/* ============================================================
   qasubmit — 官网样式
   设计取向：纸感浅色 + 墨色排版 + 极细线 + 克制动效
   ============================================================ */

/* ---------- 设计令牌 ---------- */
:root {
    --paper: #faf9f6;
    --paper-2: #f3f1eb;
    --paper-3: #ebe8df;
    --ink: #101418;
    --ink-2: #343b42;
    --muted: #6d757d;
    --line: rgba(16, 20, 24, 0.1);
    --line-strong: rgba(16, 20, 24, 0.2);
    --accent: #1e4b40;
    --accent-2: #2f6b58;
    --accent-soft: #e7eee9;
    --gold: #8d6f45;
    --danger: #8c3a2b;

    --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI",
        "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", sans-serif;
    --font-serif: Georgia, "Times New Roman", "Songti SC", "Noto Serif SC", serif;
    --font-mono: "JetBrains Mono", "SFMono-Regular", "Cascadia Mono", Consolas, "Courier New", monospace;

    --nav-h: 68px;
    --wrap: 1180px;
    --radius: 3px;
    --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

/* ---------- 复位 ---------- */
*,
*::before,
*::after {
    box-sizing: border-box;
}

html {
    -webkit-text-size-adjust: 100%;
    scroll-behavior: smooth;
    scroll-padding-top: calc(var(--nav-h) + 24px);
}

body {
    margin: 0;
    background: var(--paper);
    color: var(--ink);
    font-family: var(--font-sans);
    font-size: 16px;
    line-height: 1.75;
    font-weight: 400;
    letter-spacing: 0.01em;
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
    overflow-x: hidden;
}

/* 极淡的纸纹 */
body::before {
    content: "";
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 0;
    opacity: 0.5;
    background-image: radial-gradient(rgba(16, 20, 24, 0.035) 1px, transparent 1px);
    background-size: 3px 3px;
    mix-blend-mode: multiply;
}

img {
    max-width: 100%;
    display: block;
}

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

button {
    font: inherit;
    color: inherit;
    border: 0;
    background: none;
    cursor: pointer;
}

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

/* ---------- 排版 ---------- */
h1,
h2,
h3,
h4 {
    margin: 0;
    font-weight: 300;
    letter-spacing: -0.025em;
    line-height: 1.14;
    color: var(--ink);
}

p {
    margin: 0;
}

.display {
    font-size: clamp(1.8rem, 3.6vw, 3.2rem);
    letter-spacing: -0.04em;
    line-height: 1.04;
    font-weight: 300;
}

.h2 {
    font-size: clamp(1.9rem, 3.2vw, 2.9rem);
    letter-spacing: -0.035em;
}

.h3 {
    font-size: 1.15rem;
    font-weight: 500;
    letter-spacing: -0.01em;
    line-height: 1.5;
}

.lead {
    font-size: clamp(1rem, 1.25vw, 1.15rem);
    color: var(--ink-2);
    line-height: 1.85;
    max-width: 62ch;
}

.muted {
    color: var(--muted);
}

.serif {
    font-family: var(--font-serif);
}

.mono {
    font-family: var(--font-mono);
    font-size: 0.82em;
    letter-spacing: 0;
}

.eyebrow {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    font-family: var(--font-mono);
    font-size: 0.7rem;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--accent);
    font-weight: 500;
}

.eyebrow::before {
    content: "";
    width: 26px;
    height: 1px;
    background: currentColor;
    opacity: 0.55;
}

/* ---------- 布局 ---------- */
.wrap {
    width: 100%;
    max-width: var(--wrap);
    margin: 0 auto;
    padding: 0 28px;
    position: relative;
    z-index: 1;
}

.section {
    position: relative;
    padding: clamp(46px, 5.5vw, 78px) 0;
}

.section + .section {
    border-top: 1px solid var(--line);
}

.section-head {
    display: grid;
    grid-template-columns: 190px 1fr;
    gap: 40px;
    align-items: start;
    margin-bottom: clamp(28px, 3.5vw, 46px);
}

.sec-index {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    letter-spacing: 0.16em;
    color: var(--muted);
    padding-top: 10px;
    text-transform: uppercase;
}

.sec-index b {
    display: block;
    font-weight: 500;
    color: var(--ink);
    font-size: 0.82rem;
    margin-bottom: 4px;
}

.section-head .h2 {
    max-width: 22ch;
}

.section-head .lead {
    margin-top: 20px;
}

/* ---------- 导航 ---------- */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-h);
    z-index: 100;
    display: flex;
    align-items: center;
    transition: background 0.35s var(--ease), border-color 0.35s var(--ease);
    border-bottom: 1px solid transparent;
}

.nav.is-scrolled {
    background: rgba(250, 249, 246, 0.86);
    backdrop-filter: saturate(180%) blur(14px);
    -webkit-backdrop-filter: saturate(180%) blur(14px);
    border-bottom-color: var(--line);
}

.nav .wrap {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
}

.brand {
    display: flex;
    align-items: baseline;
    gap: 11px;
    font-size: 1.06rem;
    letter-spacing: -0.02em;
    font-weight: 500;
}

.brand-mark {
    width: 22px;
    height: 22px;
    flex: none;
    align-self: center;
}

.brand small {
    font-family: var(--font-mono);
    font-size: 0.6rem;
    letter-spacing: 0.14em;
    color: var(--muted);
    font-weight: 400;
    text-transform: uppercase;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 34px;
    margin-left: auto;
    margin-right: 30px;
}

.nav-links a {
    font-size: 0.875rem;
    color: var(--ink-2);
    position: relative;
    padding: 4px 0;
    transition: color 0.25s var(--ease);
}

.nav-links a::after {
    content: "";
    position: absolute;
    left: 0;
    right: 100%;
    bottom: 0;
    height: 1px;
    background: var(--accent);
    transition: right 0.35s var(--ease);
}

