/* 必过啦 static website styles — scaffold */

:root {
  --paper: #f7f1e6;
  --paper-dark: #f0e9df;
  --ink: #1c1916;
  --ink-soft: #2b2622;
  --muted: #7a6f63;
  --vermilion: #c8102e;
  --gold: #c9a227;
  --gold-soft: #b89a6c;
  --border-gold: rgba(201, 162, 39, 0.2);
  --shadow: rgba(74, 64, 56, 0.12);
  --max-width: 1200px;
  --radius: 20px;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  font-family: 'Noto Serif SC', 'Noto Sans SC', serif;
  background: var(--paper);
  color: var(--ink-soft);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
a { text-decoration: none; color: inherit; }

/* Accessible/SEO-only text kept out of view without display:none (crawlable) */
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  border: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
}

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

/* 3D scroll perspective: each section is a 3D stage. */
main > section {
  perspective: 1200px;
  perspective-origin: 50% 30%;
}

main, .site-footer {
  position: relative;
  z-index: 1;
}

/* Section depth card: JS sets --rx (tilt) and --tz (depth push) per scroll
   position so every panel floats in 3D space and flattens as it passes centre. */
main > section > .container {
  transform: perspective(1200px) rotateX(var(--rx, 0deg)) translateZ(var(--tz, 0px));
  transition: transform 0.18s linear;
  will-change: transform;
}

@media (prefers-reduced-motion: reduce) {
  main > section > .container {
    transform: none !important;
    transition: none !important;
    will-change: auto;
  }
}

/* Reveal: elements rise out of depth with a slight 3D tilt as they enter. */
.reveal {
  opacity: 0;
  transform: translate3d(0, 70px, -120px) rotateX(14deg) scale(0.94);
  transform-origin: 50% 100%;
  transition:
    opacity 0.7s cubic-bezier(0.22, 1, 0.36, 1),
    transform 0.9s cubic-bezier(0.22, 1, 0.36, 1);
  will-change: opacity, transform;
}

.reveal.visible {
  opacity: 1;
  transform: translate3d(0, 0, 0) rotateX(0) scale(1);
}

/* Parallax layers get moved continuously by JS via --parallax-y (px). */
[data-parallax] {
  transform: translate3d(0, var(--parallax-y, 0px), 0);
  will-change: transform;
}

/* Pointer tilt: JS sets --tilt while the cursor is over a card. Overrides the
   card's resting transform so the lean tracks the pointer in 3D. */
.tilting {
  transform: var(--tilt) !important;
  transition: transform 0.12s ease-out !important;
}

/* Cursor glow: a soft vermilion/gold light tracks the pointer across cards,
   giving an interactive, high-tech surface without leaving the palette. */
/* 组选择器只保留在用卡片类(pain/feature/stat/testimonial),solution/quiz 已随删节清理 */
.pain-card, .feature-card, .stat-card, .testimonial {
  position: relative;
  overflow: hidden;
}

.pain-card::before,
.feature-card::before, .stat-card::before, .testimonial::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: radial-gradient(
    180px circle at var(--mx, 50%) var(--my, 50%),
    rgba(200, 16, 46, 0.12),
    rgba(201, 162, 39, 0.08) 40%,
    transparent 70%
  );
  opacity: 0;
  transition: opacity 0.3s ease;
  pointer-events: none;
  z-index: 0;
}

.pain-card.glow::before,
.feature-card.glow::before, .stat-card.glow::before, .testimonial.glow::before {
  opacity: 1;
}

/* Keep card content above the glow layer. */
.pain-card > *,
.feature-card > *, .stat-card > *, .testimonial > * {
  position: relative;
  z-index: 1;
}

/* Stagger utilities: siblings in a grid fade in sequentially.
   Applied per-section below so single-reveal containers stay at 0ms. */

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }
  [data-parallax] {
    transform: none !important;
  }
  .dust {
    animation: none;
  }
  .phone-mockup {
    animation: none;
    transform: none;
  }
  .lecture-live-dot {
    animation: none;
  }
  .hero-cta {
    animation: none;
  }
  .hero-net {
    display: none;
  }
  .scroll-progress {
    transition: none;
  }
  .chat-msg {
    opacity: 1;
    transform: none;
    transition: none;
  }
  /* Zero out per-section stagger delays so nothing waits under reduced motion. */
  .feature-card.reveal:nth-child(2),
  .feature-card.reveal:nth-child(3),
  .feature-card.reveal:nth-child(4),
  .pain-card.reveal:nth-child(2),
  .pain-card.reveal:nth-child(3),
  .stat-card.reveal:nth-child(2),
  .stat-card.reveal:nth-child(3),
  .stat-card.reveal:nth-child(4),
  .testimonial.reveal:nth-child(2) {
    transition-delay: 0s;
  }
}

/* ---------- Scroll progress (tech accent) ---------- */

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0;
  z-index: 200;
  background: linear-gradient(90deg, var(--vermilion), var(--gold));
  box-shadow: 0 0 12px rgba(201, 162, 39, 0.6);
  transition: width 0.1s linear;
}

/* ===== Background oracle-bone-script particle canvas ===== */
.bg-particles {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
  opacity: 0.32;
}

