/* ============ RESET ============ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
    font-family: 'Space Mono', 'JetBrains Mono', 'Noto Sans SC', monospace, system-ui, -apple-system, sans-serif;
    background: #000;
    color: #fff;
    line-height: 1.6;
    overflow-x: hidden;
    font-size: 15px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}
img, picture, svg, video { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; transition: color .2s ease; }
ul { list-style: none; }
button { background: transparent; border: 0; color: inherit; cursor: pointer; font-family: inherit; }
h1, h2, h3, h4 { font-family: 'Space Mono', 'JetBrains Mono', 'Noto Sans SC', monospace; font-weight: 700; line-height: 1.15; letter-spacing: -.01em; }
p { color: #c5c5c5; }

/* ============ VARIABLES ============ */
:root {
    --bg: #000;
    --bg-card: #0a0a0a;
    --bg-card-2: #111;
    --border: #1a1a1a;
    --border-2: #222;
    --text: #fff;
    --text-mute: #888;
    --text-dim: #555;
    --accent: #39ff14;
    --accent-2: #b6ff5c;
    --accent-soft: rgba(57,255,20,.12);
    --danger: #ff5555;
    --warning: #ffb86c;
    --pink: #ff4d8d;
    --container: 1240px;
    --header-h: 72px;
}

/* ============ LAYOUT ============ */
.container {
    max-width: var(--container);
    margin: 0 auto;
    padding: 0 24px;
    width: 100%;
}

/* ============ HEADER ============ */
.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(0,0,0,.85);
    backdrop-filter: saturate(180%) blur(14px);
    -webkit-backdrop-filter: saturate(180%) blur(14px);
    border-bottom: 1px solid var(--border);
}
.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: var(--header-h);
    gap: 24px;
}
.logo {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-family: 'Space Mono', monospace;
    font-weight: 700;
    font-size: 18px;
    letter-spacing: .04em;
    flex-shrink: 0;
}
.logo-mark {
    color: var(--accent);
    font-size: 26px;
    line-height: 1;
    transform: translateY(2px);
}
.logo-text { color: #fff; }
.logo-accent { color: var(--accent); }

.primary-nav > ul {
    display: flex;
    align-items: center;
    gap: 28px;
}
.nav-link {
    position: relative;
    font-size: 13px;
    font-weight: 700;
    color: #d0d0d0;
    letter-spacing: .08em;
    text-transform: uppercase;
    padding: 8px 0;
    transition: color .2s ease;
}
.nav-link:hover, .nav-link.active { color: var(--accent); }
.nav-link::after {
    content: '';
    position: absolute;
    left: 0; right: 0; bottom: -4px;
    height: 1px;
    background: var(--accent);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform .25s ease;
}
.nav-link:hover::after, .nav-link.active::after { transform: scaleX(1); }

/* Mega menu */
.has-mega { position: relative; }
.mega-menu {
    position: absolute;
    top: calc(100% + 16px);
    left: 50%;
    transform: translateX(-50%) translateY(8px);
    width: 720px;
    background: #0a0a0a;
    border: 1px solid var(--border);
    border-radius: 4px;
    padding: 24px;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: all .25s ease;
    box-shadow: 0 24px 60px rgba(0,0,0,.6);
}
.mega-menu::before {
    content: '';
    position: absolute;
    top: -6px; left: 50%;
    transform: translateX(-50%) rotate(45deg);
    width: 12px; height: 12px;
    background: #0a0a0a;
    border-left: 1px solid var(--border);
    border-top: 1px solid var(--border);
}
.has-mega:hover .mega-menu,
.has-mega:focus-within .mega-menu {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    transform: translateX(-50%) translateY(0);
}
.mega-col h4 {
    color: var(--accent);
    font-size: 12px;
    letter-spacing: .1em;
    margin-bottom: 12px;
    text-transform: uppercase;
    border-bottom: 1px dashed var(--border-2);
    padding-bottom: 8px;
}
.mega-col a {
    display: block;
    color: #c5c5c5;
    font-size: 13px;
    padding: 6px 0;
    transition: color .2s;
}
.mega-col a:hover { color: var(--accent); }

