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

:root {
    --text-primary: #1a1a1a;
    --text-secondary: #555;
    --text-tertiary: #888;
    --text-quaternary: #bbb;
    --surface: #fff;
    --surface-muted: #f7f7f8;
    --surface-raised: #fff;
    --border: #e5e5e5;
    --positive: #22c55e;
    --chart-1: #3b82f6;
    --chart-2: #ef4444;
    --chart-3: #22c55e;
    --radius: 10px;
    --radius-sm: 6px;
    --radius-lg: 12px;
    --t-fast: 0.15s;
    --t-normal: 0.25s;
    --t-slow: 0.4s;
}

@media (prefers-color-scheme: dark) {
    :root {
        --text-primary: #f0f0f0;
        --text-secondary: #aaa;
        --text-tertiary: #777;
        --text-quaternary: #555;
        --surface: #1a1a1a;
        --surface-muted: #242424;
        --surface-raised: #2a2a2a;
        --border: #333;
    }
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
    color: var(--text-primary);
    background: var(--surface);
    line-height: 1.5;
}

.btn {
    cursor: pointer;
    border: none;
    font-family: inherit;
    transition: all var(--t-fast) ease-out;
}

.btn-primary {
    background: var(--text-primary);
    color: var(--surface);
    padding: 8px 20px;
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-weight: 500;
}

.btn-primary:hover {
    opacity: 0.85;
}

.btn-ghost {
    background: transparent;
    color: var(--text-secondary);
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    font-size: 14px;
}

.btn-ghost:hover {
    background: var(--surface-muted);
    color: var(--text-primary);
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 14px;
    font-weight: 400;
    padding: 6px 0;
    position: relative;
    transition: color var(--t-fast);
}

.nav-link:hover {
    color: var(--text-primary);
}

.nav-link::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 1.5px;
    background: var(--text-primary);
    transition: width var(--t-fast) ease-out;
}

.nav-link:hover::after {
    width: 100%;
}

.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.45);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 100;
    opacity: 0;
    transition: opacity var(--t-normal) ease-out;
}

.modal-overlay.active {
    display: flex;
    opacity: 1;
}

.modal {
    background: var(--surface);
    border-radius: var(--radius-lg);
    width: 420px;
    max-width: 92vw;
    padding: 28px;
    box-shadow: 0 8px 40px rgba(0, 0, 0, 0.12);
    transform: translateY(16px) scale(0.97);
    transition: transform var(--t-normal) ease-out;
}

.modal-overlay.active .modal {
    transform: translateY(0) scale(1);
}

.input {
    width: 100%;
    padding: 10px 14px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 14px;
    font-family: inherit;
    background: var(--surface);
    color: var(--text-primary);
    outline: none;
    transition: border-color var(--t-fast);
}

.input:focus {
    border-color: var(--text-primary);
}

.input::placeholder {
    color: var(--text-quaternary);
}

.tab-btn {
    flex: 1;
    padding: 10px;
    border: none;
    background: transparent;
    font-size: 15px;
    font-weight: 500;
    color: var(--text-tertiary);
    cursor: pointer;
    border-bottom: 2px solid transparent;
    transition: all var(--t-fast);
    font-family: inherit;
}

.tab-btn.active {
    color: var(--text-primary);
    border-bottom-color: var(--text-primary);
}

.tab-btn:hover:not(.active) {
    color: var(--text-secondary);
}

.product-card {
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 24px;
    background: var(--surface);
    transition: all var(--t-fast);
}

.product-card:hover {
    border-color: var(--text-quaternary);
    transform: translateY(-2px);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
}

.tag {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 3px 10px;
    border-radius: 6px;
    font-size: 12px;
    font-weight: 500;
}

.tag-blue {
    background: rgba(59, 130, 246, 0.12);
    color: var(--chart-1);
}

.tag-green {
    background: rgba(34, 197, 94, 0.12);
    color: var(--chart-3);
}

.tag-red {
    background: rgba(239, 68, 68, 0.12);
    color: var(--chart-2);
}

.hero-bg {
    background: linear-gradient(135deg, var(--surface-muted) 0%, var(--surface) 50%, var(--surface-muted) 100%);
}

