/* ═══════════════════════════════════════════
   闪电快传 Swift Upload — 宣传站样式
   ═══════════════════════════════════════════ */

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

:root {
  --shell: 1120px;
  --radius-sm: 10px;
  --radius: 16px;
  --radius-lg: 24px;

  --accent: #6366f1;
  --accent-2: #8b5cf6;
  --accent-3: #d946ef;
  --accent-soft: rgba(99, 102, 241, 0.14);

  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

/* ── 深色（默认） ── */
html[data-theme="dark"] {
  color-scheme: dark;
  --bg: #070a12;
  --bg-2: #0b0f19;
  --surface: rgba(255, 255, 255, 0.038);
  --surface-2: rgba(255, 255, 255, 0.06);
  --border: rgba(255, 255, 255, 0.09);
  --border-strong: rgba(255, 255, 255, 0.16);
  --text: #f8fafc;
  --body: #c3ccda;
  --muted: #8a97a9;
  --faint: #64748b;
  --panel-bg: rgba(17, 22, 34, 0.82);
  --canvas: #111827;
  --shadow: 0 26px 60px -28px rgba(0, 0, 0, 0.9);
  --shadow-sm: 0 12px 28px -18px rgba(0, 0, 0, 0.85);
  --orb-a: rgba(99, 102, 241, 0.42);
  --orb-b: rgba(217, 70, 239, 0.28);
  --orb-c: rgba(56, 189, 248, 0.22);
}

/* ── 浅色 ── */
html[data-theme="light"] {
  color-scheme: light;
  --bg: #f7f8fc;
  --bg-2: #ffffff;
  --surface: rgba(15, 23, 42, 0.038);
  --surface-2: rgba(15, 23, 42, 0.06);
  --border: rgba(15, 23, 42, 0.09);
  --border-strong: rgba(15, 23, 42, 0.16);
  --text: #0d1526;
  --body: #3b4759;
  --muted: #64748b;
  --faint: #94a3b8;
  --panel-bg: rgba(255, 255, 255, 0.9);
  --canvas: #ffffff;
  --shadow: 0 26px 60px -34px rgba(15, 23, 42, 0.45);
  --shadow-sm: 0 12px 28px -20px rgba(15, 23, 42, 0.35);
  --orb-a: rgba(99, 102, 241, 0.3);
  --orb-b: rgba(217, 70, 239, 0.18);
  --orb-c: rgba(56, 189, 248, 0.2);
}

html { scroll-behavior: smooth; scroll-padding-top: 90px; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", Roboto, sans-serif;
  background: var(--bg);
  color: var(--body);
  line-height: 1.68;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

.shell { width: 100%; max-width: var(--shell); margin: 0 auto; padding: 0 24px; }
.shell.narrow { max-width: 780px; }

h1, h2, h3, strong { color: var(--text); letter-spacing: -0.015em; }
a { color: inherit; text-decoration: none; }
code {
  font-family: "SF Mono", ui-monospace, Menlo, Monaco, monospace;
  font-size: 0.88em;
  padding: 2px 6px;
  border-radius: 6px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--accent);
  white-space: nowrap;
}
html[data-theme="light"] code { color: #4f46e5; }

/* ═══════ 背景光晕 ═══════ */
.atmosphere { position: fixed; inset: 0; z-index: -1; overflow: hidden; pointer-events: none; }
.orb { position: absolute; border-radius: 50%; filter: blur(90px); }
.orb-a { width: 620px; height: 620px; top: -260px; left: -120px; background: var(--orb-a); }
.orb-b { width: 560px; height: 560px; top: 60px; right: -180px; background: var(--orb-b); }
.orb-c { width: 700px; height: 520px; top: 720px; left: 34%; background: var(--orb-c); }
.grid-veil {
  position: absolute; inset: 0;
  background-image:
    linear-gradient(var(--border) 1px, transparent 1px),
    linear-gradient(90deg, var(--border) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: radial-gradient(ellipse 90% 55% at 50% 0%, #000 12%, transparent 70%);
  -webkit-mask-image: radial-gradient(ellipse 90% 55% at 50% 0%, #000 12%, transparent 70%);
  opacity: 0.55;
}

