/* ============ VoNote 设计 token ============ */
/* 品牌色取自 App 图标：靛蓝 #565CF6 → 紫 #8B5CF6（左上→右下对角渐变） */
:root {
  --bg: #F7F8FC;
  --bg-soft: #EFF1FA;
  --card: #FFFFFF;
  --primary: #565CF6;
  --primary-strong: #4B4FE0;
  --primary-soft: #EEF0FE;
  --accent: #8B5CF6;
  --teal: #12A594;
  --ink: #1B1E33;
  --muted: #6B7183;
  --line: #E7E9F2;
  --radius-lg: 24px;
  --radius-md: 16px;
  --radius-sm: 10px;
  --shadow-card: 0 16px 44px -16px rgba(86, 92, 246, .28);
  --shadow-soft: 0 8px 24px -10px rgba(27, 30, 51, .12);
  --font-display: "Inter", "Noto Sans SC", "Noto Sans JP", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", -apple-system, "Segoe UI", sans-serif;
  --font-body: "Inter", "Noto Sans SC", "Noto Sans JP", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", -apple-system, "Segoe UI", sans-serif;
}

/* ============ Reset ============ */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-body);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img, svg { display: block; }
a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; }
.container { width: min(1160px, 92%); margin: 0 auto; }

/* ============ Progress bar ============ */
.progress-bar {
  position: fixed; top: 0; left: 0; height: 3px; width: 0;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  z-index: 1000; transition: width .1s linear;
}

/* ============ Buttons ============ */
.btn {
  display: inline-flex; align-items: center; gap: 8px; justify-content: center;
  font-weight: 700; font-family: var(--font-display);
  border-radius: 999px; border: none; transition: transform .18s ease, box-shadow .18s ease, background .18s ease;
  white-space: nowrap;
  padding: 13px 24px; font-size: 15px;
}
.btn-primary { background: linear-gradient(135deg, var(--primary), var(--accent)); color: #fff; box-shadow: 0 10px 24px -8px rgba(86, 92, 246, .55); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 14px 30px -8px rgba(86, 92, 246, .6); }
.btn-ghost { background: #fff; color: var(--ink); border: 1.5px solid var(--line); }
.btn-ghost:hover { border-color: var(--primary); color: var(--primary-strong); transform: translateY(-2px); }
.btn-lg { padding: 15px 30px; font-size: 16px; }
.btn-sm { padding: 9px 18px; font-size: 14px; }

/* ============ Header ============ */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(247, 248, 252, .86);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color .2s, box-shadow .2s;
}
.site-header.scrolled { border-bottom-color: var(--line); box-shadow: 0 6px 20px -14px rgba(27, 30, 51, .25); }
.header-inner { display: flex; align-items: center; gap: 20px; height: 72px; }
.brand { display: inline-flex; align-items: center; gap: 10px; }
.brand-mark { width: 40px; height: 40px; display: grid; place-items: center; border-radius: 12px; overflow: hidden; }
.brand-text { display: flex; flex-direction: column; line-height: 1.15; }
.brand-name { font-weight: 800; font-size: 17px; letter-spacing: -.2px; }
.brand-sub { font-size: 11px; font-weight: 600; color: var(--primary); letter-spacing: .6px; }

.nav { display: flex; align-items: center; gap: 4px; margin-left: auto; }
.nav a { padding: 8px 14px; border-radius: 999px; font-weight: 600; font-size: 15px; color: var(--ink); transition: background .18s, color .18s; }
.nav a:hover { background: var(--primary-soft); color: var(--primary-strong); }

.header-actions { display: flex; align-items: center; gap: 12px; }

/* Language switch */
.lang-switch { position: relative; }
.lang-btn {
  display: inline-flex; align-items: center; gap: 6px;
  background: #fff; border: 1.5px solid var(--line); border-radius: 999px;
  padding: 8px 12px; font-size: 14px; font-weight: 700; color: var(--ink);
  transition: border-color .18s;
}
.lang-btn:hover { border-color: var(--primary); }
.lang-menu {
  position: absolute; top: calc(100% + 8px); right: 0; min-width: 150px;
  background: #fff; border: 1px solid var(--line); border-radius: 14px;
  box-shadow: var(--shadow-soft); padding: 6px; list-style: none;
  opacity: 0; transform: translateY(-6px) scale(.98); pointer-events: none; transition: .18s ease;
}
.lang-switch.open .lang-menu { opacity: 1; transform: translateY(0) scale(1); pointer-events: auto; }
.lang-menu li button {
  width: 100%; text-align: left; padding: 9px 12px; border-radius: 9px;
  background: none; border: none; font-size: 14px; font-weight: 600; color: var(--ink);
  display: flex; align-items: center; justify-content: space-between;
}
.lang-menu li button:hover { background: var(--bg-soft); }
.lang-menu li button.active { color: var(--primary-strong); font-weight: 800; }
.lang-menu li button.active::after { content: "✓"; }