.header-cta {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-shrink: 0;
}
.btn-link {
    color: #fff;
    font-size: 13px;
    font-weight: 700;
    letter-spacing: .08em;
    text-transform: uppercase;
    padding: 8px 4px;
}
.btn-link:hover { color: var(--accent); }

.btn-primary, .btn-ghost {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-family: 'Space Mono', monospace;
    font-size: 13px;
    font-weight: 700;
    letter-spacing: .1em;
    text-transform: uppercase;
    padding: 12px 24px;
    border: 1px solid #fff;
    border-radius: 0;
    transition: all .2s ease;
    cursor: pointer;
    user-select: none;
    white-space: nowrap;
}
.btn-primary { background: #fff; color: #000; }
.btn-primary:hover { background: var(--accent); border-color: var(--accent); color: #000; box-shadow: 0 0 24px rgba(57,255,20,.4); }
.btn-ghost { background: transparent; color: #fff; }
.btn-ghost:hover { background: #fff; color: #000; }
.btn-lg { padding: 16px 32px; font-size: 14px; }

.mobile-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    width: 32px;
    height: 32px;
    align-items: center;
    justify-content: center;
}
.mobile-toggle span {
    display: block;
    width: 22px;
    height: 2px;
    background: #fff;
    transition: all .25s ease;
}

/* ============ HERO ============ */
.hero {
    position: relative;
    min-height: calc(100vh - var(--header-h));
    display: flex;
    align-items: center;
    padding: 80px 0 100px;
    border-bottom: 1px solid var(--border);
    overflow: hidden;
}
.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background:
        radial-gradient(ellipse at top left, rgba(57,255,20,.08), transparent 50%),
        radial-gradient(ellipse at bottom right, rgba(57,255,20,.04), transparent 50%);
    pointer-events: none;
}
.hero::after {
    content: '';
    position: absolute;
    inset: 0;
    background-image:
        linear-gradient(to right, rgba(255,255,255,.02) 1px, transparent 1px),
        linear-gradient(to bottom, rgba(255,255,255,.02) 1px, transparent 1px);
    background-size: 40px 40px;
    pointer-events: none;
    mask-image: radial-gradient(ellipse at center, #000 30%, transparent 70%);
    -webkit-mask-image: radial-gradient(ellipse at center, #000 30%, transparent 70%);
}
.hero-inner {
    display: grid;
    grid-template-columns: 1.1fr 1fr;
    gap: 64px;
    align-items: center;
    position: relative;
    z-index: 1;
}
.hero-title {
    font-size: clamp(56px, 9vw, 128px);
    font-weight: 700;
    line-height: .95;
    letter-spacing: -.03em;
    color: #fff;
    margin-bottom: 32px;
    text-transform: uppercase;
}
.hero-title.glitch {
    position: relative;
    color: #fff;
}
.hero-title.glitch::before,
.hero-title.glitch::after {
    content: attr(data-text);
    position: absolute;
    top: 0; left: 0;
    width: 100%;
    overflow: hidden;
    color: var(--accent);
    opacity: .7;
    pointer-events: none;
}
.hero-title.glitch::before {
    transform: translate(-2px, 0);
    clip-path: polygon(0 0, 100% 0, 100% 35%, 0 35%);
    animation: glitchTop 4s infinite steps(1);
}
.hero-title.glitch::after {
    transform: translate(2px, 0);
    clip-path: polygon(0 65%, 100% 65%, 100% 100%, 0 100%);
    animation: glitchBot 4s infinite steps(1);
}
@keyframes glitchTop {
    0%, 92%, 100% { transform: translate(0,0); opacity: 0; }
    93% { transform: translate(-3px, -1px); opacity: .8; }
    95% { transform: translate(2px, 1px); opacity: .6; }
    97% { transform: translate(-1px, 0); opacity: .4; }
}
@keyframes glitchBot {
    0%, 92%, 100% { transform: translate(0,0); opacity: 0; }
    93% { transform: translate(3px, 1px); opacity: .8; }
    95% { transform: translate(-2px, -1px); opacity: .6; }
    97% { transform: translate(1px, 0); opacity: .4; }
}
.hero-sub {
    font-size: 16px;
    color: #b5b5b5;
    margin-bottom: 36px;
    max-width: 540px;
    line-height: 1.7;
}
.hero-actions {
    display: flex;
    gap: 16px;
    margin-bottom: 28px;
    flex-wrap: wrap;
}
.hero-stats {
    font-size: 13px;
    color: var(--text-mute);
    letter-spacing: .04em;
}
.hero-stats strong { color: var(--accent); }

