/* ========================================
   白玉楼图创 — 产品宣传网站
   Apple 风格 · 暖灰底 · 蓝色 CTA
   ======================================== */

/* --- CSS Variables --- */
:root {
  --bg-body: #f5f5f7;
  --bg-card: #ffffff;
  --text-primary: #1d1d1f;
  --text-secondary: #6e6e73;
  --text-tertiary: #86868b;
  --accent: #0071e3;
  --accent-hover: #0077ed;
  --border: #e5e5e5;
  --bg-hover: #f0f0f0;
  --font-stack: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Helvetica Neue", sans-serif;
  --max-width: 1200px;
  --nav-height: 56px;
  --radius-card: 12px;
  --radius-btn: 24px;
}

/* --- Reset --- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--font-stack);
  background: var(--bg-body);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }

/* --- Container --- */
.container { max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }

/* --- Section Shared --- */
.section { padding: 80px 0; }
.section-label {
  font-size: 13px;
  color: var(--text-tertiary);
  letter-spacing: 2px;
  text-transform: uppercase;
  text-align: center;
  margin-bottom: 12px;
}
.section-title-left { text-align: left; }

.section-title {
  font-size: 36px;
  font-weight: 600;
  text-align: center;
  margin-bottom: 12px;
  color: var(--text-primary);
}
.section-desc {
  font-size: 18px;
  color: var(--text-secondary);
  text-align: center;
  max-width: 600px;
  margin: 0 auto 48px;
  line-height: 1.7;
}

/* --- Animations --- */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s ease-out, transform 0.7s ease-out;
}
.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* --- Buttons --- */
.btn {
  display: inline-block;
  padding: 12px 28px;
  border-radius: var(--radius-btn);
  font-size: 15px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
  border: none;
  font-family: inherit;
}
.btn-primary {
  background: var(--accent);
  color: #fff;
}
.btn-primary:hover { background: var(--accent-hover); }
.btn-secondary {
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent);
}
.btn-secondary:hover { background: rgba(0,113,227,0.06); }

/* --- Navigation --- */
#navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--nav-height);
  z-index: 100;
  background: transparent;
  transition: background 0.4s, box-shadow 0.3s, backdrop-filter 0.4s;
}
/* .nav-static 用于二级页面（白色背景），导航需始终白底深字，否则白字看不见 */
#navbar.scrolled,
#navbar.nav-static {
  background: rgba(255,255,255,0.92);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  box-shadow: 0 1px 0 var(--border);
}
.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-logo {
  font-size: 17px;
  font-weight: 600;
  color: #ffffff;
  letter-spacing: 1px;
  transition: color 0.3s, text-shadow 0.3s;
  text-shadow: 0 1px 6px rgba(0,0,0,0.45);
}
#navbar.scrolled .nav-logo,
#navbar.nav-static .nav-logo { color: var(--text-primary); text-shadow: none; }

.nav-links { display: flex; gap: 32px; }
.nav-links a {
  font-size: 13px;
  color: rgba(255,255,255,0.9);
  transition: color 0.2s, text-shadow 0.3s;
  text-shadow: 0 1px 6px rgba(0,0,0,0.45);
}
.nav-links a:hover { color: #ffffff; }
#navbar.scrolled .nav-links a,
#navbar.nav-static .nav-links a { color: var(--text-secondary); text-shadow: none; }
#navbar.scrolled .nav-links a:hover,
#navbar.nav-static .nav-links a:hover { color: var(--text-primary); }
#navbar.scrolled .nav-links a.active,
#navbar.nav-static .nav-links a.active { color: var(--accent); }
.nav-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 24px;
  cursor: pointer;
  color: #ffffff;
  text-shadow: 0 1px 6px rgba(0,0,0,0.45);
}
#navbar.scrolled .nav-toggle,
#navbar.nav-static .nav-toggle { color: var(--text-primary); text-shadow: none; }

/* --- Hero --- */
html {
  scroll-behavior: smooth;
}
/* --- Hero --- */
.section-hero {
  position: relative;
  height: 100vh;
  height: 100svh; /* 移动端更准确，排除地址栏高度 */
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  overflow: hidden;
  padding-top: var(--nav-height);
}
/* --- Hero 轮播背景 --- */
.hero-slides {
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 100%;
}
/*
  用 contain 等比完整显示：图片不变形、整张完整可见。
  屏幕比例与图不一致时，两侧或上下出现留边（透出页面暖灰底）。
  （2026-08-25 定案：不要用 100% 100% 拉伸[变形]，也不用 cover[顶部被裁]）
*/
.hero-slide {
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 100%;
  background-size: contain;
  background-position: center;
  background-repeat: no-repeat;
  opacity: 0;
  transition: opacity 1s ease-in-out;
}
.hero-slide.active { opacity: 1; }

