/* ============== Base ============== */
*,*::before,*::after { box-sizing: border-box; }
:root {
    --primary: #1E6FFF;
    --primary-dark: #1656CC;
    --primary-light: #5DA0FF;
    --text: #1A2235;
    --text-soft: #5C6479;
    --text-mute: #8C92A4;
    --bg: #FFFFFF;
    --bg-alt: #F7F9FC;
    --bg-soft: #EEF3FB;
    --border: #E5E9F2;
    --shadow-sm: 0 1px 2px rgba(20,30,60,.04), 0 4px 12px rgba(20,30,60,.04);
    --shadow-md: 0 8px 24px rgba(20,30,60,.08);
    --shadow-lg: 0 24px 60px rgba(20,30,60,.12);
    --radius: 12px;
    --radius-lg: 18px;
    --grad-primary: linear-gradient(135deg, #1E6FFF 0%, #5DA0FF 100%);
}

html { scroll-behavior: smooth; }
body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Helvetica Neue",
                 "Microsoft YaHei", "Segoe UI", Roboto, sans-serif;
    color: var(--text);
    background: var(--bg);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; transition: color .15s; }
a:hover { color: var(--primary); }
h1,h2,h3,h4 { margin: 0 0 .5em; line-height: 1.25; font-weight: 700; letter-spacing: -.01em; }
h1 { font-size: clamp(2rem, 4vw, 3.2rem); }
h2 { font-size: clamp(1.6rem, 3vw, 2.2rem); }
h3 { font-size: 1.15rem; }
p { margin: 0 0 1em; color: var(--text-soft); }

.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }
.grad-text {
    background: var(--grad-primary);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* ============== Buttons ============== */
.btn {
    display: inline-flex; align-items: center; justify-content: center;
    padding: 10px 22px;
    border-radius: 10px;
    font-weight: 600;
    font-size: .95rem;
    border: 1px solid transparent;
    cursor: pointer;
    transition: transform .15s, box-shadow .15s, background .15s;
    white-space: nowrap;
}
.btn-lg { padding: 14px 28px; font-size: 1rem; }
.btn-block { width: 100%; }
.btn-primary {
    background: var(--grad-primary);
    color: #fff;
    box-shadow: 0 6px 20px rgba(30,111,255,.3);
}
.btn-primary:hover { transform: translateY(-1px); box-shadow: 0 10px 28px rgba(30,111,255,.36); color: #fff; }
.btn-ghost {
    background: transparent;
    color: var(--text);
    border-color: var(--border);
}
.btn-ghost:hover { border-color: var(--primary); color: var(--primary); }

/* ============== Nav ============== */
.nav {
    position: sticky; top: 0; z-index: 100;
    background: rgba(255,255,255,.85);
    backdrop-filter: saturate(180%) blur(12px);
    -webkit-backdrop-filter: saturate(180%) blur(12px);
    border-bottom: 1px solid transparent;
    transition: border-color .2s, box-shadow .2s;
}
.nav.scrolled {
    border-color: var(--border);
    box-shadow: var(--shadow-sm);
}
.nav-inner {
    height: 68px;
    display: flex; align-items: center; gap: 24px;
}
.logo { display: flex; align-items: center; gap: 10px; font-weight: 700; }
.logo-mark { display: inline-flex; }
.logo-text { font-size: 1.15rem; letter-spacing: .02em; }
.nav-links {
    display: flex; gap: 28px;
    margin-left: 36px;
    flex: 1;
}
.nav-links a { color: var(--text-soft); font-size: .95rem; font-weight: 500; }
.nav-links a:hover { color: var(--text); }
.nav-cta { font-size: .9rem; padding: 9px 18px; }
.nav-toggle {
    display: none;
    background: none; border: none; cursor: pointer; padding: 8px;
    flex-direction: column; gap: 4px;
}
.nav-toggle span {
    display: block; width: 22px; height: 2px;
    background: var(--text); border-radius: 2px;
    transition: transform .2s, opacity .2s;
}

