/* ==========================================================================
   AuralTap 官网样式
   --------------------------------------------------------------------------
   设计原则：
   - 浅色主题、低饱和、留白足；品牌色 = 苹果系统蓝 #007AFF（与 App 图标同源）
   - 全站零 JS：折叠用 <details>，移动端菜单同样零脚本
   - RTL：布局全部用逻辑属性（margin-inline / padding-inline / inset-inline），
     dir="rtl" 时自动镜像，不用写第二套样式
   ========================================================================== */

:root {
    --bg: #ffffff;
    --bg-tint: #f6f8fb;
    --ink: #16202b;
    --muted: #5c6b7c;
    --accent: #007aff;
    --accent-strong: #0067d6;
    --accent-soft: #eaf3ff;
    --line: #e4e9f0;
    --ok: #2e9e5b;
    --radius: 14px;
    --radius-sm: 9px;
    --shadow: 0 1px 2px rgba(16, 24, 40, .05), 0 10px 30px rgba(16, 24, 40, .06);
    --font: -apple-system, BlinkMacSystemFont, "SF Pro Text", "PingFang SC",
            "Hiragino Sans GB", "Helvetica Neue", "Segoe UI", Roboto,
            "Noto Sans", "Noto Sans Arabic", "Noto Sans JP", "Noto Sans KR",
            Arial, sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
    margin: 0;
    font-family: var(--font);
    color: var(--ink);
    background: var(--bg);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
}

img { max-width: 100%; height: auto; }

a { color: var(--accent-strong); text-decoration: none; }
a:hover { text-decoration: underline; }

h1, h2, h3 { line-height: 1.25; letter-spacing: -.01em; }
h1 { font-size: clamp(1.9rem, 4.4vw, 3rem); margin: .2em 0 .4em; }
h2 { font-size: clamp(1.4rem, 2.6vw, 1.9rem); margin: 0 0 .5em; }
h3 { font-size: 1.06rem; margin: 0 0 .35em; }

p { margin: 0 0 1em; }

.container { max-width: 1080px; margin-inline: auto; padding-inline: 22px; }
.container.narrow { max-width: 780px; }

/* --------------------------------------------------------------------------
   可访问性：键盘跳转链接
   -------------------------------------------------------------------------- */
.skip-link {
    position: absolute;
    inset-inline-start: -9999px;
    top: 8px;
    z-index: 100;
    background: var(--ink);
    color: #fff;
    padding: 8px 14px;
    border-radius: 8px;
}
.skip-link:focus { inset-inline-start: 8px; }

/* --------------------------------------------------------------------------
   Header
   -------------------------------------------------------------------------- */
.site-header {
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(255, 255, 255, .88);
    backdrop-filter: saturate(1.4) blur(10px);
    border-block-end: 1px solid var(--line);
}

.header-inner {
    display: flex;
    align-items: center;
    gap: 18px;
    min-height: 58px;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 9px;
    color: var(--ink);
    font-weight: 650;
    font-size: 1.02rem;
}
.brand:hover { text-decoration: none; }
/* App 真实图标。⛔ 不要加 border-radius：macOS 图标的圆角已在 PNG 的 alpha 里，
   再套 CSS 圆角会把正确的形状切掉。图标由 tools/make_site_icons.py 从 App 工程导出。 */
.brand-icon { display: block; }

.main-nav {
    display: flex;
    align-items: center;
    gap: 20px;
    margin-inline-start: auto;
}
.main-nav a { color: var(--muted); font-size: .95rem; }
.main-nav a:hover { color: var(--ink); text-decoration: none; }

.main-nav .nav-download {
    color: #fff;
    background: var(--accent);
    padding: 7px 14px;
    border-radius: 999px;
    font-weight: 550;
}
.main-nav .nav-download:hover { background: var(--accent-strong); color: #fff; }

/* 语言切换（<details> 折叠，零 JS） */
.lang-switcher { position: relative; }
.lang-switcher summary {
    list-style: none;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    color: var(--muted);
    font-size: .9rem;
    padding: 7px 10px;
    border: 1px solid var(--line);
    border-radius: 999px;
    white-space: nowrap;
}
.lang-switcher summary::-webkit-details-marker { display: none; }
.lang-switcher[open] summary { background: var(--bg-tint); }
.lang-switcher .chevron { transition: transform .15s ease; }
.lang-switcher[open] .chevron { transform: rotate(180deg); }