/* ═══════ 导航 ═══════ */
.nav {
  position: sticky; top: 0; z-index: 90;
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  background: color-mix(in srgb, var(--bg) 72%, transparent);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s ease, background 0.3s ease;
}
.nav.scrolled { border-bottom-color: var(--border); background: color-mix(in srgb, var(--bg) 88%, transparent); }

.nav-inner { display: flex; align-items: center; gap: 20px; height: 68px; }

.brand { display: inline-flex; align-items: center; gap: 10px; }
.brand-mark { border-radius: 9px; display: block; }
.brand-text { display: flex; flex-direction: column; line-height: 1.2; }
.brand-text strong { font-size: 15px; font-weight: 700; }
.brand-text em { font-style: normal; font-size: 10.5px; color: var(--faint); letter-spacing: 0.6px; }

.nav-links { display: flex; gap: 4px; margin-left: auto; }
.nav-links a {
  font-size: 13.5px; font-weight: 500; color: var(--muted);
  padding: 7px 12px; border-radius: 999px;
  transition: color 0.18s ease, background 0.18s ease;
}
.nav-links a:hover { color: var(--text); background: var(--surface-2); }

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

.icon-btn, .lang-btn {
  appearance: none; border: 1px solid var(--border); background: var(--surface);
  color: var(--muted); cursor: pointer; font-family: inherit;
  display: inline-flex; align-items: center; justify-content: center;
  transition: color 0.18s ease, border-color 0.18s ease, background 0.18s ease;
}
.icon-btn { width: 34px; height: 34px; border-radius: 10px; }
.lang-btn { height: 34px; padding: 0 12px; border-radius: 999px; font-size: 11.5px; font-weight: 700; letter-spacing: 0.4px; }
.icon-btn:hover, .lang-btn:hover { color: var(--text); border-color: var(--accent); }
.icon-btn svg { width: 17px; height: 17px; fill: none; stroke: currentColor; stroke-width: 1.7; stroke-linecap: round; }
html[data-theme="dark"] .i-sun { display: none; }
html[data-theme="light"] .i-moon { display: none; }

/* ═══════ 按钮 ═══════ */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 9px;
  border-radius: 12px; font-weight: 600; font-family: inherit; cursor: pointer;
  border: 1px solid transparent; transition: transform 0.18s var(--ease), box-shadow 0.22s ease,
    background 0.22s ease, border-color 0.22s ease, color 0.22s ease;
  white-space: nowrap;
}
.btn-sm { padding: 8px 15px; font-size: 13px; }
.btn-lg { padding: 14px 26px; font-size: 15px; border-radius: 14px; }
.btn-block { width: 100%; padding: 13px 20px; font-size: 14.5px; }

.btn-primary {
  color: #fff;
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent-2) 55%, var(--accent-3) 120%);
  box-shadow: 0 12px 26px -12px rgba(99, 102, 241, 0.75), inset 0 1px 0 rgba(255, 255, 255, 0.28);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 18px 34px -14px rgba(139, 92, 246, 0.85), inset 0 1px 0 rgba(255, 255, 255, 0.34); }
.btn-primary:active { transform: translateY(0) scale(0.99); }

.btn-ghost { color: var(--text); background: var(--surface); border-color: var(--border); }
.btn-ghost:hover { background: var(--surface-2); border-color: var(--border-strong); transform: translateY(-2px); }

.btn svg { width: 18px; height: 18px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
.btn .i-apple { fill: currentColor; stroke: none; }

/* ═══════ HERO ═══════ */
.hero { padding: 78px 0 40px; position: relative; }
.hero-inner { display: grid; grid-template-columns: 1.05fr 1fr; gap: 56px; align-items: center; }