/* ============== Hero ============== */
.hero {
    position: relative;
    overflow: hidden;
    padding: 80px 0 100px;
}
.hero-bg {
    position: absolute; inset: 0;
    background:
        radial-gradient(60% 60% at 80% 0%, rgba(93,160,255,.18), transparent 60%),
        radial-gradient(50% 50% at 0% 30%, rgba(30,111,255,.12), transparent 60%),
        linear-gradient(180deg, #fbfdff 0%, #fff 100%);
    z-index: -1;
}
.hero-inner {
    display: grid;
    grid-template-columns: 1.05fr 1fr;
    gap: 56px;
    align-items: center;
}
.badge {
    display: inline-block;
    padding: 6px 14px;
    background: rgba(30,111,255,.1);
    color: var(--primary);
    border-radius: 100px;
    font-size: .82rem;
    font-weight: 600;
    margin-bottom: 24px;
}
.hero h1 { margin-bottom: 24px; }
.hero-sub {
    font-size: 1.1rem;
    color: var(--text-soft);
    max-width: 560px;
    margin-bottom: 32px;
}
.hero-cta {
    display: flex; gap: 12px; flex-wrap: wrap;
    margin-bottom: 40px;
}
.hero-meta {
    display: flex; gap: 32px; flex-wrap: wrap;
    font-size: .88rem;
    color: var(--text-mute);
}
.hero-meta strong {
    display: block;
    color: var(--text);
    font-size: .92rem;
    margin-bottom: 2px;
}

/* Hero mock window */
.hero-mock { position: relative; }
.mock-window {
    background: #fff;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    overflow: hidden;
    border: 1px solid var(--border);
    transform: perspective(1200px) rotateY(-2deg) rotateX(2deg);
}
.mock-bar {
    height: 36px;
    background: #F1F4FA;
    display: flex; align-items: center; gap: 6px;
    padding: 0 14px;
    border-bottom: 1px solid var(--border);
}
.mock-bar span {
    width: 11px; height: 11px; border-radius: 50%;
    background: #FF5F57;
}
.mock-bar span:nth-child(2) { background: #FEBC2E; }
.mock-bar span:nth-child(3) { background: #28C840; }
.mock-body {
    display: grid;
    grid-template-columns: 200px 1fr;
    height: 380px;
}
.mock-side {
    border-right: 1px solid var(--border);
    background: #FAFBFD;
    padding: 12px 8px;
    overflow: hidden;
}
.mock-search {
    height: 28px;
    background: #fff;
    border: 1px solid var(--border);
    border-radius: 6px;
    margin-bottom: 10px;
}
.mock-chat {
    display: grid;
    grid-template-columns: 32px 1fr auto;
    align-items: center;
    gap: 10px;
    padding: 8px;
    border-radius: 8px;
    cursor: pointer;
    margin-bottom: 2px;
}
.mock-chat.active { background: rgba(30,111,255,.08); }
.mock-avatar {
    width: 32px; height: 32px;
    border-radius: 50%;
    color: #fff;
    display: flex; align-items: center; justify-content: center;
    font-size: .78rem;
    font-weight: 600;
}
.mock-avatar.sm { width: 26px; height: 26px; font-size: .7rem; }
.mock-name { font-size: .85rem; font-weight: 600; }
.mock-msg {
    font-size: .72rem;
    color: var(--text-mute);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    max-width: 130px;
}
.mock-dot {
    width: 7px; height: 7px;
    background: #FF5C5C;
    border-radius: 50%;
}
.mock-main {
    padding: 14px;
    background: #fff;
    display: flex; flex-direction: column;
}
.mock-header {
    font-size: .85rem;
    font-weight: 600;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border);
    margin-bottom: 14px;
}
.mock-bubble {
    display: flex; gap: 8px;
    margin-bottom: 12px;
    align-items: flex-start;
}
.mock-bubble.outgoing {
    justify-content: flex-end;
}
.bubble {
    background: #F1F4FA;
    padding: 8px 12px;
    border-radius: 10px;
    font-size: .8rem;
    max-width: 240px;
    line-height: 1.4;
}
.outgoing .bubble {
    background: var(--primary);
    color: #fff;
}
.bubble.file {
    display: flex; gap: 10px; align-items: center;
    background: #fff;
    border: 1px solid var(--border);
}
.file-ico {
    width: 32px; height: 38px;
    background: var(--primary);
    color: #fff;
    border-radius: 4px;
    display: flex; align-items: center; justify-content: center;
    font-size: .65rem;
    font-weight: 700;
}
.file-name { font-size: .8rem; font-weight: 600; color: var(--text); }
.file-meta { font-size: .68rem; color: var(--text-mute); }
.mock-input {
    margin-top: auto;
    padding: 10px 12px;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: .78rem;
    color: var(--text-mute);
}

