/* 抖音评论助手 · 官网 — 抖音夜间霓虹风 */

:root {
  --ink: #f5f4fb;
  --ink-soft: #b9b6c8;
  --ink-faint: #83809a;
  --bg: #08070d;
  --bg-2: #0d0b16;

  --cyan: #25f4ee;          /* 抖音青 */
  --pink: #fe2c55;          /* 抖音玫红 */
  --panel: rgba(255, 255, 255, 0.035);
  --panel-2: rgba(255, 255, 255, 0.055);
  --line: rgba(255, 255, 255, 0.09);
  --line-2: rgba(255, 255, 255, 0.16);
  --ok: #37e6a4;

  --radius: 20px;
  --radius-sm: 13px;
  --radius-pill: 999px;

  --glow-cyan: 0 0 0 1px rgba(37, 244, 238, 0.18), 0 24px 70px -24px rgba(37, 244, 238, 0.4);
  --glow-pink: 0 24px 70px -24px rgba(254, 44, 85, 0.4);
  --shadow-deep: 0 50px 120px -40px rgba(0, 0, 0, 0.9);

  --maxw: 1160px;
  --text-hero: clamp(2.7rem, 1.2rem + 5.2vw, 5.6rem);
  --text-h2: clamp(1.8rem, 1.1rem + 2.2vw, 3rem);

  --font: "PingFang SC", -apple-system, BlinkMacSystemFont, "Microsoft YaHei",
    "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --mono: "SF Mono", "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  line-height: 1.62;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  background: var(--bg);
  overflow-x: hidden;
}

/* 连续色雾——不切条带，青在右上、玫红在左下 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background:
    radial-gradient(1100px 780px at 86% -6%, rgba(37, 244, 238, 0.16), transparent 58%),
    radial-gradient(1000px 820px at 4% 18%, rgba(254, 44, 85, 0.14), transparent 55%),
    radial-gradient(1200px 1000px at 50% 108%, rgba(37, 244, 238, 0.08), transparent 60%),
    linear-gradient(180deg, var(--bg), var(--bg-2) 60%, var(--bg));
}

/* 颗粒，压掉塑料感 */
.grain {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  opacity: 0.5;
  mix-blend-mode: overlay;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.55'/%3E%3C/svg%3E");
}

main, header, footer { position: relative; z-index: 1; }
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
.wrap { width: min(100% - 2.4rem, var(--maxw)); margin-inline: auto; }

/* 发光渐变边框环——设备框复用 */
.ring { position: relative; }
.ring::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  padding: 1px;
  background: linear-gradient(135deg, rgba(37, 244, 238, 0.75), rgba(255, 255, 255, 0.05) 42%,
    rgba(255, 255, 255, 0.05) 58%, rgba(254, 44, 85, 0.75));
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  pointer-events: none;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.9rem 1.6rem;
  border-radius: var(--radius-pill);
  font-size: 1rem;
  font-weight: 700;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.18s var(--ease), box-shadow 0.22s var(--ease),
    background 0.18s var(--ease), border-color 0.18s var(--ease), color 0.18s var(--ease);
}
.btn-primary {
  color: #05121a;
  background: linear-gradient(100deg, var(--cyan), #7ef0ff 42%, #ff6f8b 62%, var(--pink));
  background-size: 160% 100%;
  box-shadow: 0 14px 34px -12px rgba(37, 244, 238, 0.6), 0 14px 40px -16px rgba(254, 44, 85, 0.5);
}
.btn-primary:hover { transform: translateY(-2px); background-position: 100% 0; box-shadow: 0 20px 44px -14px rgba(37, 244, 238, 0.7), 0 20px 50px -16px rgba(254, 44, 85, 0.6); }
.btn-ghost { background: var(--panel); border-color: var(--line-2); color: var(--ink); backdrop-filter: blur(6px); }
.btn-ghost:hover { background: var(--panel-2); border-color: var(--cyan); color: #fff; transform: translateY(-2px); }
.btn-sm { padding: 0.55rem 1.15rem; font-size: 0.92rem; }
.btn-lg { padding: 1.05rem 2rem; font-size: 1.1rem; }
.btn:active { transform: translateY(0); }

/* ---------- Topbar ---------- */
.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.75rem clamp(1.2rem, 4vw, 2.4rem);
  background: rgba(8, 7, 13, 0.6);
  backdrop-filter: saturate(160%) blur(16px);
  border-bottom: 1px solid var(--line);
}
.brand { display: flex; align-items: center; gap: 0.7rem; font-weight: 800; }
.brand-mark {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  border-radius: 12px;
  background: linear-gradient(150deg, var(--cyan), var(--pink));
  color: #06121a;
  font-size: 1.2rem;
  font-weight: 800;
  box-shadow: 0 8px 22px -8px rgba(37, 244, 238, 0.6);
}
.brand-name { font-size: 1.08rem; letter-spacing: -0.01em; }
.topnav { display: flex; gap: 1.9rem; }
.topnav a { font-size: 0.98rem; color: var(--ink-soft); font-weight: 500; transition: color 0.18s var(--ease); }
.topnav a:hover { color: #fff; }
@media (max-width: 860px) { .topnav { display: none; } }