.nav-links a:hover {
    color: var(--ink);
}

.nav-links a:hover::after {
    right: 0;
}

/* ---------- 按钮 ---------- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 9px;
    height: 46px;
    padding: 0 24px;
    border-radius: var(--radius);
    font-size: 0.9rem;
    font-weight: 500;
    letter-spacing: 0.01em;
    white-space: nowrap;
    transition: transform 0.25s var(--ease), background 0.25s var(--ease),
        color 0.25s var(--ease), border-color 0.25s var(--ease), box-shadow 0.25s var(--ease);
}

.btn-primary {
    background: var(--ink);
    color: #fbfaf7;
    border: 1px solid var(--ink);
}

.btn-primary:hover {
    background: var(--accent);
    border-color: var(--accent);
    transform: translateY(-1px);
    box-shadow: 0 10px 26px -14px rgba(16, 20, 24, 0.7);
}

.btn-ghost {
    border: 1px solid var(--line-strong);
    color: var(--ink);
}

.btn-ghost:hover {
    border-color: var(--ink);
    transform: translateY(-1px);
}

.btn-sm {
    height: 38px;
    padding: 0 16px;
    font-size: 0.82rem;
}

.btn-block {
    width: 100%;
}

.btn .arrow {
    transition: transform 0.3s var(--ease);
}

.btn:hover .arrow {
    transform: translateX(3px);
}

/* ---------- Hero ---------- */
.hero {
    padding-top: calc(var(--nav-h) + clamp(36px, 4.5vw, 64px));
    padding-bottom: clamp(36px, 4.5vw, 60px);
    position: relative;
    overflow: hidden;
}

.hero::after {
    content: "";
    position: absolute;
    top: -18%;
    right: -12%;
    width: 780px;
    height: 780px;
    background: radial-gradient(circle, rgba(47, 107, 88, 0.09), transparent 62%);
    pointer-events: none;
    z-index: 0;
}

.hero-grid {
    display: grid;
    grid-template-columns: minmax(0, 1.06fr) minmax(0, 0.94fr);
    gap: clamp(36px, 5vw, 76px);
    align-items: center;
}

.hero h1 {
    margin: 22px 0 26px;
}

.hero h1 em {
    font-family: var(--font-serif);
    font-style: italic;
    color: var(--accent);
    letter-spacing: -0.02em;
}

.hero .lead {
    max-width: 46ch;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 36px;
}

.hero-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 8px 26px;
    margin-top: 30px;
    font-family: var(--font-mono);
    font-size: 0.7rem;
    letter-spacing: 0.06em;
    color: var(--muted);
    text-transform: uppercase;
}

.hero-meta span {
    display: inline-flex;
    align-items: center;
    gap: 7px;
}

.hero-meta span::before {
    content: "";
    width: 4px;
    height: 4px;
    border-radius: 50%;
    background: var(--accent-2);
}

/* 终端卡片 */
.terminal {
    background: #12161a;
    border-radius: 6px;
    box-shadow:
        0 2px 4px rgba(16, 20, 24, 0.08),
        0 26px 60px -28px rgba(16, 20, 24, 0.45),
        0 0 0 1px rgba(255, 255, 255, 0.06) inset;
    overflow: hidden;
    color: #d8dee3;
    font-family: var(--font-mono);
    font-size: 0.79rem;
    line-height: 1.95;
    transform: perspective(1400px) rotateY(-3.4deg) rotateX(1.6deg);
    transition: transform 0.7s var(--ease);
}

.terminal:hover {
    transform: perspective(1400px) rotateY(0) rotateX(0);
}

.terminal-bar {
    display: flex;
    align-items: center;
    gap: 7px;
    padding: 11px 15px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.07);
    background: rgba(255, 255, 255, 0.02);
}

.terminal-bar i {
    width: 9px;
    height: 9px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.16);
}

.terminal-bar span {
    margin-left: 8px;
    font-size: 0.68rem;
    letter-spacing: 0.08em;
    color: rgba(255, 255, 255, 0.4);
}

.terminal-body {
    padding: 20px 18px 22px;
    white-space: pre-wrap;
    word-break: break-word;
}

.terminal-body .c-dim {
    color: #6b7a85;
}

.terminal-body .c-key {
    color: #8fc7ad;
}

.terminal-body .c-str {
    color: #d3b689;
}

.terminal-body .c-ok {
    color: #7fd1a8;
}

.caret {
    display: inline-block;
    width: 7px;
    height: 14px;
    background: #8fc7ad;
    vertical-align: -2px;
    animation: blink 1.1s steps(1) infinite;
}

@keyframes blink {
    50% {
        opacity: 0;
    }
}

/* ---------- 指标条 ---------- */
.metrics {
    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
    background: linear-gradient(180deg, rgba(243, 241, 235, 0.5), transparent);
}

.metrics-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
}

.metric {
    padding: 34px 22px;
    border-left: 1px solid var(--line);
}

.metric:first-child {
    border-left: 0;
    padding-left: 0;
}

.metric b {
    display: block;
    font-size: clamp(1.9rem, 2.6vw, 2.5rem);
    font-weight: 300;
    letter-spacing: -0.04em;
    line-height: 1.1;
    font-variant-numeric: tabular-nums;
}

.metric b i {
    font-style: normal;
    font-size: 0.9rem;
    color: var(--muted);
    margin-left: 3px;
    letter-spacing: 0;
}

.metric span {
    display: block;
    margin-top: 8px;
    font-size: 0.8rem;
    color: var(--muted);
    letter-spacing: 0.04em;
}

/* ---------- 问题陈述 ---------- */
.problem-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1px;
    background: var(--line);
    border: 1px solid var(--line);
}

.problem {
    background: var(--paper);
    padding: 34px 30px 38px;
    transition: background 0.4s var(--ease);
}

.problem:hover {
    background: #fff;
}

.problem .num {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    color: var(--gold);
    letter-spacing: 0.14em;
}

.problem h3 {
    margin: 16px 0 12px;
}

.problem p {
    font-size: 0.92rem;
    color: var(--muted);
    line-height: 1.8;
}