@media (prefers-reduced-motion: reduce) {
  .bg-particles { display: none; }
}

/* ---------- Back to top button ---------- */

.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  border: none;
  background: linear-gradient(135deg, var(--vermilion), #9b0f24);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  z-index: 90;
  opacity: 0;
  visibility: hidden;
  transform: translateY(16px);
  transition: opacity 0.3s ease, transform 0.3s ease, box-shadow 0.3s ease;
  box-shadow:
    0 6px 20px rgba(200, 16, 46, 0.35),
    0 0 0 1px rgba(201, 162, 39, 0.3);
  pointer-events: none;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
  pointer-events: auto;
}

.back-to-top:hover {
  transform: translateY(-3px);
  box-shadow:
    0 10px 28px rgba(200, 16, 46, 0.5),
    0 0 0 1px rgba(201, 162, 39, 0.55),
    0 0 24px rgba(200, 16, 46, 0.3);
}

.back-to-top:focus-visible {
  outline: 2px solid var(--gold);
  outline-offset: 3px;
}

.back-to-top svg {
  transition: transform 0.3s ease;
}

.back-to-top:hover svg {
  transform: translateY(-2px);
}

@media (max-width: 560px) {
  .back-to-top { bottom: 20px; right: 20px; width: 42px; height: 42px; }
  .back-to-top svg { width: 18px; height: 18px; }
}

@media (prefers-reduced-motion: reduce) {
  .back-to-top { transition: none; }
  .back-to-top:hover { transform: none; }
  .back-to-top:hover svg { transform: none; }
}

/* ---------- Top navigation ---------- */

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 14px 0;
  transition: background 0.3s ease, box-shadow 0.3s ease;
}

.site-header.scrolled {
  background: rgba(247, 241, 230, 0.92);
  backdrop-filter: blur(8px);
  box-shadow: 0 2px 16px var(--shadow);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.header-brand {
  display: flex;
  align-items: center;
  gap: 18px;
}

.header-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
}

.header-logo img {
  width: 38px;
  height: auto;
  filter: drop-shadow(0 2px 4px rgba(74, 64, 56, 0.12));
}

.header-logo-text {
  font-family: 'Noto Sans SC', sans-serif;
  font-size: 20px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.5px;
  color: var(--ink);
}

.header-slogan {
  font-family: 'Noto Sans SC', sans-serif;
  font-size: 13px;
  font-weight: 500;
  color: var(--muted);
  letter-spacing: 0.5px;
  padding: 5px 12px;
  background: rgba(201, 162, 39, 0.08);
  border: 1px solid rgba(201, 162, 39, 0.18);
  border-radius: 999px;
  white-space: nowrap;
}

.header-cta {
  padding: 8px 20px;
  border: 1.5px solid var(--ink-soft);
  border-radius: 6px;
  font-size: 14px;
  font-weight: 600;
  transition: background 0.2s, color 0.2s;
}

.header-cta:hover {
  background: var(--ink-soft);
  color: var(--paper);
}

@media (max-width: 720px) {
  .header-cta { padding: 6px 14px; font-size: 13px; }
  .header-brand { gap: 10px; }
  .header-logo img { width: 32px; }
  .header-logo-text { font-size: 17px; }
  .header-slogan { font-size: 11px; padding: 4px 10px; }
}

@media (max-width: 480px) {
  .header-slogan { display: none; }
}

/* ---------- Hero ---------- */

.hero {
  position: relative;
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: 120px 24px 80px;
  overflow: hidden;
  background:
    radial-gradient(circle at 10% 12%, rgba(200, 16, 46, 0.09), transparent 38%),
    radial-gradient(circle at 90% 88%, rgba(201, 162, 39, 0.11), transparent 42%),
    var(--paper);
}

.hero-net {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  z-index: 1;
  pointer-events: none;
  opacity: 0.55;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background-image: radial-gradient(rgba(74, 64, 56, 0.04) 1px, transparent 1px);
  background-size: 5px 5px;
  opacity: 0.7;
  pointer-events: none;
}

.dust {
  position: absolute;
  width: 3px;
  height: 3px;
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 8px rgba(201, 162, 39, 0.6);
  opacity: 0.45;
  animation: twinkle 4s ease-in-out infinite;
}

.dust-1 { top: 16%; left: 16%; animation-delay: 0s; }
.dust-2 { top: 28%; left: 84%; animation-delay: 1.1s; }
.dust-3 { top: 78%; left: 24%; animation-delay: 2.2s; }
.dust-4 { top: 66%; left: 80%; animation-delay: 0.6s; }
.dust-5 { top: 12%; left: 52%; animation-delay: 1.7s; }

@keyframes twinkle {
  0%, 100% { opacity: 0.15; transform: scale(0.8); }
  50% { opacity: 0.65; transform: scale(1.3); }
}

.hero-content { position: relative; z-index: 2; }

@keyframes heroRise {
  from { opacity: 0; transform: translateY(28px); }
  to { opacity: 1; transform: translateY(0); }
}