/* ---------- Section scaffolding ---------- */
section { padding-block: clamp(4.5rem, 3rem + 6vw, 8.5rem); }
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.36rem 0.9rem;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--cyan);
  background: rgba(37, 244, 238, 0.08);
  border: 1px solid rgba(37, 244, 238, 0.28);
  border-radius: var(--radius-pill);
}
.eyebrow::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 10px var(--cyan);
}
.section-h {
  font-size: var(--text-h2);
  line-height: 1.12;
  letter-spacing: -0.02em;
  font-weight: 800;
  margin: 1.1rem 0 0;
}
.section-sub { color: var(--ink-soft); font-size: 1.1rem; max-width: 46ch; margin: 1rem 0 0; }

/* ---------- Hero ---------- */
.hero {
  padding-top: clamp(3.5rem, 2rem + 6vw, 7rem);
  padding-bottom: clamp(3.5rem, 2rem + 5vw, 6.5rem);
}
.hero-copy { max-width: 46rem; }
.hero h1 {
  font-size: var(--text-hero);
  line-height: 1.0;
  letter-spacing: -0.04em;
  font-weight: 900;
  margin: 1.2rem 0 0;
}
.hero h1 .hl {
  background: linear-gradient(105deg, var(--cyan) 12%, #b6f7ff 40%, #ff8aa0 62%, var(--pink) 92%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  filter: drop-shadow(0 6px 30px rgba(37, 244, 238, 0.35)) drop-shadow(0 6px 34px rgba(254, 44, 85, 0.28));
}
.lede { font-size: 1.2rem; color: var(--ink-soft); margin: 1.5rem 0 0; }
.hero-actions { display: flex; gap: 0.9rem; margin-top: 2.1rem; flex-wrap: wrap; }
.trust-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem 0.7rem;
  list-style: none;
  padding: 0;
  margin: 2.3rem 0 0;
}
.trust-chips li {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--ink-soft);
  padding: 0.42rem 0.95rem;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius-pill);
}
.trust-chips li::before { content: "▹ "; color: var(--cyan); }

/* ---------- Pain ---------- */
.pain-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.1rem;
  margin-top: 3rem;
}
.pain-card {
  padding: 1.7rem 1.4rem;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: transform 0.2s var(--ease), border-color 0.2s var(--ease), background 0.2s var(--ease);
}
.pain-card:hover { transform: translateY(-5px); border-color: rgba(254, 44, 85, 0.4); background: var(--panel-2); }
.ico {
  display: grid;
  place-items: center;
  width: 48px;
  height: 48px;
  border-radius: 14px;
  background: rgba(254, 44, 85, 0.12);
  color: var(--pink);
  margin-bottom: 1.15rem;
  box-shadow: inset 0 0 0 1px rgba(254, 44, 85, 0.28);
}
.ico svg { width: 24px; height: 24px; }
.pain-card h3 { font-size: 1.12rem; margin: 0 0 0.45rem; letter-spacing: -0.01em; }
.pain-card p { margin: 0; color: var(--ink-soft); font-size: 0.96rem; }
@media (max-width: 900px) { .pain-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 520px) { .pain-grid { grid-template-columns: 1fr; } }

/* ---------- How (steps) ---------- */
.steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.1rem;
  margin-top: 3rem;
  padding: 0;
  list-style: none;
  counter-reset: step;
}
.step-card {
  position: relative;
  padding: 1.9rem 1.4rem 1.5rem;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}
.step-no {
  display: inline-grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border-radius: 12px;
  font-family: var(--mono);
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--cyan);
  background: rgba(37, 244, 238, 0.08);
  border: 1px solid rgba(37, 244, 238, 0.3);
  margin-bottom: 1rem;
}
.step-card:first-child .step-no { color: #06121a; background: linear-gradient(140deg, var(--cyan), var(--pink)); border-color: transparent; }
.step-card h3 { margin: 0 0 0.45rem; font-size: 1.1rem; letter-spacing: -0.01em; }
.step-card p { margin: 0; color: var(--ink-soft); font-size: 0.95rem; }
@media (max-width: 900px) { .steps { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 520px) { .steps { grid-template-columns: 1fr; } }