/* ---------- 流水线 ---------- */
.flow {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0;
    border-top: 1px solid var(--line);
}

.flow-step {
    position: relative;
    padding: 34px 30px 34px 0;
    border-bottom: 1px solid var(--line);
}

.flow-step:nth-child(3n + 2),
.flow-step:nth-child(3n + 3) {
    padding-left: 30px;
    border-left: 1px solid var(--line);
}

.flow-step .idx {
    font-family: var(--font-mono);
    font-size: 0.68rem;
    letter-spacing: 0.16em;
    color: var(--accent);
    display: flex;
    align-items: center;
    gap: 9px;
}

.flow-step .idx::after {
    content: "";
    flex: 1;
    height: 1px;
    background: var(--line);
}

.flow-step h3 {
    margin: 17px 0 10px;
    font-size: 1.06rem;
    font-weight: 500;
}

.flow-step p {
    font-size: 0.9rem;
    color: var(--muted);
    line-height: 1.8;
}

.flow-step code {
    display: inline-block;
    margin-top: 14px;
    font-family: var(--font-mono);
    font-size: 0.72rem;
    background: var(--paper-2);
    border: 1px solid var(--line);
    border-radius: 2px;
    padding: 4px 8px;
    color: var(--accent);
}

/* ---------- 质检表 ---------- */
.qc {
    border: 1px solid var(--line);
    background: #fff;
}

.qc-row {
    display: grid;
    grid-template-columns: 52px 1.05fr 1.35fr 150px;
    gap: 24px;
    align-items: baseline;
    padding: 22px 26px;
    border-bottom: 1px solid var(--line);
    transition: background 0.3s var(--ease);
}

.qc-row:last-child {
    border-bottom: 0;
}

.qc-row:hover {
    background: #fcfbf8;
}

.qc-row .no {
    font-family: var(--font-mono);
    font-size: 0.72rem;
    color: var(--gold);
}

.qc-row .name {
    font-size: 0.98rem;
    font-weight: 500;
}

.qc-row .name small {
    display: block;
    font-weight: 400;
    font-size: 0.78rem;
    color: var(--muted);
    margin-top: 3px;
    letter-spacing: 0.02em;
}

.qc-row .desc {
    font-size: 0.87rem;
    color: var(--muted);
    line-height: 1.75;
}

.tag {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-family: var(--font-mono);
    font-size: 0.66rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    padding: 4px 9px;
    border-radius: 2px;
    border: 1px solid;
    white-space: nowrap;
}

.tag-hard {
    color: var(--danger);
    border-color: rgba(140, 58, 43, 0.32);
    background: rgba(140, 58, 43, 0.05);
}

.tag-soft {
    color: var(--accent);
    border-color: rgba(30, 75, 64, 0.28);
    background: var(--accent-soft);
}

.tag-both {
    color: #6a5327;
    border-color: rgba(141, 111, 69, 0.35);
    background: rgba(141, 111, 69, 0.07);
}

.qc-note {
    display: flex;
    gap: 14px;
    align-items: flex-start;
    margin-top: 20px;
    font-size: 0.84rem;
    color: var(--muted);
    line-height: 1.75;
}

.qc-note b {
    color: var(--ink);
    font-weight: 500;
}

/* ---------- 双角色 ---------- */
.roles {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.role {
    border: 1px solid var(--line);
    background: #fff;
    padding: 38px 34px 40px;
    position: relative;
    overflow: hidden;
    transition: border-color 0.4s var(--ease), transform 0.4s var(--ease);
}

.role:hover {
    border-color: var(--line-strong);
    transform: translateY(-2px);
}

.role::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--accent);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.55s var(--ease);
}

.role:hover::before {
    transform: scaleX(1);
}

.role-head {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 16px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--line);
}

.role-head h3 {
    font-size: 1.3rem;
}

.role-head .badge {
    font-family: var(--font-mono);
    font-size: 0.66rem;
    letter-spacing: 0.12em;
    color: var(--muted);
    text-transform: uppercase;
}

.role ul {
    list-style: none;
    margin: 22px 0 0;
    padding: 0;
}

.role li {
    position: relative;
    padding-left: 20px;
    margin-bottom: 13px;
    font-size: 0.92rem;
    color: var(--ink-2);
    line-height: 1.7;
}

.role li::before {
    content: "";
    position: absolute;
    left: 0;
    top: 11px;
    width: 7px;
    height: 1px;
    background: var(--accent-2);
}

.role li em {
    font-style: normal;
    color: var(--muted);
}

/* ---------- 部署形态 ---------- */
.surfaces {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1px;
    background: var(--line);
    border: 1px solid var(--line);
}

.surface {
    background: var(--paper);
    padding: 32px 30px;
    transition: background 0.35s var(--ease);
}

.surface:hover {
    background: #fff;
}

.surface-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
}

.surface .icon {
    width: 34px;
    height: 34px;
    stroke: var(--accent);
    fill: none;
    stroke-width: 1.25;
    stroke-linecap: round;
    stroke-linejoin: round;
}

.surface .kind {
    font-family: var(--font-mono);
    font-size: 0.65rem;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--muted);
}

.surface h3 {
    margin: 20px 0 9px;
    font-size: 1.06rem;
    font-weight: 500;
}

.surface p {
    font-size: 0.89rem;
    color: var(--muted);
    line-height: 1.78;
}

/* ---------- 阶段时间轴 ---------- */
.timeline {
    position: relative;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 0;
    padding-top: 26px;
}

.timeline::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: var(--line-strong);
}

.stage {
    padding-right: 26px;
    position: relative;
}

.stage::before {
    content: "";
    position: absolute;
    top: -31px;
    left: 0;
    width: 9px;
    height: 9px;
    border-radius: 50%;
    background: var(--paper);
    border: 1px solid var(--accent);
}

