/* ============================================
   NexTech Club — 极简科技风格
   ============================================ */

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

:root {
    --bg: #0a0a0f;
    --bg-card: #111118;
    --bg-card-hover: #181825;
    --text: #e8e8ed;
    --text-dim: #6b6b80;
    --accent: #00d4ff;
    --accent-dim: rgba(0, 212, 255, 0.15);
    --border: #1e1e2e;
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', monospace;
}

html {
    scroll-behavior: smooth;
}

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

a {
    color: var(--accent);
    text-decoration: none;
    transition: opacity 0.2s;
}
a:hover { opacity: 0.7; }

/* --- Particle Canvas --- */
#particles {
    position: fixed;
    top: 0; left: 0;
    width: 100vw;
    height: 100vh;
    z-index: 0;
    pointer-events: none;
}

/* --- Navbar --- */
.navbar {
    position: fixed;
    top: 0; left: 0; right: 0;
    z-index: 100;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.2rem 4rem;
    background: rgba(10, 10, 15, 0.7);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
}

.logo {
    font-size: 1.4rem;
    font-weight: 700;
    letter-spacing: -0.02em;
}
.logo span {
    color: var(--accent);
}

.navbar nav {
    display: flex;
    gap: 2rem;
}
.navbar nav a {
    color: var(--text-dim);
    font-size: 0.9rem;
    font-weight: 500;
    transition: color 0.2s;
    position: relative;
}
.navbar nav a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--accent);
    transition: width 0.3s;
}
.navbar nav a:hover {
    color: var(--text);
}
.navbar nav a:hover::after {
    width: 100%;
}

/* --- Hero --- */
.hero {
    position: relative;
    z-index: 1;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 2rem;
}

.hero-content {
    max-width: 720px;
}

.hero h1 {
    font-size: clamp(3rem, 10vw, 6rem);
    font-weight: 800;
    letter-spacing: -0.04em;
    line-height: 1;
    margin-bottom: 1.5rem;
    position: relative;
}

/* Glitch effect */
.glitch {
    position: relative;
    color: var(--text);
}
.glitch::before,
.glitch::after {
    content: attr(data-text);
    position: absolute;
    top: 0; left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
}
.glitch::before {
    color: #ff00c1;
    z-index: -1;
    animation: glitch1 4s infinite;
}
.glitch::after {
    color: #00ffea;
    z-index: -1;
    animation: glitch2 4s infinite;
}

@keyframes glitch1 {
    0%, 90%, 100% { transform: translate(0); opacity: 0; }
    92% { transform: translate(-3px, 1px); opacity: 0.6; }
    94% { transform: translate(3px, -1px); opacity: 0.4; }
    96% { transform: translate(-1px, 2px); opacity: 0.5; }
}
@keyframes glitch2 {
    0%, 90%, 100% { transform: translate(0); opacity: 0; }
    92% { transform: translate(2px, -2px); opacity: 0.5; }
    94% { transform: translate(-2px, 1px); opacity: 0.3; }
    96% { transform: translate(1px, -1px); opacity: 0.4; }
}

.subtitle {
    font-size: 1.2rem;
    color: var(--accent);
    font-family: var(--font-mono);
    margin-bottom: 1rem;
    letter-spacing: 0.05em;
}

.desc {
    font-size: 1.05rem;
    color: var(--text-dim);
    max-width: 520px;
    margin: 0 auto 2.5rem;
}

.btn-primary {
    display: inline-block;
    padding: 0.85rem 2.5rem;
    background: transparent;
    color: var(--accent);
    border: 1px solid var(--accent);
    font-size: 0.95rem;
    font-weight: 600;
    font-family: var(--font-sans);
    cursor: pointer;
    transition: all 0.3s;
    letter-spacing: 0.03em;
}
.btn-primary:hover {
    background: var(--accent-dim);
    box-shadow: 0 0 30px rgba(0, 212, 255, 0.15);
    opacity: 1;
}

