:root {
  --ink: #252525;
  --muted: #756f61;
  --soft-muted: #9d927b;
  --paper: #fffaf0;
  --paper-deep: #f6eddc;
  --white: #ffffff;
  --yellow: #ffdf59;
  --yellow-soft: #fff2a8;
  --yellow-pale: #fff7d6;
  --line: #eadfca;
  --red: #e5525c;
  --green: #3d9b6d;
  --blue: #4f7dd6;
  --shadow: 0 24px 70px rgba(81, 63, 24, 0.13);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    linear-gradient(rgba(255, 255, 255, 0.34) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.34) 1px, transparent 1px),
    var(--paper);
  background-size: 34px 34px;
  font-family: "Microsoft YaHei", "PingFang SC", "Noto Sans SC", sans-serif;
}

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

button {
  font: inherit;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  width: min(1120px, calc(100% - 32px));
  margin: 18px auto 0;
  padding: 10px 12px;
  border: 1px solid rgba(234, 223, 202, 0.86);
  border-radius: 999px;
  background: rgba(255, 250, 240, 0.88);
  box-shadow: 0 12px 40px rgba(96, 76, 32, 0.08);
  backdrop-filter: blur(16px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding-right: 12px;
  font-weight: 800;
}

.brand-icon {
  width: 38px;
  height: 38px;
  border-radius: 12px;
  box-shadow: 0 8px 18px rgba(37, 37, 37, 0.14);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--muted);
  font-size: 14px;
}

.nav-links a {
  padding: 9px 12px;
  border-radius: 999px;
}

.nav-contact {
  border: 0;
  padding: 9px 12px;
  border-radius: 999px;
  background: transparent;
  color: inherit;
  cursor: pointer;
}

.nav-links a:hover,
.nav-contact:hover {
  background: var(--yellow-pale);
  color: var(--ink);
}

main {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
}

.hero-section {
  display: grid;
  grid-template-columns: minmax(0, 0.92fr) minmax(360px, 1.08fr);
  gap: 52px;
  align-items: center;
  min-height: calc(100vh - 76px);
  padding: 58px 0 72px;
}

.eyebrow {
  margin: 0 0 12px;
  color: #8b7100;
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  letter-spacing: 0;
}

h1 {
  max-width: 560px;
  margin: 0;
  font-size: clamp(46px, 7vw, 86px);
  line-height: 0.98;
  font-weight: 900;
}

h2 {
  margin: 0;
  font-size: clamp(30px, 4vw, 52px);
  line-height: 1.08;
  font-weight: 900;
}

h3 {
  margin: 0;
  font-size: 23px;
}

.hero-text {
  max-width: 520px;
  margin: 24px 0 0;
  color: var(--muted);
  font-size: 18px;
  line-height: 1.9;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 34px;
}

.primary-action,
.secondary-action {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 22px;
  border-radius: 999px;
  cursor: pointer;
  transition: transform 0.18s ease, box-shadow 0.18s ease, background 0.18s ease;
}

.primary-action {
  border: 0;
  color: var(--ink);
  background: var(--yellow);
  box-shadow: 0 14px 30px rgba(185, 144, 0, 0.2);
  font-weight: 900;
}

.secondary-action {
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.74);
  color: var(--muted);
  font-weight: 800;
}

.primary-action:hover,
.secondary-action:hover {
  transform: translateY(-2px);
}

.primary-action:focus-visible,
.secondary-action:focus-visible,
.nav-links a:focus-visible,
.nav-contact:focus-visible,
.contact-close:focus-visible {
  outline: 3px solid rgba(79, 125, 214, 0.36);
  outline-offset: 3px;
}

.download-hint {
  width: fit-content;
  margin: 16px 0 0;
  padding: 9px 13px;
  border: 1px dashed #d8c980;
  border-radius: 999px;
  color: var(--soft-muted);
  background: rgba(255, 247, 214, 0.68);
  font-size: 13px;
}

.download-hint.is-visible {
  color: var(--ink);
  background: var(--yellow-pale);
}