.menu-toggle { display: none; flex-direction: column; gap: 5px; background: none; border: none; padding: 8px; }
.menu-toggle span { width: 24px; height: 2.5px; background: var(--ink); border-radius: 2px; transition: .2s; }

/* ============ Hero ============ */
.hero { position: relative; padding: 56px 0 80px; overflow: hidden; }
.hero-bg { position: absolute; inset: 0; pointer-events: none; }
.blob { position: absolute; border-radius: 50%; filter: blur(70px); opacity: .55; }
.blob-1 { width: 460px; height: 460px; background: #D9DBFF; top: -170px; right: -110px; }
.blob-2 { width: 360px; height: 360px; background: #E4D9FF; top: 42%; left: -170px; }
.blob-3 { width: 300px; height: 300px; background: #D6F5F1; bottom: -130px; left: 32%; }

.hero-grid { display: grid; grid-template-columns: 1.06fr .94fr; gap: 44px; align-items: center; position: relative; }
.badge {
  display: inline-flex; align-items: center; gap: 8px;
  background: var(--primary-soft); color: var(--primary-strong);
  font-weight: 700; font-size: 13px; padding: 7px 14px; border-radius: 999px; margin-bottom: 20px;
}
.badge::before { content: ""; width: 7px; height: 7px; border-radius: 50%; background: var(--primary); box-shadow: 0 0 0 3px rgba(86,92,246,.22); }
.hero-title { font-family: var(--font-display); font-size: clamp(32px, 5.2vw, 56px); font-weight: 800; line-height: 1.16; letter-spacing: -1.2px; }
.hero-title .highlight {
  background: linear-gradient(120deg, var(--primary) 0%, var(--accent) 100%);
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero-sub { margin: 22px 0 28px; font-size: 16.5px; color: var(--muted); max-width: 540px; }
.hero-cta { display: flex; gap: 14px; flex-wrap: wrap; }
.hero-note { display: inline-flex; align-items: center; gap: 8px; margin-top: 22px; font-size: 13.5px; color: var(--muted); font-weight: 600; }
.hero-note .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--teal); box-shadow: 0 0 0 3px rgba(18,165,148,.2); }

/* ---------- 手机模型 ---------- */
.hero-visual { display: flex; justify-content: center; position: relative; }
.phone-stage { position: relative; width: min(360px, 100%); }
.stage-glow {
  position: absolute; inset: 6% 2%; border-radius: 50%;
  background: radial-gradient(circle at 50% 45%, rgba(139,92,246,.22) 0%, transparent 70%);
  filter: blur(8px);
}
.phone-mock { position: relative; width: 100%; height: auto; }

.float-chip {
  position: absolute; z-index: 3;
  display: inline-flex; align-items: center; gap: 6px;
  background: #fff; border: 1px solid var(--line); border-radius: 999px;
  padding: 7px 13px; font-size: 12.5px; font-weight: 700; color: var(--ink);
  box-shadow: var(--shadow-soft); white-space: nowrap;
}
.float-chip svg { color: var(--primary); }
.chip-offline { top: 12%; left: -26px; animation: floaty 4.8s ease-in-out infinite; }
.chip-noupload { top: 40%; right: -30px; animation: floaty 5.6s ease-in-out infinite .5s; }
.chip-category { bottom: 16%; left: -22px; animation: floaty 6.2s ease-in-out infinite .9s; }
/* 第四个角：右下。前面三个占掉了左上/右中/左下，「联网需你同意」放在这里不与它们重叠 */
.chip-network { bottom: 2%; right: -24px; animation: floaty 5.2s ease-in-out infinite .3s; }
.float-chip.chip-noupload svg { color: var(--teal); }
.float-chip.chip-category svg { color: var(--accent); }
.float-chip.chip-network svg { color: var(--teal); }