/* 文案区域 — 第2-5张隐藏 */
.hero-content {
  transition: opacity 0.6s ease;
}
.hero-content.hidden {
  opacity: 0;
  pointer-events: none;
}

/* 文案区域 — 逐条淡入微动画 */
@keyframes hero-elem-in {
  0%   { opacity: 0; transform: translateY(18px); }
  100% { opacity: 1; transform: translateY(0); }
}
.hero-content > * {
  opacity: 0;
  animation: hero-elem-in 0.7s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}
.hero-label    { animation-delay: 0.05s; }
.hero-title    { animation-delay: 0.20s; }
.hero-subtitle { animation-delay: 0.40s; }
.hero-actions  { animation-delay: 0.60s; }

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 960px;
  padding: 0 24px;
}
.hero-label {
  font-size: 21px;
  color: rgba(255,255,255,0.95);
  letter-spacing: 4px;
  margin-bottom: 30px;
  text-shadow: 0 2px 10px rgba(0,0,0,0.35);
}
.hero-title {
  font-size: 86px;
  font-weight: 600;
  line-height: 1.1;
  margin-bottom: 30px;
  color: #ffffff;
  text-shadow: 0 3px 14px rgba(0,0,0,0.4);
}
.hero-subtitle {
  font-size: 28px;
  color: rgba(255,255,255,0.95);
  line-height: 1.55;
  margin-bottom: 50px;
  text-shadow: 0 2px 10px rgba(0,0,0,0.35);
}
.hero-actions { display: flex; gap: 16px; justify-content: center; margin-bottom: 20px; }
.hero-actions .btn-secondary {
  color: rgba(255,255,255,0.9);
  border-color: rgba(255,255,255,0.6);
}
.hero-actions .btn-secondary:hover {
  background: rgba(255,255,255,0.1);
  border-color: #ffffff;
}

/* --- Hero 导航圆点 --- */
.hero-dots {
  position: absolute;
  bottom: 80px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 5;
  display: flex;
  gap: 10px;
}
.hero-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  border: none;
  background: rgba(255,255,255,0.4);
  cursor: pointer;
  transition: background 0.3s, transform 0.3s;
  padding: 0;
  box-shadow: 0 1px 4px rgba(0,0,0,0.2);
}
.hero-dot.active {
  background: #ffffff;
  transform: scale(1.4);
}

/* --- Hero 左右箭头 --- */
.hero-arrow {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  z-index: 6;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: 1px solid rgba(255,255,255,0.25);
  background: rgba(0,0,0,0.2);
  backdrop-filter: blur(8px);
  color: #fff;
  font-size: 26px;
  line-height: 40px;
  text-align: center;
  cursor: pointer;
  transition: background 0.3s, opacity 0.3s;
  opacity: 0;
  user-select: none;
}
.section-hero:hover .hero-arrow { opacity: 1; }
.hero-arrow:hover { background: rgba(0,0,0,0.4); }
.hero-arrow-left  { left: 24px; }
.hero-arrow-right { right: 24px; }
@media (max-width: 768px) {
  .hero-arrow { display: none; }
  /* 手机端切换为竖版海报 m1~m5（去掉 m1，m5 放第一位，共 4 张） */
  .hero-slide:nth-child(1) { background-image: url('../images/m5.webp') !important; }
  .hero-slide:nth-child(2) { background-image: url('../images/m2.webp') !important; }
  .hero-slide:nth-child(3) { background-image: url('../images/m3.webp') !important; }
  .hero-slide:nth-child(4) { background-image: url('../images/m4.webp') !important; }
}

/* --- Scroll Hint --- */
.scroll-hint {
  position: absolute;
  bottom: 36px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  animation: float-down 2.5s ease-in-out infinite;
}
.scroll-hint span {
  font-size: 11px;
  color: rgba(255,255,255,0.5);
  letter-spacing: 2px;
  white-space: nowrap;
}
.scroll-arrow {
  width: 20px;
  height: 20px;
  border-right: 2px solid rgba(255,255,255,0.5);
  border-bottom: 2px solid rgba(255,255,255,0.5);
  transform: rotate(45deg);
  animation: bounce 2.5s ease-in-out infinite;
}
@keyframes float-down {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50% { transform: translateX(-50%) translateY(6px); }
}
@keyframes bounce {
  0%, 100% { opacity: 0.4; }
  50% { opacity: 1; }
}
}
@keyframes float-down {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50% { transform: translateX(-50%) translateY(6px); }
}
@keyframes bounce {
  0%, 100% { opacity: 0.4; }
  50% { opacity: 1; }
}