.pill {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 6px 14px 6px 11px; border-radius: 999px;
  background: var(--surface); border: 1px solid var(--border);
  font-size: 12.5px; font-weight: 500; color: var(--muted);
}
.pill-dot { width: 7px; height: 7px; border-radius: 50%; background: #22c55e; box-shadow: 0 0 0 3px rgba(34, 197, 94, 0.18); }

.hero h1 { font-size: clamp(34px, 4.6vw, 55px); line-height: 1.1; font-weight: 800; margin: 22px 0 20px; }
.grad {
  background: linear-gradient(120deg, #818cf8 0%, #a78bfa 40%, #e879f9 90%);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
}

.lead { font-size: 16.5px; color: var(--body); max-width: 33em; }

.hero-cta { display: flex; flex-wrap: wrap; gap: 12px; margin: 30px 0 22px; }

.hero-trust { list-style: none; display: flex; flex-wrap: wrap; gap: 8px 20px; font-size: 13px; color: var(--muted); }
.hero-trust li { display: inline-flex; align-items: center; gap: 7px; }
.hero-trust li::before {
  content: ''; width: 15px; height: 15px; flex: none; border-radius: 50%;
  background: var(--accent-soft);
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%236366f1' stroke-width='3.4' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M20 6 9 17l-5-5'/%3E%3C/svg%3E");
  background-size: 10px; background-repeat: no-repeat; background-position: center;
}

/* ── 面板复刻 ── */
.hero-stage { position: relative; }
.fake-page {
  position: relative;
  border-radius: var(--radius-lg);
  background: var(--panel-bg);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  overflow: visible;
}
.fake-bar { display: flex; align-items: center; gap: 6px; padding: 13px 16px; border-bottom: 1px solid var(--border); }
.fake-bar .dot { width: 10px; height: 10px; border-radius: 50%; background: var(--surface-2); border: 1px solid var(--border); }
.fake-url {
  margin-left: 12px; flex: 1; font-size: 11px; color: var(--faint);
  background: var(--surface); border: 1px solid var(--border);
  border-radius: 999px; padding: 4px 12px;
  font-family: "SF Mono", ui-monospace, Menlo, monospace;
}

.fake-body { padding: 26px 24px 30px; display: flex; flex-direction: column; gap: 18px; }
.fake-field { display: flex; flex-direction: column; gap: 9px; }
.fake-label { height: 9px; width: 30%; border-radius: 5px; background: var(--surface-2); }
.fake-input { height: 40px; border-radius: 10px; background: var(--surface); border: 1px solid var(--border); }
.fake-upload {
  display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 10px;
  padding: 30px; border-radius: 14px; text-align: center;
  border: 1.5px dashed var(--border-strong);
  color: var(--muted); font-size: 13.5px;
  background: var(--surface);
}
.fake-upload svg { width: 26px; height: 26px; fill: none; stroke: currentColor; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; }

.panel {
  position: absolute; left: 50%; transform: translateX(-50%);
  bottom: -34px;
  display: flex; align-items: center; gap: 10px;
  padding: 10px 12px; border-radius: 14px;
  background: var(--canvas);
  border: 1px solid var(--border-strong);
  box-shadow: var(--shadow), 0 0 30px rgba(99, 102, 241, 0.14);
  animation: float 5.5s ease-in-out infinite;
}
@keyframes float { 0%, 100% { transform: translateX(-50%) translateY(0); } 50% { transform: translateX(-50%) translateY(-7px); } }

.panel-paste {
  display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 8px;
  padding: 0 20px; height: 74px; border-radius: 10px;
  border: 1px dashed var(--border-strong); background: var(--surface);
}
.panel-paste kbd {
  font-family: inherit; font-size: 11px; font-weight: 700; letter-spacing: 0.5px;
  padding: 2px 8px; border-radius: 5px;
  background: var(--surface-2); border: 1px solid var(--border); color: var(--text);
}
.panel-paste span { font-size: 11px; color: var(--muted); }

