/* Mnemo 官网样式。一套字号、一种强调色、系统字体；深色模式只换变量。无外部资源。 */
:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --bg-2: #f6f6f4;
  --fg: #111110;
  --fg-2: #5c5c58;
  --fg-3: #8a8a85;
  --line: rgba(0, 0, 0, 0.08);
  --accent: #2f6b4a;
  --accent-fg: #ffffff;
  --shadow: 0 24px 60px -28px rgba(0, 0, 0, 0.35), 0 1px 3px rgba(0, 0, 0, 0.06);
  --max: 960px;
  --font: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue", "Segoe UI", sans-serif;
  --mono: ui-monospace, "SF Mono", Menlo, monospace;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #101110;
    --bg-2: #171917;
    --fg: #ededea;
    --fg-2: #a8a8a3;
    --fg-3: #777772;
    --line: rgba(255, 255, 255, 0.09);
    --accent: #7fc39a;
    --accent-fg: #0f1a13;
    --shadow: 0 24px 60px -28px rgba(0, 0, 0, 0.9), 0 1px 3px rgba(0, 0, 0, 0.5);
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  font: 17px/1.55 var(--font);
  color: var(--fg);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
a:hover { color: var(--accent); }
img { max-width: 100%; height: auto; display: block; }
h1, h2, h3, p { margin: 0; }
h1 { font-size: clamp(40px, 6vw, 64px); font-weight: 650; line-height: 1.05; letter-spacing: -0.03em; }
h2 { font-size: 15px; font-weight: 600; letter-spacing: 0.02em; color: var(--fg-3); text-transform: uppercase; }
h3 { font-size: 22px; font-weight: 600; letter-spacing: -0.015em; }
code { font-family: var(--mono); font-size: 0.9em; background: var(--bg-2); padding: 0.1em 0.4em; border-radius: 5px; }
.wrap { max-width: var(--max); margin: 0 auto; padding: 0 24px; }
.muted { color: var(--fg-2); }
.small { font-size: 14px; }

/* 顶栏 */
header { position: sticky; top: 0; z-index: 10; background: color-mix(in srgb, var(--bg) 85%, transparent); backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); }
header .wrap { display: flex; align-items: center; gap: 24px; height: 60px; }
.brand { display: flex; align-items: center; gap: 10px; font-weight: 650; }
.brand svg { width: 24px; height: 24px; }
nav { margin-left: auto; display: flex; align-items: center; gap: 22px; font-size: 15px; color: var(--fg-2); }
/* 语言切换：原生 select 去掉边框，只留文字和一个小箭头（伪元素，不用图片，CSP 不放行 data:） */
.langwrap { position: relative; display: inline-flex; align-items: center; }
.langwrap::after { content: "▾"; position: absolute; right: 2px; top: 50%; transform: translateY(-52%); pointer-events: none; color: var(--fg-3); font-size: 12px; }
.lang {
  appearance: none; -webkit-appearance: none; border: 0; background: transparent; color: var(--fg-2);
  font: inherit; font-size: 14px; letter-spacing: 0.04em; padding: 4px 16px 4px 4px; cursor: pointer;
}
.lang:hover { color: var(--fg); }
@media (max-width: 600px) { nav { gap: 12px; } nav a:not(.btn) { display: none; } nav .btn { padding: 8px 12px; } }

/* 按钮 */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 11px 18px; border-radius: 9px; font-size: 15px; font-weight: 600;
  background: var(--fg); color: var(--bg);
}
.btn:hover { color: var(--bg); background: var(--accent); }
.btn.accent { background: var(--accent); color: var(--accent-fg); }
.btn.accent:hover { background: var(--fg); color: var(--bg); }

/* Hero */
.hero { padding: 104px 0 64px; text-align: center; }
.hero h1 { max-width: 11em; margin: 0 auto; }
html[lang="ja"] .hero h1, html[lang="ko"] .hero h1 { max-width: none; font-size: clamp(34px, 5vw, 54px); letter-spacing: -0.01em; }
html[lang="ko"] .hero h1 { word-break: keep-all; }
.hero .sub { max-width: 34em; margin: 22px auto 0; font-size: 19px; color: var(--fg-2); }
.hero .cta { margin-top: 32px; display: flex; flex-direction: column; align-items: center; gap: 12px; }
.hero .terms { font-size: 15px; color: var(--fg-2); }
.hero .req { font-size: 13.5px; color: var(--fg-3); }
.shot { border-radius: 12px; overflow: hidden; border: 1px solid var(--line); box-shadow: var(--shadow); }
.hero .shot { margin-top: 56px; }