/* --- Intro / Value Grid --- */
.container-narrow { max-width: 800px; }

.value-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  max-width: 960px;
  margin: 0 auto 44px;
}
.value-card {
  text-align: center;
  padding: 0 8px;
}
.value-icon {
  font-size: 32px;
  margin-bottom: 18px;
  opacity: 0.7;
}
.value-title {
  font-size: 22px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 12px;
}
.value-desc {
  font-size: 16px;
  color: var(--text-secondary);
  line-height: 1.7;
  max-width: 300px;
  margin: 0 auto;
}

.intro-divider {
  width: 60px;
  height: 1px;
  background: var(--border);
  margin: 0 auto 40px;
}
.stats-row {
  display: flex;
  justify-content: center;
  gap: 0;
}
.stats-row .stat-item {
  text-align: center;
  padding: 0 48px;
}
.stats-row .stat-item + .stat-item {
  border-left: 1px solid var(--border);
}
.stat-number {
  font-size: 40px;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 6px;
  letter-spacing: -0.5px;
}
.stat-label {
  font-size: 15px;
  color: var(--text-tertiary);
  font-weight: 400;
}

/* --- Features --- */
.features-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px 64px;
  max-width: 960px;
  margin: 0 auto;
}
.feature-group {
  break-inside: avoid;
}
.feature-group-header {
  font-size: 11px;
  font-weight: 600;
  color: var(--accent);
  letter-spacing: 2px;
  text-transform: uppercase;
  margin-bottom: 20px;
  padding-bottom: 10px;
  position: relative;
}
.feature-group-header::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--border);
  transition: width 0.8s ease-out;
}
.feature-group.visible .feature-group-header::after {
  width: 100%;
}
.feature-item {
  margin-bottom: 20px;
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.5s ease-out, transform 0.5s ease-out;
}
.feature-group.visible .feature-item {
  opacity: 1;
  transform: translateY(0);
}
.feature-item:last-child { margin-bottom: 0; }
.feature-name {
  font-size: 17px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 4px;
}
.feature-desc {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* --- Showcase --- */
.category-tabs {
  display: flex;
  gap: 4px;
  flex-wrap: wrap;
  justify-content: center;
  margin-bottom: 16px;
  background: var(--bg-card);
  padding: 4px;
  border-radius: 12px;
  max-width: fit-content;
  margin-left: auto;
  margin-right: auto;
  border: 1px solid var(--border);
}
.category-tab {
  padding: 7px 18px;
  border-radius: 9px;
  font-size: 13px;
  cursor: pointer;
  border: none;
  background: transparent;
  color: var(--text-secondary);
  transition: all 0.25s;
  font-family: inherit;
  font-weight: 500;
  white-space: nowrap;
}
.category-tab:hover { color: var(--text-primary); }
.category-tab.active { background: var(--accent); color: #fff; }

/*
  小类标签：视觉上弱于大类，做出层级区分。
  纯文字无容器，选中态用蓝字 + 下划线，而非大类那种蓝底胶囊。
*/
.category-subtabs {
  display: flex;
  gap: 22px;
  justify-content: center;
  margin: 0 auto 36px;
}
.category-subtab {
  padding: 4px 0;
  font-size: 13px;
  cursor: pointer;
  border: none;
  background: transparent;
  color: var(--text-tertiary);
  transition: color 0.25s;
  font-family: inherit;
  font-weight: 500;
  white-space: nowrap;
  position: relative;
}
.category-subtab:hover { color: var(--text-secondary); }
.category-subtab.active { color: var(--accent); }
.category-subtab.active::after {
  content: '';
  position: absolute;
  left: 0; right: 0; bottom: -2px;
  height: 2px;
  background: var(--accent);
  border-radius: 1px;
}

.showcase-content {
  position: relative;
  min-height: 200px;
}
.showcase-content.fade-transition {
  opacity: 0;
  transform: translateY(8px);
}

.showcase-label {
  font-size: 12px;
  color: var(--text-tertiary);
  font-weight: 600;
  letter-spacing: 1px;
  margin-bottom: 16px;
}
.showcase-grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  margin-bottom: 40px;
}
.showcase-grid-4 img, .showcase-grid-detail img {
  width: 100%;
  border-radius: 12px;
  cursor: pointer;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  box-shadow: 0 2px 8px rgba(0,0,0,0.04);
}
.showcase-grid-4 img:hover, .showcase-grid-detail img:hover {
  transform: scale(1.03);
  box-shadow: 0 8px 24px rgba(0,0,0,0.1);
}
.showcase-grid-detail {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
}
.showcase-grid-detail img { aspect-ratio: 3/4; object-fit: cover; }

