/* ════════════════════════════════════════════════════════════
   CPA WIKI Landing — 事务所年报 / Editorial 风格
   独立样式，不依赖 style.css；仅本页加载
   ════════════════════════════════════════════════════════════ */

:root {
    --paper: #f7f5f0;
    --paper-deep: #f0ede5;
    --ink: #1e3a5f;
    --ink-soft: #3e5475;
    --crimson: #a32638;
    --crimson-soft: #e06070;
    --muted: #6f6f68;
    --hairline: rgba(30, 58, 95, 0.14);
    --hairline-soft: rgba(30, 58, 95, 0.08);
    --night: #16263c;
    --night-2: #1d3046;
    --serif: "Noto Serif SC", "Songti SC", "SimSun", Georgia, serif;
    --sans: "DM Sans", "PingFang SC", "Microsoft YaHei", sans-serif;
    --maxw: 1080px;
}

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

html { scroll-behavior: smooth; }

body {
    background: var(--paper);
    color: var(--ink);
    font-family: var(--sans);
    font-size: 16px;
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    /* clip 不产生滚动容器，保住 .nav 的 position:sticky（hidden 会废掉它） */
    overflow-x: hidden;
    overflow-x: clip;
}

/* 纸面颗粒 */
body::before {
    content: "";
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 1;
    opacity: 0.035;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='2'/%3E%3C/filter%3E%3Crect width='160' height='160' filter='url(%23n)'/%3E%3C/svg%3E");
}

::selection { background: var(--crimson); color: #fff; }

a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }

.container {
    max-width: var(--maxw);
    margin: 0 auto;
    padding: 0 32px;
    position: relative;
    z-index: 2;
}

/* ── 全页竖向网格线（印刷版心线） ───────────── */
.grid-rules {
    position: fixed;
    inset: 0;
    max-width: var(--maxw);
    margin: 0 auto;
    pointer-events: none;
    z-index: 0;
    display: flex;
    justify-content: space-between;
    padding: 0 32px;
}
.grid-rules i {
    width: 1px;
    background: var(--hairline-soft);
}
.grid-rules i:nth-child(2) { margin: 0 auto; }

/* ════════ 按钮 ════════ */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-family: var(--sans);
    font-size: 0.92rem;
    font-weight: 500;
    letter-spacing: 0.04em;
    padding: 12px 28px;
    border: 1.5px solid var(--ink);
    transition: all 0.25s ease;
    cursor: pointer;
}
.btn .arr { transition: transform 0.25s ease; }
.btn:hover .arr { transform: translateX(4px); }
.btn-solid {
    background: var(--ink);
    color: var(--paper);
}
.btn-solid:hover {
    background: var(--crimson);
    border-color: var(--crimson);
}
.btn-ghost {
    background: transparent;
    color: var(--ink);
}
.btn-ghost:hover {
    border-color: var(--crimson);
    color: var(--crimson);
}
.btn-lg { padding: 16px 44px; font-size: 1.02rem; }

/* ════════ NAV ════════ */
.nav {
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(247, 245, 240, 0.92);
    backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--hairline);
}
.nav-inner {
    max-width: var(--maxw);
    margin: 0 auto;
    padding: 14px 32px;
    display: flex;
    align-items: center;
    gap: 28px;
}
.nav-brand { display: flex; align-items: center; gap: 14px; }
.nav-logo { height: 30px; width: auto; }
.nav-sep { width: 1px; height: 22px; background: var(--hairline); }
.nav-wordmark {
    font-family: var(--sans);
    font-weight: 700;
    letter-spacing: 0.22em;
    font-size: 0.88rem;
}
.nav-links {
    display: flex;
    gap: 26px;
    margin-left: auto;
    font-size: 0.86rem;
    letter-spacing: 0.06em;
    color: var(--ink-soft);
}
.nav-links a { position: relative; padding: 4px 0; }
.nav-links a::after {
    content: "";
    position: absolute;
    left: 0; right: 100%; bottom: 0;
    height: 1.5px;
    background: var(--crimson);
    transition: right 0.25s ease;
}
.nav-links a:hover::after { right: 0; }
.nav-cta { padding: 9px 20px; font-size: 0.85rem; }