/* 区块 */
section { padding: 96px 0 0; }
section h2 { margin-bottom: 28px; }
.pillars { display: grid; grid-template-columns: repeat(3, 1fr); gap: 40px; }
.pillars h3 { margin-bottom: 8px; }
.pillars p { color: var(--fg-2); }
.pillars .shot { grid-column: 1 / -1; margin-top: 24px; }
@media (max-width: 760px) { .pillars { grid-template-columns: 1fr; gap: 32px; } }

/* 隐私 */
.privacy .lead { font-size: 22px; font-weight: 550; letter-spacing: -0.01em; max-width: 30em; }
table { border-collapse: collapse; width: 100%; margin-top: 28px; font-size: 15px; }
th, td { text-align: left; vertical-align: top; padding: 14px 0; border-top: 1px solid var(--line); }
th { font-size: 13px; font-weight: 600; color: var(--fg-3); border-top: 0; padding-top: 0; }
td:first-child { font-weight: 600; white-space: nowrap; padding-right: 24px; }
td:nth-child(2) { color: var(--fg-2); padding-right: 24px; }
td:last-child { color: var(--fg-2); }
.privacy .more { margin-top: 20px; font-size: 15px; }
.privacy .more a { color: var(--accent); }
@media (max-width: 600px) {
  table, thead, tbody, tr, th, td { display: block; }
  thead { display: none; }
  td { padding: 4px 0; border: 0; }
  tr { padding: 14px 0; border-top: 1px solid var(--line); }
  td:first-child { white-space: normal; }
}

/* 定价 */
.plan { border: 1px solid var(--line); border-radius: 14px; padding: 32px; max-width: 520px; background: var(--bg-2); }
.plan .amount { font-size: 48px; font-weight: 650; letter-spacing: -0.03em; line-height: 1; }
.plan .amount small { font-size: 16px; font-weight: 500; color: var(--fg-2); letter-spacing: 0; margin-left: 8px; }
.plan ul { list-style: none; margin: 22px 0 0; padding: 0; color: var(--fg-2); }
.plan li { padding: 6px 0 6px 26px; position: relative; }
.plan li::before { content: "✓"; position: absolute; left: 0; color: var(--accent); font-weight: 700; }
.plan .btn { margin-top: 24px; width: 100%; }
.plan .fine { margin-top: 16px; font-size: 13.5px; color: var(--fg-3); }

/* FAQ */
.faq details { border-top: 1px solid var(--line); }
.faq details:last-child { border-bottom: 1px solid var(--line); }
.faq summary { cursor: pointer; list-style: none; padding: 16px 32px 16px 0; font-weight: 600; position: relative; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; position: absolute; right: 0; top: 14px; color: var(--fg-3); font-weight: 400; font-size: 20px; }
.faq details[open] summary::after { content: "–"; }
.faq p { padding: 0 0 18px; color: var(--fg-2); max-width: 46em; }

/* 页脚 */
footer { margin-top: 112px; padding: 32px 0 48px; border-top: 1px solid var(--line); font-size: 14px; color: var(--fg-3); }
footer .wrap { display: flex; flex-wrap: wrap; gap: 8px 24px; }
footer a:hover { color: var(--accent); }

/* 隐私全文页 */
.doc { padding: 80px 0 0; }
.doc h1 { font-size: clamp(32px, 4.5vw, 44px); }
.doc .meta { margin-top: 12px; font-size: 14px; color: var(--fg-3); }
.doc h2 { margin: 48px 0 12px; }
.doc p, .doc li { color: var(--fg-2); max-width: 44em; }
.doc p + p { margin-top: 12px; }
.doc ul { margin: 12px 0 0; padding-left: 22px; }
.doc li { margin-top: 6px; }
.doc .lead { font-size: 22px; font-weight: 550; color: var(--fg); letter-spacing: -0.01em; }
.doc table { margin-top: 12px; }