.seal {
  position: absolute;
  top: 18px;
  right: 22px;
  width: 84px;
  height: 84px;
  border-radius: 10px;
  background: linear-gradient(135deg, #d12a3c 0%, #a50d22 100%);
  color: var(--paper);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: 'Ma Shan Zheng', serif;
  font-size: 20px;
  line-height: 1.05;
  letter-spacing: 1px;
  text-align: center;
  transform: rotate(-10deg);
  box-shadow:
    0 10px 28px rgba(200, 16, 46, 0.5),
    0 0 0 2px rgba(247, 241, 230, 0.75),
    0 0 0 4px rgba(201, 162, 39, 0.45),
    0 0 36px rgba(200, 16, 46, 0.28);
  padding: 8px;
  z-index: 3;
  animation: sealGlow 3.5s ease-in-out infinite;
  will-change: box-shadow;
}

@keyframes sealGlow {
  0%, 100% {
    box-shadow:
      0 10px 28px rgba(200, 16, 46, 0.5),
      0 0 0 2px rgba(247, 241, 230, 0.75),
      0 0 0 4px rgba(201, 162, 39, 0.45),
      0 0 36px rgba(200, 16, 46, 0.28);
  }
  50% {
    box-shadow:
      0 14px 36px rgba(200, 16, 46, 0.6),
      0 0 0 2px rgba(247, 241, 230, 0.85),
      0 0 0 5px rgba(201, 162, 39, 0.6),
      0 0 60px rgba(200, 16, 46, 0.48);
  }
}

.hero-cta,
.ai-class-cta-btn {
  display: inline-block;
  margin-top: 24px;
  padding: 13px 42px;
  border-radius: 6px;
  border: 1.5px solid var(--ink-soft);
  color: var(--ink-soft);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 3px;
  transition: background 0.2s, color 0.2s, transform 0.2s, box-shadow 0.2s;
}

.hero-cta:hover,
.ai-class-cta-btn:hover {
  background: var(--ink-soft);
  color: var(--paper);
  transform: translateY(-2px);
  box-shadow: 0 12px 28px rgba(28, 25, 22, 0.22);
}

.hero-cta:focus-visible,
.ai-class-cta-btn:focus-visible {
  outline: 2px solid var(--vermilion);
  outline-offset: 3px;
}

/* ===== Hero enhancement: spotlight + dramatic entrance ===== */

/* Mouse spotlight: soft radial glow follows the cursor across the hero */
.hero-spotlight {
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  background: radial-gradient(
    340px circle at var(--mx, 50%) var(--my, 50%),
    rgba(201, 162, 39, 0.18),
    rgba(200, 16, 46, 0.08) 40%,
    transparent 70%
  );
  opacity: 0;
  transition: opacity 0.4s ease;
  mix-blend-mode: screen;
}

.hero.spotlight-active .hero-spotlight {
  opacity: 1;
}

/* Dramatic entrance: CTA gets its own spring-in entrance.
   Uses fill-mode: backwards so that after the animation ends, the element reverts
   to its base styles — freeing up `transform` for the cursor-parallax rules below.
   (旧 hero-logo/topbar/hero-blessing 入场动画已随元素一并删除;
    倒计时入场走下方 1.0 区 .hero-countdown 的 heroRise,此前的 heroCountdownEnter 因被覆盖已删) */
.hero-cta {
  animation: heroCtaEnter 0.9s cubic-bezier(0.34, 1.56, 0.64, 1) 0.95s backwards;
}

@keyframes heroCtaEnter {
  0% { opacity: 0; transform: scale(0.6); }
  60% { opacity: 1; transform: scale(1.08); }
  100% { opacity: 1; transform: scale(1); }
}

/* 3D cursor parallax: JS sets --px and --py (normalized -1..1) on .hero,
   each element reads its own depth via data-hero-depth and translates accordingly. */
.hero-content > * {
  transition: transform 0.25s ease-out;
}

.hero[data-cursor] .seal {
  transform: rotate(-8deg) translate3d(calc(var(--px, 0) * -22px), calc(var(--py, 0) * -22px), 0);
}

.hero[data-cursor] .hero-countdown {
  transform: translate3d(calc(var(--px, 0) * 8px), calc(var(--py, 0) * 8px), 0);
}

@media (prefers-reduced-motion: reduce) {
  .hero-spotlight { display: none; }
  .seal { animation: none; }
  .hero-countdown,
  .hero-cta {
    animation: none !important;
    opacity: 1 !important;
    transform: none !important;
    filter: none !important;
  }
  .hero[data-cursor] .seal,
  .hero[data-cursor] .hero-countdown {
    transform: none !important;
  }
}

/* Countdown tablet: time-to-exam readout, styled like an ancient almanac tile. */
.hero-countdown {
  margin: 28px auto 0;
  text-align: center;
  animation: heroRise 1s cubic-bezier(0.22, 1, 0.36, 1) 0.6s both;
}

.countdown-label {
  font-family: 'Noto Serif SC', 'Noto Sans SC', serif;
  font-size: 14px;
  letter-spacing: 4px;
  color: var(--muted);
  margin-bottom: 14px;
}

.countdown-label #cd-date {
  color: var(--vermilion);
  font-weight: 700;
}

.countdown-grid {
  display: flex;
  align-items: stretch;
  justify-content: center;
  gap: 6px;
}

.countdown-unit {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-width: 66px;
  padding: 10px 8px 8px;
  background: rgba(255, 255, 255, 0.55);
  border: 1px solid var(--border-gold);
  border-radius: 10px;
  backdrop-filter: blur(4px);
}