/* ════════ HERO ════════ */
.hero { padding: 96px 0 0; }

.kicker {
    font-size: 0.78rem;
    letter-spacing: 0.32em;
    color: var(--crimson);
    margin-bottom: 30px;
}

.hero-title {
    font-family: var(--serif);
    font-weight: 900;
    font-size: clamp(2.6rem, 7vw, 4.8rem);
    line-height: 1.18;
    letter-spacing: 0.02em;
    margin-bottom: 28px;
}
.hero-title em {
    font-style: normal;
    color: var(--crimson);
    position: relative;
}
.hero-title em::after {
    content: "";
    position: absolute;
    left: 2px; right: 2px; bottom: 6px;
    height: 2px;
    background: var(--crimson);
    opacity: 0.45;
}
.hero-title .period { color: var(--crimson); }

.hero-lede {
    font-size: clamp(1rem, 2vw, 1.18rem);
    color: var(--ink-soft);
    margin-bottom: 40px;
    line-height: 1.9;
}
.hero-lede strong { color: var(--ink); font-weight: 700; }

.hero-actions { display: flex; gap: 16px; flex-wrap: wrap; margin-bottom: 72px; }
.arr-down { display: inline-block; animation: bob 2.2s ease-in-out infinite; }
@keyframes bob {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(4px); }
}

.hero-stats {
    display: flex;
    gap: 0;
    border-top: 1px solid var(--hairline);
    border-bottom: 1px solid var(--hairline);
}
.stat {
    flex: 1;
    padding: 26px 28px 24px;
    border-left: 1px solid var(--hairline);
}
.stat:first-child { border-left: none; padding-left: 0; }
.stat-num {
    font-family: var(--serif);
    font-weight: 700;
    font-size: clamp(1.9rem, 4vw, 2.7rem);
    line-height: 1.1;
    font-variant-numeric: tabular-nums;
}
.stat-num.accent { color: var(--crimson); }
.stat-plus { font-size: 0.7em; vertical-align: 0.18em; margin-left: 2px; }
.stat-label {
    font-size: 0.78rem;
    letter-spacing: 0.14em;
    color: var(--muted);
    margin-top: 8px;
}

/* 滚动题库 */
.marquee { margin-top: 72px; border-bottom: 1px solid var(--hairline); position: relative; z-index: 2; }
.marquee-head {
    max-width: var(--maxw);
    margin: 0 auto;
    padding: 0 32px 10px;
    font-size: 0.74rem;
    letter-spacing: 0.3em;
    color: var(--muted);
}
.marquee-clip { overflow: hidden; border-top: 1px solid var(--hairline); background: var(--paper-deep); }
.marquee-track {
    display: flex;
    align-items: center;
    gap: 42px;
    width: max-content;
    padding: 16px 0;
    animation: marquee 56s linear infinite;
}
.marquee-clip:hover .marquee-track { animation-play-state: paused; }
.marquee-track span {
    font-family: var(--serif);
    font-size: 0.94rem;
    color: var(--ink-soft);
    white-space: nowrap;
}
.marquee-track i { color: var(--crimson); font-style: normal; font-size: 0.8rem; }
@keyframes marquee {
    from { transform: translateX(0); }
    to { transform: translateX(-50%); }
}

/* ════════ SECTION 通用 ════════ */
.section { padding: 110px 0; border-bottom: 1px solid var(--hairline); position: relative; }
.section-tight { padding: 90px 0; }

.sec-head {
    display: flex;
    align-items: flex-end;
    gap: 28px;
    margin-bottom: 30px;
}
.sec-no {
    font-family: var(--serif);
    font-weight: 900;
    font-size: clamp(4rem, 9vw, 6.5rem);
    line-height: 0.85;
    color: transparent;
    -webkit-text-stroke: 1.5px rgba(163, 38, 56, 0.5);
}
.section-dark .sec-no { -webkit-text-stroke: 1.5px rgba(224, 96, 112, 0.55); }
.sec-title {
    font-family: var(--serif);
    font-weight: 700;
    font-size: clamp(1.6rem, 3.6vw, 2.4rem);
    line-height: 1.25;
}
.sec-sub {
    font-size: 0.76rem;
    letter-spacing: 0.28em;
    color: var(--muted);
    margin-top: 8px;
}
.sec-lede {
    color: var(--ink-soft);
    max-width: 760px;
    margin-bottom: 54px;
    line-height: 2;
}