.section-title {
    font-size: 28px;
    font-weight: 500;
    line-height: 1.2;
    margin: 0 0 8px 0;
}

.section-sub {
    font-size: 16px;
    color: var(--text-secondary);
    line-height: 1.5;
    margin: 0;
}

.grid-3 {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.ad-card {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 18px 22px;
    border-radius: var(--radius);
    background: var(--surface-raised);
    border: 1px solid var(--border);
    cursor: pointer;
    text-decoration: none;
    color: inherit;
    transition: all var(--t-fast) ease-out;
}

.ad-card:hover {
    border-color: var(--text-quaternary);
    transform: translateX(4px);
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.05);
}

.ad-brand {
    width: 44px;
    height: 44px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    font-weight: 600;
    color: #fff;
    flex-shrink: 0;
    text-transform: uppercase;
}

.ad-badge {
    font-size: 11px;
    padding: 2px 8px;
    border-radius: 4px;
    background: var(--surface-muted);
    color: var(--text-tertiary);
    border: 1px solid var(--border);
    white-space: nowrap;
}

.records-wrap {
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    background: var(--surface);
}

.records-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 14px 20px;
    border-bottom: 1px solid var(--border);
    background: var(--surface-muted);
}

.records-table {
    width: 100%;
    border-collapse: collapse;
}

.records-table th {
    text-align: left;
    padding: 12px 20px;
    font-size: 13px;
    font-weight: 500;
    color: var(--text-secondary);
    border-bottom: 1px solid var(--border);
    background: var(--surface-muted);
}

.records-table td {
    padding: 12px 20px;
    font-size: 14px;
    color: var(--text-primary);
    border-bottom: 1px solid var(--border);
}

.records-table tr:last-child td {
    border-bottom: none;
}

.records-table tr:hover td {
    background: var(--surface-muted);
}

.records-table td:last-child {
    color: var(--text-secondary);
}

.num-badge {
    display: inline-block;
    padding: 2px 10px;
    border-radius: 4px;
    background: var(--surface-muted);
    border: 1px solid var(--border);
    font-size: 13px;
    font-family: "SF Mono", Monaco, monospace;
    color: var(--text-primary);
}

.scroll-top {
    position: fixed;
    bottom: 28px;
    right: 28px;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: var(--text-primary);
    color: var(--surface);
    border: none;
    cursor: pointer;
    z-index: 90;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: all var(--t-fast) ease-out;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
}

.scroll-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.scroll-top:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.2);
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

.spinning {
    animation: spin 0.6s linear infinite;
}

@media (max-width: 720px) {
    .grid-3 {
        grid-template-columns: 1fr;
    }

    .nav-links {
        display: none;
    }

    .hero-api {
        grid-template-columns: 1fr !important;
    }

    .records-table th,
    .records-table td {
        padding: 10px 12px;
        font-size: 13px;
    }
}


/* ================= 由模板内联 style 提炼的类（不与此前公共类重叠） ================= */

/* --- 布局原子与容器 --- */
.u-mb-16 {
    margin-bottom: 16px;
}

.u-mb-20 {
    margin-bottom: 20px;
}

.u-mb-24 {
    margin-bottom: 24px;
}

.u-fs-14 {
    font-size: 14px;
}

.container-1100 {
    max-width: 1100px;
    margin: 0 auto;
}

.section-wrap {
    padding: 56px 20px;
    max-width: 1100px;
    margin: 0 auto;
}

.section-soft {
    padding: 56px 20px;
    background: var(--surface-muted);
}

.section-intro {
    text-align: center;
    margin-bottom: 40px;
}

.vstack {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

/* --- 导航 --- */
.site-nav {
    position: sticky;
    top: 0;
    z-index: 50;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
}

.site-nav-inner {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 60px;
}

.nav-left {
    display: flex;
    align-items: center;
    gap: 32px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 18px;
    font-weight: 500;
    cursor: pointer;
}

.nav-links {
    display: flex;
    gap: 24px;
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 8px;
}