.count-num {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 28px;
  font-weight: 600;
  color: var(--vermilion);
  line-height: 1;
  letter-spacing: 1px;
}

.count-cap {
  font-family: 'Noto Serif SC', 'Noto Sans SC', serif;
  font-size: 12px;
  color: var(--muted);
  margin-top: 5px;
  letter-spacing: 2px;
}

.countdown-sep {
  display: flex;
  align-items: center;
  font-family: 'Space Grotesk', sans-serif;
  font-size: 22px;
  font-weight: 600;
  color: var(--gold);
}

@media (max-width: 560px) {
  .seal { width: 64px; height: 64px; font-size: 16px; top: 12px; right: 12px; padding: 6px; }
  .countdown-unit { min-width: 54px; padding: 8px 6px 6px; }
  .count-num { font-size: 22px; }
  .countdown-sep { font-size: 18px; }
}

/* ---------- Positioning ---------- */

.positioning {
  padding: 80px 0;
}

.positioning-card {
  position: relative;
  background: rgba(255, 255, 255, 0.72);
  border: 1px solid var(--border-gold);
  border-radius: var(--radius);
  padding: 48px 32px;
  text-align: center;
  overflow: hidden;
}

.scroll-decor {
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: linear-gradient(180deg, var(--vermilion), var(--gold));
  transform: scaleY(0);
  transform-origin: top;
  transition: transform 0.8s ease-out;
}

.positioning-card.visible .scroll-decor {
  transform: scaleY(1);
}

.positioning-label {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 12px;
  letter-spacing: 4px;
  color: var(--vermilion);
  margin-bottom: 12px;
}

.positioning-title {
  font-family: 'Zhi Mang Xing', serif;
  font-size: 36px;
  font-weight: 400;
  color: var(--ink);
  margin-bottom: 18px;
  letter-spacing: 3px;
}

.positioning-tags {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  color: var(--muted);
  font-size: 14px;
}

.positioning-tags span {
  padding: 6px 16px;
  border-radius: 999px;
  background: rgba(201, 162, 39, 0.1);
  border: 1px solid var(--border-gold);
}

/* ===== AI 课堂板块 — dark tech stage ===== */
.ai-class {
  position: relative;
  padding: 130px 0;
  overflow: hidden;
  background:
    radial-gradient(circle at 80% 8%, rgba(200, 16, 46, 0.22), transparent 45%),
    radial-gradient(circle at 12% 92%, rgba(201, 162, 39, 0.16), transparent 48%),
    linear-gradient(160deg, #1a1613 0%, #241d18 55%, #1c1714 100%);
  color: #f3ece0;
}

/* Faint tech grid overlay */
.ai-class-grid {
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(201, 162, 39, 0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(201, 162, 39, 0.06) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(circle at 50% 40%, #000 0%, transparent 78%);
  -webkit-mask-image: radial-gradient(circle at 50% 40%, #000 0%, transparent 78%);
}

/* Soft drifting glow blob for depth */
.ai-class-glow {
  position: absolute;
  top: -120px;
  left: 50%;
  width: 620px;
  height: 620px;
  transform: translateX(-50%);
  z-index: 0;
  pointer-events: none;
  background: radial-gradient(circle, rgba(200, 16, 46, 0.28), transparent 62%);
  filter: blur(30px);
  animation: aiGlowFloat 9s ease-in-out infinite;
}

@keyframes aiGlowFloat {
  0%, 100% { transform: translateX(-50%) translateY(0); opacity: 0.8; }
  50% { transform: translateX(-46%) translateY(28px); opacity: 1; }
}

.ai-class .container { position: relative; z-index: 1; }

.ai-class-header {
  text-align: center;
  position: relative;
  margin-bottom: 60px;
}

.ai-class-seal {
  position: absolute;
  top: 0;
  right: 0;
  width: 52px;
  height: 52px;
  border-radius: 8px;
  background: var(--vermilion);
  color: var(--paper);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: 'Ma Shan Zheng', serif;
  font-size: 13px;
  line-height: 1.05;
  text-align: center;
  transform: rotate(-8deg);
  box-shadow: 0 6px 20px rgba(200, 16, 46, 0.5);
  border: 2px solid rgba(247, 241, 230, 0.35);
  padding: 5px;
}

.ai-class-label {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 12px;
  letter-spacing: 4px;
  color: var(--gold);
  margin-bottom: 12px;
}

.ai-class-title {
  font-family: 'Zhi Mang Xing', serif;
  font-size: 44px;
  font-weight: 400;
  line-height: 1.3;
  color: #fdf8ee;
  margin-bottom: 16px;
  letter-spacing: 3px;
}

.ai-class-title span {
  color: var(--gold);
  text-shadow: 0 0 24px rgba(201, 162, 39, 0.5);
}

.ai-class-subtitle {
  font-size: 15px;
  color: rgba(243, 236, 224, 0.72);
  max-width: 580px;
  margin: 0 auto;
  line-height: 1.8;
}

.ai-class-body {
  display: grid;
  grid-template-columns: 300px 1fr;
  gap: 56px;
  align-items: center;
}