.panel-history { display: flex; gap: 8px; padding: 0 10px; border-left: 1px solid var(--border); border-right: 1px solid var(--border); }
.thumb { position: relative; width: 66px; height: 66px; border-radius: 11px; border: 1px solid var(--border); }
.thumb.t1 { background: linear-gradient(135deg, #6366f1, #ec4899); }
.thumb.t2 { background: linear-gradient(135deg, #22d3ee, #6366f1); }
.thumb.t3 { background: linear-gradient(135deg, #f59e0b, #ef4444); }
.badge {
  position: absolute; top: 3px; left: 3px; font-size: 8.5px; font-weight: 700;
  padding: 1px 4px; border-radius: 3px; background: var(--accent); color: #fff;
}

.panel-pick {
  display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 6px;
  padding: 0 18px; height: 74px; border-radius: 10px;
  background: var(--surface); border: 1px solid var(--border);
  font-size: 11px; color: var(--muted);
}
.panel-pick svg { width: 20px; height: 20px; fill: none; stroke: currentColor; stroke-width: 1.6; stroke-linejoin: round; }

.drop-chip {
  position: absolute; right: -14px; bottom: -76px;
  display: inline-flex; align-items: center; gap: 8px;
  padding: 9px 15px; border-radius: 999px;
  font-size: 12px; font-weight: 600; color: #fff;
  background: linear-gradient(135deg, #10b981, #059669);
  box-shadow: 0 14px 30px -14px rgba(16, 185, 129, 0.8);
  animation: chipIn 0.9s var(--ease) 0.9s both;
}
.drop-chip svg { width: 15px; height: 15px; fill: none; stroke: currentColor; stroke-width: 2.6; stroke-linecap: round; stroke-linejoin: round; }
@keyframes chipIn { from { opacity: 0; transform: translateY(10px) scale(0.9); } to { opacity: 1; transform: none; } }

/* ═══════ PAIN ═══════ */
.pain { padding: 74px 0 30px; }
.pain-inner { text-align: center; display: flex; flex-direction: column; align-items: center; gap: 14px; }
.pain-line { font-size: clamp(14px, 1.7vw, 17px); color: var(--faint); }
.pain-line b { color: var(--faint); font-weight: 400; padding: 0 4px; }
.pain-new { font-size: clamp(20px, 2.6vw, 27px); font-weight: 700; color: var(--text); }
.kbd-inline {
  display: inline-block; padding: 2px 12px; margin: 0 4px; border-radius: 10px;
  background: linear-gradient(135deg, var(--accent), var(--accent-3));
  color: #fff; font-weight: 700; box-shadow: 0 10px 24px -12px rgba(139, 92, 246, 0.9);
}

/* ═══════ 通用 section ═══════ */
.section { padding: 92px 0; }
.section-alt { background: color-mix(in srgb, var(--bg-2) 62%, transparent); border-block: 1px solid var(--border); }

.sec-head { max-width: 660px; margin: 0 auto 52px; text-align: center; }
.sec-head h2 { font-size: clamp(26px, 3.4vw, 38px); line-height: 1.22; font-weight: 800; margin: 12px 0 14px; }
.sec-head p { font-size: 15.5px; }

.eyebrow {
  display: inline-block; font-size: 12px; font-weight: 700; letter-spacing: 1.6px;
  text-transform: uppercase; color: var(--accent);
}
html[data-theme="light"] .eyebrow { color: #4f46e5; }

/* ═══════ 功能卡片 ═══════ */
.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.card {
  padding: 26px 24px 28px; border-radius: var(--radius);
  background: var(--surface); border: 1px solid var(--border);
  transition: transform 0.3s var(--ease), border-color 0.3s ease, background 0.3s ease, box-shadow 0.3s ease;
}
.card:hover { transform: translateY(-4px); border-color: color-mix(in srgb, var(--accent) 45%, var(--border)); background: var(--surface-2); box-shadow: var(--shadow-sm); }
.card-icon {
  display: inline-flex; align-items: center; justify-content: center;
  width: 42px; height: 42px; border-radius: 12px; margin-bottom: 16px;
  background: var(--accent-soft); color: var(--accent);
}
html[data-theme="light"] .card-icon { color: #4f46e5; }
.card-icon svg { width: 21px; height: 21px; fill: none; stroke: currentColor; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; }
.card h3 { font-size: 16.5px; font-weight: 700; margin-bottom: 9px; }
.card p { font-size: 14px; color: var(--muted); line-height: 1.7; }