/* Terminal card */
.terminal-card {
    background: #050505;
    border: 1px solid var(--border);
    border-radius: 4px;
    overflow: hidden;
    box-shadow:
        0 30px 60px rgba(0,0,0,.5),
        0 0 0 1px rgba(57,255,20,.06) inset;
    position: relative;
}
.terminal-card::after {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0; bottom: 0;
    background: repeating-linear-gradient(
        to bottom,
        transparent 0,
        transparent 2px,
        rgba(255,255,255,.02) 3px
    );
    pointer-events: none;
}
.terminal-bar {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 16px;
    background: #111;
    border-bottom: 1px solid var(--border);
    position: relative;
    z-index: 1;
}
.dot {
    width: 12px; height: 12px;
    border-radius: 50%;
    display: inline-block;
}
.dot.red { background: #ff5f57; }
.dot.yellow { background: #ffbd2e; }
.dot.green { background: #28c941; }
.terminal-title {
    margin-left: 12px;
    font-size: 12px;
    color: var(--text-mute);
    letter-spacing: .04em;
}
.terminal-body {
    padding: 24px;
    font-family: 'JetBrains Mono', 'Space Mono', monospace;
    font-size: 13px;
    line-height: 1.7;
    color: #cfcfcf;
    position: relative;
    z-index: 1;
    min-height: 200px;
}
.terminal-body pre, .terminal-body code {
    font-family: inherit;
    color: inherit;
    white-space: pre-wrap;
    word-break: break-all;
}
.terminal-body strong { color: var(--accent); font-weight: 700; }
.terminal-large { max-width: 880px; margin: 0 auto; }
.terminal-large .terminal-body { padding: 32px; font-size: 14px; }

.cursor-blink {
    display: inline-block;
    color: var(--accent);
    animation: blink 1s steps(2) infinite;
    font-weight: 700;
}
@keyframes blink { 50% { opacity: 0; } }

/* Scroll down */
.scroll-down {
    position: absolute;
    bottom: 28px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    color: var(--text-mute);
    font-size: 11px;
    letter-spacing: .2em;
    text-transform: uppercase;
    z-index: 2;
}
.scroll-down .arrow {
    font-size: 16px;
    color: var(--accent);
    animation: bounce 1.6s ease-in-out infinite;
}
@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(6px); }
}

/* ============ MARQUEE ============ */
.marquee {
    background: var(--accent);
    color: #000;
    overflow: hidden;
    padding: 14px 0;
    border-top: 1px solid #000;
    border-bottom: 1px solid #000;
}
.marquee-track {
    display: inline-flex;
    white-space: nowrap;
    animation: marquee 30s linear infinite;
    gap: 24px;
    font-family: 'Space Mono', monospace;
    font-weight: 700;
    font-size: 16px;
    letter-spacing: .04em;
}
.marquee-track span { padding: 0 8px; }
@keyframes marquee {
    from { transform: translateX(0); }
    to { transform: translateX(-50%); }
}

/* ============ SECTIONS ============ */
.section {
    padding: 100px 0;
    border-bottom: 1px solid var(--border);
    position: relative;
}
.section.alt { background: #050505; }
.section-head {
    margin-bottom: 56px;
    max-width: 880px;
}
.section-num {
    display: inline-block;
    color: var(--accent);
    font-family: 'Space Mono', monospace;
    font-size: 14px;
    letter-spacing: .2em;
    font-weight: 700;
    margin-bottom: 12px;
}
.section-title {
    font-size: clamp(36px, 5vw, 56px);
    font-weight: 700;
    text-transform: uppercase;
    margin-bottom: 16px;
    line-height: 1.1;
}
.section-title .text-mute { color: var(--text-mute); }
.section-lead {
    font-size: 16px;
    color: #b5b5b5;
    line-height: 1.7;
    max-width: 720px;
}
.text-accent { color: var(--accent); }
.text-mute { color: var(--text-mute); }