.hero-board {
  position: relative;
  min-height: 630px;
}

.memo-card {
  position: absolute;
  z-index: 3;
  width: 306px;
  padding: 24px;
  border: 1px solid #e9d581;
  border-radius: 20px;
  background: #fff5bd;
  box-shadow: var(--shadow);
  transform: rotate(-2.5deg);
}

.memo-main {
  top: 56px;
  left: 8px;
}

.memo-date {
  display: inline-flex;
  margin-bottom: 14px;
  padding: 6px 10px;
  border-radius: 999px;
  background: var(--white);
  color: #8b7100;
  font-size: 13px;
  font-weight: 800;
}

.memo-card strong {
  display: block;
  font-size: 30px;
  line-height: 1.16;
}

.memo-card p {
  margin: 14px 0 0;
  color: #6c603d;
  line-height: 1.7;
}

.category-strip {
  position: absolute;
  left: 34px;
  bottom: 92px;
  z-index: 5;
  display: flex;
  flex-wrap: wrap;
  width: 272px;
  gap: 10px;
}

.category-strip span,
.ai-methods span,
.ai-steps span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 34px;
  padding: 0 13px;
  border: 1px solid #ead675;
  border-radius: 999px;
  background: var(--yellow-pale);
  color: #6f5d00;
  font-weight: 800;
}

.phone-frame {
  overflow: hidden;
  border: 10px solid var(--ink);
  border-radius: 34px;
  background: var(--white);
  box-shadow: 0 28px 80px rgba(37, 37, 37, 0.18);
}

.phone-frame img {
  display: block;
  width: 100%;
}

.phone-front {
  position: absolute;
  right: 12px;
  top: 20px;
  z-index: 4;
  width: min(338px, 58vw);
  transform: rotate(3deg);
}

.paper-dot {
  position: absolute;
  border-radius: 999px;
  opacity: 0.92;
}

.dot-red {
  right: 14px;
  bottom: 78px;
  width: 110px;
  height: 110px;
  background: rgba(229, 82, 92, 0.18);
}

.dot-blue {
  left: 250px;
  top: 286px;
  width: 70px;
  height: 70px;
  background: rgba(79, 125, 214, 0.18);
}

.feature-section,
.screens-section,
.ai-section,
.download-section {
  padding: 72px 0;
}

.section-heading {
  max-width: 720px;
  margin-bottom: 28px;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
}

.feature-note {
  position: relative;
  min-height: 230px;
  padding: 34px 26px 28px;
  border: 1px solid #ead675;
  border-radius: 20px;
  background: #fff3b8;
  box-shadow: 0 18px 50px rgba(97, 78, 28, 0.1);
}

.feature-note:nth-child(2) {
  transform: rotate(1.2deg);
}

.feature-note:nth-child(3) {
  transform: rotate(-1deg);
}

.feature-note:nth-child(4) {
  transform: rotate(0.8deg);
}

.feature-note p {
  margin: 14px 0 0;
  color: var(--muted);
  line-height: 1.8;
}

.note-warm {
  background: #fff7d6;
}

.note-mint {
  border-color: #cfe7d7;
  background: #eefaf2;
}

.note-cool {
  border-color: #d9e2f6;
  background: #f4f8ff;
}

.note-pin {
  position: absolute;
  top: 16px;
  right: 18px;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--red);
  box-shadow: inset -3px -3px 0 rgba(0, 0, 0, 0.1);
}

.screen-gallery {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 22px;
  align-items: start;
}

.screen-card {
  margin: 0;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 28px;
  background: rgba(255, 255, 255, 0.8);
  box-shadow: var(--shadow);
}

.screen-card img {
  display: block;
  width: 100%;
  border-radius: 22px;
}

.screen-card figcaption {
  padding: 14px 4px 4px;
  color: var(--muted);
  font-weight: 800;
  text-align: center;
}

.screen-raised {
  margin-top: 34px;
}

.ai-card,
.download-card {
  padding: 36px;
  border: 1px solid var(--line);
  border-radius: 28px;
  background:
    linear-gradient(135deg, rgba(255, 223, 89, 0.34), rgba(255, 255, 255, 0.78)),
    var(--white);
  box-shadow: var(--shadow);
}

