:root {
  --bg: #f6f8fb;
  --surface: #ffffff;
  --surface-soft: #edf5f3;
  --text: #14213d;
  --muted: #667085;
  --line: #d8e3ea;
  --brand: #0f766e;
  --brand-deep: #115e59;
  --accent: #2563eb;
  --warm: #b7791f;
  --danger: #b42318;
  --shadow: 0 22px 56px rgba(20, 33, 61, 0.12);
  --nav-bg: rgba(255, 255, 255, 0.92);
  --footer-bg: #eaf0f5;
}

body.site-night {
  --bg: #081214;
  --surface: #101b20;
  --surface-soft: #102a2c;
  --text: #e8f2f2;
  --muted: #a2b6b8;
  --line: rgba(201, 226, 226, 0.16);
  --brand: #2dd4bf;
  --brand-deep: #7dd3fc;
  --accent: #93c5fd;
  --warm: #fbbf24;
  --danger: #fca5a5;
  --shadow: 0 24px 64px rgba(0, 0, 0, 0.34);
  --nav-bg: rgba(8, 18, 20, 0.92);
  --footer-bg: #061012;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--text);
  background: var(--bg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  line-height: 1.65;
}

a {
  color: inherit;
  text-decoration: none;
}

img {
  max-width: 100%;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 22px;
  min-height: 72px;
  padding: 12px clamp(18px, 5vw, 78px);
  background: var(--nav-bg);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(18px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
  font-weight: 850;
}

.brand-logo {
  width: 42px;
  height: 42px;
  border-radius: 8px;
  object-fit: cover;
  box-shadow: 0 12px 24px rgba(15, 118, 110, 0.18);
}

.brand-text {
  font-size: 20px;
  white-space: nowrap;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: clamp(14px, 3vw, 30px);
  color: var(--muted);
  font-size: 15px;
  font-weight: 750;
}

.site-nav a {
  transition: color 0.18s ease;
}

.site-nav a:hover {
  color: var(--brand);
}

.site-theme-switch {
  display: inline-flex;
  gap: 4px;
  padding: 4px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--surface);
}

.site-theme-button {
  min-width: 56px;
  min-height: 30px;
  padding: 0 12px;
  border: 0;
  border-radius: 999px;
  color: var(--muted);
  background: transparent;
  font: inherit;
  font-size: 13px;
  font-weight: 800;
  cursor: pointer;
}

.site-theme-button-active {
  color: #ffffff;
  background: var(--brand);
}

.hero {
  display: flex;
  justify-content: space-between;
  gap: clamp(30px, 6vw, 88px);
  align-items: center;
  padding: clamp(48px, 7vw, 82px) clamp(18px, 5vw, 78px) clamp(36px, 5vw, 62px);
  background:
    linear-gradient(135deg, rgba(15, 118, 110, 0.10), rgba(37, 99, 235, 0.08) 42%, rgba(183, 121, 31, 0.08)),
    var(--surface);
  border-bottom: 1px solid var(--line);
}

.hero-content {
  position: relative;
  z-index: 1;
  flex: 1 1 560px;
  max-width: 760px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--brand);
  font-size: 14px;
  font-weight: 850;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 18px;
  font-size: clamp(58px, 11vw, 112px);
  line-height: 0.96;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 12px;
  font-size: clamp(30px, 4vw, 48px);
  line-height: 1.15;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 10px;
  font-size: 21px;
  line-height: 1.28;
}

.hero-copy {
  max-width: 700px;
  color: var(--muted);
  font-size: clamp(18px, 2.3vw, 23px);
}

.platform-row {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin-top: 28px;
}

.platform-item {
  min-height: 76px;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
}

.platform-item span,
.platform-item strong {
  display: block;
}

.platform-item span {
  color: var(--muted);
  font-size: 13px;
  font-weight: 760;
}

.platform-item strong {
  margin-top: 4px;
  color: var(--text);
  font-size: 17px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 30px;
}

.primary-action,
.secondary-action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 22px;
  border-radius: 8px;
  font-weight: 800;
}

.primary-action {
  color: #ffffff;
  background: var(--brand);
  box-shadow: 0 16px 32px rgba(15, 118, 110, 0.22);
}

.secondary-action {
  color: var(--brand);
  background: var(--surface);
  border: 1px solid var(--line);
}

.hero-media {
  position: relative;
  z-index: 0;
  flex: 0 0 min(38vw, 480px);
  display: grid;
  justify-items: center;
  gap: 16px;
}

.product-frame {
  overflow: hidden;
  width: min(100%, 360px);
  margin: 0;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.product-frame img {
  display: block;
  width: 100%;
  height: min(68vh, 620px);
  object-fit: cover;
  object-position: top center;
  background: #eef2f7;
}