.phone-mockup {
  position: relative;
  width: 100%;
  max-width: 270px;
  margin: 0 auto;
  background: #14100d;
  border-radius: 30px;
  padding: 10px;
  box-shadow:
    0 30px 70px rgba(0, 0, 0, 0.5),
    0 0 0 1.5px rgba(201, 162, 39, 0.4),
    0 0 40px rgba(200, 16, 46, 0.25);
  transform-style: preserve-3d;
}

/* Halo behind the phone */
.phone-glow {
  position: absolute;
  inset: -30px;
  z-index: -1;
  border-radius: 40px;
  background: radial-gradient(circle, rgba(201, 162, 39, 0.3), transparent 68%);
  filter: blur(24px);
  animation: phoneHalo 5s ease-in-out infinite;
}

@keyframes phoneHalo {
  0%, 100% { opacity: 0.55; }
  50% { opacity: 1; }
}

/* Phone reveal: fade in while settling into its resting 3D tilt (not flat),
   so the reveal end-state doesn't cancel the dimensional pose. */
.phone-mockup.reveal {
  opacity: 0;
  transform: perspective(1000px) rotateY(-24deg) rotateX(12deg) translateY(60px);
  transition:
    opacity 0.8s cubic-bezier(0.22, 1, 0.36, 1),
    transform 1s cubic-bezier(0.22, 1, 0.36, 1);
}

.phone-mockup.reveal.visible {
  opacity: 1;
  transform: perspective(1000px) rotateY(-14deg) rotateX(6deg) translateY(0);
  animation: phoneFloat 6s ease-in-out infinite 1s;
}

.phone-mockup:hover {
  transform: perspective(1000px) rotateY(0deg) rotateX(0deg) scale(1.04) !important;
  animation-play-state: paused;
}

@keyframes phoneFloat {
  0%, 100% { translate: 0 0; }
  50% { translate: 0 -12px; }
}

.phone-screen {
  width: 100%;
  aspect-ratio: 9/16;
  background: #f5eeea;
  border-radius: 22px;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  font-family: 'Noto Sans SC', system-ui, sans-serif;
}

.phone-header {
  height: 42px;
  background: linear-gradient(135deg, var(--vermilion), #9b0f24);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  color: #fff;
  font-size: 12px;
  font-weight: 600;
}

.phone-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.85);
  box-shadow: 9px 0 0 rgba(255,255,255,0.5), -9px 0 0 rgba(255,255,255,0.5);
  margin-right: 12px;
}

.lecture-area {
  flex: 1;
  margin: 10px;
  border-radius: 12px;
  position: relative;
  overflow: hidden;
  min-height: 150px;
  background:
    linear-gradient(160deg, rgba(200,16,46,0.4), rgba(20,16,13,0.9)),
    #221a16;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* Sweeping scan line inside the lecture screen for a live/tech feel */
.lecture-scan {
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  height: 40%;
  background: linear-gradient(180deg, rgba(201,162,39,0.22), transparent);
  animation: lectureScan 3.2s ease-in-out infinite;
  pointer-events: none;
}

@keyframes lectureScan {
  0% { transform: translateY(-100%); opacity: 0; }
  30% { opacity: 1; }
  70% { opacity: 1; }
  100% { transform: translateY(260%); opacity: 0; }
}

.lecture-live {
  position: absolute;
  top: 10px;
  left: 10px;
  display: flex;
  align-items: center;
  gap: 5px;
  padding: 4px 9px;
  border-radius: 999px;
  background: rgba(0, 0, 0, 0.5);
  color: #fff;
  font-size: 10px;
  font-weight: 600;
  z-index: 2;
}

.lecture-live-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: #20e070;
  box-shadow: 0 0 0 0 rgba(32, 224, 112, 0.6);
  animation: livePulse 1.6s ease-out infinite;
}

@keyframes livePulse {
  0% { box-shadow: 0 0 0 0 rgba(32, 224, 112, 0.5); }
  100% { box-shadow: 0 0 0 8px rgba(32, 224, 112, 0); }
}

.lecture-play {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.95);
  color: var(--vermilion);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  padding-left: 3px;
  box-shadow: 0 6px 22px rgba(0, 0, 0, 0.4);
  z-index: 2;
  animation: playPulse 2.4s ease-in-out infinite;
}

@keyframes playPulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.08); }
}

.lecture-tip {
  position: absolute;
  left: 10px;
  right: 10px;
  bottom: 10px;
  padding: 8px 10px;
  border-radius: 8px;
  background: rgba(15, 12, 10, 0.78);
  color: #fff;
  z-index: 2;
}

.lecture-tip-title {
  font-size: 11px;
  font-weight: 700;
}

.lecture-tip-desc {
  font-size: 9.5px;
  opacity: 0.85;
  margin-top: 2px;
}

.chat-preview {
  padding: 10px 12px;
  background: #fff;
  border-top: 1px solid #e8ddd5;
}

.chat-tab {
  font-size: 10px;
  font-weight: 700;
  color: var(--vermilion);
  padding: 2px 0 8px;
}

.chat-msg {
  display: flex;
  gap: 8px;
  margin-bottom: 10px;
  opacity: 0;
  transform: translateY(8px);
}

.chat-msg.visible {
  opacity: 1;
  transform: translateY(0);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.chat-avatar {
  width: 26px;
  height: 26px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 11px;
  color: #fff;
  flex-shrink: 0;
}