/* ============== Sections ============== */
.section { padding: 96px 0; }
.section-alt { background: var(--bg-alt); }
.section-head { text-align: center; max-width: 720px; margin: 0 auto 56px; }
.kicker {
    color: var(--primary);
    font-weight: 600;
    letter-spacing: .12em;
    font-size: .82rem;
    text-transform: uppercase;
    margin-bottom: 12px;
    display: inline-block;
}

/* ============== Grid ============== */
.grid { display: grid; gap: 24px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }

/* Feature card */
.card {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 32px;
    transition: transform .2s, box-shadow .2s, border-color .2s;
}
.card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
    border-color: transparent;
}
.card-ico {
    width: 56px; height: 56px;
    border-radius: 14px;
    display: inline-flex;
    align-items: center; justify-content: center;
    margin-bottom: 20px;
}

/* Scene card */
.scene-card {
    background: #fff;
    border-radius: var(--radius-lg);
    padding: 36px 32px;
    border-left: 4px solid var(--primary);
    box-shadow: var(--shadow-sm);
}
.scene-card h3 { margin-bottom: 12px; }

/* ============== Showcase ============== */
.showcase {
    display: grid;
    grid-template-columns: 1fr 1.4fr;
    gap: 40px;
    align-items: center;
}
.show-tabs { display: flex; flex-direction: column; gap: 12px; }
.show-tab {
    padding: 20px 24px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    background: #fff;
    cursor: pointer;
    transition: border-color .15s, transform .15s;
}
.show-tab:hover { border-color: var(--primary-light); }
.show-tab.active {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(30,111,255,.08);
}
.show-tab strong { display: block; margin-bottom: 4px; font-size: 1rem; }
.show-tab span { font-size: .88rem; color: var(--text-mute); }

.show-frame {
    background: #fff;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    box-shadow: var(--shadow-md);
    overflow: hidden;
}
.show-frame-bar {
    background: #F1F4FA;
    height: 32px;
    display: flex; align-items: center; gap: 6px;
    padding: 0 12px;
}
.show-frame-bar span {
    width: 9px; height: 9px; border-radius: 50%;
    background: #FF5F57;
}
.show-frame-bar span:nth-child(2) { background: #FEBC2E; }
.show-frame-bar span:nth-child(3) { background: #28C840; }
.show-frame-body {
    display: grid;
    grid-template-columns: 180px 1fr;
    min-height: 320px;
}
.ph-side {
    background: #FAFBFD;
    border-right: 1px solid var(--border);
    padding: 16px 12px;
}
.ph-line {
    height: 12px; border-radius: 4px;
    background: linear-gradient(90deg, #E5E9F2, #F5F7FB);
    margin-bottom: 12px;
    width: 100%;
}
.ph-line.w50 { width: 50%; }
.ph-line.w60 { width: 60%; }
.ph-line.w70 { width: 70%; }
.ph-line.w80 { width: 80%; }
.ph-main { padding: 20px; display: flex; flex-direction: column; gap: 12px; }
.ph-bubble {
    height: 36px;
    width: 60%;
    background: #F1F4FA;
    border-radius: 10px;
}
.ph-bubble.right {
    align-self: flex-end;
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    width: 50%;
}
.ph-bubble.short { width: 35%; }