/* --- Hero 首屏 --- */
.hero {
    padding: 72px 20px;
    text-align: center;
}

.hero-inner {
    max-width: 720px;
    margin: 0 auto;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 5px 14px;
    border-radius: 20px;
    border: 1px solid var(--border);
    font-size: 13px;
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.hero-badge-dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--positive);
    display: inline-block;
}

.hero-title {
    font-size: 40px;
    font-weight: 500;
    line-height: 1.15;
    margin: 0 0 16px 0;
}

.hero-desc {
    font-size: 17px;
    color: var(--text-secondary);
    line-height: 1.6;
    margin: 0 0 32px 0;
}

.hero-cta {
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
}

.btn-lg {
    padding: 12px 28px;
    font-size: 15px;
    border-radius: var(--radius);
}

.btn-outline {
    border: 1px solid var(--border);
    background: transparent;
    color: var(--text-primary);
    cursor: pointer;
}

.btn-outline:hover {
    background: var(--surface-muted);
}

.stats-row {
    margin-top: 40px;
    display: flex;
    gap: 32px;
    justify-content: center;
    flex-wrap: wrap;
}

.stat-item {
    text-align: center;
}

.stat-num {
    font-size: 28px;
    font-weight: 500;
    font-variant-numeric: tabular-nums;
}

.stat-label {
    font-size: 13px;
    color: var(--text-tertiary);
    margin-top: 4px;
}

.stat-divider {
    width: 1px;
    background: var(--border);
}

/* --- 广告卡 --- */
.ad-text {
    flex: 1;
    min-width: 0;
}

.ad-name {
    font-size: 16px;
    font-weight: 500;
    margin-bottom: 3px;
}

.ad-desc {
    font-size: 13px;
    color: var(--text-secondary);
}

.ad-meta {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-shrink: 0;
}

.ad-meta svg {
    color: var(--text-quaternary);
}

.ad-brand-indigo {
    background: linear-gradient(135deg, #4f46e5, #7c3aed);
}

.ad-brand-red {
    background: linear-gradient(135deg, #dc2626, #ea580c);
}

.ad-brand-teal {
    background: linear-gradient(135deg, #059669, #0d9488);
}

/* --- 产品卡 / 特性说明 --- */
.icon-box {
    width: 44px;
    height: 44px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 16px;
}

.icon-box-blue {
    background: rgba(59, 130, 246, 0.1);
}

.icon-box-blue svg {
    color: var(--chart-1);
}

.icon-box-red {
    background: rgba(239, 68, 68, 0.1);
}

.icon-box-red svg {
    color: var(--chart-2);
}

.icon-box-green {
    background: rgba(34, 197, 94, 0.1);
}

.icon-box-green svg {
    color: var(--chart-3);
}

.card-head {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 8px;
}

.card-title {
    font-size: 17px;
    font-weight: 500;
    margin: 0;
}

.card-desc {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.6;
    margin: 0 0 16px 0;
}

.card-pills {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.chip {
    font-size: 12px;
    color: var(--text-tertiary);
    padding: 3px 8px;
    border: 1px solid var(--border);
    border-radius: 4px;
}

.feature-row {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    border-radius: var(--radius);
    border: 1px solid var(--border);
}

.feature-check {
    color: var(--positive);
    flex-shrink: 0;
}

/* --- API 文档代码窗口 --- */
.hero-api {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    align-items: center;
}

.code-window {
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    overflow: hidden;
    background: var(--surface);
}

.code-bar {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 10px 14px;
    border-bottom: 1px solid var(--border);
    background: var(--surface-muted);
}

.code-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--text-quaternary);
}

.code-label {
    font-size: 12px;
    color: var(--text-tertiary);
    margin-left: 8px;
    font-family: 'SF Mono', Monaco, 'Cascadia Code', monospace;
}

.code-body {
    padding: 16px;
    font-family: 'SF Mono', Monaco, 'Cascadia Code', monospace;
    font-size: 13px;
    line-height: 1.7;
    color: var(--text-secondary);
    overflow-x: auto;
}