.lang-menu {
    position: absolute;
    inset-inline-end: 0;
    top: calc(100% + 8px);
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow);
    display: grid;
    grid-template-columns: repeat(2, minmax(150px, 1fr));
    padding: 6px;
    min-width: 300px;
    z-index: 60;
}
.lang-menu a {
    padding: 8px 12px;
    border-radius: 7px;
    color: var(--ink);
    font-size: .92rem;
    white-space: nowrap;
}
.lang-menu a:hover { background: var(--bg-tint); text-decoration: none; }
.lang-menu a[aria-current="page"] { color: var(--accent-strong); font-weight: 600; }

/* --------------------------------------------------------------------------
   Hero
   -------------------------------------------------------------------------- */
.hero { padding-block: 58px 26px; }

.hero-grid {
    display: grid;
    grid-template-columns: minmax(0, 5fr) minmax(0, 6fr);
    gap: 40px;
    align-items: center;
}

.hero-kicker {
    color: var(--accent-strong);
    font-size: .86rem;
    font-weight: 600;
    letter-spacing: .02em;
    margin-block-end: 6px;
}

.hero-sub {
    color: var(--muted);
    font-size: 1.08rem;
    max-width: 34em;
}

.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-block-start: 22px; }

.hero-shot { margin: 0; }
/* 真实窗口截图：圆角与投影已经烘焙在 PNG 的 alpha 里，
   再叠 border-radius / border / box-shadow 会框住透明外边距，看着像多了一圈白边。 */
.hero-shot img {
    display: block;
    width: 100%;
    height: auto;
}

/* 按钮 */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 11px 20px;
    border-radius: 999px;
    font-size: .97rem;
    font-weight: 570;
    border: 1px solid transparent;
    transition: background .15s ease, border-color .15s ease;
}
.btn:hover { text-decoration: none; }
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-strong); color: #fff; }
.btn-ghost { border-color: var(--line); color: var(--ink); background: #fff; }
.btn-ghost:hover { border-color: var(--muted); }
.btn-lg { padding: 13px 26px; font-size: 1.03rem; }

/* --------------------------------------------------------------------------
   通用 section
   -------------------------------------------------------------------------- */
.section { padding-block: 54px; }
.section-tinted { background: var(--bg-tint); }

.section-head { text-align: center; max-width: 640px; margin-inline: auto; margin-block-end: 34px; }
.section-head p { color: var(--muted); margin: 0; }

.section-note { text-align: center; color: var(--muted); font-size: .92rem; margin: 26px 0 0; }
.section-sub { color: var(--muted); margin-block-end: 24px; }
.section-link { text-align: center; margin-block-start: 22px; }

.page-head { padding-block-end: 10px; }
.page-head h1 { margin-block-end: .3em; }
.lead { color: var(--muted); font-size: 1.05rem; max-width: 40em; }
.doc-updated { color: var(--muted); font-size: .88rem; }

/* --------------------------------------------------------------------------
   USP 条
   -------------------------------------------------------------------------- */
.usp { padding-block: 26px 8px; }
.usp-grid {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 22px;
}
.usp-item {
    border-inline-start: 2px solid var(--accent);
    padding-inline-start: 14px;
}
.usp-item h2 {
    font-size: 1rem;
    margin: 0 0 2px;
}
.usp-item p { color: var(--muted); font-size: .92rem; margin: 0; }

/* --------------------------------------------------------------------------
   为什么 / 文本节
   -------------------------------------------------------------------------- */
.why p { color: var(--muted); }
.why h2 { margin-block-end: .6em; }

.check-list { list-style: none; margin: 18px 0 0; padding: 0; }
.check-list li {
    position: relative;
    padding-inline-start: 30px;
    margin-block-end: 10px;
}
.check-list li::before {
    content: "";
    position: absolute;
    inset-inline-start: 0;
    top: .35em;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--accent-soft);
    /* 对勾图标：用背景 SVG，RTL 下 position 已用逻辑属性处理 */
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%230067d6' stroke-width='3' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M5 13l4 4 10-11'/%3E%3C/svg%3E");
    background-size: 11px;
    background-position: center;
    background-repeat: no-repeat;
}

/* --------------------------------------------------------------------------
   功能卡片
   -------------------------------------------------------------------------- */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 20px;
}
.feature-card {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 24px 22px;
    transition: box-shadow .15s ease, transform .15s ease;
}
.feature-card:hover { box-shadow: var(--shadow); transform: translateY(-2px); }
.feature-icon { color: var(--accent); margin-block-end: 12px; display: block; }
.feature-card p { color: var(--muted); font-size: .95rem; margin: 0; }