@keyframes floaty { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-10px); } }

/* 声波：逐根跳动（围绕自身中心缩放，不改几何） */
.wave .bar {
  transform-box: fill-box; transform-origin: center;
  animation: barPulse 1.5s ease-in-out infinite;
}
.wave .b1 { animation-delay: 0s; }
.wave .b2 { animation-delay: .1s; }
.wave .b3 { animation-delay: .2s; }
.wave .b4 { animation-delay: .3s; }
.wave .b5 { animation-delay: .4s; }
.wave .b6 { animation-delay: .5s; }
.wave .b7 { animation-delay: .6s; }
@keyframes barPulse {
  0%, 100% { transform: scaleY(.34); }
  50% { transform: scaleY(1); }
}

/* 录音小红点：呼吸 */
.rec-dot { animation: dotBlink 1.4s ease-in-out infinite; }
@keyframes dotBlink { 0%, 100% { opacity: 1; } 50% { opacity: .25; } }

/* 静音提示：录了一会儿才出现，出现后停住（不循环，免得整页一直闪）*/
.silent-tip { opacity: 0; animation: tipIn .7s ease-out 2.2s forwards; }
@keyframes tipIn { from { opacity: 0; transform: translateY(-6px); } to { opacity: 1; transform: none; } }

/* 整理结果：文字行从左逐条写出 */
.doc-lines rect {
  transform-box: fill-box; transform-origin: left center;
  animation: lineIn 6.4s ease-in-out infinite;
}
.doc-lines .l1 { animation-delay: 0s; }
.doc-lines .l2 { animation-delay: .16s; }
.doc-lines .l3 { animation-delay: .32s; }
.doc-lines .l4 { animation-delay: .48s; }
.doc-lines .l5 { animation-delay: .64s; }
.doc-lines .l6 { animation-delay: .80s; }
@keyframes lineIn {
  0%, 6% { transform: scaleX(0); opacity: 0; }
  20%, 82% { transform: scaleX(1); opacity: 1; }
  94%, 100% { transform: scaleX(0); opacity: 0; }
}

/* 完成徽标：文字写完后打钩 */
.done-badge { transform-box: fill-box; transform-origin: center; opacity: 0; animation: popIn .5s cubic-bezier(.2,.8,.2,1) 1.9s forwards; }
@keyframes popIn { from { opacity: 0; transform: scale(.4); } to { opacity: 1; transform: scale(1); } }

/* 标题：先于正文出现 */
.note-title { opacity: 0; animation: tipIn .5s ease-out 1.3s forwards; }

/* 主按钮呼吸环 */
.pulse { transform-box: fill-box; transform-origin: center; animation: ring 2.6s ease-out infinite; }
@keyframes ring {
  0% { transform: scale(1); opacity: .5; }
  70%, 100% { transform: scale(1.45); opacity: 0; }
}

/* ============ Stats ============ */
.stats { border-block: 1px solid var(--line); background: #fff; }
.stats-grid { display: grid; grid-template-columns: repeat(4, 1fr); }
.stat { padding: 30px 16px; text-align: center; border-right: 1px solid var(--line); }
.stat:last-child { border-right: none; }
.stat-value { display: block; font-family: var(--font-display); font-size: 28px; font-weight: 800; color: var(--primary-strong); letter-spacing: -.6px; }
.stat-label { font-size: 13.5px; color: var(--muted); font-weight: 600; }

/* ============ Sections ============ */
.section { padding: 84px 0; }
.section-head { text-align: center; max-width: 660px; margin: 0 auto 54px; }
.section-head h2 { font-family: var(--font-display); font-size: clamp(26px, 3.5vw, 38px); font-weight: 800; letter-spacing: -.8px; margin-bottom: 14px; }
.section-head p { color: var(--muted); font-size: 16.5px; }

/* ============ Features ============ */
.features-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.feature-card {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius-lg);
  padding: 30px 28px; transition: transform .2s ease, box-shadow .2s ease, border-color .2s;
}
.feature-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-card); border-color: transparent; }
.feature-icon { width: 52px; height: 52px; border-radius: 15px; display: grid; place-items: center; margin-bottom: 18px; }
.feature-icon svg { width: 26px; height: 26px; }
.feature-card h3 { font-size: 17.5px; font-weight: 700; margin-bottom: 10px; font-family: var(--font-display); }
.feature-card p { font-size: 14.5px; color: var(--muted); }