/* ═══════ 步骤 ═══════ */
.steps { list-style: none; display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; counter-reset: step; }
.step {
  position: relative; padding: 30px 24px 28px; border-radius: var(--radius);
  background: var(--surface); border: 1px solid var(--border);
  transition: transform 0.3s var(--ease), border-color 0.3s ease;
}
.step:hover { transform: translateY(-4px); border-color: color-mix(in srgb, var(--accent) 40%, var(--border)); }
.step-no {
  display: inline-flex; align-items: center; justify-content: center;
  width: 30px; height: 30px; border-radius: 9px; margin-bottom: 15px;
  font-size: 13px; font-weight: 800; color: #fff;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  box-shadow: 0 8px 18px -10px rgba(99, 102, 241, 0.9);
}
.step h3 { font-size: 16px; font-weight: 700; margin-bottom: 9px; }
.step p { font-size: 14px; color: var(--muted); line-height: 1.72; }

/* ═══════ 文本复制 ═══════ */
.split { display: grid; grid-template-columns: 1fr 0.92fr; gap: 60px; align-items: center; }
.split-copy h2 { font-size: clamp(25px, 3.2vw, 36px); font-weight: 800; line-height: 1.22; margin: 12px 0 14px; }
.split-copy > p { font-size: 15.5px; }
.split-note { margin-top: 18px; font-size: 13px; color: var(--faint); }

.modes { display: flex; flex-direction: column; gap: 10px; margin-top: 28px; }
.mode {
  display: flex; flex-direction: column; gap: 3px;
  padding: 14px 18px; border-radius: var(--radius-sm);
  background: var(--surface); border: 1px solid var(--border);
  transition: border-color 0.22s ease, background 0.22s ease, transform 0.22s var(--ease);
}
.mode[data-mode="auto"] { border-color: color-mix(in srgb, var(--accent) 55%, var(--border)); background: var(--accent-soft); }
.mode:hover { transform: translateX(4px); }
.mode strong { font-size: 14.5px; font-weight: 700; }
.mode span { font-size: 13px; color: var(--muted); }

.split-visual { display: flex; justify-content: center; }
.demo-doc {
  position: relative; width: 100%; max-width: 380px; padding: 28px 26px 30px;
  border-radius: var(--radius-lg); background: var(--panel-bg);
  border: 1px solid var(--border); box-shadow: var(--shadow);
  backdrop-filter: blur(18px); -webkit-backdrop-filter: blur(18px);
  display: flex; flex-direction: column; gap: 14px;
}
.demo-line { font-size: 14px; color: var(--faint); line-height: 1.75; }
.demo-selected {
  color: var(--text);
  background: linear-gradient(90deg, rgba(99, 102, 241, 0.28), rgba(217, 70, 239, 0.2));
  border-radius: 4px; padding: 2px 4px; margin: -2px -4px;
  box-shadow: inset 0 0 0 1px rgba(129, 140, 248, 0.4);
}
.demo-btn {
  align-self: flex-start; margin-top: 8px;
  display: inline-flex; align-items: center; gap: 7px;
  padding: 8px 14px; border-radius: 9px; font-size: 12.5px; font-weight: 600;
  background: var(--canvas); color: var(--text);
  border: 1px solid var(--border-strong);
  box-shadow: 0 12px 26px -16px rgba(0, 0, 0, 0.6);
  animation: float2 4.5s ease-in-out infinite;
}
@keyframes float2 { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-5px); } }
.demo-icon svg { width: 15px; height: 15px; display: block; fill: none; stroke: currentColor; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; }