.stage.is-active::before {
    background: var(--accent);
}

.stage .t {
    font-family: var(--font-mono);
    font-size: 0.68rem;
    letter-spacing: 0.14em;
    color: var(--accent);
    text-transform: uppercase;
}

.stage h3 {
    font-size: 1rem;
    font-weight: 500;
    margin: 10px 0 9px;
}

.stage p {
    font-size: 0.86rem;
    color: var(--muted);
    line-height: 1.75;
}

/* ---------- 工程细节 ---------- */
.facts {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 28px 48px;
}

.fact {
    padding-top: 18px;
    border-top: 1px solid var(--line-strong);
}

.fact h3 {
    font-size: 0.98rem;
    font-weight: 500;
    margin-bottom: 8px;
    display: flex;
    align-items: baseline;
    gap: 10px;
}

.fact h3 span {
    font-family: var(--font-mono);
    font-size: 0.66rem;
    color: var(--gold);
    letter-spacing: 0.1em;
}

.fact p {
    font-size: 0.88rem;
    color: var(--muted);
    line-height: 1.8;
}

/* ---------- FAQ ---------- */
.faq {
    border-top: 1px solid var(--line);
}

.faq-item {
    border-bottom: 1px solid var(--line);
}

.faq-q {
    width: 100%;
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 24px;
    padding: 24px 0;
    text-align: left;
    font-size: 1rem;
    font-weight: 500;
    letter-spacing: -0.005em;
    transition: color 0.25s var(--ease);
}

.faq-q:hover {
    color: var(--accent);
}

.faq-q .plus {
    flex: none;
    position: relative;
    width: 14px;
    height: 14px;
    margin-top: 6px;
}

.faq-q .plus::before,
.faq-q .plus::after {
    content: "";
    position: absolute;
    background: currentColor;
    transition: transform 0.35s var(--ease);
}

.faq-q .plus::before {
    left: 0;
    top: 6.5px;
    width: 14px;
    height: 1px;
}

.faq-q .plus::after {
    left: 6.5px;
    top: 0;
    width: 1px;
    height: 14px;
}

.faq-item.is-open .plus::after {
    transform: scaleY(0);
}

.faq-a {
    display: grid;
    grid-template-rows: 0fr;
    transition: grid-template-rows 0.4s var(--ease);
}

.faq-item.is-open .faq-a {
    grid-template-rows: 1fr;
}

.faq-a > div {
    overflow: hidden;
}

.faq-a p {
    padding: 0 44px 26px 0;
    font-size: 0.92rem;
    color: var(--muted);
    line-height: 1.85;
    max-width: 78ch;
}

/* ---------- CTA ---------- */
.cta {
    position: relative;
    overflow: hidden;
    background: #101418;
    color: #f4f2ec;
    padding: clamp(44px, 5.5vw, 76px) 0;
}

.cta::before {
    content: "";
    position: absolute;
    top: -50%;
    left: 50%;
    width: 900px;
    height: 900px;
    transform: translateX(-50%);
    background: radial-gradient(circle, rgba(143, 199, 173, 0.13), transparent 60%);
    pointer-events: none;
}

.cta .wrap {
    position: relative;
    text-align: center;
}

.cta h2 {
    color: #f7f5ef;
    font-size: clamp(2rem, 4vw, 3.3rem);
    letter-spacing: -0.04em;
    max-width: 20ch;
    margin: 0 auto;
}

.cta p {
    color: rgba(244, 242, 236, 0.62);
    margin: 22px auto 0;
    max-width: 54ch;
    font-size: 1rem;
    line-height: 1.8;
}

.cta .btn-primary {
    background: #f4f2ec;
    color: #101418;
    border-color: #f4f2ec;
}

.cta .btn-primary:hover {
    background: #fff;
    border-color: #fff;
}

.cta .btn-ghost {
    color: #f4f2ec;
    border-color: rgba(244, 242, 236, 0.3);
}

.cta .btn-ghost:hover {
    border-color: #f4f2ec;
}

.cta-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    justify-content: center;
    margin-top: 38px;
}

/* ---------- 页脚 ---------- */
.footer {
    background: var(--paper);
    border-top: 1px solid var(--line);
    padding: 44px 0 30px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 1.6fr repeat(3, 1fr);
    gap: 40px;
}

.footer-brand p {
    margin-top: 16px;
    font-size: 0.85rem;
    color: var(--muted);
    line-height: 1.8;
    max-width: 34ch;
}

.footer h4 {
    font-family: var(--font-mono);
    font-size: 0.66rem;
    letter-spacing: 0.16em;
    text-transform: uppercase;
    color: var(--muted);
    font-weight: 500;
    margin-bottom: 16px;
}

.footer ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

.footer li {
    margin-bottom: 9px;
}

.footer li a {
    font-size: 0.87rem;
    color: var(--ink-2);
    transition: color 0.25s var(--ease);
}

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

.footer-bottom {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    gap: 14px;
    margin-top: 54px;
    padding-top: 24px;
    border-top: 1px solid var(--line);
    font-size: 0.78rem;
    color: var(--muted);
}

.footer-bottom .mono {
    letter-spacing: 0.06em;
}

/* ---------- 滚动出现动画 ---------- */
.reveal {
    opacity: 0;
    transform: translateY(18px);
    transition: opacity 0.75s var(--ease), transform 0.75s var(--ease);
}

.reveal.is-in {
    opacity: 1;
    transform: none;
}

.reveal[data-delay="1"] {
    transition-delay: 0.08s;
}

.reveal[data-delay="2"] {
    transition-delay: 0.16s;
}

.reveal[data-delay="3"] {
    transition-delay: 0.24s;
}

.reveal[data-delay="4"] {
    transition-delay: 0.32s;
}

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    .reveal {
        opacity: 1;
        transform: none;
        transition: none;
    }

    .terminal {
        transform: none;
    }

    .caret {
        animation: none;
    }
}

/* ---------- 移动端菜单 ---------- */
.menu-btn {
    display: none;
    width: 40px;
    height: 40px;
    align-items: center;
    justify-content: center;
}