/* --- Pricing --- */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  max-width: 1100px;
  margin: 0 auto;
}
.pricing-card {
  background: var(--bg-card);
  border-radius: 14px;
  border: 1px solid var(--border);
  padding: 28px 24px;
  text-align: center;
  position: relative;
}
.pricing-card.recommended {
  border-color: var(--accent);
  box-shadow: 0 2px 20px rgba(0,113,227,0.1);
}
.pricing-badge {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--accent);
  color: #fff;
  padding: 4px 14px;
  border-radius: 12px;
  font-size: 12px;
  font-weight: 500;
}
.pricing-name {
  font-size: 14px;
  color: var(--text-tertiary);
  font-weight: 600;
  letter-spacing: 1px;
  margin-bottom: 8px;
}
.pricing-original {
  font-size: 13px;
  color: var(--text-tertiary);
  text-decoration: line-through;
  margin-bottom: 2px;
}
.pricing-price {
  font-size: 40px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 4px;
}
.pricing-unit {
  font-size: 16px;
  font-weight: 400;
  color: var(--text-secondary);
}
.pricing-quota {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 20px;
}
.pricing-save {
  font-size: 14px;
  color: var(--accent);
  font-weight: 500;
  margin-bottom: 16px;
}
.pricing-divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 0 0 16px;
}
.pricing-features { text-align: left; }
.pricing-feature {
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 8px;
}
.pricing-footnote {
  text-align: center;
  font-size: 13px;
  color: var(--text-tertiary);
  margin-top: 24px;
}

/* --- Download --- */
.download-about p {
  font-size: 15px;
  color: var(--text-secondary);
  margin-bottom: 16px;
  line-height: 1.8;
}
.download-about .about-lead { transition-delay: 0.05s; }
.download-about p:nth-of-type(2) { transition-delay: 0.15s; }
.download-about .about-security { transition-delay: 0.25s; }
.download-about .about-proof { transition-delay: 0.35s; }
.download-about .about-evolution { transition-delay: 0.45s; }
.download-about .about-lead {
  font-size: 17px;
  color: var(--text-primary);
  font-weight: 500;
  margin-bottom: 20px;
}
.download-about .about-security {
  color: var(--text-secondary);
}
.download-about .about-proof {
  color: var(--text-secondary);
}
.download-about .about-evolution {
  color: var(--text-secondary);
  margin-bottom: 0;
}
.download-cta-inner {
  text-align: center;
  margin-top: 48px;
  padding-top: 40px;
  border-top: 1px solid var(--border);
}
.download-cta-inner h3 {
  font-size: 22px;
  font-weight: 600;
  margin-bottom: 8px;
}
.download-cta-inner > p {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 20px;
}
.download-badge {
  display: inline-block;
  background: var(--bg-body);
  padding: 4px 16px;
  border-radius: 12px;
  font-size: 13px;
  color: var(--text-tertiary);
  margin-bottom: 24px;
}

/* --- Lightbox --- */
.lightbox {
  display: none;
  position: fixed;
  top: 0; left: 0;
  width: 100%; height: 100%;
  background: rgba(0,0,0,0.9);
  z-index: 200;
  justify-content: center;
  align-items: center;
}
.lightbox.open { display: flex; }
.lightbox-img {
  max-width: 90%;
  max-height: 90%;
  object-fit: contain;
  border-radius: 8px;
}
.lightbox-close {
  position: absolute;
  top: 24px;
  right: 32px;
  font-size: 36px;
  color: #fff;
  cursor: pointer;
}

/* --- Modal --- */
.modal {
  display: none;
  position: fixed;
  top: 0; left: 0;
  width: 100%; height: 100%;
  z-index: 300;
  justify-content: center;
  align-items: center;
}
.modal.open { display: flex; }
.modal-overlay {
  position: absolute;
  top: 0; left: 0; width: 100%; height: 100%;
  background: rgba(0,0,0,0.5);
}
.modal-content {
  position: relative;
  background: var(--bg-card);
  border-radius: 16px;
  padding: 32px;
  max-width: 420px;
  width: 90%;
  z-index: 1;
}
.modal-content h3 {
  font-size: 20px;
  margin-bottom: 16px;
}
.modal-body p { margin-bottom: 12px; font-size: 14px; color: var(--text-secondary); }
.modal-note { font-size: 13px; color: var(--text-tertiary); }
.modal-divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 16px 0 12px;
}
.modal-security {
  font-size: 12px;
  color: var(--text-tertiary);
  line-height: 1.7;
  text-align: left;
  margin-bottom: 0;
}
.modal-close {
  position: absolute;
  top: 16px; right: 20px;
  font-size: 24px;
  cursor: pointer;
  color: var(--text-tertiary);
}
.modal-form {
  display: flex;
  gap: 8px;
  margin-top: 16px;
}
.modal-input {
  flex: 1;
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: 12px;
  font-size: 14px;
  font-family: inherit;
  outline: none;
}
.modal-input:focus { border-color: var(--accent); }