.code-comment {
    color: var(--text-tertiary);
}

/* --- 免费号码记录表 --- */
.table-scroll {
    overflow-x: auto;
}

.col-wide {
    width: 200px;
}

.record-title {
    font-size: 15px;
    font-weight: 500;
}

.btn-export {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 8px 16px;
    font-size: 13px;
}

.export-icon {
    transition: transform 0.3s;
}

/* --- 免费号码卡片 --- */
.free-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
    margin-bottom: 20px;
}

.free-card {
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    background: var(--surface);
    padding: 14px 16px 16px;
    text-align: center;
    transition: all var(--t-fast);
}

.free-card:hover {
    border-color: var(--text-quaternary);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.06);
}

.free-card-label {
    font-size: 11px;
    letter-spacing: 1px;
    color: var(--text-tertiary);
    margin-bottom: 6px;
}

.free-card-num {
    font-family: "SF Mono", Monaco, "Cascadia Code", monospace;
    font-size: 16px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 10px;
    overflow-wrap: anywhere;
}

.free-card-copy {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-secondary);
    font-size: 13px;
    font-family: inherit;
    padding: 4px 18px;
    border-radius: 20px;
    cursor: pointer;
    transition: all var(--t-fast);
}

.free-card-copy:hover {
    background: var(--surface-muted);
    color: var(--text-primary);
}

.free-card-copy.copied {
    background: var(--positive);
    border-color: var(--positive);
    color: #fff;
}

@media (max-width: 900px) {
    .free-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 560px) {
    .free-grid {
        grid-template-columns: 1fr;
    }
}

/* --- 页脚 --- */
.site-footer {
    border-top: 1px solid var(--border);
    padding: 40px 20px;
    text-align: center;
}

.footer-brand {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    font-size: 16px;
    font-weight: 500;
    margin-bottom: 16px;
}

.footer-slogan {
    font-size: 13px;
    color: var(--text-tertiary);
    margin: 0;
}

.footer-copy {
    font-size: 12px;
    color: var(--text-quaternary);
    margin-top: 8px;
}

/* --- 弹窗 / 表单 --- */
.modal-head {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.tab-group {
    display: flex;
    width: 100%;
}

.modal-close {
    background: transparent;
    border: none;
    padding: 4px;
    cursor: pointer;
    color: var(--text-tertiary);
    flex-shrink: 0;
}

.form-label {
    display: block;
    font-size: 13px;
    color: var(--text-secondary);
    margin-bottom: 6px;
}

.btn-block {
    width: 100%;
    padding: 11px;
    font-size: 15px;
    border-radius: var(--radius);
}

.form-hint {
    text-align: center;
    font-size: 13px;
    color: var(--text-tertiary);
    margin-top: 16px;
}

.link-strong {
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
}

.link-main {
    color: var(--text-primary);
    text-decoration: none;
}

.form-link {
    font-size: 13px;
    color: var(--text-secondary);
    text-decoration: none;
}

.check-row {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 13px;
    color: var(--text-secondary);
    cursor: pointer;
}

.check-row input {
    margin-top: 2px;
    accent-color: var(--text-primary);
}

.agree-row {
    display: flex;
    align-items: flex-start;
    gap: 6px;
    font-size: 13px;
    color: var(--text-secondary);
    margin-bottom: 20px;
    cursor: pointer;
}

.agree-row input {
    accent-color: var(--text-primary);
    margin-top: 2px;
}

/* --- 两列卡片网格（核心产品服务改为 2 张卡后使用） --- */
.grid-2 {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

@media (max-width: 720px) {
    .grid-2 {
        grid-template-columns: 1fr;
    }
}
/* --- 全局轻提示 Toast（顶部弹出） --- */
.toast {
    position: fixed;
    left: 50%;
    top: 20px;
    transform: translateX(-50%) translateY(-18px);
    max-width: 78vw;
    padding: 10px 24px;
    background: rgba(17, 17, 17, 0.92);
    color: #fff;
    font-size: 14px;
    border-radius: 999px;
    box-shadow: 0 8px 28px rgba(0, 0, 0, 0.2);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    z-index: 300;
    text-align: center;
    backdrop-filter: blur(4px);
    transition: opacity 0.25s ease, transform 0.25s ease, visibility 0.25s;
}