/* --------------------------------------------------------------------------
   三步走
   -------------------------------------------------------------------------- */
.steps {
    list-style: none;
    margin: 0;
    padding: 0;
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 20px;
    counter-reset: step;
}
.step { text-align: center; padding-inline: 12px; }
.step-num {
    display: inline-grid;
    place-items: center;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--accent-soft);
    color: var(--accent-strong);
    font-weight: 650;
    margin-block-end: 12px;
}
.step h3 { margin-block-start: 2px; }
.step p { color: var(--muted); font-size: .95rem; }

/* --------------------------------------------------------------------------
   对比表 / 规格表
   -------------------------------------------------------------------------- */
.table-wrap { overflow-x: auto; }
.compare-table, .specs-table {
    width: 100%;
    border-collapse: collapse;
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    overflow: hidden;
    font-size: .95rem;
}
.compare-table th, .compare-table td,
.specs-table th, .specs-table td {
    padding: 12px 16px;
    text-align: start;
    border-block-end: 1px solid var(--line);
    vertical-align: top;
}
.compare-table thead th { background: var(--bg-tint); font-size: .9rem; }
.compare-table tbody th, .specs-table tbody th {
    font-weight: 550;
    color: var(--ink);
    width: 34%;
}
.compare-table .cell-us { color: var(--accent-strong); font-weight: 550; }
.compare-table .cell-them { color: var(--muted); }
.specs-table tbody th { width: 30%; background: #fbfcfe; }
.specs-table tr:last-child > *, .compare-table tr:last-child > * { border-block-end: none; }

/* --------------------------------------------------------------------------
   使用场景
   -------------------------------------------------------------------------- */
.usecase-grid {
    list-style: none;
    margin: 0;
    padding: 0;
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 12px;
}
.usecase-grid li {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius-sm);
    padding: 14px 18px;
    font-size: .95rem;
    color: var(--ink);
    display: flex;
    align-items: center;
    gap: 10px;
}
.usecase-grid li::before {
    content: "";
    flex: none;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--accent);
}

/* --------------------------------------------------------------------------
   版本 / 价格
   -------------------------------------------------------------------------- */
.pricing-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px;
    max-width: 760px;
    margin-inline: auto;
}
.plan {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 26px 24px;
}
.plan-pro {
    border-color: var(--accent);
    box-shadow: 0 0 0 1px var(--accent) inset;
}
.plan h3 { font-size: 1.15rem; }
.plan-desc { color: var(--muted); font-size: .94rem; }
.plan-limit {
    margin: 16px 0 0;
    padding-block-start: 14px;
    border-block-start: 1px dashed var(--line);
    color: var(--muted);
    font-size: .9rem;
}

/* --------------------------------------------------------------------------
   FAQ 手风琴
   -------------------------------------------------------------------------- */
.faq-list { display: grid; gap: 10px; }
.faq-item {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius-sm);
    padding: 4px 18px;
}
.faq-item summary {
    cursor: pointer;
    font-weight: 570;
    padding-block: 12px;
    list-style: none;
    position: relative;
    padding-inline-end: 28px;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
    content: "";
    position: absolute;
    inset-inline-end: 4px;
    top: 50%;
    width: 9px;
    height: 9px;
    border-inline-end: 2px solid var(--muted);
    border-block-end: 2px solid var(--muted);
    transform: translateY(-70%) rotate(45deg);
    transition: transform .15s ease;
}
.faq-item[open] summary::after { transform: translateY(-30%) rotate(225deg); }
.faq-item p { color: var(--muted); font-size: .95rem; }

/* --------------------------------------------------------------------------
   功能详情页
   -------------------------------------------------------------------------- */
.capability-list { display: grid; gap: 34px; }
.capability h3 { font-size: 1.2rem; margin-block-end: 8px; }
.capability p { color: var(--muted); margin: 0; }
.capability-lede { color: var(--ink) !important; font-weight: 550; }

/* 锚点定位时给标题留出 header 高度 */
.capability { scroll-margin-top: 80px; }
.doc-section { scroll-margin-top: 80px; }

.notdo-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 20px;
}
.notdo-card {
    background: #fff;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 22px;
}
.notdo-card h3::before {
    content: "×";
    display: inline-grid;
    place-items: center;
    width: 22px;
    height: 22px;
    border-radius: 50%;
    background: #fdeaea;
    color: #c0392b;
    font-weight: 700;
    margin-inline-end: 9px;
    font-size: .95rem;
    vertical-align: -3px;
}
.notdo-card p { color: var(--muted); font-size: .95rem; margin: 0; }

.perm-list { display: grid; gap: 22px; }
.perm-item h3 { font-size: 1.05rem; }
.perm-item p { color: var(--muted); margin: 0; }

