:root {
    --color-bg: #ffffff;
    --color-bg-soft: #f7f7f8;
    --color-bg-dark: #0f172a;
    --color-text: #1f2937;
    --color-text-light: #6b7280;
    --color-accent: #b91c1c;
    --color-accent-light: #fee2e2;
    --color-border: #e5e7eb;
    --font-stack: 'Inter', 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    --radius: 0.75rem;
    --shadow: 0 4px 24px rgba(0, 0, 0, 0.06);
    --max-width: 1200px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-stack);
    color: var(--color-text);
    background: var(--color-bg);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
}

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

.container {
    width: min(92%, var(--max-width));
    margin-inline: auto;
}

/* Header */
.site-header {
    position: fixed;
    inset: 0 0 auto 0;
    z-index: 100;
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--color-border);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    font-weight: 600;
    font-size: 1.25rem;
}

.logo-disk {
    position: relative;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    flex-shrink: 0;
}

.cogency-disk {
    position: relative;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    overflow: hidden;
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.18);
}

.cogency-disk canvas {
    width: 100%;
    height: 100%;
    border-radius: 50%;
}

.cogency-disk.large {
    width: 110px;
    height: 110px;
}

@keyframes spin-logo {
    from { transform: rotateY(0deg); }
    to { transform: rotateY(360deg); }
}

.main-nav {
    display: flex;
    align-items: center;
    gap: 2rem;
    font-size: 0.95rem;
    color: var(--color-text-light);
}

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

.nav-cta {
    padding: 0.5rem 1.1rem;
    background: var(--color-text);
    color: #fff;
    border-radius: 999px;
    transition: background 0.2s;
}

.nav-cta:hover {
    background: var(--color-accent);
    color: #fff;
}

.lang-switch {
    display: flex;
    border: 1px solid var(--color-border);
    border-radius: 999px;
    overflow: hidden;
}

.lang-btn {
    border: none;
    background: transparent;
    padding: 0.35rem 0.75rem;
    cursor: pointer;
    font-size: 0.85rem;
    color: var(--color-text-light);
}

.lang-btn.active {
    background: var(--color-accent);
    color: #fff;
}

.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: transparent;
    border: none;
    cursor: pointer;
}

.menu-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--color-text);
}

/* Hero */
.hero {
    padding: 9rem 0 5rem;
    background: linear-gradient(180deg, #fff 0%, var(--color-bg-soft) 100%);
    overflow: hidden;
}

.hero-inner {
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    gap: 4rem;
    align-items: center;
}

.eyebrow {
    color: var(--color-accent);
    font-weight: 500;
    letter-spacing: 0.05em;
    margin-bottom: 1rem;
}

.hero h1 {
    font-size: clamp(2.2rem, 5vw, 3.6rem);
    line-height: 1.15;
    font-weight: 700;
    margin-bottom: 1.5rem;
}

.hero-lead {
    font-size: 1.15rem;
    color: var(--color-text-light);
    max-width: 540px;
    margin-bottom: 2rem;
}

.hero-actions {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.85rem 1.6rem;
    border-radius: 999px;
    font-weight: 500;
    transition: transform 0.15s, box-shadow 0.2s;
    border: none;
    cursor: pointer;
}

.btn:hover {
    transform: translateY(-2px);
}

.btn-primary {
    background: var(--color-accent);
    color: #fff;
    box-shadow: 0 4px 16px rgba(185, 28, 28, 0.25);
}

.btn-secondary {
    background: #fff;
    color: var(--color-text);
    border: 1px solid var(--color-border);
}

/* AI orbit visual */
.hero-visual {
    display: grid;
    place-items: center;
}

@keyframes ai-orbit-spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

@keyframes ai-node-counter {
    from { transform: rotate(0deg); }
    to { transform: rotate(-360deg); }
}

.ai-orbit-system {
    position: relative;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 340px;
    height: 340px;
}

.ai-orbit-system:hover .ai-orbit-ring,
.ai-orbit-system:hover .ai-orbit-node-inner {
    animation-play-state: paused;
}

.ai-orbit-logo {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.ai-orbit-ring {
    position: absolute;
    inset: 0;
    border-radius: 50%;
    pointer-events: none;
}

.ai-ring-inner {
    animation: ai-orbit-spin 22s linear infinite;
}

.ai-ring-outer {
    animation: ai-orbit-spin 30s linear infinite reverse;
}

@keyframes ai-orbit-spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

@keyframes ai-node-counter {
    from { transform: rotate(0deg); }
    to { transform: rotate(-360deg); }
}

.ai-orbit-node {
    position: absolute;
    display: grid;
    place-items: center;
    width: 64px;
    height: 64px;
    border-radius: 50%;
    font-size: 0.75rem;
    font-weight: 600;
    color: #fff;
    text-align: center;
    line-height: 1.1;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.12);
}

.ai-orbit-node-inner {
    display: inline-block;
    animation: ai-node-counter 22s linear infinite;
}