.menu-btn span {
    position: relative;
    width: 18px;
    height: 1px;
    background: var(--ink);
    transition: background 0.2s;
}

.menu-btn span::before,
.menu-btn span::after {
    content: "";
    position: absolute;
    left: 0;
    width: 18px;
    height: 1px;
    background: var(--ink);
    transition: transform 0.3s var(--ease);
}

.menu-btn span::before {
    top: -6px;
}

.menu-btn span::after {
    top: 6px;
}

body.menu-open .menu-btn span {
    background: transparent;
}

body.menu-open .menu-btn span::before {
    transform: translateY(6px) rotate(45deg);
}

body.menu-open .menu-btn span::after {
    transform: translateY(-6px) rotate(-45deg);
}

/* ============================================================
   下载页
   ============================================================ */
.page-head {
    padding-top: calc(var(--nav-h) + clamp(32px, 4vw, 56px));
    padding-bottom: clamp(28px, 3.5vw, 44px);
}

.page-head h1 {
    margin: 18px 0 20px;
    font-size: clamp(1.8rem, 3.4vw, 2.9rem);
    letter-spacing: -0.04em;
    font-weight: 300;
}

.page-head .lead {
    max-width: 58ch;
}

.dl-grid {
    display: grid;
    grid-template-columns: 1.35fr 1fr;
    gap: 20px;
    align-items: start;
}

.dl-card {
    border: 1px solid var(--line);
    background: #fff;
    padding: 34px;
    position: relative;
}

.dl-card.primary {
    border-color: rgba(30, 75, 64, 0.34);
    box-shadow: 0 18px 48px -34px rgba(16, 20, 24, 0.45);
}

.dl-card.primary::after {
    content: "推荐";
    position: absolute;
    top: 0;
    right: 0;
    background: var(--accent);
    color: #f4f2ec;
    font-family: var(--font-mono);
    font-size: 0.6rem;
    letter-spacing: 0.14em;
    padding: 5px 11px;
}

.dl-os {
    display: flex;
    align-items: center;
    gap: 14px;
}

.dl-os svg {
    width: 30px;
    height: 30px;
    fill: var(--ink);
}

.dl-os h2 {
    font-size: 1.32rem;
    font-weight: 400;
}

.dl-os .ver {
    font-family: var(--font-mono);
    font-size: 0.66rem;
    color: var(--muted);
    letter-spacing: 0.08em;
    margin-left: auto;
}

.dl-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 8px 18px;
    margin: 20px 0 24px;
    font-family: var(--font-mono);
    font-size: 0.7rem;
    color: var(--muted);
    letter-spacing: 0.04em;
}

.dl-status {
    margin-top: 14px;
    font-size: 0.78rem;
    color: var(--muted);
    display: flex;
    align-items: center;
    gap: 8px;
    line-height: 1.6;
}

.dl-status .dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--accent-2);
    flex: none;
}

.dl-status.is-pending .dot {
    background: var(--gold);
}

.dl-list {
    border: 1px solid var(--line);
    background: var(--paper-2);
}

.dl-list-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    padding: 20px 26px;
    border-bottom: 1px solid var(--line);
}

.dl-list-item:last-child {
    border-bottom: 0;
}

.dl-list-item .t {
    font-size: 0.94rem;
    font-weight: 500;
}

.dl-list-item .s {
    font-size: 0.78rem;
    color: var(--muted);
    margin-top: 2px;
}

.dl-list-item .badge-off {
    font-family: var(--font-mono);
    font-size: 0.64rem;
    letter-spacing: 0.1em;
    color: var(--muted);
    border: 1px solid var(--line-strong);
    padding: 4px 9px;
    border-radius: 2px;
    white-space: nowrap;
}

/* 安装步骤 */
.steps {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1px;
    background: var(--line);
    border: 1px solid var(--line);
}

.step {
    background: var(--paper);
    padding: 30px 28px;
}

.step .n {
    font-family: var(--font-mono);
    font-size: 0.68rem;
    letter-spacing: 0.16em;
    color: var(--gold);
}

.step h3 {
    margin: 14px 0 9px;
    font-size: 1rem;
    font-weight: 500;
}

.step p {
    font-size: 0.87rem;
    color: var(--muted);
    line-height: 1.78;
}

/* 代码块 + 复制 */
.codeblock {
    position: relative;
    background: #12161a;
    border-radius: 4px;
    padding: 18px 20px;
    color: #d8dee3;
    font-family: var(--font-mono);
    font-size: 0.79rem;
    line-height: 1.95;
    overflow-x: auto;
    white-space: pre;
}

.codeblock .c-dim {
    color: #6b7a85;
}

.copy-btn {
    position: absolute;
    top: 10px;
    right: 10px;
    font-family: var(--font-mono);
    font-size: 0.62rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: rgba(255, 255, 255, 0.5);
    border: 1px solid rgba(255, 255, 255, 0.16);
    border-radius: 2px;
    padding: 4px 9px;
    transition: color 0.2s, border-color 0.2s, background 0.2s;
}

.copy-btn:hover {
    color: #fff;
    border-color: rgba(255, 255, 255, 0.4);
}

.copy-btn.is-done {
    color: #7fd1a8;
    border-color: rgba(127, 209, 168, 0.4);
}

/* 更新日志 */
.changelog {
    border-top: 1px solid var(--line);
}

.log-item {
    display: grid;
    grid-template-columns: 130px 1fr;
    gap: 28px;
    padding: 26px 0;
    border-bottom: 1px solid var(--line);
}

.log-item .v {
    font-family: var(--font-mono);
    font-size: 0.76rem;
    color: var(--accent);
    letter-spacing: 0.08em;
}

.log-item .d {
    font-family: var(--font-mono);
    font-size: 0.7rem;
    color: var(--muted);
    margin-top: 4px;
}

.log-item ul {
    margin: 0;
    padding-left: 18px;
    font-size: 0.9rem;
    color: var(--ink-2);
    line-height: 1.85;
}