.sub-head {
    font-size: 18px;
    color: var(--accent);
    text-transform: uppercase;
    letter-spacing: .15em;
    margin: 48px 0 20px;
    font-weight: 700;
    border-left: 3px solid var(--accent);
    padding-left: 12px;
}

/* ============ FEATURE GRID ============ */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1px;
    background: var(--border);
    border: 1px solid var(--border);
}
.feature-grid.grid-4 { grid-template-columns: repeat(4, 1fr); }

.feature-card {
    background: #000;
    padding: 36px 28px;
    position: relative;
    transition: background .2s ease, transform .2s ease;
    min-height: 220px;
    display: flex;
    flex-direction: column;
}
.feature-card > .card-link {
    position: absolute;
    inset: 0;
    z-index: 2;
    text-decoration: none;
    color: inherit;
    display: flex;
    flex-direction: column;
}
.feature-card > .card-link:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: -2px;
}
.feature-card > .card-link > * {
    pointer-events: none;
}
.feature-card:hover {
    background: #0a0a0a;
    transform: translateY(-2px);
    box-shadow: 0 16px 40px rgba(57,255,20,.08);
}
.feature-card.small { padding: 28px 22px; min-height: 180px; }
.card-num {
    font-family: 'Space Mono', monospace;
    font-size: 12px;
    color: var(--accent);
    letter-spacing: .15em;
    font-weight: 700;
    margin-bottom: 12px;
}
.feature-card h3 {
    font-size: 17px;
    color: #fff;
    margin-bottom: 10px;
    line-height: 1.3;
}
.feature-card.small h3 { font-size: 15px; }
.feature-card p {
    font-size: 13px;
    color: #a5a5a5;
    line-height: 1.65;
    flex: 1;
}
.feature-card::after {
    content: '↗';
    position: absolute;
    top: 24px;
    right: 24px;
    color: var(--text-dim);
    font-size: 14px;
    transition: color .2s ease, transform .2s ease;
}
.feature-card:hover::after {
    color: var(--accent);
    transform: translate(2px, -2px);
}

/* ============ TERMINAL SECTION ============ */
.section-terminal { background: #050505; padding: 80px 0; }

/* ============ PRICING ============ */
.pricing-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1px;
    background: var(--border);
    border: 1px solid var(--border);
}
.price-card {
    background: #000;
    padding: 40px 32px;
    display: flex;
    flex-direction: column;
    transition: background .2s ease;
}
.price-card:hover { background: #0a0a0a; }
.price-card.featured {
    background: #050505;
    position: relative;
    border: 2px solid var(--accent);
    box-shadow: 0 0 60px rgba(57,255,20,.15);
    transform: scale(1.02);
    z-index: 1;
}
.price-card.featured::before {
    content: '★ 推荐';
    position: absolute;
    top: -12px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--accent);
    color: #000;
    font-size: 11px;
    font-weight: 700;
    padding: 4px 12px;
    letter-spacing: .15em;
    font-family: 'Space Mono', monospace;
}
.price-card header { margin-bottom: 24px; border-bottom: 1px dashed var(--border-2); padding-bottom: 20px; }
.price-tag {
    display: inline-block;
    color: var(--accent);
    font-size: 13px;
    font-weight: 700;
    letter-spacing: .1em;
    margin-bottom: 8px;
    text-transform: uppercase;
}
.price-card h3 {
    font-size: 26px;
    color: #fff;
    margin-bottom: 4px;
}
.price-card ul {
    flex: 1;
    margin-bottom: 24px;
}
.price-card li {
    color: #c5c5c5;
    font-size: 13px;
    padding: 8px 0;
    border-bottom: 1px dashed var(--border);
    display: flex;
    align-items: flex-start;
    gap: 8px;
    line-height: 1.6;
}
.price-card li::before {
    content: '✓';
    color: var(--accent);
    font-weight: 700;
    flex-shrink: 0;
}
.price-card .btn-primary,
.price-card .btn-ghost {
    width: 100%;
    text-align: center;
}