/* ============== About ============== */
.about-grid { gap: 48px; align-items: center; }
.lead { font-size: 1.1rem; color: var(--text); }
.about-stats {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}
.stat {
    background: #fff;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px 20px;
    text-align: center;
}
.stat-num {
    font-size: 2rem;
    font-weight: 700;
    background: var(--grad-primary);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 6px;
}
.stat-label {
    font-size: .85rem;
    color: var(--text-soft);
}

/* ============== CTA ============== */
.cta-section {
    background: linear-gradient(135deg, #0A2A6B 0%, #1E6FFF 100%);
    color: #fff;
}
.cta-section h2 { color: #fff; margin-bottom: 12px; }
.cta-section p { color: rgba(255,255,255,.8); margin: 0; }
.cta-inner {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 56px;
    align-items: center;
}
.cta-card {
    background: rgba(255,255,255,.08);
    border: 1px solid rgba(255,255,255,.18);
    border-radius: var(--radius-lg);
    padding: 32px;
    backdrop-filter: blur(8px);
}
.cta-row {
    display: flex; flex-direction: column; gap: 4px;
    margin-bottom: 24px;
}
.cta-label {
    font-size: .82rem;
    color: rgba(255,255,255,.6);
}
.cta-link {
    font-size: 1.4rem;
    font-weight: 700;
    color: #fff;
    word-break: break-all;
}
.cta-link:hover { color: #fff; opacity: .85; }

/* ============== Footer ============== */
.footer {
    background: #0E1424;
    color: rgba(255,255,255,.6);
    padding: 64px 0 0;
}
.footer-inner {
    display: grid;
    grid-template-columns: 1.2fr 2fr;
    gap: 56px;
    padding-bottom: 48px;
}
.logo-light .logo-text { color: #fff; }
.footer-desc { color: rgba(255,255,255,.5); margin-top: 8px; }
.footer-cols {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}
.footer-cols h4 {
    color: #fff;
    font-size: .92rem;
    margin-bottom: 16px;
}
.footer-cols a {
    display: block;
    font-size: .88rem;
    color: rgba(255,255,255,.55);
    margin-bottom: 10px;
}
.footer-cols a:hover { color: #fff; }
.footer-base {
    border-top: 1px solid rgba(255,255,255,.08);
    padding-top: 24px; padding-bottom: 24px;
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 12px;
    font-size: .82rem;
    color: rgba(255,255,255,.45);
}
.footer-base a:hover { color: #fff; }

/* ============== Responsive ============== */
@media (max-width: 960px) {
    .nav-links { display: none; }
    .nav-toggle { display: inline-flex; }
    .nav-cta { display: none; }
    .nav.menu-open .nav-links {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 68px; left: 0; right: 0;
        background: #fff;
        border-bottom: 1px solid var(--border);
        padding: 16px 24px;
        margin: 0;
        gap: 8px;
    }
    .nav.menu-open .nav-links a { padding: 10px 0; }

    .hero { padding: 56px 0 72px; }
    .hero-inner { grid-template-columns: 1fr; gap: 48px; }
    .hero-mock { order: -1; transform: scale(.95); transform-origin: top center; }
    .mock-window { transform: none; }

    .section { padding: 64px 0; }
    .grid-2, .grid-3 { grid-template-columns: 1fr; }
    .showcase { grid-template-columns: 1fr; }
    .about-grid { grid-template-columns: 1fr; }
    .about-stats { grid-template-columns: repeat(2, 1fr); }

    .cta-inner { grid-template-columns: 1fr; gap: 32px; }
    .footer-inner { grid-template-columns: 1fr; gap: 32px; }
    .footer-cols { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 480px) {
    .mock-body { grid-template-columns: 1fr; height: auto; }
    .mock-side { display: none; }
    .about-stats { grid-template-columns: 1fr; }
    .footer-cols { grid-template-columns: 1fr; }
}