.product-frame figcaption {
  padding: 14px 16px 16px;
}

.product-frame strong,
.product-frame span {
  display: block;
}

.product-frame strong {
  color: var(--text);
  font-size: 18px;
}

.product-frame span {
  color: var(--muted);
  font-size: 14px;
}

.hero-proof {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 8px;
  width: min(100%, 520px);
}

.hero-proof span {
  min-height: 38px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--brand-deep);
  background: var(--surface);
  font-size: 13px;
  font-weight: 850;
  text-align: center;
}

.section {
  padding: clamp(58px, 8vw, 92px) clamp(18px, 5vw, 78px);
}

.section-head {
  max-width: 860px;
  margin-bottom: 30px;
}

.section-head p {
  max-width: 780px;
  color: var(--muted);
  font-size: 18px;
}

.scenario-grid,
.assurance-grid {
  display: grid;
  gap: 18px;
}

.scenario-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
}

.assurance-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.scenario-card,
.assurance-item,
.contact-panel,
.feedback-qr-card,
.info-list,
.legal-document,
.faq-list details {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.scenario-card {
  min-height: 330px;
  padding: 24px;
}

.scenario-icon {
  width: 42px;
  height: 42px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 18px;
  border-radius: 8px;
  color: #ffffff;
  background: var(--brand);
  font-weight: 900;
}

.scenario-card:nth-child(2) .scenario-icon {
  background: var(--accent);
}

.scenario-card:nth-child(3) .scenario-icon {
  background: var(--warm);
}

.scenario-card:nth-child(4) .scenario-icon {
  background: #334155;
}

.scenario-card p,
.assurance-item p,
.about-copy p,
.contact-panel p,
.info-list dd,
.legal-document p,
.legal-document li,
.faq-list p {
  color: var(--muted);
}

.scenario-card ul,
.shot-copy ul {
  margin: 18px 0 0;
  padding: 0;
  list-style: none;
}

.scenario-card li,
.shot-copy li {
  position: relative;
  margin: 8px 0;
  padding-left: 18px;
  color: var(--muted);
}

.scenario-card li::before,
.shot-copy li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.75em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--brand);
}

.trust-section,
.screenshots-section,
.contact-section,
.faq-section {
  background: var(--surface-soft);
}

.assurance-item {
  min-height: 198px;
  padding: 24px;
}

.check-mark {
  width: 34px;
  height: 34px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 18px;
  border-radius: 8px;
  background: rgba(15, 118, 110, 0.12);
}

.check-mark::before {
  content: "";
  width: 13px;
  height: 7px;
  border-left: 3px solid var(--brand);
  border-bottom: 3px solid var(--brand);
  transform: rotate(-45deg) translate(1px, -1px);
}

.shot-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 18px;
}

.shot-tab {
  min-height: 40px;
  padding: 0 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  color: var(--muted);
  background: var(--surface);
  font: inherit;
  font-weight: 850;
  cursor: pointer;
}

.shot-tab-active {
  color: #ffffff;
  background: var(--brand);
  border-color: var(--brand);
}

.shot-stage {
  display: grid;
  grid-template-columns: minmax(260px, 360px) minmax(0, 1fr);
  align-items: center;
  gap: clamp(24px, 5vw, 70px);
  padding: clamp(18px, 4vw, 34px);
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
}

.shot-phone {
  overflow: hidden;
  margin: 0;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #eef2f7;
  box-shadow: var(--shadow);
}

.shot-phone img {
  display: block;
  width: 100%;
  height: min(72vh, 680px);
  object-fit: contain;
  object-position: top center;
}

.shot-copy {
  max-width: 620px;
}

.shot-copy h3 {
  font-size: clamp(26px, 3vw, 42px);
}

.shot-copy p {
  color: var(--muted);
  font-size: 18px;
}

.faq-list {
  display: grid;
  gap: 12px;
  max-width: 980px;
}

.faq-list details {
  padding: 0 22px;
}

.faq-list summary {
  min-height: 62px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  color: var(--text);
  font-size: 18px;
  font-weight: 850;
  cursor: pointer;
}

.faq-list summary::-webkit-details-marker {
  display: none;
}

.faq-list summary::after {
  content: "+";
  color: var(--brand);
  font-size: 24px;
  font-weight: 700;
}

.faq-list details[open] summary::after {
  content: "-";
}

.faq-list p {
  margin: -4px 0 20px;
}

.about-section {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(320px, 1fr);
  gap: clamp(28px, 6vw, 80px);
  align-items: start;
}

.about-copy p {
  font-size: 18px;
}

.info-list {
  display: grid;
  margin: 0;
  overflow: hidden;
}

.info-list div {
  display: grid;
  grid-template-columns: 138px minmax(0, 1fr);
  gap: 18px;
  padding: 18px 22px;
  border-bottom: 1px solid var(--line);
}