/* Scroll indicator */
.scroll-indicator {
    position: absolute;
    bottom: 2.5rem;
    left: 50%;
    transform: translateX(-50%);
}
.scroll-indicator span {
    display: block;
    width: 1px;
    height: 40px;
    background: linear-gradient(to bottom, var(--accent), transparent);
    animation: scrollPulse 2s ease-in-out infinite;
}
@keyframes scrollPulse {
    0%, 100% { opacity: 0.3; transform: scaleY(0.5); }
    50% { opacity: 1; transform: scaleY(1); }
}

/* --- Sections --- */
.section {
    position: relative;
    z-index: 1;
    max-width: 1100px;
    margin: 0 auto;
    padding: 6rem 2rem;
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 3rem;
    letter-spacing: -0.02em;
}
.section-title .accent {
    color: var(--accent);
    font-family: var(--font-mono);
}

/* --- About --- */
.about-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.about-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    padding: 2.5rem 2rem;
    transition: all 0.3s;
    cursor: default;
}
.about-card:hover {
    background: var(--bg-card-hover);
    border-color: var(--accent);
    transform: translateY(-4px);
}

.about-card .icon {
    font-size: 2rem;
    margin-bottom: 1rem;
    color: var(--accent);
}

.about-card h3 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.about-card p {
    color: var(--text-dim);
    font-size: 0.95rem;
    line-height: 1.7;
}

/* --- SVG Icons --- */
.nc-icon {
    width: 1.2em;
    height: 1.2em;
    vertical-align: -0.2em;
    display: inline-block;
}
.nc-icon-lg {
    width: 1.8em;
    height: 1.8em;
    vertical-align: -0.35em;
}

/* --- Section Desc --- */
.section-desc {
    color: var(--text-dim);
    margin-bottom: 2.5rem;
    font-size: 1rem;
}

/* --- Products --- */
.products-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
    gap: 1.5rem;
}

.product-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    padding: 2rem;
    transition: all 0.3s;
    display: flex;
    flex-direction: column;
    gap: 1rem;
    text-decoration: none;
    color: inherit;
    cursor: pointer;
}
.product-card:hover {
    background: var(--bg-card-hover);
    border-color: var(--accent);
    transform: translateY(-4px);
}

.product-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.product-cat {
    font-family: var(--font-mono);
    font-size: 0.8rem;
    color: var(--accent);
    background: var(--accent-dim);
    padding: 0.2rem 0.6rem;
    border-radius: 2px;
}

.product-count {
    font-size: 0.75rem;
    color: #4ade80;
    background: rgba(74, 222, 128, 0.12);
    padding: 0.15rem 0.5rem;
    border-radius: 2px;
    font-weight: 500;
    font-family: var(--font-mono);
}

.product-card h3 {
    font-size: 1.15rem;
    font-weight: 600;
}

.product-card > p {
    color: var(--text-dim);
    font-size: 0.9rem;
    line-height: 1.7;
}

.product-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    padding-top: 0.5rem;
    border-top: 1px solid var(--border);
}
.product-tags span {
    font-family: var(--font-mono);
    font-size: 0.73rem;
    color: var(--text-dim);
    background: rgba(255,255,255,0.04);
    padding: 0.2rem 0.55rem;
    border-radius: 3px;
    border: 1px solid var(--border);
    transition: all 0.2s;
}
.product-tags span:hover {
    color: var(--accent);
    border-color: var(--accent);
    background: var(--accent-dim);
}

/* --- News --- */
.news-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 1.25rem;
}

.news-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    padding: 1.75rem;
    transition: all 0.3s;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}
.news-card:hover {
    background: var(--bg-card-hover);
    border-color: var(--accent);
    transform: translateY(-4px);
}

.news-tag {
    display: inline-block;
    width: fit-content;
    font-size: 0.72rem;
    font-weight: 600;
    color: var(--accent);
    background: var(--accent-dim);
    padding: 0.2rem 0.65rem;
    border-radius: 2px;
    font-family: var(--font-mono);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.news-card h3 {
    font-size: 1.1rem;
    font-weight: 600;
    line-height: 1.4;
}