.chat-avatar.teacher { background: linear-gradient(135deg, #9b4d2f, #d79a52); }
.chat-avatar.student { background: linear-gradient(135deg, #6f8f5b, #a7bd7f); }
.chat-avatar.assistant { background: linear-gradient(135deg, #5d7f9f, #8bb1c7); }

.chat-body {
  flex: 1;
  background: #faf7f0;
  border-radius: 10px;
  padding: 8px 10px;
  font-size: 11px;
  color: #5a4e44;
  line-height: 1.5;
}

.chat-name {
  font-size: 10px;
  color: #9b4d2f;
  font-weight: 700;
  margin-bottom: 3px;
}

.ai-features {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 18px;
}

.feature-card {
  position: relative;
  display: flex;
  gap: 14px;
  align-items: flex-start;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(201, 162, 39, 0.22);
  border-radius: 16px;
  padding: 24px 22px;
  overflow: hidden;
  backdrop-filter: blur(6px);
  transition: opacity 0.6s ease-out, transform 0.35s ease, border-color 0.35s ease, background 0.35s ease, box-shadow 0.35s ease;
}

.feature-card.reveal:nth-child(2) { transition-delay: 0.1s; }
.feature-card.reveal:nth-child(3) { transition-delay: 0.2s; }
.feature-card.reveal:nth-child(4) { transition-delay: 0.3s; }

.feature-card:hover {
  transform: translateY(-6px);
  background: rgba(255, 255, 255, 0.09);
  border-color: rgba(201, 162, 39, 0.55);
  box-shadow: 0 18px 40px rgba(0, 0, 0, 0.4), 0 0 24px rgba(201, 162, 39, 0.18);
}

/* Cursor glow tuned for the dark surface */
.feature-card::before {
  background: radial-gradient(
    180px circle at var(--mx, 50%) var(--my, 50%),
    rgba(201, 162, 39, 0.22),
    rgba(200, 16, 46, 0.12) 42%,
    transparent 70%
  );
}

.feature-index {
  position: absolute;
  top: 14px;
  right: 16px;
  font-family: 'Space Grotesk', sans-serif;
  font-size: 30px;
  font-weight: 600;
  color: rgba(201, 162, 39, 0.22);
  line-height: 1;
}

.feature-text { position: relative; }

.feature-card h3 {
  font-size: 16px;
  font-weight: 700;
  color: #fdf8ee;
  margin-bottom: 6px;
}

.feature-card p {
  font-size: 13px;
  color: rgba(243, 236, 224, 0.68);
  line-height: 1.6;
}

.feature-icon {
  width: 46px;
  height: 46px;
  border-radius: 13px;
  background: linear-gradient(135deg, var(--vermilion), #9b0f24);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-family: 'Noto Serif SC', 'Noto Sans SC', serif;
  font-size: 20px;
  flex-shrink: 0;
  box-shadow: 0 6px 18px rgba(200, 16, 46, 0.4);
}

.ai-class-cta {
  text-align: center;
  margin-top: 52px;
}

/* CTA on the dark stage: gold-outlined, glows on hover */
.ai-class .ai-class-cta-btn {
  border-color: var(--gold);
  color: var(--gold);
}

.ai-class .ai-class-cta-btn:hover {
  background: var(--gold);
  color: #1a1613;
  box-shadow: 0 12px 30px rgba(201, 162, 39, 0.4);
}

@media (max-width: 900px) {
  .ai-class-body {
    grid-template-columns: 1fr;
    gap: 44px;
  }
  .ai-features {
    max-width: 560px;
    margin: 0 auto;
  }
}

@media (max-width: 560px) {
  .ai-features { grid-template-columns: 1fr; }
  .ai-class-title { font-size: 32px; }
}

/* ===== Pain points ===== */
.pain-points {
  padding: 130px 0;
}

.section-header {
  text-align: center;
  margin-bottom: 64px;
}

.section-header h2 {
  font-family: 'Zhi Mang Xing', serif;
  font-size: 42px;
  font-weight: 400;
  letter-spacing: 3px;
  color: var(--ink);
  margin-bottom: 14px;
}

.section-header p {
  font-size: 16px;
  color: var(--muted);
}

.pain-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.pain-card {
  background: rgba(255, 255, 255, 0.72);
  border: 1px solid var(--border-gold);
  border-radius: var(--radius);
  padding: 36px 28px;
  text-align: center;
  transition: opacity 0.6s ease-out, transform 0.25s ease, box-shadow 0.25s ease;
}

.pain-card.reveal:nth-child(2) { transition-delay: 0.12s; }
.pain-card.reveal:nth-child(3) { transition-delay: 0.24s; }

.pain-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 16px 40px var(--shadow);
  transition-delay: 0s;
}

.pain-icon {
  font-size: 40px;
  margin-bottom: 16px;
}

.pain-card h3 {
  font-size: 20px;
  color: var(--ink);
  margin-bottom: 10px;
}

.pain-card p {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.7;
}

@media (max-width: 768px) {
  .pain-grid { grid-template-columns: 1fr; }
}

/* Social proof section */
.proof {
  padding: 130px 0;
  background: var(--paper-dark);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-bottom: 48px;
}

.stats-grid-3 {
  grid-template-columns: repeat(3, 1fr);
  max-width: 840px;
  margin-left: auto;
  margin-right: auto;
}