/* ═══════ 隐私 ═══════ */
.priv-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }
.priv-card {
  padding: 24px 22px 26px; border-radius: var(--radius);
  background: var(--surface); border: 1px solid var(--border);
  transition: transform 0.3s var(--ease), border-color 0.3s ease;
}
.priv-card:hover { transform: translateY(-3px); border-color: color-mix(in srgb, var(--accent) 40%, var(--border)); }
.priv-card h3 { font-size: 15px; font-weight: 700; margin-bottom: 9px; }
.priv-card p { font-size: 13.5px; color: var(--muted); line-height: 1.7; }

/* ═══════ 定价 ═══════ */
.price-wrap { display: grid; grid-template-columns: repeat(2, minmax(0, 380px)); gap: 22px; justify-content: center; align-items: stretch; }
.price-card {
  position: relative; display: flex; flex-direction: column;
  padding: 32px 28px 28px; border-radius: var(--radius-lg);
  background: var(--surface); border: 1px solid var(--border);
}
.price-featured {
  border-color: color-mix(in srgb, var(--accent) 60%, var(--border));
  background: linear-gradient(180deg, var(--accent-soft), transparent 60%), var(--surface-2);
  box-shadow: var(--shadow);
}
.ribbon {
  position: absolute; top: -13px; left: 50%; transform: translateX(-50%);
  padding: 5px 14px; border-radius: 999px; font-size: 11.5px; font-weight: 700; color: #fff;
  background: linear-gradient(135deg, var(--accent), var(--accent-3));
  box-shadow: 0 10px 24px -12px rgba(139, 92, 246, 0.9);
  white-space: nowrap;
}
.price-tag {
  display: inline-block; font-size: 11px; font-weight: 700; letter-spacing: 1.2px;
  text-transform: uppercase; padding: 4px 10px; border-radius: 999px;
  background: var(--surface-2); border: 1px solid var(--border); color: var(--muted);
  margin-bottom: 14px;
}
.price-tag.accent { color: var(--accent); border-color: color-mix(in srgb, var(--accent) 50%, transparent); }
html[data-theme="light"] .price-tag.accent { color: #4f46e5; }
.price-card h3 { font-size: 25px; font-weight: 800; }
.price-sub { font-size: 13.5px; color: var(--muted); margin-top: 6px; }
.price-list { list-style: none; display: flex; flex-direction: column; gap: 11px; margin: 26px 0 30px; flex: 1; }
.price-list li { display: flex; gap: 10px; font-size: 14px; color: var(--body); }
.price-list li::before {
  content: ''; flex: none; width: 17px; height: 17px; margin-top: 3px; border-radius: 50%;
  background: var(--accent-soft);
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%236366f1' stroke-width='3.2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M20 6 9 17l-5-5'/%3E%3C/svg%3E");
  background-size: 11px; background-repeat: no-repeat; background-position: center;
}
.price-hint { margin-top: 12px; font-size: 11.5px; color: var(--faint); text-align: center; line-height: 1.6; }

/* ═══════ FAQ ═══════ */
.faq-list { display: flex; flex-direction: column; gap: 10px; }
.faq {
  border-radius: var(--radius-sm); background: var(--surface); border: 1px solid var(--border);
  overflow: hidden; transition: border-color 0.25s ease, background 0.25s ease;
}
.faq[open] { border-color: color-mix(in srgb, var(--accent) 45%, var(--border)); background: var(--surface-2); }
.faq summary {
  list-style: none; cursor: pointer; padding: 17px 52px 17px 20px; position: relative;
  font-size: 15px; font-weight: 600; color: var(--text);
  transition: color 0.2s ease;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: ''; position: absolute; right: 20px; top: 50%; width: 9px; height: 9px;
  border-right: 2px solid var(--muted); border-bottom: 2px solid var(--muted);
  transform: translateY(-70%) rotate(45deg); transition: transform 0.25s var(--ease);
}
.faq[open] summary::after { transform: translateY(-30%) rotate(225deg); }
.faq p { padding: 0 20px 19px; font-size: 14px; color: var(--muted); line-height: 1.75; }