/* ════════ 01 DEMO ════════ */
.demo-window {
    background: #fffdf9;
    border: 1px solid var(--hairline);
    box-shadow: 0 24px 60px -18px rgba(30, 58, 95, 0.18);
}
.demo-chrome {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 22px;
    border-bottom: 1px solid var(--hairline);
    background: var(--paper-deep);
}
.demo-dot {
    width: 8px; height: 8px;
    border-radius: 50%;
    background: var(--crimson);
    animation: pulse 1.8s ease-in-out infinite;
}
@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.35; }
}
.demo-meta { font-size: 0.78rem; letter-spacing: 0.1em; color: var(--ink-soft); }
.demo-live {
    margin-left: auto;
    font-size: 0.68rem;
    letter-spacing: 0.22em;
    color: var(--crimson);
    border: 1px solid rgba(163, 38, 56, 0.4);
    padding: 2px 10px;
}

.demo-role {
    font-size: 0.7rem;
    letter-spacing: 0.26em;
    color: var(--muted);
    margin-bottom: 14px;
}
.demo-role-note { letter-spacing: 0.1em; margin-left: 6px; color: var(--crimson); }

.demo-q { padding: 28px 30px 24px; border-bottom: 1px dashed var(--hairline); }
.demo-q p {
    font-family: var(--serif);
    font-size: 1.02rem;
    line-height: 1.9;
    color: var(--ink);
    border-left: 3px solid var(--ink);
    padding-left: 18px;
}

.demo-trace { padding: 24px 30px; border-bottom: 1px dashed var(--hairline); }
.trace-row {
    display: flex;
    align-items: baseline;
    gap: 14px;
    padding: 9px 0;
    opacity: 0;
    transform: translateX(-14px);
    transition: opacity 0.5s ease, transform 0.5s ease;
}
.demo-window.play .trace-row { opacity: 1; transform: none; }
.demo-window.play .trace-row:nth-child(2) { transition-delay: 0.15s; }
.demo-window.play .trace-row:nth-child(3) { transition-delay: 0.5s; }
.demo-window.play .trace-row:nth-child(4) { transition-delay: 0.85s; }
.demo-window.play .trace-row:nth-child(5) { transition-delay: 1.2s; }
.demo-window.play .trace-row:nth-child(6) { transition-delay: 1.55s; }
.trace-no {
    font-family: var(--serif);
    font-size: 0.8rem;
    color: var(--muted);
    min-width: 24px;
}
.trace-domain {
    font-size: 0.84rem;
    font-weight: 700;
    color: var(--crimson);
    border: 1px solid rgba(163, 38, 56, 0.35);
    padding: 1px 10px;
    white-space: nowrap;
}
.trace-leader {
    flex: 1;
    border-bottom: 1px dotted var(--hairline);
    transform: translateY(-4px);
}
.trace-what { font-size: 0.84rem; color: var(--ink-soft); }
.trace-ok { color: var(--crimson); font-weight: 700; font-size: 0.85rem; }

.demo-a { padding: 26px 30px 30px; }
.demo-answer {
    font-family: var(--serif);
    font-size: 0.97rem;
    line-height: 2.05;
    color: var(--ink);
    min-height: 200px;
    white-space: pre-wrap;
}
.demo-answer strong { color: var(--crimson); font-weight: 700; }
.caret {
    display: inline-block;
    width: 2px;
    height: 1.1em;
    background: var(--crimson);
    vertical-align: -0.15em;
    animation: blink 0.9s step-end infinite;
}
@keyframes blink {
    0%, 100% { opacity: 1; }
    50% { opacity: 0; }
}
.demo-cites {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    align-items: center;
    margin-top: 22px;
    padding-top: 18px;
    border-top: 1px dotted var(--hairline);
    opacity: 0;
    transform: translateY(10px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}
.demo-cites.show { opacity: 1; transform: none; }
.cite-chip {
    font-size: 0.78rem;
    color: var(--ink);
    background: var(--paper-deep);
    border: 1px solid var(--hairline);
    padding: 4px 12px;
}
.cite-chip::before { content: "📄 "; font-size: 0.7rem; }
.cite-more { font-size: 0.76rem; color: var(--muted); letter-spacing: 0.08em; }