.news-card p {
    color: var(--text-dim);
    font-size: 0.9rem;
    line-height: 1.7;
    flex: 1;
}

.news-meta {
    display: flex;
    gap: 0.5rem;
    font-size: 0.8rem;
    color: var(--text-dim);
    font-family: var(--font-mono);
}

/* --- Forum --- */
.forum-section {
    text-align: center;
}
.forum-section .section-title {
    text-align: left;
}

.forum-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 1.25rem;
    text-align: left;
    margin-bottom: 2.5rem;
}

.forum-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    padding: 2rem 1.5rem;
    transition: all 0.3s;
    text-decoration: none;
    color: inherit;
    display: block;
    cursor: pointer;
}
.forum-card:hover {
    background: var(--bg-card-hover);
    border-color: var(--accent);
    transform: translateY(-4px);
}

.forum-icon {
    font-size: 2rem;
    margin-bottom: 1rem;
}

.forum-card h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.forum-card p {
    color: var(--text-dim);
    font-size: 0.9rem;
    line-height: 1.7;
    margin-bottom: 1.2rem;
}

.forum-stats {
    display: flex;
    gap: 1.2rem;
    font-size: 0.8rem;
    color: var(--text-dim);
    font-family: var(--font-mono);
}

.forum-cta {
    padding: 3rem 2rem;
    background: var(--bg-card);
    border: 1px solid var(--border);
}
.forum-cta p {
    color: var(--text-dim);
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
}

/* --- Join --- */
.join-section {
    text-align: center;
}

.join-desc {
    color: var(--text-dim);
    margin-bottom: 2rem;
    font-size: 1.05rem;
}

.join-form {
    display: flex;
    justify-content: center;
    gap: 0.75rem;
    flex-wrap: wrap;
}

.join-form input {
    padding: 0.85rem 1.5rem;
    background: var(--bg-card);
    border: 1px solid var(--border);
    color: var(--text);
    font-size: 0.95rem;
    font-family: var(--font-sans);
    min-width: 280px;
    outline: none;
    transition: border-color 0.3s;
}
.join-form input:focus {
    border-color: var(--accent);
}
.join-form input::placeholder {
    color: var(--text-dim);
}

.form-tip {
    margin-top: 1rem;
    font-size: 0.8rem;
    color: var(--text-dim);
}

/* --- Footer --- */
footer {
    position: relative;
    z-index: 1;
    border-top: 1px solid var(--border);
    padding: 2rem 4rem;
}

.footer-inner {
    max-width: 1100px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.footer-brand .logo {
    font-size: 1.1rem;
}
.footer-brand p {
    font-size: 0.8rem;
    color: var(--text-dim);
    margin-top: 0.3rem;
}

.footer-links {
    display: flex;
    gap: 1.5rem;
}
.footer-links a {
    color: var(--text-dim);
    font-size: 0.9rem;
}

/* --- Responsive --- */
@media (max-width: 768px) {
    .navbar {
        padding: 1rem 1.5rem;
    }
    .navbar nav {
        gap: 0.8rem;
    }
    .navbar nav a {
        font-size: 0.75rem;
    }
    .section {
        padding: 4rem 1.5rem;
    }
    .join-form input {
        min-width: 100%;
    }
    .footer-inner {
        flex-direction: column;
        text-align: center;
    }
    .products-grid {
        grid-template-columns: 1fr;
    }
    .news-grid {
        grid-template-columns: 1fr;
    }
    .forum-grid {
        grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    }
}

@media (max-width: 480px) {
    .navbar nav a:nth-child(5) {
        display: none;
    }
    .hero h1 {
        font-size: 2.5rem;
    }
    .product-tags {
        gap: 0.35rem;
    }
    .product-tags span {
        font-size: 0.68rem;
        padding: 0.15rem 0.4rem;
    }
}