/* ============ How ============ */
.how { background: var(--bg-soft); }
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.step {
  background: #fff; border-radius: var(--radius-lg); padding: 32px 28px;
  border: 1px solid var(--line); text-align: center;
}
.step-num {
  width: 44px; height: 44px; border-radius: 50%; margin: 0 auto 18px;
  background: linear-gradient(135deg, var(--primary), var(--accent)); color: #fff;
  display: grid; place-items: center; font-weight: 800; font-size: 17px; font-family: var(--font-display);
}
.step h3 { font-size: 17.5px; font-weight: 700; margin-bottom: 10px; font-family: var(--font-display); }
.step p { font-size: 14.5px; color: var(--muted); }

/* ============ Privacy ============ */
.privacy-card {
  display: grid; grid-template-columns: 1.5fr .5fr; gap: 28px; align-items: center;
  background: linear-gradient(135deg, #262A52, #171A38); color: #fff;
  border-radius: 30px; padding: 52px 56px; position: relative; overflow: hidden;
}
.privacy-card::after {
  content: ""; position: absolute; width: 380px; height: 380px; border-radius: 50%;
  background: rgba(139,92,246,.22); filter: blur(70px); top: -150px; right: -110px;
}
.badge-dark { background: rgba(139,92,246,.26); color: #CFC6FF; }
.badge-dark::before { background: var(--accent); box-shadow: 0 0 0 3px rgba(139,92,246,.3); }
.privacy-card h2 { font-size: clamp(24px, 3vw, 34px); font-weight: 800; margin-bottom: 8px; font-family: var(--font-display); letter-spacing: -.6px; }
.privacy-sub { font-size: 17px; font-weight: 700; color: #C6CBFF; margin-bottom: 14px; }
.privacy-desc { color: rgba(255,255,255,.76); font-size: 15px; max-width: 560px; }
.privacy-points { list-style: none; margin-top: 26px; display: grid; gap: 14px; position: relative; z-index: 2; }
.privacy-points li { display: flex; gap: 12px; align-items: flex-start; }
.pp-icon {
  flex: 0 0 auto; width: 32px; height: 32px; border-radius: 10px;
  background: rgba(255,255,255,.1); display: grid; place-items: center; color: #B9AEFF;
}
.pp-icon svg { width: 17px; height: 17px; }
.pp-copy { display: flex; flex-direction: column; }
.pp-copy strong { font-size: 14.5px; font-weight: 700; }
.pp-copy span { font-size: 13.5px; color: rgba(255,255,255,.68); line-height: 1.6; }
.privacy-visual { display: grid; place-items: center; position: relative; z-index: 2; }

/* ============ Download ============ */
.download-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 22px; max-width: 760px; margin: 0 auto; }
/* 只剩 App Store 一张卡时收窄成一列 —— 沿用两列会把卡片拉成两个屏宽 */
.download-grid-single { grid-template-columns: minmax(0, 1fr); max-width: 420px; }
.download-card {
  background: #fff; border: 1px solid var(--line); border-radius: var(--radius-lg);
  padding: 34px 32px; text-align: center; transition: transform .2s, box-shadow .2s, border-color .2s;
  display: flex; flex-direction: column; align-items: center; gap: 6px;
}
.download-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-card); border-color: transparent; }
.os-icon { width: 64px; height: 64px; border-radius: 20px; background: var(--primary-soft); color: var(--primary-strong); display: grid; place-items: center; margin-bottom: 12px; }
.os-name { font-size: 18.5px; font-weight: 700; font-family: var(--font-display); }
.os-ver { font-size: 13px; color: var(--muted); }
.os-cta { margin-top: 16px; display: inline-block; padding: 10px 26px; border-radius: 999px; background: linear-gradient(135deg, var(--primary), var(--accent)); color: #fff; font-weight: 700; font-size: 15px; box-shadow: 0 10px 22px -8px rgba(86,92,246,.5); }
.download-note { text-align: center; margin-top: 28px; color: var(--muted); font-size: 14px; }

