;
    border-bottom-color: rgba(255, 255, 255, 0.3);
}

.link-icon {
    width: 30px;
    height: 30px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8rem;
    font-weight: 600;
}

.location-info p {
    font-size: 1rem;
    opacity: 0.8;
}

/* Footer */
.footer {
    background: #000000;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding: 3rem 0;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.8rem;
    opacity: 0.6;
    letter-spacing: 0.05em;
}

/* Responsive Design */
@media (max-width: 768px) {
    .nav-right {
        gap: 1rem;
    }
    
    .nav-menu {
        position: fixed;
        top: 80px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 80px);
        background: rgba(0, 0, 0, 0.95);
        backdrop-filter: blur(20px);
        flex-direction: column;
        justify-content: center;
        align-items: center;
        gap: 3rem;
        transition: left 0.3s ease;
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-toggle {
        display: flex;
    }

    .nav-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }

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

    .nav-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }

    .hero-tags {
        flex-direction: column;
        gap: 1rem;
    }

    .community-grid,
    .contact-grid {
        grid-template-columns: 1fr;
        gap: 3rem;
    }

    .vision-item {
        flex-direction: column;
        text-align: left;
    }

    .vision-year {
        width: auto;
        margin-bottom: 0.5rem;
    }

    .vision-content {
        padding-left: 0;
        border-left: none;
        margin-left: 0;
        border-top: 1px solid rgba(255, 255, 255, 0.2);
        padding-top: 1rem;
    }

    .footer-content {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }

    .platform-card {
        padding: 2rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 1rem;
    }

    .nav-container {
        padding: 0 1rem;
    }

    .contact-form-container {
        padding: 2rem;
    }

    .hero-tags {
        gap: 0.5rem;
    }

    .tag {
        padding: 0.4rem 0.8rem;
        font-size: 0.8rem;
    }
}

/* Utility Classes */
.visible {
    opacity: 1 !important;
    transform: translateY(0) !important;
}

.glass {
    background: rgba(255, 255, 255, 0.05);
    backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.1);
}