/* ---------- Showcase (功能：知识库 + 防封护栏) ---------- */
.showcase { display: grid; gap: clamp(3.5rem, 3rem + 4vw, 6rem); }
.show-row {
  display: grid;
  grid-template-columns: 1fr 1.14fr;
  gap: clamp(2rem, 4vw, 4.5rem);
  align-items: center;
}
.show-row.reverse .show-media { order: -1; }
.show-copy .section-h { margin-top: 0.8rem; }
.show-copy p { color: var(--ink-soft); font-size: 1.08rem; margin: 1.1rem 0 0; }
.show-media { position: relative; }

/* "怎么对上号" 三步流：点破不是走模型 */
.reply-flow {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.55rem;
  margin-top: 1.5rem;
}
.rf-step {
  font-family: var(--mono);
  font-size: 0.85rem;
  color: var(--ink);
  padding: 0.5rem 0.9rem;
  border-radius: var(--radius-pill);
  background: rgba(37, 244, 238, 0.07);
  border: 1px solid rgba(37, 244, 238, 0.26);
}
.rf-arrow { color: var(--cyan); font-weight: 700; font-size: 1.05rem; }
.show-copy .rf-note { font-size: 0.92rem; color: var(--ink-faint); margin-top: 0.95rem; }

.func-panel {
  border-radius: 18px;
  padding: 1.75rem 1.85rem;
  background: linear-gradient(180deg, rgba(20, 18, 32, 0.82), rgba(12, 10, 22, 0.82));
  box-shadow: var(--glow-cyan), var(--shadow-deep);
}
.fp-head {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  font-family: var(--mono);
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  color: var(--ink-faint);
  margin: 0 0 1.35rem;
}
.fp-head::before {
  content: "";
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 10px var(--cyan);
}
.func-list { list-style: none; display: grid; gap: 1.15rem; }
.func-list li {
  position: relative;
  padding-left: 1.6rem;
  font-size: 0.96rem;
  color: var(--ink-soft);
  line-height: 1.45;
}
.func-list li::before {
  content: "▹";
  position: absolute;
  left: 0;
  top: 0.05rem;
  color: var(--cyan);
  font-weight: 700;
}
.func-list li b { display: block; color: var(--ink); font-weight: 600; font-size: 1.06rem; margin-bottom: 0.2rem; }

/* 防封 HUD 面板 */
.guard-hud {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border-radius: 16px;
  overflow: hidden;
  background: linear-gradient(180deg, rgba(20, 18, 32, 0.8), rgba(12, 10, 22, 0.8));
  border: 1px solid var(--line);
}
.figure { padding: 1.3rem 1rem; border-right: 1px solid var(--line); }
.figure:last-child { border-right: 0; }
.fig-num {
  font-family: var(--mono);
  font-size: clamp(1.7rem, 1.2rem + 1.6vw, 2.4rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1;
  color: var(--cyan);
  text-shadow: 0 0 22px rgba(37, 244, 238, 0.45);
}
.fig-num small { font-size: 0.82rem; font-weight: 600; color: var(--ink-faint); text-shadow: none; margin-left: 0.15rem; }
.fig-label { font-size: 0.86rem; color: var(--ink-soft); margin-top: 0.55rem; }

@media (max-width: 860px) {
  .show-row, .show-row.reverse .show-media { grid-template-columns: 1fr; order: 0; }
  .show-media { max-width: 34rem; }
}

/* ---------- Features bento ---------- */
.feat-bento {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.1rem;
  margin-top: 3rem;
}
.feat {
  padding: 1.75rem 1.5rem;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: transform 0.2s var(--ease), border-color 0.2s var(--ease), background 0.2s var(--ease);
}
.feat:hover { transform: translateY(-5px); border-color: rgba(37, 244, 238, 0.4); background: var(--panel-2); }
.feat h3 { margin: 0.2rem 0 0.55rem; font-size: 1.18rem; letter-spacing: -0.01em; display: flex; align-items: center; gap: 0.6rem; }
.feat h3 svg { width: 24px; height: 24px; color: var(--cyan); flex: none; filter: drop-shadow(0 0 8px rgba(37, 244, 238, 0.5)); }
.feat p { margin: 0; color: var(--ink-soft); font-size: 0.98rem; }
.feat-lg {
  grid-row: span 2;
  background:
    radial-gradient(500px 300px at 120% -10%, rgba(37, 244, 238, 0.16), transparent 60%),
    radial-gradient(500px 300px at -20% 120%, rgba(254, 44, 85, 0.16), transparent 60%),
    var(--panel-2);
  border-color: var(--line-2);
}
.feat-lg h3 { font-size: 1.5rem; }
.feat-lg h3 svg { color: var(--pink); filter: drop-shadow(0 0 8px rgba(254, 44, 85, 0.5)); }
.feat-badge {
  display: inline-block;
  margin-top: 1.2rem;
  padding: 0.32rem 0.85rem;
  background: linear-gradient(100deg, var(--cyan), var(--pink));
  color: #06121a;
  font-size: 0.8rem;
  font-weight: 800;
  border-radius: var(--radius-pill);
}
.feat-wide { grid-column: span 2; }
@media (max-width: 900px) {
  .feat-bento { grid-template-columns: 1fr 1fr; }
  .feat-lg { grid-row: span 1; }
  .feat-wide { grid-column: span 2; }
}
@media (max-width: 520px) {
  .feat-bento { grid-template-columns: 1fr; }
  .feat-wide, .feat-lg { grid-column: span 1; }
}