/* 表 */
.spec-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
}

.spec-table th,
.spec-table td {
    text-align: left;
    padding: 14px 16px;
    border-bottom: 1px solid var(--line);
    vertical-align: top;
}

.spec-table th {
    font-family: var(--font-mono);
    font-size: 0.66rem;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--muted);
    font-weight: 500;
    background: var(--paper-2);
}

.spec-table td:first-child {
    width: 210px;
    font-weight: 500;
}

.spec-table td {
    color: var(--ink-2);
}

/* 提示条 */
.notice {
    display: flex;
    gap: 14px;
    padding: 18px 22px;
    border: 1px solid rgba(141, 111, 69, 0.28);
    background: rgba(141, 111, 69, 0.055);
    border-radius: 3px;
    font-size: 0.86rem;
    color: #5c4a30;
    line-height: 1.8;
}

.notice svg {
    flex: none;
    width: 18px;
    height: 18px;
    stroke: var(--gold);
    fill: none;
    stroke-width: 1.5;
    margin-top: 3px;
}

/* 轻提示 */
.toast {
    position: fixed;
    left: 50%;
    bottom: 34px;
    transform: translate(-50%, 18px);
    background: var(--ink);
    color: #f4f2ec;
    font-size: 0.84rem;
    padding: 12px 20px;
    border-radius: 3px;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s var(--ease), transform 0.3s var(--ease);
    z-index: 200;
    box-shadow: 0 16px 40px -20px rgba(16, 20, 24, 0.7);
}

.toast.is-show {
    opacity: 1;
    transform: translate(-50%, 0);
}

/* ---------- 响应式 ---------- */
@media (max-width: 1024px) {
    .hero-grid {
        grid-template-columns: 1fr;
    }

    .terminal {
        transform: none;
    }

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

    .metric:nth-child(4) {
        border-left: 0;
        padding-left: 0;
    }

    .problem-grid,
    .flow,
    .steps {
        grid-template-columns: 1fr 1fr;
    }

    .flow-step:nth-child(3n + 2),
    .flow-step:nth-child(3n + 3) {
        padding-left: 0;
        border-left: 0;
    }

    .flow-step:nth-child(even) {
        padding-left: 24px;
        border-left: 1px solid var(--line);
    }

    .timeline {
        grid-template-columns: 1fr 1fr;
        gap: 34px 0;
    }

    .timeline::before {
        display: none;
    }

    .stage::before {
        display: none;
    }

    .section-head {
        grid-template-columns: 1fr;
        gap: 18px;
    }

    .dl-grid {
        grid-template-columns: 1fr;
    }

    .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: 34px;
    }
}

@media (max-width: 720px) {
    :root {
        --nav-h: 60px;
    }

    .wrap {
        padding: 0 20px;
    }

    .nav-links {
        position: fixed;
        top: var(--nav-h);
        left: 0;
        right: 0;
        flex-direction: column;
        align-items: flex-start;
        gap: 0;
        margin: 0;
        padding: 8px 20px 22px;
        background: rgba(250, 249, 246, 0.98);
        backdrop-filter: blur(14px);
        border-bottom: 1px solid var(--line);
        transform: translateY(-12px);
        opacity: 0;
        pointer-events: none;
        transition: opacity 0.3s var(--ease), transform 0.3s var(--ease);
    }

    body.menu-open .nav-links {
        opacity: 1;
        transform: none;
        pointer-events: auto;
    }

    .nav-links a {
        width: 100%;
        padding: 13px 0;
        border-bottom: 1px solid var(--line);
        font-size: 0.95rem;
    }

    .nav-links a:last-child {
        border-bottom: 0;
    }

    .nav .btn {
        display: none;
    }

    .menu-btn {
        display: flex;
    }

    .metrics-grid {
        grid-template-columns: 1fr 1fr;
    }

    .metric {
        padding: 24px 0;
        border-left: 0;
    }

    .metric:nth-child(even) {
        padding-left: 20px;
        border-left: 1px solid var(--line);
    }

    .problem-grid,
    .flow,
    .roles,
    .surfaces,
    .facts,
    .steps,
    .timeline {
        grid-template-columns: 1fr;
    }

    .flow-step {
        padding: 26px 0;
    }

    .flow-step:nth-child(even) {
        padding-left: 0;
        border-left: 0;
    }

    .qc-row {
        grid-template-columns: 1fr;
        gap: 10px;
        padding: 20px;
    }

    .qc-row .no {
        display: none;
    }

    .role,
    .surface {
        padding: 26px 22px;
    }

    .dl-card {
        padding: 24px 20px;
    }

    .footer-grid {
        grid-template-columns: 1fr;
    }

    .log-item {
        grid-template-columns: 1fr;
        gap: 10px;
    }

    .spec-table td:first-child {
        width: 120px;
    }

    .spec-table th,
    .spec-table td {
        padding: 11px 10px;
        font-size: 0.84rem;
    }
}

/* ============================================================
   v2 — 客户端为主角的板块
   ============================================================ */

/* ---------- 客户端特写：登录投屏 mock ---------- */
.spotlight {
    display: grid;
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
    gap: clamp(36px, 5vw, 72px);
    align-items: center;
}

.spotlight-points {
    margin: 26px 0 0;
    padding: 0;
    list-style: none;
}

.spotlight-points li {
    position: relative;
    padding: 18px 0 18px 34px;
    border-top: 1px solid var(--line);
    font-size: 0.94rem;
    line-height: 1.75;
    color: var(--ink-2);
}

.spotlight-points li b {
    display: block;
    font-weight: 500;
    color: var(--ink);
    margin-bottom: 3px;
    font-size: 1rem;
}

.spotlight-points li::before {
    content: "";
    position: absolute;
    left: 4px;
    top: 27px;
    width: 14px;
    height: 14px;
    border: 1px solid var(--accent-2);
    border-radius: 50%;
}