/* ═══════ CTA ═══════ */
.cta { padding: 40px 0 100px; }
.cta-inner {
  display: flex; flex-direction: column; align-items: center; text-align: center; gap: 16px;
  padding: 58px 30px 62px; border-radius: 28px;
  background: linear-gradient(160deg, var(--accent-soft), transparent 62%), var(--surface);
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}
.cta-icon { border-radius: 18px; box-shadow: 0 18px 40px -18px rgba(99, 102, 241, 0.85); }
.cta-inner h2 { font-size: clamp(24px, 3.2vw, 34px); font-weight: 800; }
.cta-inner > p { font-size: 15.5px; color: var(--muted); }
.cta-inner .btn { margin-top: 10px; }

/* ═══════ FOOTER ═══════ */
.footer { border-top: 1px solid var(--border); padding: 42px 0 50px; background: color-mix(in srgb, var(--bg-2) 55%, transparent); }
.footer-inner { display: flex; flex-direction: column; align-items: center; gap: 20px; text-align: center; }
.footer-brand { display: flex; align-items: center; gap: 11px; }
.footer-brand img { border-radius: 8px; }
.footer-brand div { display: flex; flex-direction: column; line-height: 1.3; text-align: left; }
.footer-brand strong { font-size: 14px; }
.footer-brand span { font-size: 11px; color: var(--faint); letter-spacing: 0.5px; }
.footer-links { display: flex; flex-wrap: wrap; justify-content: center; gap: 6px 22px; font-size: 13.5px; }
.footer-links a { color: var(--muted); transition: color 0.18s ease; }
.footer-links a:hover { color: var(--text); }
.footer-note { font-size: 12px; color: var(--faint); }

/* ═══════ 滚动入场 ═══════ */
.reveal { opacity: 0; transform: translateY(22px); }
.reveal.in { opacity: 1; transform: none; transition: opacity 0.7s var(--ease), transform 0.7s var(--ease); }
@media (prefers-reduced-motion: reduce) {
  .reveal, .reveal.in { opacity: 1; transform: none; transition: none; }
  .panel, .demo-btn, .drop-chip { animation: none !important; }
  html { scroll-behavior: auto; }
}

/* ═══════ 响应式 ═══════ */
@media (max-width: 1020px) {
  .hero-inner { grid-template-columns: 1fr; gap: 62px; }
  .hero-stage { max-width: 560px; margin: 0 auto; width: 100%; }
  .cards, .steps { grid-template-columns: repeat(2, 1fr); }
  .priv-grid { grid-template-columns: repeat(2, 1fr); }
  .split { grid-template-columns: 1fr; gap: 44px; }
  .nav-links { display: none; }
}

@media (max-width: 720px) {
  .shell { padding: 0 18px; }
  .hero { padding: 52px 0 20px; }
  .section { padding: 68px 0; }
  .cards, .steps, .priv-grid { grid-template-columns: 1fr; }
  .price-wrap { grid-template-columns: 1fr; }
  .btn-lg { padding: 13px 20px; font-size: 14px; }
  .hero-cta { flex-direction: column; align-items: stretch; }
  .hero-cta .btn { width: 100%; }
  .panel { left: 12px; right: 12px; transform: none; animation: none; bottom: -26px; gap: 8px; padding: 9px 10px; }
  .panel-paste { padding: 0 12px; } .panel-pick { padding: 0 12px; }
  .panel-history { padding: 0 7px; gap: 6px; }
  .thumb { width: 52px; height: 52px; }
  .drop-chip { right: auto; left: 50%; transform: translateX(-50%); bottom: -68px; font-size: 11px; }
  .pain { padding: 56px 0 10px; }
  .faq summary { font-size: 14px; padding: 15px 46px 15px 16px; }
  .cta-inner { padding: 44px 20px 48px; }
}