/* ════════ 02 引擎（深色版面） ════════ */
.section-dark {
    background: linear-gradient(165deg, var(--night) 0%, var(--night-2) 100%);
    color: #e9eef5;
    border-bottom: none;
}
.section-dark::after {
    content: "";
    position: absolute;
    top: -120px; right: -120px;
    width: 420px; height: 420px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(224, 96, 112, 0.12), transparent 65%);
    pointer-events: none;
}
.section-dark .sec-title { color: #f2f5f8; }
.section-dark .sec-sub { color: #8fa3ba; }

.dark-claim {
    font-family: var(--serif);
    font-size: clamp(1.25rem, 2.8vw, 1.7rem);
    line-height: 1.8;
    color: #cfdae6;
    margin-bottom: 60px;
    max-width: 720px;
}
.dark-claim em {
    font-style: normal;
    color: var(--crimson-soft);
}

.term-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1px;
    background: rgba(255, 255, 255, 0.12);
    border: 1px solid rgba(255, 255, 255, 0.12);
}
.term-card {
    background: var(--night-2);
    padding: 32px 28px 30px;
    transition: background 0.3s ease;
}
.term-card:hover { background: #24405e; }
.term-no {
    font-family: var(--serif);
    font-size: 1.6rem;
    color: var(--crimson-soft);
    margin-bottom: 14px;
}
.term-card h3 {
    font-family: var(--sans);
    font-weight: 700;
    font-size: 1.02rem;
    letter-spacing: 0.04em;
    margin-bottom: 10px;
    color: #f2f5f8;
}
.term-card p {
    font-size: 0.86rem;
    line-height: 1.85;
    color: #9fb2c4;
}

/* ════════ 03 防幻觉工程 ════════ */
.guard-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    border-top: 1px solid var(--hairline);
    border-left: 1px solid var(--hairline);
}
.guard-item {
    padding: 38px 36px 34px;
    border-right: 1px solid var(--hairline);
    border-bottom: 1px solid var(--hairline);
    position: relative;
    transition: background 0.3s ease;
}
.guard-item:hover { background: #fffdf9; }
.guard-no {
    font-family: var(--serif);
    font-weight: 900;
    font-size: 2.6rem;
    line-height: 1;
    color: var(--crimson);
    margin-bottom: 16px;
}
.guard-item h3 {
    font-family: var(--serif);
    font-weight: 700;
    font-size: 1.16rem;
    margin-bottom: 10px;
}
.guard-item p { font-size: 0.9rem; color: var(--ink-soft); line-height: 1.9; }

/* ════════ 04 能力总览 ════════ */
.caps-grid {
    display: flex;
    border-top: 1px solid var(--hairline);
}
.cap {
    flex: 1;
    padding: 34px 30px 8px;
    border-left: 1px solid var(--hairline);
}
.cap:first-child { border-left: none; padding-left: 0; }
.cap h3 {
    font-family: var(--serif);
    font-weight: 700;
    font-size: 1.2rem;
    margin-bottom: 12px;
    color: var(--ink);
}
.cap p { font-size: 0.89rem; color: var(--ink-soft); line-height: 1.95; }

/* ════════ CTA ════════ */
.cta-block { text-align: center; padding: 130px 0; }
.cta-kicker {
    font-size: 0.74rem;
    letter-spacing: 0.4em;
    color: var(--muted);
    margin-bottom: 22px;
}
.cta-title {
    font-family: var(--serif);
    font-weight: 900;
    font-size: clamp(1.9rem, 5vw, 3.2rem);
    margin-bottom: 40px;
}
.cta-title em { font-style: normal; color: var(--crimson); }