.ai-card {
  display: block;
}

.ai-card p,
.download-card p {
  max-width: 700px;
  margin: 16px 0 0;
  color: var(--muted);
  line-height: 1.85;
}

.ai-intro {
  display: grid;
  grid-template-columns: minmax(0, 0.94fr) minmax(280px, 0.72fr);
  gap: 34px;
  align-items: center;
}

.ai-methods {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 22px;
}

.ai-feature-image {
  margin: 0;
  padding: 12px;
  border: 1px solid rgba(234, 214, 117, 0.92);
  border-radius: 24px;
  background: rgba(255, 255, 255, 0.66);
  box-shadow: 0 18px 44px rgba(97, 78, 28, 0.11);
  transform: rotate(1.5deg);
}

.ai-feature-image img {
  display: block;
  width: 100%;
  border-radius: 18px;
}

.ai-feature-image figcaption {
  padding: 12px 6px 4px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 800;
  line-height: 1.55;
}

.ai-tutorial-heading {
  margin-top: 30px;
  margin-bottom: 16px;
}

.ai-tutorial-heading h3 {
  font-size: 26px;
}

.ai-detail-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
  margin-top: 26px;
}

.ai-detail-card {
  position: relative;
  display: grid;
  grid-template-columns: 176px minmax(0, 1fr);
  gap: 18px;
  align-items: center;
  padding: 14px;
  border: 1px solid rgba(234, 214, 117, 0.92);
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.7);
  box-shadow: 0 14px 34px rgba(97, 78, 28, 0.08);
}

.ai-detail-card img {
  display: block;
  width: 100%;
  height: 218px;
  object-fit: contain;
  object-position: top;
  border-radius: 12px;
  border: 1px solid var(--line);
  background: rgba(255, 250, 240, 0.8);
}

.ai-detail-card span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border-radius: 50%;
  background: var(--yellow);
  color: var(--ink);
  font-size: 13px;
  font-weight: 900;
}

.ai-detail-card h3 {
  margin-top: 10px;
  font-size: 18px;
}

.ai-detail-card p {
  margin-top: 7px;
  font-size: 14px;
  line-height: 1.7;
}

.ai-confirm-card {
  grid-template-columns: minmax(0, 1fr) 180px;
  padding: 20px;
}

.ai-confirm-note {
  display: grid;
  place-content: center;
  min-height: 150px;
  border: 1px dashed #d8c980;
  border-radius: 18px;
  background: var(--yellow-pale);
  text-align: center;
}

.ai-confirm-note strong {
  font-size: 24px;
}

.ai-confirm-note small {
  margin-top: 8px;
  color: var(--muted);
  font-weight: 800;
}

.ai-steps {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  min-width: 220px;
}

.download-card {
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: center;
  background:
    linear-gradient(135deg, rgba(255, 247, 214, 0.88), rgba(255, 255, 255, 0.9)),
    var(--white);
}

.download-action {
  white-space: nowrap;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
  padding: 28px 0 34px;
  border-top: 1px solid var(--line);
  color: var(--soft-muted);
  font-size: 14px;
}

.is-modal-open {
  overflow: hidden;
}

.contact-modal[hidden] {
  display: none;
}

.contact-modal {
  position: fixed;
  inset: 0;
  z-index: 50;
  display: grid;
  place-items: center;
  padding: 18px;
}

.contact-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(37, 37, 37, 0.34);
  backdrop-filter: blur(6px);
}

.contact-panel {
  position: relative;
  z-index: 1;
  width: min(520px, 100%);
  padding: 30px;
  border: 1px solid var(--line);
  border-radius: 28px;
  background:
    linear-gradient(135deg, rgba(255, 247, 214, 0.94), rgba(255, 255, 255, 0.96)),
    var(--white);
  box-shadow: 0 30px 90px rgba(37, 37, 37, 0.24);
}