/* ---------- Demo ---------- */
.demo { text-align: center; }
.demo .eyebrow, .demo .section-h { justify-content: center; }
.demo .eyebrow { margin-inline: auto; }
.demo .section-sub { margin-inline: auto; text-align: center; }
.video-frame {
  margin-top: 2.8rem;
  border-radius: var(--radius);
  overflow: hidden;
  background: #0b0a13;
  box-shadow: var(--glow-cyan), var(--glow-pink), var(--shadow-deep);
  aspect-ratio: 16 / 10;
  position: relative;
}
.video-frame video { width: 100%; height: 100%; object-fit: cover; display: block; }
.video-fallback {
  position: absolute;
  inset: 0;
  color: var(--ink-faint);
  font-size: 1.05rem;
  font-weight: 600;
}
.video-fallback:not([hidden]) { display: grid; place-items: center; }

/* ---------- CTA ---------- */
.cta { text-align: center; }
.cta-card {
  position: relative;
  overflow: hidden;
  padding: clamp(2.8rem, 2rem + 3vw, 4.8rem) 1.6rem;
  border-radius: 26px;
  background:
    radial-gradient(720px 400px at 82% -20%, rgba(37, 244, 238, 0.2), transparent 60%),
    radial-gradient(720px 400px at 12% 120%, rgba(254, 44, 85, 0.2), transparent 60%),
    linear-gradient(180deg, rgba(20, 18, 32, 0.9), rgba(12, 10, 22, 0.9));
  box-shadow: var(--shadow-deep);
}
.cta-card h2 { font-size: var(--text-h2); letter-spacing: -0.02em; font-weight: 900; margin: 0; }
.cta-card p { color: var(--ink-soft); font-size: 1.1rem; max-width: 44ch; margin: 1rem auto 0; }
.cta-actions { display: flex; gap: 0.9rem; justify-content: center; margin-top: 2.1rem; flex-wrap: wrap; }
.cta-fine { font-size: 0.9rem; color: var(--ink-faint); margin-top: 1.7rem; }

/* ---------- FAQ ---------- */
.faq-list { margin-top: 2.8rem; display: grid; gap: 0.8rem; max-width: 47rem; }
.faq-item {
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--panel);
  padding: 0 1.35rem;
  transition: border-color 0.18s var(--ease), background 0.18s var(--ease);
}
.faq-item[open] { border-color: rgba(37, 244, 238, 0.35); background: var(--panel-2); }
.faq-item summary {
  cursor: pointer;
  list-style: none;
  padding: 1.15rem 0;
  font-weight: 600;
  font-size: 1.05rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: "+";
  font-size: 1.5rem;
  color: var(--cyan);
  font-weight: 300;
  transition: transform 0.2s var(--ease);
}
.faq-item[open] summary::after { transform: rotate(45deg); }
.faq-item p { margin: 0 0 1.15rem; color: var(--ink-soft); font-size: 0.98rem; }

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--line);
  padding: 2.8rem clamp(1.2rem, 4vw, 2.4rem);
  display: flex;
  flex-direction: column;
  gap: 0.7rem;
  align-items: center;
  text-align: center;
}
.foot-brand { display: flex; align-items: center; gap: 0.6rem; font-weight: 700; }
.foot-brand .brand-mark { width: 32px; height: 32px; font-size: 1rem; border-radius: 10px; }
.foot-fine { color: var(--ink-faint); font-size: 0.88rem; margin: 0; max-width: 54ch; }

/* ---------- Motion ---------- */
@keyframes rise {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}
.hero-copy > * { animation: rise 0.7s var(--ease) both; }
.hero-copy > *:nth-child(2) { animation-delay: 0.06s; }
.hero-copy > *:nth-child(3) { animation-delay: 0.12s; }
.hero-copy > *:nth-child(4) { animation-delay: 0.18s; }
.hero-copy > *:nth-child(5) { animation-delay: 0.24s; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { animation: none !important; transition-duration: 1ms !important; }
}