/* ============ COURSES ============ */
.course-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1px;
    background: var(--border);
    border: 1px solid var(--border);
}
.course-card {
    background: #000;
    padding: 32px 28px;
    transition: background .2s ease;
    position: relative;
}
.course-card:hover { background: #0a0a0a; }
.course-num {
    font-family: 'Space Mono', monospace;
    font-size: 12px;
    color: var(--accent);
    letter-spacing: .15em;
    font-weight: 700;
    margin-bottom: 16px;
}
.course-card h3 {
    font-size: 18px;
    color: #fff;
    margin-bottom: 12px;
    line-height: 1.35;
}
.course-card p {
    font-size: 13px;
    color: #a5a5a5;
    line-height: 1.65;
    margin-bottom: 16px;
}
.course-meta {
    display: inline-block;
    color: var(--accent);
    font-size: 11px;
    font-weight: 700;
    letter-spacing: .1em;
    text-transform: uppercase;
    border: 1px solid var(--accent);
    padding: 4px 10px;
    border-radius: 0;
}

/* ============ BLOG ============ */
.blog-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}
.blog-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    padding: 32px 28px;
    transition: all .2s ease;
}
.blog-card:hover {
    border-color: var(--accent);
    transform: translateY(-4px);
    box-shadow: 0 16px 40px rgba(57,255,20,.1);
}
.blog-date {
    color: var(--accent);
    font-size: 12px;
    font-weight: 700;
    letter-spacing: .1em;
    margin-bottom: 12px;
    font-family: 'Space Mono', monospace;
}
.blog-card h3 {
    font-size: 19px;
    color: #fff;
    margin-bottom: 12px;
    line-height: 1.4;
}
.blog-card p {
    font-size: 13px;
    color: #a5a5a5;
    line-height: 1.7;
    margin-bottom: 16px;
}
.read-more {
    color: var(--accent);
    font-size: 12px;
    font-weight: 700;
    letter-spacing: .1em;
    text-transform: uppercase;
    font-family: 'Space Mono', monospace;
}
.read-more:hover { text-decoration: underline; }

/* ============ FAQ ============ */
.faq-list {
    max-width: 880px;
    margin: 0 auto;
}
.faq-item {
    border: 1px solid var(--border);
    border-bottom: 0;
    background: #000;
    transition: border-color .2s ease;
}
.faq-item:last-child { border-bottom: 1px solid var(--border); }
.faq-item[open] { border-color: var(--accent); background: #050505; }
.faq-item summary {
    list-style: none;
    cursor: pointer;
    padding: 22px 28px;
    font-size: 15px;
    color: #fff;
    font-weight: 700;
    position: relative;
    transition: color .2s ease;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
    content: '+';
    position: absolute;
    right: 28px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--accent);
    font-size: 22px;
    font-weight: 300;
    transition: transform .25s ease;
    line-height: 1;
}
.faq-item[open] summary::after { content: '−'; }
.faq-item summary:hover { color: var(--accent); }
.faq-item p {
    padding: 0 28px 24px;
    color: #b5b5b5;
    font-size: 14px;
    line-height: 1.75;
}

/* ============ CTA ============ */
.section-cta {
    padding: 100px 0;
    background:
        radial-gradient(ellipse at center, rgba(57,255,20,.08), transparent 60%),
        #000;
    text-align: center;
    border-bottom: 1px solid var(--border);
}
.cta-title {
    font-size: clamp(36px, 6vw, 72px);
    font-weight: 700;
    text-transform: uppercase;
    margin-bottom: 20px;
    line-height: 1.1;
}
.section-cta p {
    font-size: 16px;
    color: #b5b5b5;
    margin-bottom: 36px;
    line-height: 1.7;
}
.cta-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