/* ════════ COLOPHON ════════ */
.colophon { padding: 64px 0 44px; position: relative; z-index: 2; }
.colophon-rule {
    border-top: 3px double var(--ink);
    margin-bottom: 44px;
}
.colophon-grid {
    display: flex;
    justify-content: space-between;
    align-items: flex-end;
    gap: 28px;
    flex-wrap: wrap;
}
.colophon-logo { height: 40px; width: auto; margin-bottom: 12px; }
.colophon-credit {
    font-size: 0.8rem;
    letter-spacing: 0.18em;
    color: var(--muted);
}
.colophon-right { text-align: right; }
.signature {
    font-family: var(--sans);
    font-size: 0.8rem;
    letter-spacing: 0.18em;
    line-height: 1.2;
    color: var(--muted);
}
.sig-en { margin-left: 4px; }
.colophon-sub {
    font-size: 0.68rem;
    letter-spacing: 0.26em;
    color: var(--muted);
    margin-bottom: 10px;
}
.colophon-base {
    display: flex;
    justify-content: space-between;
    gap: 18px;
    flex-wrap: wrap;
    margin-top: 48px;
    padding-top: 16px;
    border-top: 1px solid var(--hairline);
    font-size: 0.7rem;
    letter-spacing: 0.18em;
    color: var(--muted);
}

/* ════════ 入场动画 ════════ */
.reveal {
    opacity: 0;
    transform: translateY(26px);
    transition: opacity 0.7s ease, transform 0.7s ease;
}
.reveal.in { opacity: 1; transform: none; }
.reveal.d1 { transition-delay: 0.1s; }
.reveal.d2 { transition-delay: 0.2s; }
.reveal.d3 { transition-delay: 0.3s; }
.reveal.d4 { transition-delay: 0.42s; }
.reveal.d5 { transition-delay: 0.55s; }
.term-grid .reveal:nth-child(2) { transition-delay: 0.1s; }
.term-grid .reveal:nth-child(3) { transition-delay: 0.2s; }
.term-grid .reveal:nth-child(4) { transition-delay: 0.3s; }
.term-grid .reveal:nth-child(5) { transition-delay: 0.4s; }
.guard-grid .reveal:nth-child(2) { transition-delay: 0.12s; }
.guard-grid .reveal:nth-child(3) { transition-delay: 0.24s; }
.guard-grid .reveal:nth-child(4) { transition-delay: 0.36s; }
.caps-grid .reveal:nth-child(2) { transition-delay: 0.12s; }
.caps-grid .reveal:nth-child(3) { transition-delay: 0.24s; }

@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    .reveal, .trace-row, .demo-cites { transition: none !important; opacity: 1 !important; transform: none !important; }
    .marquee-track { animation: none; }
    .arr-down, .demo-dot { animation: none; }
}

/* ════════ 响应式 ════════ */
@media (max-width: 900px) {
    .term-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
    .grid-rules { display: none; }
    .container { padding: 0 22px; }
    .nav-inner { padding: 12px 18px; gap: 14px; }
    .nav-links { display: none; }
    .nav-logo { height: 24px; }
    .nav-wordmark { letter-spacing: 0.14em; font-size: 0.8rem; }
    .nav-cta { margin-left: auto; padding: 8px 16px; }

    .hero { padding-top: 64px; }
    .bk-d { display: none; }
    .hero-actions { margin-bottom: 52px; }
    .hero-stats { flex-direction: column; }
    .stat { padding: 18px 0; border-left: none; border-top: 1px solid var(--hairline); }
    .stat:first-child { border-top: none; }
    .marquee { margin-top: 52px; }
    .marquee-head { padding: 0 22px 10px; }

    .section { padding: 72px 0; }
    .sec-head { gap: 18px; align-items: center; }
    .sec-lede { margin-bottom: 38px; }

    .demo-q, .demo-trace, .demo-a { padding-left: 18px; padding-right: 18px; }
    .trace-row { flex-wrap: wrap; gap: 8px; }
    .trace-leader { display: none; }
    .trace-what { flex-basis: 100%; padding-left: 32px; }
    .trace-ok { position: absolute; right: 0; }
    .trace-row { position: relative; }
    .demo-answer { min-height: 260px; }

    .term-grid { grid-template-columns: 1fr; }
    .guard-grid { grid-template-columns: 1fr; }
    .guard-item { padding: 28px 22px 26px; }

    .caps-grid { flex-direction: column; }
    .cap { border-left: none; border-top: 1px solid var(--hairline); padding: 26px 0 6px; }
    .cap:first-child { border-top: none; }

    .cta-block { padding: 88px 0; }
    .colophon-grid { flex-direction: column; align-items: flex-start; }
    .colophon-right { text-align: left; }
    .colophon-base { flex-direction: column; gap: 6px; }
}