/* ============ Subscribe ============ */
.subscribe-card {
  background: linear-gradient(135deg, #EFF1FE, #E9E3FE); border-radius: 30px; padding: 56px;
  border: 1px solid #E0E2FA;
}
.subscribe-form { max-width: 580px; margin: 0 auto; }
.input-row { display: flex; gap: 10px; }
.input-row .text-input { flex: 1; }
.text-input {
  width: 100%; padding: 14px 18px; font-size: 15px; font-family: var(--font-body);
  border: 1.5px solid var(--line); border-radius: 14px; background: #fff; color: var(--ink);
  transition: border-color .18s, box-shadow .18s; outline: none;
}
.text-input:focus { border-color: var(--primary); box-shadow: 0 0 0 4px rgba(86,92,246,.14); }
.interests { margin-top: 20px; }
.interests-label { display: block; font-size: 13px; font-weight: 700; color: var(--muted); margin-bottom: 10px; }
.chips { display: flex; flex-wrap: wrap; gap: 10px; }
.chip {
  padding: 8px 16px; border-radius: 999px; border: 1.5px solid var(--line); background: #fff;
  font-size: 13.5px; font-weight: 600; color: var(--ink); transition: .15s;
}
.chip:hover { border-color: var(--primary); }
.chip.active { background: var(--primary); color: #fff; border-color: var(--primary); }
.form-msg { margin-top: 14px; font-size: 14px; font-weight: 700; min-height: 20px; }
.form-msg.success { color: #0E8C7C; }
.form-msg.error { color: #D0452F; }

/* ============ Feedback ============ */
.feedback-form { max-width: 720px; margin: 0 auto; background: #fff; border: 1px solid var(--line); border-radius: var(--radius-lg); padding: 40px; box-shadow: var(--shadow-soft); }
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; margin-bottom: 18px; }
.field { display: flex; flex-direction: column; gap: 8px; }
.field label { font-size: 13.5px; font-weight: 700; color: var(--ink); }
.field select.text-input {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%236B7183' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E");
  background-repeat: no-repeat; background-position: right 16px center;
}
.stars { display: flex; gap: 6px; }
.star { background: none; border: none; font-size: 28px; line-height: 1; color: #D8DBE8; transition: color .12s, transform .12s; }
.star:hover { transform: scale(1.12); }
.star.active { color: #E8A93A; }
.feedback-actions { display: flex; align-items: center; gap: 18px; margin-top: 22px; flex-wrap: wrap; }
.feedback-actions .form-msg { margin-top: 0; }

/* ============ Footer ============ */
.site-footer { background: #1B1E33; color: #E7E9F2; padding: 60px 0 28px; }
.footer-inner { display: grid; grid-template-columns: 1.6fr 1fr 1fr 1fr 1fr; gap: 36px; }
.footer-brand .brand-name { color: #fff; }
.footer-brand .brand-sub { color: #A9AEF0; }
.footer-tagline { margin-top: 16px; color: rgba(231,233,242,.62); font-size: 14px; max-width: 260px; }
.footer-col h4 { font-size: 13px; text-transform: uppercase; letter-spacing: 1.5px; color: rgba(231,233,242,.45); margin-bottom: 16px; }
.footer-col a { display: block; padding: 5px 0; font-size: 14.5px; color: rgba(231,233,242,.8); transition: color .15s; }
.footer-col a:hover { color: #fff; }
.footer-bottom { margin-top: 44px; padding-top: 22px; border-top: 1px solid rgba(255,255,255,.1); display: flex; justify-content: space-between; flex-wrap: wrap; gap: 8px; font-size: 13px; color: rgba(231,233,242,.45); }

/* ============ Toast ============ */
.toast {
  position: fixed; bottom: 28px; left: 50%; transform: translate(-50%, 80px);
  background: var(--ink); color: #fff; padding: 13px 22px; border-radius: 14px;
  font-size: 14.5px; font-weight: 700; box-shadow: 0 12px 30px -10px rgba(0,0,0,.35);
  opacity: 0; transition: .3s cubic-bezier(.2,.8,.2,1); z-index: 1000; pointer-events: none;
  max-width: 90%;
}
.toast.show { opacity: 1; transform: translate(-50%, 0); }
.toast.success { background: #0E8C7C; }
.toast.error { background: #D0452F; }

/* ============ Reveal ============ */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity .6s ease, transform .6s ease; }
.reveal.in { opacity: 1; transform: none; }