.stat-card {
  background: rgba(255, 255, 255, 0.8);
  border: 1px solid var(--border-gold);
  border-radius: var(--radius);
  padding: 32px 20px;
  text-align: center;
}

.stat-card.reveal:nth-child(2) { transition-delay: 0.1s; }
.stat-card.reveal:nth-child(3) { transition-delay: 0.2s; }
.stat-card.reveal:nth-child(4) { transition-delay: 0.3s; }

.stat-number {
  font-family: 'Space Grotesk', sans-serif;
  font-size: 36px;
  font-weight: 600;
  color: var(--vermilion);
  margin-bottom: 8px;
}

.stat-label {
  font-size: 14px;
  color: var(--muted);
}

.testimonials {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.testimonial {
  background: rgba(255, 255, 255, 0.8);
  border-left: 4px solid var(--vermilion);
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 28px;
}

.testimonial.reveal:nth-child(2) { transition-delay: 0.12s; }

.testimonial p {
  font-size: 15px;
  color: var(--ink-soft);
  line-height: 1.7;
  margin-bottom: 16px;
}

.testimonial span {
  font-size: 13px;
  color: var(--muted);
}

@media (max-width: 900px) {
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .testimonials { grid-template-columns: 1fr; }
}

/* Footer CTA */
.site-footer {
  padding: 100px 0 40px;
  background:
    radial-gradient(circle at 50% 0%, rgba(200, 16, 46, 0.08), transparent 50%),
    var(--paper);
  text-align: center;
}

.footer-content h2 {
  font-family: 'Zhi Mang Xing', serif;
  font-size: 42px;
  font-weight: 400;
  color: var(--ink);
  margin-bottom: 12px;
  letter-spacing: 3px;
}

.footer-content p {
  font-size: 16px;
  color: var(--muted);
  margin-bottom: 28px;
}

.footer-copy {
  margin-top: 48px;
  font-size: 13px;
  color: var(--muted);
}

/* ── 国潮2.0:首屏价值主张(2026-10 改版) ─────────────────── */
.hero-kicker {
  font-size: 14px; letter-spacing: 6px; color: var(--muted);
  margin-bottom: 14px;
}
.hero-claim {
  font-size: clamp(34px, 6vw, 64px); font-weight: 800; line-height: 1.2;
  color: var(--ink); margin: 0 0 16px;
}
.hero-claim .claim-red { color: var(--vermilion); }
.hero-sub {
  max-width: 560px; margin: 0 auto 26px; color: var(--muted); font-size: 15px; line-height: 1.8;
}
.hero-cta-row { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; margin-bottom: 30px; }
.hero-cta {
  display: inline-block; background: var(--vermilion); color: var(--paper); padding: 13px 38px;
  border-radius: 999px; font-size: 16px; font-weight: 700; text-decoration: none;
  box-shadow: 0 8px 22px rgba(200, 16, 46, .28); transition: transform .2s ease, box-shadow .2s ease;
}
.hero-cta:hover { transform: translateY(-2px); box-shadow: 0 12px 26px rgba(200, 16, 46, .34); }
.hero-cta-ghost {
  display: inline-block; border: 1px solid rgba(201, 162, 39, .6); color: #8a6d1f;
  padding: 13px 30px; border-radius: 999px; font-size: 16px; font-weight: 600; text-decoration: none;
  transition: background .2s ease;
}
.hero-cta-ghost:hover { background: rgba(201, 162, 39, .12); }

/* 覆盖旧 .hero-cta 规则泄漏(见上方 1.0 区 .hero-cta 旧规则块:margin-top/border/letter-spacing/hover 深色) */
.hero-cta { margin-top: 0; border: 0; letter-spacing: normal; }
.hero-cta:hover { background: var(--vermilion); color: var(--paper); }

@media (max-width: 640px) {
  .hero-kicker { letter-spacing: 3px; font-size: 12px; }
  .hero-countdown .countdown-grid { transform: scale(.85); }
}

/* ── 国潮2.0:学情引擎闭环步骤图(2026-10 改版) ───────────── */
/* 段落节奏:与全站内容段一致的内边距与纸底氛围(参考被删 .ai-quiz 的写法) */
.engine { padding: 130px 0; background: var(--paper); position: relative; }
/* 标签字级/字距对齐兄弟段落标签(12px/3px),颜色用品牌金;字体族对齐被删的 .ai-quiz-label(Space Grotesk) */
.engine-label { font-family: 'Space Grotesk', sans-serif; letter-spacing: 3px; color: var(--gold); font-size: 12px; margin-bottom: 10px; }
.engine-flow {
  list-style: none; margin: 40px 0 0; padding: 0;
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px;
}
.engine-step {
  background: var(--paper, #fff); border: 1px solid rgba(201, 162, 39, .25); border-radius: 14px;
  padding: 22px 18px; position: relative; opacity: .35; transform: translateY(14px);
  transition: opacity .5s ease, transform .5s ease, border-color .5s ease;
}
.engine-step.lit { opacity: 1; transform: none; border-color: rgba(200, 16, 46, .45); }
.step-no {
  display: inline-flex; width: 30px; height: 30px; align-items: center; justify-content: center;
  border-radius: 50%; background: var(--vermilion, #c8102e); color: var(--paper, #f7f1e6);
  font-weight: 700; margin-bottom: 10px;
}
.engine-step h3 { font-size: 16px; margin: 0 0 6px; color: var(--ink, #1c1916); }
.engine-step p { font-size: 13px; color: var(--muted, #7a6f63); line-height: 1.7; margin: 0; }
.engine-note { margin-top: 26px; text-align: center; color: var(--muted, #7a6f63); font-size: 13px; }