.spotlight-points li::after {
    content: "";
    position: absolute;
    left: 8px;
    top: 31.5px;
    width: 6px;
    height: 3px;
    border-left: 1px solid var(--accent);
    border-bottom: 1px solid var(--accent);
    transform: rotate(-45deg);
}

/* 模拟登录面板 */
.mock {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: 6px;
    overflow: hidden;
    box-shadow: 0 2px 4px rgba(16, 20, 24, 0.05), 0 30px 70px -40px rgba(16, 20, 24, 0.5);
    transform: perspective(1500px) rotateY(3.6deg) rotateX(1.4deg);
    transition: transform 0.7s var(--ease);
}

.mock:hover {
    transform: none;
}

.mock-head {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 13px 18px;
    border-bottom: 1px solid var(--line);
    background: var(--paper-2);
}

.mock-head .t {
    font-size: 0.9rem;
    font-weight: 500;
}

.mock-head .u {
    font-family: var(--font-mono);
    font-size: 0.66rem;
    color: var(--muted);
    letter-spacing: 0.03em;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.mock-close {
    margin-left: auto;
    flex: none;
    font-size: 0.72rem;
    color: var(--muted);
    border: 1px solid var(--line-strong);
    border-radius: 2px;
    padding: 3px 9px;
}

.mock-screen {
    position: relative;
    aspect-ratio: 16 / 10.4;
    background:
        radial-gradient(circle at 30% 30%, rgba(47, 107, 88, 0.06), transparent 55%),
        repeating-linear-gradient(0deg, transparent, transparent 31px, rgba(16, 20, 24, 0.028) 32px),
        repeating-linear-gradient(90deg, transparent, transparent 31px, rgba(16, 20, 24, 0.028) 32px),
        #f6f4ef;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 14px;
}

.mock-qr {
    width: 118px;
    height: 118px;
    border: 1px solid var(--line-strong);
    border-radius: 4px;
    padding: 12px;
    background: #fff;
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    grid-auto-rows: 1fr;
    gap: 2px;
}

.mock-qr i {
    background: var(--ink);
    opacity: 0.85;
}

.mock-qr i.o {
    opacity: 0;
}

.mock-screen .cap {
    font-size: 0.78rem;
    color: var(--muted);
}

.mock-cursor {
    position: absolute;
    left: 66%;
    top: 38%;
    width: 15px;
    height: 15px;
}

.mock-foot {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 18px;
    border-top: 1px solid var(--line);
    background: var(--accent-soft);
    font-size: 0.78rem;
    color: var(--accent);
    line-height: 1.6;
}

.mock-foot .dot {
    flex: none;
    width: 7px;
    height: 7px;
    border-radius: 50%;
    background: var(--accent-2);
    animation: pulse 1.8s var(--ease) infinite;
}

@keyframes pulse {
    50% {
        opacity: 0.35;
    }
}

/* ---------- 三种运行形态 ---------- */
.modes {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.mode {
    border: 1px solid var(--line);
    background: #fff;
    padding: 30px 28px 32px;
    position: relative;
    transition: border-color 0.35s var(--ease), transform 0.35s var(--ease);
}

.mode:hover {
    border-color: var(--line-strong);
    transform: translateY(-2px);
}

.mode .flag {
    position: absolute;
    top: 0;
    right: 0;
    font-family: var(--font-mono);
    font-size: 0.6rem;
    letter-spacing: 0.14em;
    padding: 5px 11px;
    background: var(--accent);
    color: #f4f2ec;
}

.mode .win {
    height: 92px;
    border: 1px solid var(--line);
    border-radius: 4px;
    background: var(--paper-2);
    position: relative;
    overflow: hidden;
    margin-bottom: 24px;
}

.mode .win::before {
    content: "";
    position: absolute;
    top: 7px;
    left: 9px;
    width: 26px;
    height: 5px;
    border-radius: 3px;
    background: var(--line-strong);
}

.mode .win .body {
    position: absolute;
    top: 24px;
    left: 9px;
    right: 9px;
    bottom: 9px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 6px;
}

.mode .win .body i {
    background: var(--line);
    border-radius: 2px;
}

/* offscreen：窗口移出屏幕 */
.mode.is-off .win {
    transform: translateX(34%) translateY(16%);
    opacity: 0.55;
}

/* visible：正常窗口 */
.mode.is-vis .win .body i:nth-child(2) {
    background: var(--accent-soft);
    border: 1px solid rgba(30, 75, 64, 0.25);
}

/* headless：无窗口 */
.mode.is-head .win {
    display: flex;
    align-items: center;
    justify-content: center;
}

.mode.is-head .win::after {
    content: "—";
    color: var(--muted);
    font-family: var(--font-mono);
    font-size: 0.7rem;
    letter-spacing: 0.3em;
}

.mode h3 {
    font-size: 1.05rem;
    font-weight: 500;
}

.mode .en {
    font-family: var(--font-mono);
    font-size: 0.64rem;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--accent);
    display: block;
    margin-bottom: 8px;
}

.mode p {
    margin-top: 10px;
    font-size: 0.88rem;
    color: var(--muted);
    line-height: 1.8;
}

/* ---------- 信任清单 ---------- */
.assure {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1px;
    background: var(--line);
    border: 1px solid var(--line);
}

.assure-item {
    background: var(--paper);
    padding: 26px 28px;
    display: flex;
    gap: 18px;
    align-items: flex-start;
    transition: background 0.35s var(--ease);
}

.assure-item:hover {
    background: #fff;
}

.assure-item svg {
    flex: none;
    width: 30px;
    height: 30px;
    stroke: var(--accent);
    fill: none;
    stroke-width: 1.2;
    stroke-linecap: round;
    stroke-linejoin: round;
    margin-top: 2px;
}

.assure-item h3 {
    font-size: 0.98rem;
    font-weight: 500;
    margin-bottom: 6px;
}

.assure-item p {
    font-size: 0.86rem;
    color: var(--muted);
    line-height: 1.75;
}