/* ============ Honeypot (anti-spam) ============ */
.hp-field { position: absolute !important; left: -9999px !important; width: 1px !important; height: 1px !important; opacity: 0 !important; pointer-events: none !important; }

/* ============ Focus 可见性（键盘导航） ============ */
a:focus-visible, button:focus-visible, input:focus-visible, select:focus-visible, textarea:focus-visible {
  outline: 2.5px solid var(--primary); outline-offset: 2px;
}

/* ============ Responsive ============ */
@media (max-width: 900px) {
  .hero-grid { grid-template-columns: 1fr; text-align: center; }
  .hero-sub { margin-inline: auto; }
  .hero-cta { justify-content: center; }
  .hero-note { justify-content: center; }
  .hero-visual { order: -1; }
  .phone-stage { width: min(300px, 80%); }
  .chip-offline { left: -10px; }
  .chip-noupload { right: -12px; }
  .chip-category { left: -8px; }
  .chip-network { right: -10px; }
  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: 1fr; }
  .privacy-card { grid-template-columns: 1fr; text-align: center; padding: 40px 28px; }
  .privacy-desc { margin-inline: auto; }
  .privacy-points { text-align: left; }
  .privacy-visual { display: none; }
  .footer-inner { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 640px) {
  .nav, .header-cta { display: none; }
  .nav.open { display: flex; flex-direction: column; position: absolute; top: 72px; left: 0; right: 0; background: #fff; padding: 16px; gap: 4px; box-shadow: var(--shadow-soft); border-bottom: 1px solid var(--line); }
  .nav.open a { width: 100%; }
  .menu-toggle { display: flex; margin-left: auto; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .stat:nth-child(2) { border-right: none; }
  .stat:nth-child(1), .stat:nth-child(2) { border-bottom: 1px solid var(--line); }
  .features-grid { grid-template-columns: 1fr; }
  .download-grid { grid-template-columns: 1fr; }
  .input-row { flex-direction: column; }
  .form-grid { grid-template-columns: 1fr; }
  .subscribe-card { padding: 32px 22px; }
  .feedback-form { padding: 28px 20px; }
  .footer-inner { grid-template-columns: 1fr; }
  .lang-btn span#langLabel { display: none; }
}

/* ============ 减少动态效果 ============ */
/* 尊重系统「减弱动态效果」：波形、文字行、呼吸环全部停在稳定状态 */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .001ms !important; animation-iteration-count: 1 !important; transition-duration: .001ms !important; }
  .reveal { opacity: 1; transform: none; }
  .silent-tip, .doc-lines rect, .done-badge, .note-title { opacity: 1; transform: none; }
  .pulse { opacity: 0; }
}

/* ============================================================
   运行原理承接卡（#principle）
   完整内容已经搬到独立页 /principle.html。首页只留这一张卡：
   一句话说清它是什么、四个要点给出「点进去能看到什么」，然后交出去。
   在这里再摆一整套可动手的控件，会把首页「说完就走」的节奏拖垮。
   ============================================================ */
.pt-sec { padding-top: 0; }

.pt-card {
  position: relative; overflow: hidden;
  display: grid; grid-template-columns: 1.12fr .88fr; gap: 42px; align-items: center;
  border-radius: 30px; padding: 46px 48px;
  background: linear-gradient(150deg, #2B2F5C, #14162E);
  box-shadow: 0 40px 84px -44px rgba(27, 30, 51, .7);
}
.pt-glow {
  position: absolute; inset: -50% -10% auto -10%; height: 540px; pointer-events: none;
  background:
    radial-gradient(38% 52% at 20% 22%, rgba(86, 92, 246, .55), transparent 70%),
    radial-gradient(38% 52% at 80% 6%, rgba(139, 92, 246, .5), transparent 70%);
}