@media (max-width: 900px) { .engine-flow { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 560px) { .engine-flow { grid-template-columns: 1fr; } }

/* 无障碍:偏好减弱动效时直接全部点亮 */
@media (prefers-reduced-motion: reduce) {
  .engine-step { opacity: 1; transform: none; transition: none; }
}

/* ── 国潮2.0:信任层政策风向卡(2026-10 改版) ─────────────── */
.policy-card {
  display: flex; align-items: flex-start; gap: 14px;
  background: var(--paper, #fff); border: 1px solid rgba(201, 162, 39, .35); border-radius: 14px;
  padding: 20px 22px; margin: 0 0 26px; box-shadow: 0 4px 14px rgba(28, 25, 22, .05);
}
.policy-seal {
  flex: none; border: 2px solid var(--vermilion, #c8102e); color: var(--vermilion, #c8102e);
  border-radius: 6px; font-weight: 700; font-size: 13px; padding: 4px 7px;
  transform: rotate(-6deg); margin-top: 2px;
}
.policy-card p { margin: 0; color: #4a443d; font-size: 14px; line-height: 1.9; }

/* ── 国潮2.0:转化终区三卡(2026-10 改版) ─────────────────── */
/* 覆盖 1.0 区 .site-footer 的径向光晕背景:2.0 终区改用素雅纸色渐变,聚焦三卡转化 */
.site-footer { background: linear-gradient(180deg, var(--paper, #f7f1e6), #f0e6d4); }
.convert-grid { display: flex; gap: 16px; justify-content: center; flex-wrap: wrap; margin: 26px 0 18px; }
.convert-card {
  background: #fff; border: 1px solid rgba(201, 162, 39, .5); border-radius: 16px;
  padding: 20px 22px; width: 216px; text-align: center;
  transition: transform .25s ease, box-shadow .25s ease;
}
.convert-card:hover { transform: translateY(-4px); box-shadow: 0 10px 24px rgba(28, 25, 22, .1); }
.convert-main { border: 2px solid var(--vermilion, #c8102e); box-shadow: 0 8px 22px rgba(200, 16, 46, .14); }
.convert-main h3 { color: var(--vermilion, #c8102e); }
.convert-card h3 { font-size: 16px; margin: 0 0 10px; color: #8a6d1f; }
.convert-qr img { border-radius: 10px; }
.convert-qr-placeholder {
  width: 150px; height: 150px; margin: 0 auto; border: 1px dashed rgba(201, 162, 39, .6);
  border-radius: 10px; display: flex; align-items: center; justify-content: center;
  color: #b3a89a; font-size: 13px; line-height: 1.6;
}
.convert-wechat {
  width: 150px; height: 150px; margin: 0 auto; background: #faf6ec;
  border: 1px dashed rgba(201, 162, 39, .5); border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
}
.wechat-id { font-size: 18px; font-weight: 700; color: var(--ink, #1c1916); letter-spacing: 1px; }
.copy-btn {
  margin-top: 12px; background: var(--gold, #c9a227); color: #fff; border: 0; border-radius: 999px;
  padding: 12px 24px; font-size: 13px; font-weight: 700; cursor: pointer; /* padding 12px 保证触控目标 ≥44px */
  transition: background .2s ease;
}
.copy-btn:hover { background: #b18f1f; }
/* 特异性说明:旧规则 .footer-content p(0,1,1)会压过单类选择器(0,1,0),故加 .footer-content 前缀(0,2,0)确保覆盖 */
.footer-content .convert-tip { font-size: 12px; color: var(--muted, #7a6f63); margin: 10px 0 0; }
.footer-content .footer-echo { font-size: 13px; color: var(--muted, #7a6f63); }
.footer-content .footer-echo b { color: var(--vermilion, #c8102e); }
.footer-links { margin-top: 20px; font-size: 12px; color: var(--muted, #7a6f63); }
.footer-links a { color: var(--muted, #7a6f63); text-decoration: none; }
.footer-links a:hover { color: var(--vermilion, #c8102e); }
.footer-content .beian { font-size: 12px; color: #9a8f82; }
/* 覆盖旧规则 .footer-content p(0,1,1)对版权区间距的影响;本选择器 (0,2,1) 特异性必胜(对齐上方 convert-tip 的前缀覆盖惯例) */
.footer-content .footer-copy p { margin-bottom: 6px; }

/* 复制成功轻提示 */
.copy-toast {
  position: fixed; left: 50%; bottom: 64px; transform: translate(-50%, 16px);
  background: rgba(28, 25, 22, .92); color: #f7f1e6; font-size: 14px;
  padding: 10px 20px; border-radius: 999px; opacity: 0; pointer-events: none;
  transition: opacity .25s ease, transform .25s ease; z-index: 999;
}
.copy-toast.show { opacity: 1; transform: translate(-50%, 0); }