/* ---------- 竖向旅程 ---------- */
.journey {
    max-width: 760px;
    margin: 0 auto;
}

.j-step {
    display: grid;
    grid-template-columns: 46px 1fr;
    gap: 24px;
    position: relative;
    padding-bottom: 38px;
}

.j-step:last-child {
    padding-bottom: 0;
}

.j-step::before {
    content: "";
    position: absolute;
    left: 22px;
    top: 46px;
    bottom: 6px;
    width: 1px;
    background: var(--line-strong);
}

.j-step:last-child::before {
    display: none;
}

.j-step .n {
    width: 46px;
    height: 46px;
    border: 1px solid var(--line-strong);
    border-radius: 50%;
    background: var(--paper);
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: var(--font-mono);
    font-size: 0.78rem;
    color: var(--accent);
    position: relative;
    z-index: 1;
}

.j-step h3 {
    font-size: 1.05rem;
    font-weight: 500;
    padding-top: 9px;
}

.j-step h3 small {
    font-family: var(--font-mono);
    font-size: 0.66rem;
    color: var(--muted);
    letter-spacing: 0.08em;
    font-weight: 400;
    margin-left: 10px;
}

.j-step p {
    margin-top: 8px;
    font-size: 0.9rem;
    color: var(--muted);
    line-height: 1.8;
    max-width: 58ch;
}

/* ---------- 客户端 vs 传统方案 对照 ---------- */
.compare {
    border: 1px solid var(--line);
    background: #fff;
    overflow: hidden;
}

.compare-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
}

.compare-row + .compare-row {
    border-top: 1px solid var(--line);
}

.compare-cell {
    padding: 20px 26px;
    font-size: 0.9rem;
    line-height: 1.7;
    color: var(--ink-2);
}

.compare-cell + .compare-cell {
    border-left: 1px solid var(--line);
    color: var(--muted);
}

.compare-cell .who {
    display: block;
    font-family: var(--font-mono);
    font-size: 0.62rem;
    letter-spacing: 0.14em;
    text-transform: uppercase;
    color: var(--muted);
    margin-bottom: 6px;
}

.compare-cell.is-us .who {
    color: var(--accent);
}

.compare-head .compare-cell {
    background: var(--paper-2);
    font-size: 0.85rem;
}

@media (max-width: 1024px) {
    .spotlight {
        grid-template-columns: 1fr;
    }

    .mock {
        transform: none;
    }

    .modes {
        grid-template-columns: 1fr;
    }

    /* 屏幕外窗口示意图在窄屏下收回，避免撑出横向滚动 */
    .mode.is-off .win {
        transform: none;
        opacity: 1;
    }
}

@media (max-width: 720px) {
    .assure {
        grid-template-columns: 1fr;
    }

    .compare-row {
        grid-template-columns: 1fr;
    }

    .compare-cell + .compare-cell {
        border-left: 0;
        border-top: 1px solid var(--line);
    }
}

/* ============================================================
   v3 — 多页面拆分
   ============================================================ */

/* 当前页导航高亮 */
.nav-links a.active {
    color: var(--ink);
}

.nav-links a.active::after {
    right: 0;
}

/* 首页板块导览卡 */
.toc-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.toc-card {
    display: flex;
    flex-direction: column;
    border: 1px solid var(--line);
    background: #fff;
    padding: 30px 28px 28px;
    position: relative;
    transition: border-color 0.35s var(--ease), transform 0.35s var(--ease), box-shadow 0.35s var(--ease);
}

.toc-card:hover {
    border-color: var(--line-strong);
    transform: translateY(-2px);
    box-shadow: 0 14px 34px -26px rgba(16, 20, 24, 0.4);
}

.toc-card .no {
    font-family: var(--font-mono);
    font-size: 0.66rem;
    letter-spacing: 0.14em;
    color: var(--gold);
}

.toc-card h3 {
    margin: 16px 0 9px;
    font-size: 1.08rem;
    font-weight: 500;
}

.toc-card p {
    font-size: 0.88rem;
    color: var(--muted);
    line-height: 1.75;
}

.toc-card .go {
    margin-top: auto;
    padding-top: 22px;
    display: inline-flex;
    align-items: center;
    gap: 7px;
    font-family: var(--font-mono);
    font-size: 0.7rem;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    color: var(--accent);
}

.toc-card .go svg {
    transition: transform 0.3s var(--ease);
}

.toc-card:hover .go svg {
    transform: translateX(3px);
}

/* 子页之间的辅助小节标题 */
.subhead {
    display: grid;
    grid-template-columns: 190px 1fr;
    gap: 40px;
    align-items: start;
    margin: clamp(32px, 4vw, 56px) 0 clamp(22px, 3vw, 34px);
}

.subhead .sec-index b {
    color: var(--accent);
}

.subhead h2 {
    font-size: clamp(1.5rem, 2.4vw, 2.1rem);
    letter-spacing: -0.03em;
    max-width: 26ch;
}

.subhead .lead {
    margin-top: 14px;
}

/* FAQ 页末提示 */
.more {
    margin-top: 34px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.more-card {
    border: 1px solid var(--line);
    background: var(--paper-2);
    padding: 26px 28px;
}

.more-card h3 {
    font-size: 1rem;
    font-weight: 500;
    margin-bottom: 8px;
}

.more-card p {
    font-size: 0.87rem;
    color: var(--muted);
    line-height: 1.75;
}

.more-card a {
    color: var(--accent);
    border-bottom: 1px solid rgba(30, 75, 64, 0.3);
    transition: border-color 0.25s var(--ease);
}

.more-card a:hover {
    border-bottom-color: var(--accent);
}

@media (max-width: 1024px) {
    .toc-cards {
        grid-template-columns: 1fr 1fr;
    }

    .subhead {
        grid-template-columns: 1fr;
        gap: 14px;
    }
}

@media (max-width: 720px) {
    .toc-cards {
        grid-template-columns: 1fr;
    }

    .more {
        grid-template-columns: 1fr;
    }
}