.ai-ring-outer .ai-orbit-node-inner {
    animation-duration: 30s;
    animation-direction: reverse;
}

/* Inner ring — 4 AIs */
.node-qwen    { top: 32px; left: 138px; background: #7c3aed; }
.node-kimi    { top: 138px; left: 232px; background: #f97316; }
.node-doubao  { top: 244px; left: 138px; background: #22c55e; }
.node-wenxin  { top: 138px; left: 44px;  background: #3b82f6; }

/* Outer ring — 6 AIs */
.node-hunyuan { top: 0; left: 138px; background: #14b8a6; }
.node-spark   { top: 58px; left: 270px; background: #ef4444; }
.node-baichuan{ top: 206px; left: 270px; background: #6366f1; font-size: 0.65rem; }
.node-zhipu   { top: 276px; left: 138px; background: #ec4899; }
.node-yuanbao { top: 206px; left: 6px;   background: #eab308; color: #1f2937; }
.node-deepseek{ top: 58px; left: 6px;    background: #475569; font-size: 0.65rem; }

/* Sections */
.section {
    padding: 6rem 0;
}

/* Coming soon */
.coming-soon {
    background: linear-gradient(135deg, var(--color-bg-dark) 0%, #1e293b 100%);
    color: #fff;
    padding: 5rem 0;
    text-align: center;
}

.coming-soon-inner {
    max-width: 760px;
    margin-inline: auto;
}

.coming-badge {
    display: inline-block;
    padding: 0.35rem 1rem;
    background: var(--color-accent);
    color: #fff;
    font-size: 0.8rem;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    border-radius: 999px;
    margin-bottom: 1.5rem;
}

.coming-soon h2 {
    font-size: clamp(1.6rem, 3.5vw, 2.2rem);
    margin-bottom: 1rem;
    line-height: 1.25;
}

.coming-soon > .container > p {
    color: #cbd5e1;
    font-size: 1.05rem;
    margin-bottom: 2rem;
}

.platform-badges {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.75rem;
    margin-bottom: 2.5rem;
}

.platform-badge {
    padding: 0.6rem 1.2rem;
    background: rgba(255, 255, 255, 0.08);
    border: 1px solid rgba(255, 255, 255, 0.15);
    border-radius: 999px;
    font-size: 0.9rem;
    font-weight: 500;
    color: #fff;
    transition: background 0.2s, transform 0.2s;
}

.platform-badge:hover {
    background: rgba(255, 255, 255, 0.16);
    transform: translateY(-2px);
}

.platform-badge.wechat {
    background: rgba(34, 197, 94, 0.18);
    border-color: rgba(34, 197, 94, 0.4);
    color: #86efac;
}

.coming-note {
    color: #94a3b8;
    font-size: 0.95rem;
    margin-bottom: 1rem;
}

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

.coming-form input {
    min-width: 280px;
    padding: 0.85rem 1.1rem;
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.08);
    color: #fff;
    font-family: inherit;
    font-size: 1rem;
}

.coming-form input::placeholder {
    color: #94a3b8;
}

.coming-form input:focus {
    outline: none;
    border-color: var(--color-accent);
    background: rgba(255, 255, 255, 0.12);
}

.coming-form button {
    padding: 0.85rem 1.8rem;
}

.section-header {
    text-align: center;
    max-width: 680px;
    margin: 0 auto 3.5rem;
}

.section-header h2 {
    font-size: clamp(1.7rem, 3.5vw, 2.4rem);
    margin-bottom: 1rem;
}

.section-header p {
    color: var(--color-text-light);
    font-size: 1.1rem;
}

/* Cards */
.cards-grid {
    display: grid;
    gap: 1.5rem;
}

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

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

.card, .case-card {
    background: #fff;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: 2rem;
    transition: box-shadow 0.2s, transform 0.2s;
}

.card:hover, .case-card:hover {
    box-shadow: var(--shadow);
    transform: translateY(-4px);
}

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

.card h3, .case-card h3 {
    font-size: 1.15rem;
    margin-bottom: 0.75rem;
}

.card p, .case-card p {
    color: var(--color-text-light);
    font-size: 0.95rem;
}

/* How */
.how {
    background: var(--color-bg-dark);
    color: #fff;
}

.how .section-header.light p {
    color: #94a3b8;
}

.steps {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

.step {
    padding: 2rem;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid rgba(255, 255, 255, 0.08);
    border-radius: var(--radius);
}

.step-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--color-accent);
    margin-bottom: 1rem;
    line-height: 1;
}

.step h3 {
    font-size: 1.2rem;
    margin-bottom: 0.75rem;
}

.step p {
    color: #cbd5e1;
}

/* Trust */
.trust-grid {
    display: grid;
    grid-template-columns: 1fr 0.6fr;
    gap: 4rem;
    align-items: center;
}