.contact-close {
  position: absolute;
  top: 14px;
  right: 14px;
  width: 38px;
  height: 38px;
  border: 1px solid var(--line);
  border-radius: 50%;
  background: var(--white);
  color: var(--ink);
  cursor: pointer;
  font-size: 24px;
  line-height: 1;
}

.contact-panel h2 {
  font-size: 30px;
}

.contact-panel p {
  color: var(--muted);
  line-height: 1.75;
}

.contact-email {
  margin: 20px 0 16px;
  padding: 16px;
  border: 1px dashed #d8c980;
  border-radius: 18px;
  background: var(--yellow-pale);
}

.contact-email span {
  display: block;
  color: #8b7100;
  font-size: 13px;
  font-weight: 900;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.contact-email strong {
  display: block;
  margin-top: 7px;
  font-size: 22px;
  word-break: break-all;
}

.contact-copy {
  width: 100%;
}

.contact-status {
  margin: 14px 0 0;
  font-size: 14px;
}

@media (max-width: 920px) {
  .site-header {
    align-items: flex-start;
    border-radius: 24px;
  }

  .nav-links {
    flex-wrap: wrap;
    justify-content: flex-end;
  }

  .hero-section {
    grid-template-columns: 1fr;
    gap: 20px;
    min-height: auto;
    padding-top: 42px;
  }

  .hero-board {
    min-height: 590px;
  }

  .phone-front {
    right: 2vw;
  }

  .feature-grid,
  .screen-gallery {
    grid-template-columns: 1fr;
  }

  .screen-raised {
    margin-top: 0;
  }

  .ai-intro,
  .ai-detail-grid,
  .ai-confirm-card,
  .download-card {
    grid-template-columns: 1fr;
  }

  .ai-feature-image {
    max-width: 360px;
    margin: 0 auto;
  }
}

@media (max-width: 560px) {
  main,
  .site-header,
  .site-footer {
    width: min(100% - 22px, 1120px);
  }

  .site-header {
    position: static;
    display: block;
  }

  .nav-links {
    margin-top: 10px;
    justify-content: flex-start;
  }

  .nav-links a {
    padding: 8px 10px;
  }

  .nav-contact {
    padding: 8px 10px;
  }

  h1 {
    font-size: 42px;
    line-height: 1.08;
  }

  .hero-text {
    font-size: 16px;
  }

  .hero-actions {
    align-items: stretch;
    flex-direction: column;
  }

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

  .hero-board {
    display: flex;
    flex-direction: column;
    min-height: auto;
    gap: 18px;
    padding-bottom: 8px;
  }

  .memo-card {
    position: relative;
    top: auto;
    left: auto;
    order: 1;
    width: 100%;
    transform: rotate(-1.5deg);
  }

  .phone-front {
    position: relative;
    top: auto;
    right: auto;
    order: 2;
    align-self: center;
    width: min(330px, 92vw);
    transform: rotate(2deg);
  }

  .category-strip {
    position: relative;
    left: auto;
    bottom: auto;
    order: 3;
    width: 100%;
    justify-content: center;
    margin-top: 4px;
  }

  .paper-dot {
    display: none;
  }

  .feature-section,
  .screens-section,
  .ai-section,
  .download-section {
    padding: 46px 0;
  }

  .feature-note,
  .ai-card,
  .download-card {
    padding: 26px 20px;
  }

  .feature-note {
    min-height: 0;
  }

  .feature-note p {
    line-height: 1.65;
  }

  .ai-detail-card {
    grid-template-columns: 112px minmax(0, 1fr);
    gap: 12px;
    padding: 12px;
  }

  .ai-detail-card img {
    height: 160px;
  }

  .ai-confirm-card {
    display: block;
    padding: 18px;
  }

  .ai-confirm-note {
    margin-top: 16px;
  }

  .site-footer {
    display: block;
  }

  .site-footer span {
    display: block;
    margin-bottom: 8px;
  }

  .contact-panel {
    padding: 26px 20px;
    border-radius: 24px;
  }

  .contact-panel h2 {
    font-size: 25px;
  }

  .contact-email strong {
    font-size: 19px;
  }
}