.toast.show {
    opacity: 1;
    visibility: visible;
    transform: translateX(-50%) translateY(0);
}

/* 默认（中性深色）通过 .toast 自带；下方为语义类型样式（Font Awesome 图标） */
.toast.success {
    background: #41d381;
}

.toast.success::before,
.toast.error::before,
.toast.warning::before,
.toast.info::before {
    font-family: "Font Awesome 6 Free";
    font-weight: 900;
    margin-right: 10px;
}

.toast.success::before {
    content: "\f00c"; /* fa-check */
}

.toast.error {
    background: #e34040;
}

.toast.error::before {
    content: "\f057"; /* fa-circle-xmark */
}

.toast.warning {
    background: #e69334;
}

.toast.warning::before {
    content: "\f071"; /* fa-triangle-exclamation */
}

.toast.info {
    background: #3f74e7;
}

.toast.info::before {
    content: "\f05a"; /* fa-circle-info */
}

/* --- 滑块验证 --- */
.slider-verify {
    margin-bottom: 20px;
}

.slider-verify-track {
    position: relative;
    height: 35px;
    background: var(--surface-muted);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    user-select: none;
    -webkit-user-select: none;
    touch-action: none;
}

.slider-verify-fill {
    position: absolute;
    top: 0;
    left: 0;
    bottom: 0;
    width: 0;
    background: rgba(34, 197, 94, 0.15);
    pointer-events: none;
}

.slider-verify-text {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 13px;
    color: var(--text-tertiary);
    pointer-events: none;
}

.slider-verify-thumb {
    position: absolute;
    top: 0;
    left: 0;
    width: 50px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--surface);
    border-right: 1px solid var(--border);
    color: var(--text-secondary);
    font-size: 14px;
    cursor: grab;
    z-index: 2;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.08);
}

.slider-verify-thumb:active {
    cursor: grabbing;
}

/* 验证通过：轨道变绿、滑块归位到右端并显示 ✓ */
.slider-verify.success .slider-verify-track {
    background: #41d381;
    border-color: #41d381;
}

.slider-verify.success .slider-verify-fill {
    background: rgba(255, 255, 255, 0.2);
}

.slider-verify.success .slider-verify-text {
    color: #fff;
}

.slider-verify.success .slider-verify-thumb {
    background: #fff;
    color: #41d381;
    /* border-color: #41d381; */
    cursor: default;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    pointer-events: none;
}

/* --- 模态框关闭按钮：右上角定位 --- */
.modal {
    position: relative;
}

.modal-head {
    margin-top: 15px;
    padding-right: 0px;
}

.modal-close {
    position: absolute;
    top: 14px;
    right: 14px;
    width: 34px;
    height: 34px;
    margin: 0;
    padding: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    color: var(--text-tertiary);
    z-index: 5;
}

.modal-close:hover {
    background: var(--surface-muted);
    color: var(--text-primary);
}

/* ================= 响应式适配（一）响应式导航 · 汉堡菜单 ================= */
.nav-toggle {
    display: none;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 4px;
    width: 38px;
    height: 38px;
    padding: 0;
    margin-left: 4px;
    background: transparent;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    cursor: pointer;
}

.nav-toggle span {
    display: block;
    width: 18px;
    height: 2px;
    margin: 0 auto;
    border-radius: 2px;
    background: currentColor;
    transition: transform 0.25s ease, opacity 0.2s ease;
}

.nav-toggle.open span:nth-child(1) {
    transform: translateY(6px) rotate(45deg);
}

.nav-toggle.open span:nth-child(2) {
    opacity: 0;
}

.nav-toggle.open span:nth-child(3) {
    transform: translateY(-6px) rotate(-45deg);
}

.nav-drawer {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    z-index: 40;
    display: none;
    flex-direction: column;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    box-shadow: 0 14px 28px rgba(0, 0, 0, 0.1);
    padding: 6px 20px 14px;
}