.trust-copy h2 {
    font-size: clamp(1.7rem, 3.5vw, 2.4rem);
    margin-bottom: 1rem;
}

.trust-copy > p {
    color: var(--color-text-light);
    margin-bottom: 2rem;
}

.trust-list {
    list-style: none;
    display: grid;
    gap: 0.75rem;
}

.trust-list li {
    position: relative;
    padding-left: 1.75rem;
    font-weight: 500;
}

.trust-list li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0.55rem;
    width: 8px;
    height: 8px;
    background: var(--color-accent);
    border-radius: 50%;
}

.trust-visual {
    display: grid;
    place-items: center;
}

.shield {
    width: 180px;
    height: 200px;
    background: linear-gradient(135deg, var(--color-accent), #991b1b);
    clip-path: polygon(50% 0, 100% 20%, 100% 60%, 50% 100%, 0 60%, 0 20%);
    display: grid;
    place-items: center;
    color: #fff;
    font-size: 4rem;
    font-weight: 700;
}

/* Contact */
.contact {
    background: var(--color-bg-soft);
    text-align: center;
}

.contact-inner {
    max-width: 680px;
}

.contact h2 {
    font-size: clamp(1.7rem, 3.5vw, 2.4rem);
    margin-bottom: 0.75rem;
}

.contact > .container > p {
    color: var(--color-text-light);
    margin-bottom: 2.5rem;
}

.contact-form {
    display: grid;
    gap: 1rem;
    text-align: left;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.contact-form input,
.contact-form textarea {
    width: 100%;
    padding: 0.9rem 1rem;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    font-family: inherit;
    font-size: 1rem;
    background: #fff;
}

.contact-form input:focus,
.contact-form textarea:focus {
    outline: none;
    border-color: var(--color-accent);
    box-shadow: 0 0 0 3px var(--color-accent-light);
}

.contact-form button {
    justify-self: center;
    min-width: 160px;
}

.contact-note {
    margin-top: 1.5rem;
    color: var(--color-text-light);
    font-size: 0.95rem;
}

/* Footer */
.site-footer {
    border-top: 1px solid var(--color-border);
    padding: 2rem 0;
}

.footer-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: var(--color-text-light);
    font-size: 0.9rem;
}

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

/* Responsive */
@media (max-width: 900px) {
    .main-nav {
        position: fixed;
        inset: 72px 0 auto 0;
        flex-direction: column;
        gap: 0;
        background: #fff;
        border-bottom: 1px solid var(--color-border);
        padding: 1rem 0;
        transform: translateY(-150%);
        transition: transform 0.3s;
    }

    .main-nav.open {
        transform: translateY(0);
    }

    .main-nav a {
        padding: 0.9rem 1.5rem;
        width: 100%;
    }

    .nav-cta {
        border-radius: 0;
        margin: 0.5rem 1rem;
        text-align: center;
    }

    .menu-toggle {
        display: flex;
    }

    .hero-inner {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-lead {
        margin-inline: auto;
    }

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

    .hero-visual {
        order: -1;
    }

    .orbit {
        width: 260px;
        height: 260px;
    }

    .orbit-node {
        width: 64px;
        height: 64px;
    }

    .orbit-node-inner {
        font-size: 0.7rem;
    }

    .cards-grid.three,
    .cards-grid.two,
    .steps,
    .trust-grid,
    .form-row {
        grid-template-columns: 1fr;
    }

    .trust-visual {
        order: -1;
    }

    .coming-form {
        flex-direction: column;
        align-items: stretch;
        max-width: 340px;
        margin-inline: auto;
    }

    .coming-form input {
        min-width: auto;
    }

    .platform-badges {
        gap: 0.5rem;
    }

    .platform-badge {
        padding: 0.5rem 0.9rem;
        font-size: 0.85rem;
    }

    .ai-orbit-system {
        width: 280px;
        height: 280px;
    }

    .cogency-disk.large {
        width: 90px;
        height: 90px;
    }

    .cogency-disk.large::after {
        inset: 22px;
    }

    .ai-orbit-node {
        width: 48px;
        height: 48px;
        font-size: 0.6rem;
    }

    .node-qwen    { top: 24px; left: 116px; }
    .node-kimi    { top: 116px; left: 192px; }
    .node-doubao  { top: 208px; left: 116px; }
    .node-wenxin  { top: 116px; left: 40px; }

    .node-hunyuan { top: 0; left: 116px; }
    .node-spark   { top: 48px; left: 220px; }
    .node-baichuan{ top: 170px; left: 220px; font-size: 0.5rem; }
    .node-zhipu   { top: 232px; left: 116px; }
    .node-yuanbao { top: 170px; left: 12px; font-size: 0.5rem; }
    .node-deepseek{ top: 48px; left: 12px; font-size: 0.5rem; }

    .header-inner {
        height: 72px;
    }

    .logo-disk {
        width: 40px;
        height: 40px;
    }

    .cogency-disk {
        width: 40px;
        height: 40px;
    }
}