.info-list div:last-child {
  border-bottom: 0;
}

.info-list dt {
  color: var(--text);
  font-weight: 850;
}

.info-list dd {
  margin: 0;
}

.contact-panel {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  overflow: hidden;
}

.contact-panel div {
  padding: 24px;
  border-right: 1px solid var(--line);
}

.contact-panel div:last-child {
  border-right: 0;
}

.contact-panel strong {
  display: block;
  margin-bottom: 10px;
  font-size: 18px;
}

.contact-panel p {
  margin-bottom: 0;
  overflow-wrap: anywhere;
}

.contact-panel a,
.legal-document a {
  color: var(--brand);
  font-weight: 800;
}

.feedback-qr-card {
  display: flex;
  align-items: center;
  gap: 18px;
  margin-top: 18px;
  padding: 18px;
}

.feedback-qr-card img {
  width: 116px;
  height: 116px;
  border-radius: 8px;
  object-fit: cover;
  background: #ffffff;
}

.feedback-qr-card strong {
  display: block;
  margin-bottom: 6px;
  font-size: 18px;
}

.feedback-qr-card p {
  margin: 0;
  color: var(--muted);
}

.site-footer {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 10px 18px;
  min-height: 96px;
  padding: 26px 20px;
  color: var(--muted);
  background: var(--footer-bg);
  border-top: 1px solid var(--line);
  font-size: 14px;
  text-align: center;
}

.site-footer p {
  margin: 0;
}

.site-footer a {
  color: var(--brand);
  font-weight: 750;
}

.legal-page {
  padding: clamp(42px, 7vw, 82px) clamp(18px, 5vw, 78px);
}

.legal-document {
  max-width: 980px;
  margin: 0 auto;
  padding: clamp(28px, 5vw, 56px);
}

.legal-document h1 {
  margin-bottom: 18px;
  font-size: clamp(36px, 6vw, 68px);
}

.legal-document h2 {
  margin: 0 0 12px;
  font-size: 24px;
}

.legal-document section {
  margin-top: 34px;
}

.legal-lead {
  color: var(--text);
  font-size: 19px;
}

.legal-document ul {
  margin: 12px 0 0;
  padding-left: 22px;
}

.legal-document li {
  margin: 8px 0;
}

.support-highlight {
  padding: 20px;
  background: var(--surface-soft);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.support-highlight p {
  margin-bottom: 0;
  font-size: 20px;
}

body.site-night .product-frame img,
body.site-night .shot-phone {
  background: #0b1518;
}

@media (max-width: 1100px) {
  .hero {
    flex-direction: column;
    align-items: flex-start;
  }

  .about-section {
    grid-template-columns: 1fr;
  }

  .hero-media {
    width: min(100%, 620px);
    align-self: center;
  }

  .scenario-grid,
  .assurance-grid,
  .contact-panel {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .contact-panel div {
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .contact-panel div:nth-child(3),
  .contact-panel div:nth-child(4) {
    border-bottom: 0;
  }
}

@media (max-width: 760px) {
  .site-header {
    align-items: stretch;
    flex-direction: column;
    gap: 12px;
    min-height: 118px;
  }

  .site-nav {
    width: 100%;
    overflow-x: auto;
    padding-bottom: 2px;
    white-space: nowrap;
  }

  .site-theme-switch {
    align-self: flex-start;
  }

  h1 {
    font-size: clamp(52px, 17vw, 76px);
  }

  .platform-row,
  .scenario-grid,
  .assurance-grid,
  .contact-panel,
  .shot-stage {
    grid-template-columns: 1fr;
  }

  .hero-actions {
    flex-direction: column;
  }

  .primary-action,
  .secondary-action {
    width: 100%;
  }

  .hero-proof {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .shot-tabs {
    flex-wrap: nowrap;
    overflow-x: auto;
    padding-bottom: 4px;
  }

  .shot-tab {
    flex: 0 0 auto;
  }

  .shot-stage {
    padding: 16px;
  }

  .shot-phone {
    max-width: 320px;
    justify-self: center;
  }

  .contact-panel div,
  .contact-panel div:nth-child(3) {
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .contact-panel div:last-child {
    border-bottom: 0;
  }

  .feedback-qr-card {
    align-items: flex-start;
    flex-direction: column;
  }

  .info-list div {
    grid-template-columns: 1fr;
    gap: 6px;
  }
}

@media (max-width: 430px) {
  .hero {
    padding-top: 34px;
  }

  .section {
    padding-left: 16px;
    padding-right: 16px;
  }

  .scenario-card,
  .assurance-item {
    padding: 20px;
  }
}