/* --------------------------------------------------------------------------
   收尾 CTA / 隐私文档
   -------------------------------------------------------------------------- */
.cta-box {
    text-align: center;
    background: var(--bg-tint);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    padding: 44px 28px;
}
.cta-box p { color: var(--muted); }
.cta-note { font-size: .88rem; margin: 14px 0 0; }

.privacy-layout { display: grid; grid-template-columns: 220px minmax(0, 1fr); gap: 40px; align-items: start; }

.doc-toc {
    position: sticky;
    top: 84px;
    font-size: .92rem;
}
.doc-toc-title { font-weight: 600; margin-block-end: 10px; }
.doc-toc ol { list-style: none; margin: 0; padding: 0; counter-reset: toc; }
.doc-toc li { margin-block-end: 8px; padding-inline-start: 26px; position: relative; }
.doc-toc li::before {
    counter-increment: toc;
    content: counter(toc);
    position: absolute;
    inset-inline-start: 0;
    top: .15em;
    color: var(--muted);
    font-size: .85rem;
    width: 18px;
    text-align: center;
}
.doc-toc a { color: var(--muted); }
.doc-toc a:hover { color: var(--accent-strong); }

.doc-section { margin-block-end: 40px; }
.doc-section h2 { font-size: 1.25rem; }
.plain-list { padding-inline-start: 22px; color: var(--muted); }
.plain-list li { margin-block-end: 6px; }

/* --------------------------------------------------------------------------
   Footer
   -------------------------------------------------------------------------- */
.site-footer {
    border-block-start: 1px solid var(--line);
    background: var(--bg-tint);
    padding-block: 40px 26px;
    margin-block-start: 20px;
}
.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1.4fr;
    gap: 30px;
}
.footer-name { font-weight: 650; margin: 0 0 4px; }
.footer-tagline { color: var(--muted); font-size: .94rem; margin: 0 0 10px; }
.footer-privacy { color: var(--muted); font-size: .85rem; margin: 0; max-width: 30em; }
.footer-col { display: grid; gap: 8px; align-content: start; }
.footer-col a { color: var(--muted); font-size: .92rem; }
.footer-col a:hover { color: var(--ink); text-decoration: none; }
.footer-col a[aria-current="page"] { color: var(--accent-strong); font-weight: 600; }
.footer-title { font-weight: 600; font-size: .9rem; margin: 0 0 4px; color: var(--ink); }
.footer-bottom {
    margin-block-start: 34px;
    padding-block-start: 18px;
    border-block-start: 1px solid var(--line);
}
.footer-bottom p { color: var(--muted); font-size: .85rem; margin: 0; }

/* --------------------------------------------------------------------------
   响应式
   -------------------------------------------------------------------------- */
@media (max-width: 960px) {
    .hero-grid { grid-template-columns: 1fr; gap: 30px; }
    .hero-copy { text-align: center; }
    .hero-sub { margin-inline: auto; }
    .hero-actions { justify-content: center; }
    .usp-grid { grid-template-columns: repeat(2, 1fr); }
    .feature-grid, .steps, .usecase-grid, .notdo-grid { grid-template-columns: repeat(2, 1fr); }
    .footer-grid { grid-template-columns: 1fr 1fr; }
    .privacy-layout { grid-template-columns: 1fr; gap: 24px; }
    .doc-toc { position: static; }
}

@media (max-width: 620px) {
    .section { padding-block: 40px; }
    .usp-grid, .feature-grid, .steps, .usecase-grid, .notdo-grid,
    .pricing-grid, .footer-grid { grid-template-columns: 1fr; }
    .main-nav { gap: 12px; }
    .main-nav a:not(.nav-download) { display: none; }
    .lang-menu { grid-template-columns: 1fr; min-width: 240px; }
    .hero { padding-block-start: 36px; }
}

/* --------------------------------------------------------------------------
   RTL（dir="rtl" 时只需微调，布局已用逻辑属性自动镜像）
   -------------------------------------------------------------------------- */
[dir="rtl"] .lang-switcher .chevron,
[dir="rtl"] .faq-item summary::after { transform-origin: center; }
[dir="rtl"] .doc-toc li { padding-inline-start: 26px; }
[dir="rtl"] body { letter-spacing: 0; }
[dir="rtl"] .hero-kicker,
[dir="rtl"] h1, [dir="rtl"] h2, [dir="rtl"] h3 { letter-spacing: 0; }

/* 打印：隐私政策常被打印留档 */
@media print {
    .site-header, .site-footer, .final-cta, .hero-actions { display: none; }
    body { color: #000; }
}