/* ============ FOOTER ============ */
.site-footer {
    background: #000;
    border-top: 1px solid var(--border);
    padding: 80px 0 24px;
}
.footer-grid {
    display: grid;
    grid-template-columns: 1.4fr repeat(4, 1fr);
    gap: 40px;
    margin-bottom: 48px;
}
.footer-brand .logo { margin-bottom: 16px; }
.footer-brand p {
    color: #a5a5a5;
    font-size: 13px;
    line-height: 1.7;
    margin-bottom: 12px;
}
.footer-meta { color: var(--text-dim) !important; font-size: 12px !important; }
.footer-beian { color: #8a8a8a; }
.footer-beian a { color: #8a8a8a; text-decoration: none; transition: color .2s; }
.footer-beian a:hover { color: var(--accent); }
.beian-icon { display: inline-block; margin-right: 4px; font-size: 11px; }
.footer-col h4 {
    color: var(--accent);
    font-size: 12px;
    letter-spacing: .15em;
    text-transform: uppercase;
    margin-bottom: 16px;
    border-bottom: 1px dashed var(--border-2);
    padding-bottom: 8px;
}
.footer-col a {
    display: block;
    color: #b5b5b5;
    font-size: 13px;
    padding: 5px 0;
    transition: color .2s ease;
}
.footer-col a:hover { color: var(--accent); }
.footer-bottom {
    border-top: 1px solid var(--border);
    padding-top: 20px;
    display: flex;
    flex-wrap: wrap;
    gap: 24px;
    font-size: 11px;
    color: var(--text-mute);
    letter-spacing: .08em;
    font-family: 'Space Mono', monospace;
}

/* ============ FLOATING BUTTONS ============ */
.back-to-top, .customer-service {
    position: fixed;
    width: 44px;
    height: 44px;
    background: rgba(10,10,10,.9);
    border: 1px solid var(--border);
    color: var(--accent);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    z-index: 90;
    font-family: 'Space Mono', monospace;
    font-size: 14px;
    font-weight: 700;
    transition: all .2s ease;
    backdrop-filter: blur(8px);
}
.back-to-top {
    right: 24px;
    bottom: 24px;
    opacity: 0;
    pointer-events: none;
}
.back-to-top.visible {
    opacity: 1;
    pointer-events: auto;
}
.customer-service {
    right: 24px;
    bottom: 80px;
    color: #fff;
}
.back-to-top:hover, .customer-service:hover {
    background: var(--accent);
    color: #000;
    border-color: var(--accent);
}

/* ============ CS MODAL (WeChat QR) ============ */
.cs-modal {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.75);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    opacity: 0;
    pointer-events: none;
    transition: opacity .25s ease;
    padding: 24px;
}
.cs-modal.open {
    opacity: 1;
    pointer-events: auto;
}
.cs-modal-box {
    background: #0a0a0a;
    border: 1px solid var(--accent, #39FF14);
    box-shadow: 0 0 40px rgba(57, 255, 20, 0.25);
    padding: 32px;
    max-width: 360px;
    width: 100%;
    position: relative;
    text-align: center;
    transform: translateY(20px);
    transition: transform .25s ease;
}
.cs-modal.open .cs-modal-box {
    transform: translateY(0);
}
.cs-modal-close {
    position: absolute;
    top: 12px;
    right: 12px;
    width: 32px;
    height: 32px;
    background: transparent;
    border: 1px solid var(--border, #1f1f1f);
    color: #fff;
    font-size: 18px;
    line-height: 1;
    cursor: pointer;
    transition: all .2s ease;
    font-family: inherit;
}
.cs-modal-close:hover {
    background: var(--accent, #39FF14);
    color: #000;
    border-color: var(--accent, #39FF14);
}
.cs-modal-qr {
    width: 240px;
    height: 240px;
    margin: 0 auto 20px;
    background: #fff;
    padding: 8px;
    display: block;
    object-fit: contain;
}
.cs-modal-title {
    font-size: 18px;
    color: #fff;
    margin: 0 0 8px;
    font-weight: 700;
    letter-spacing: .04em;
}
.cs-modal-wechat {
    color: var(--accent, #39FF14);
    font-family: 'Space Mono', monospace;
    font-size: 22px;
    font-weight: 700;
    margin: 0 0 12px;
    letter-spacing: .08em;
}
.cs-modal-tip {
    color: #888;
    font-size: 13px;
    margin: 0;
    line-height: 1.5;
}