.pt-main { position: relative; }
.pt-badge {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 7px 14px; border-radius: 999px;
  background: rgba(255, 255, 255, .12); border: 1px solid rgba(255, 255, 255, .2);
  font-family: var(--font-display); font-size: 11.5px; font-weight: 800;
  letter-spacing: .1em; text-transform: uppercase; color: #fff;
}
.pt-main h2 {
  font-family: var(--font-display); color: #fff;
  font-size: clamp(26px, 3.2vw, 36px); font-weight: 800; letter-spacing: -.9px;
  margin: 18px 0 14px;
}
.pt-sub { color: rgba(255, 255, 255, .74); font-size: 16px; max-width: 560px; }
.pt-points { list-style: none; display: grid; grid-template-columns: 1fr 1fr; gap: 13px 22px; margin: 26px 0 30px; }
.pt-points li { display: flex; gap: 10px; align-items: flex-start; color: rgba(255, 255, 255, .9); font-size: 14px; line-height: 1.6; }
.pt-points li::before {
  content: ""; flex: none; width: 7px; height: 7px; border-radius: 2px; margin-top: 7px;
  background: linear-gradient(135deg, #8B9CFF, #C6A8FF);
}
.pt-actions { display: flex; gap: 12px; flex-wrap: wrap; }
.pt-note { margin-top: 18px; font-size: 12.5px; color: rgba(255, 255, 255, .5); }

/* 右侧迷你预览：一眼看出「有声波、有文字、有档位」 */
.pt-side { display: block; }
.pt-visual {
  display: grid; gap: 13px; border-radius: 22px; padding: 18px;
  background: rgba(255, 255, 255, .07); border: 1px solid rgba(255, 255, 255, .14);
  transition: transform .3s ease, box-shadow .3s ease;
}
.pt-side:hover .pt-visual { transform: translateY(-4px); box-shadow: 0 26px 54px -26px rgba(0, 0, 0, .6); }
.pt-visual-bar { display: flex; align-items: center; gap: 6px; }
.pt-visual-bar > span { width: 7px; height: 7px; border-radius: 50%; background: rgba(255, 255, 255, .28); }
.pt-visual-bar em {
  font-style: normal; margin-left: auto; font-family: var(--font-display);
  font-size: 10px; font-weight: 800; letter-spacing: .1em; text-transform: uppercase;
  color: rgba(255, 255, 255, .44);
}
.pt-visual-wave { display: flex; align-items: center; gap: 3px; height: 54px; }
.pt-visual-wave i {
  flex: 1; display: block; height: 100%; border-radius: 2px;
  background: linear-gradient(180deg, #8B9CFF, rgba(139, 92, 246, .5));
  transform: scaleY(.3); transform-origin: center;
  animation: ptGlow 2.8s ease-in-out infinite;
}
/* 高低起伏全靠 nth-child，省掉 22 个内联高度 */
.pt-visual-wave i:nth-child(2n) { transform: scaleY(.58); animation-delay: .2s; }
.pt-visual-wave i:nth-child(3n) { transform: scaleY(.82); animation-delay: .4s; }
.pt-visual-wave i:nth-child(4n+1) { transform: scaleY(1); animation-delay: .6s; }
.pt-visual-wave i:nth-child(5n+2) { transform: scaleY(.42); animation-delay: .3s; }
.pt-visual-wave i:nth-child(7n) { transform: scaleY(.94); animation-delay: .5s; }
@keyframes ptGlow { 0%, 100% { opacity: .72; } 50% { opacity: 1; } }

.pt-visual-lines { display: grid; gap: 7px; }
.pt-visual-lines span { display: block; height: 7px; border-radius: 4px; background: rgba(255, 255, 255, .2); }
.pt-visual-lines span:nth-child(1) { width: 78%; }
.pt-visual-lines span:nth-child(2) { width: 100%; }
.pt-visual-lines span:nth-child(3) { width: 56%; }

.pt-visual-tiers { display: flex; gap: 7px; }
.pt-visual-tier { flex: 1; height: 26px; border-radius: 8px; background: rgba(255, 255, 255, .1); }
.pt-visual-tier.is-on { background: linear-gradient(135deg, rgba(139, 156, 255, .8), rgba(198, 168, 255, .5)); }

@media (max-width: 900px) {
  .pt-card { grid-template-columns: 1fr; gap: 30px; padding: 36px 28px; }
  .pt-side { order: -1; }
  .pt-points { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  .pt-card { padding: 30px 20px; border-radius: 24px; }
  .pt-actions .btn { flex: 1 1 100%; }
}

@media (prefers-reduced-motion: reduce) {
  .pt-glow { display: none; }
  .pt-visual-wave i { animation: none; opacity: .9; }
  .pt-side:hover .pt-visual { transform: none; }
}