/* --- Footer --- */
.footer {
  text-align: center;
  padding: 32px 0;
  border-top: 1px solid var(--border);
  font-size: 13px;
  color: var(--text-tertiary);
}
.footer-copy { font-size: 12px; color: var(--text-tertiary); margin-top: 4px; }
.footer-icp { font-size: 12px; margin-top: 8px; }
.footer-icp a {
  color: var(--text-tertiary);
  text-decoration: none;
}
.footer-icp a:hover { color: var(--accent); }

/* --- 联系我们（二级页面）--- */
.section-contact {
  padding-top: calc(var(--nav-height) + 80px);
  padding-bottom: 100px;
  text-align: center;
}
.contact-desc {
  font-size: 17px;
  color: var(--text-secondary);
  line-height: 1.7;
  max-width: 480px;
  margin: 0 auto 56px;
}
.contact-card {
  display: inline-block;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 36px 40px;
  box-shadow: 0 2px 16px rgba(0,0,0,0.05);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.contact-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 28px rgba(0,0,0,0.09);
}
.contact-qr {
  width: 200px;
  height: 200px;
  display: block;
  border-radius: 10px;
}
/* 二维码未上传时的占位框 */
.contact-qr-placeholder {
  width: 200px;
  height: 200px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 2px dashed var(--border);
  border-radius: 10px;
  color: var(--text-tertiary);
  font-size: 13px;
  background: var(--bg-body);
}
.contact-card-title {
  font-size: 17px;
  font-weight: 600;
  color: var(--text-primary);
  margin-top: 22px;
}
.contact-card-hint {
  font-size: 13px;
  color: var(--text-tertiary);
  margin-top: 6px;
}

/* --- Mobile Responsive --- */
@media (max-width: 768px) {
  .hero-label { font-size: 16px; letter-spacing: 3px; }
  .hero-title { font-size: 48px; }
  .hero-subtitle { font-size: 20px; }
  .section-title { font-size: 26px; }
  .section { padding: 50px 0; }
  /* 小类横向可滑动，不折行 */
  .category-subtabs {
    gap: 18px;
    overflow-x: auto;
    justify-content: flex-start;
    padding: 0 4px 4px;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
  }
  .category-subtabs::-webkit-scrollbar { display: none; }
  .section-contact { padding-top: calc(var(--nav-height) + 48px); padding-bottom: 64px; }
  .contact-desc { font-size: 15px; margin-bottom: 40px; }
  .contact-card { padding: 28px 30px; }
  .contact-qr,
  .contact-qr-placeholder { width: 170px; height: 170px; }
  .nav-links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    width: 100%;
    background: rgba(255,255,255,0.98);
    flex-direction: column;
    padding: 16px 24px;
    gap: 16px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.06);
  }
  .nav-links.open { display: flex; }
  /* 移动端菜单内文字始终为深色，无论导航状态 */
  .nav-links a { color: var(--text-secondary) !important; }
  .nav-links a:hover { color: var(--text-primary) !important; }
  .nav-links a.active { color: var(--accent) !important; }
  .nav-toggle { display: block; }

  .value-grid { grid-template-columns: 1fr; gap: 28px; max-width: 400px; }
  .value-desc { max-width: 100%; }
  .stats-row { flex-direction: column; gap: 24px; align-items: center; }
  .stats-row .stat-item { padding: 0; }
  .stats-row .stat-item + .stat-item { border-left: none; padding-top: 24px; border-top: 1px solid var(--border); }
  .stat-number { font-size: 28px; }
  .features-grid { grid-template-columns: 1fr; gap: 36px; }
  .pricing-grid { grid-template-columns: 1fr; max-width: 400px; }
  .showcase-grid-4 { grid-template-columns: repeat(2, 1fr); gap: 10px; }
  .showcase-grid-detail { grid-template-columns: repeat(2, 1fr); gap: 10px; }
}

@media (max-width: 480px) {
  .hero-title { font-size: 36px; }
  .hero-subtitle { font-size: 18px; }
  .hero-actions { flex-direction: column; align-items: center; }
  .intro-title { font-size: 28px; }
  .modal-form { flex-direction: column; }
}