.nav-drawer.open {
    display: flex;
}

.nav-drawer .nav-link {
    padding: 13px 0;
    font-size: 15px;
    border-bottom: 1px solid var(--border);
}

.nav-drawer .nav-link:last-child {
    border-bottom: none;
}

/* 平板及以下：收起顶部链接，改为汉堡菜单 */
@media (max-width: 920px) {
    .nav-links {
        display: none;
    }

    .nav-toggle {
        display: inline-flex;
    }
}

/* 桌面端抽屉永不显示 */
@media (min-width: 921px) {
    .nav-drawer {
        display: none !important;
    }
}

/* ================= 响应式适配（二）区块与布局断点 ================= */
/* 平板：双栏区块收窄/收一列 */
@media (max-width: 920px) {
    .hero-inner {
        max-width: 640px;
    }

    .hero-api {
        grid-template-columns: 1fr;
        gap: 28px;
    }
}

/* 移动端（≤768）：数据行一行四个、Hero/区块内边距与字号收紧 */
@media (max-width: 768px) {
    .stats-row {
        flex-wrap: nowrap;
        gap: 4px;
        margin-top: 24px;
    }

    .stats-row .stat-item {
        flex: 1 1 0;
        min-width: 0;
    }

    .stats-row .stat-divider {
        display: none;
    }

    .stats-row .stat-num {
        font-size: clamp(17px, 5vw, 24px);
    }

    .stats-row .stat-label {
        font-size: clamp(10px, 2.8vw, 12px);
        white-space: nowrap;
    }

    .hero {
        padding: 46px 16px;
    }

    .hero-title {
        font-size: 30px;
    }

    .hero-desc {
        font-size: 15px;
        line-height: 1.6;
    }

    .hero-cta {
        gap: 10px;
    }

    .hero-badge {
        font-size: 12px;
        margin-bottom: 18px;
        padding: 4px 12px;
    }

    .section-wrap,
    .section-soft {
        padding: 44px 16px;
    }

    .section-intro {
        margin-bottom: 28px;
    }

    .site-footer {
        padding: 32px 16px;
    }

    .modal {
        padding: 22px;
    }
}

/* 小屏手机（≤560） */
@media (max-width: 560px) {
    .site-nav-inner {
        padding: 0 14px;
    }

    .logo {
        font-size: 16px;
        gap: 6px;
    }

    .nav-actions {
        gap: 4px;
    }

    .nav-actions .btn {
        padding: 8px 14px;
        font-size: 13px;
    }

    .hero-title {
        font-size: 26px;
    }

    .hero-cta {
        flex-direction: column;
    }

    .hero-cta .btn {
        width: 100%;
    }

    .section-title {
        font-size: 24px;
    }

    .ad-card {
        padding: 12px;
    }

    .footer-brand {
        font-size: 15px;
    }

    .modal {
        padding: 20px 16px;
    }
}

/* 极窄屏：按钮压缩排版（登录/注册保留在顶栏，不再重复于抽屉） */
@media (max-width: 420px) {
    .site-nav .nav-actions {
        gap: 2px;
    }

    .site-nav .nav-actions .btn {
        padding: 7px 10px;
        font-size: 12px;
    }

    .site-nav .logo {
        font-size: 15px;
        gap: 4px;
    }
}

/* 顶栏登录按钮：主色描边样式（与注册主按钮保持主次，但更醒目） */
.site-nav .nav-actions .btn-outline {
    padding: 8px 16px;
    font-size: 14px;
    border-radius: var(--radius-sm);
}

/* Hero 双按钮：响应式一行两个（等宽并排） */
.hero-cta {
    flex-direction: row;
    flex-wrap: nowrap;
}

.hero-cta .btn {
    flex: 1 1 0;
    min-width: 0;
    white-space: nowrap;
}

@media (max-width: 560px) {
    .hero-cta {
        gap: 8px;
    }

    .hero-cta .btn {
        padding-left: 8px;
        padding-right: 8px;
    }
}

/* u-mb-24 与 section-intro 组合时，底部间距保持 24px */
.section-intro.u-mb-24 {
    margin-bottom: 24px;
}