/* ============ RESPONSIVE ============ */
@media (max-width: 1024px) {
    .hero-inner { grid-template-columns: 1fr; gap: 48px; }
    .feature-grid, .feature-grid.grid-4 { grid-template-columns: repeat(2, 1fr); }
    .pricing-grid { grid-template-columns: 1fr; }
    .price-card.featured { transform: none; }
    .course-grid { grid-template-columns: repeat(2, 1fr); }
    .blog-grid { grid-template-columns: 1fr; }
    .footer-grid { grid-template-columns: repeat(2, 1fr); gap: 32px; }
    .mega-menu { width: 600px; grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
    :root { --header-h: 60px; }
    .primary-nav {
        position: fixed;
        top: var(--header-h);
        left: 0; right: 0;
        background: #000;
        border-bottom: 1px solid var(--border);
        padding: 24px;
        max-height: calc(100vh - var(--header-h));
        overflow-y: auto;
        transform: translateY(-110%);
        transition: transform .3s ease;
        z-index: 99;
    }
    .primary-nav.open { transform: translateY(0); }
    .primary-nav > ul {
        flex-direction: column;
        align-items: stretch;
        gap: 0;
    }
    .primary-nav > ul > li { border-bottom: 1px solid var(--border); }
    .nav-link { display: block; padding: 14px 0; font-size: 14px; }
    .mega-menu {
        position: static;
        width: 100%;
        transform: none;
        opacity: 1;
        visibility: visible;
        pointer-events: auto;
        padding: 12px 0 0;
        background: transparent;
        border: 0;
        grid-template-columns: 1fr;
        box-shadow: none;
    }
    .mega-menu::before { display: none; }
    .header-cta .btn-link { display: none; }
    .header-cta .btn-primary { padding: 8px 16px; font-size: 12px; }
    .mobile-toggle { display: flex; }
    .hero { min-height: auto; padding: 60px 0 80px; }
    .section { padding: 64px 0; }
    .feature-grid, .feature-grid.grid-4 { grid-template-columns: 1fr; }
    .course-grid { grid-template-columns: 1fr; }
    .footer-grid { grid-template-columns: 1fr; }
    .scroll-down { display: none; }
    .customer-service { bottom: 80px; right: 16px; width: 40px; height: 40px; font-size: 12px; }
    .back-to-top { right: 16px; bottom: 16px; width: 40px; height: 40px; }
}

/* ============ QUICK ACCESS ============ */
.quick-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1px;
    background: var(--border);
    border: 1px solid var(--border);
}
.quick-card {
    background: #000;
    padding: 56px 40px;
    position: relative;
    transition: background .2s ease, transform .2s ease;
    min-height: 280px;
    display: flex;
    flex-direction: column;
    color: inherit;
}
.quick-card:hover {
    background: #0a0a0a;
    transform: translateY(-4px);
    box-shadow: 0 20px 50px rgba(57,255,20,.1);
}
.quick-card:hover .quick-arrow {
    color: var(--accent);
    transform: translateX(6px);
}
.quick-num {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 56px;
    height: 56px;
    background: transparent;
    border: 2px solid var(--accent);
    color: var(--accent);
    font-family: 'Space Mono', monospace;
    font-size: 28px;
    font-weight: 700;
    margin-bottom: 24px;
}
.quick-card h3 {
    font-size: 24px;
    color: #fff;
    margin-bottom: 12px;
}
.quick-card p {
    color: #a5a5a5;
    font-size: 14px;
    line-height: 1.7;
    flex: 1;
}
.quick-arrow {
    color: var(--text-dim);
    font-size: 24px;
    margin-top: 20px;
    transition: color .2s ease, transform .2s ease;
    display: inline-block;
}

/* ============ REVEAL ANIMATION ============ */
.reveal { opacity: 0; transform: translateY(20px); transition: opacity .6s ease, transform .6s ease; }
.reveal.in-view { opacity: 1; transform: translateY(0); }
.reveal:nth-child(2) { transition-delay: .05s; }
.reveal:nth-child(3) { transition-delay: .1s; }
.reveal:nth-child(4) { transition-delay: .15s; }
.reveal:nth-child(5) { transition-delay: .2s; }
.reveal:nth-child(6) { transition-delay: .25s; }

/* ============ HEADER SCROLLED ============ */
.site-header.scrolled {
    background: rgba(0,0,0,.95);
    border-bottom-color: var(--border-2);
}

/* ============ ACCESSIBILITY ============ */
:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: .01ms !important;
        transition-duration: .01ms !important;
    }
}