:root {
  color-scheme: light;
  --bg: #f7f8fa;
  --surface: #ffffff;
  --ink: #111827;
  --muted: #6b7280;
  --line: #e5e7eb;
  --accent: #315cf6;
  --accent-dark: #2445c4;
  --accent-soft: #eef3ff;
  --radius: 16px;
  --radius-lg: 22px;
  --maxw: 1120px;
  --shadow-sm: 0 1px 2px rgba(17, 24, 39, 0.04), 0 1px 3px rgba(17, 24, 39, 0.06);
  --shadow-md: 0 10px 30px rgba(17, 24, 39, 0.06);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  width: 100%;
  overflow-x: hidden;
}

body {
  margin: 0;
  width: 100%;
  max-width: 100%;
  overflow-x: hidden;
  color: var(--ink);
  background: var(--bg);
  font-family:
    -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img,
svg {
  max-width: 100%;
}

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

h1,
h2,
h3,
p,
li,
dd,
span,
a {
  margin: 0;
  overflow-wrap: break-word;
}

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  gap: 24px;
  max-width: 100vw;
  height: 64px;
  padding: 0 clamp(20px, 5vw, 40px);
  background: rgba(247, 248, 250, 0.82);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent;
  transition: border-color 180ms ease, background 180ms ease;
}

main {
  max-width: 100vw;
  overflow-x: clip;
}

.site-header.is-scrolled {
  border-bottom-color: var(--line);
  background: rgba(247, 248, 250, 0.92);
}

.brand {
  display: flex;
  align-items: center;
  min-width: 0;
}

.brand-logo {
  height: 36px;
  width: auto;
  display: block;
}

.nav {
  display: none;
  gap: 26px;
  margin-left: auto;
  color: var(--muted);
  font-size: 15px;
}

.nav a {
  transition: color 160ms ease;
}

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

.nav-cta {
  margin-left: auto;
  padding: 8px 16px;
  border-radius: 999px;
  background: var(--accent);
  color: #fff;
  font-size: 14px;
  font-weight: 600;
  transition: background 160ms ease;
}

.nav-cta:hover {
  background: var(--accent-dark);
}

@media (min-width: 860px) {
  .nav {
    display: flex;
  }
  .nav-cta {
    margin-left: 0;
  }
}

/* ---------- Section base ---------- */
.section {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: clamp(48px, 6vw, 72px) clamp(20px, 5vw, 40px);
}

.section-head {
  width: 100%;
  max-width: 680px;
  margin-bottom: 44px;
}

.kicker {
  margin-bottom: 14px;
  color: var(--accent);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.section-head h2 {
  max-width: 100%;
  font-size: clamp(26px, 3.6vw, 38px);
  line-height: 1.2;
  letter-spacing: -0.02em;
  font-weight: 800;
  overflow-wrap: break-word;
}

.section-note {
  margin-top: 14px;
  color: var(--muted);
  font-size: 15px;
}

/* ---------- Hero ---------- */
.hero {
  padding-top: clamp(48px, 7vw, 64px);
  padding-bottom: clamp(48px, 6vw, 72px);
}

.eyebrow {
  display: inline-block;
  margin-bottom: 22px;
  padding: 6px 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--surface);
  color: var(--muted);
  font-size: 13px;
  font-weight: 600;
}

.hero h1 {
  max-width: 100%;
  font-size: clamp(36px, 9.6vw, 80px);
  line-height: 1.04;
  letter-spacing: -0.04em;
  font-weight: 800;
  overflow-wrap: break-word;
}

.hero-subtitle {
  width: 100%;
  max-width: 640px;
  margin-top: 24px;
  color: var(--muted);
  font-size: clamp(17px, 2.2vw, 20px);
  line-height: 1.7;
  overflow-wrap: break-word;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 32px;
  max-width: 100%;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 0 24px;
  max-width: 100%;
  border: 1px solid transparent;
  border-radius: 12px;
  font-size: 15px;
  font-weight: 600;
  text-align: center;
  white-space: normal;
  transition: transform 160ms ease, background 160ms ease, box-shadow 160ms ease;
}

.button.primary {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 6px 16px rgba(49, 92, 246, 0.24);
}

.button.primary:hover {
  background: var(--accent-dark);
  transform: translateY(-1px);
}

.button.ghost {
  background: var(--surface);
  border-color: var(--line);
  color: var(--ink);
}

.button.ghost:hover {
  border-color: var(--ink);
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
  max-width: 640px;
  margin: 56px 0 0;
  padding-top: 28px;
  border-top: 1px solid var(--line);
}

.hero-stats dt {
  font-size: 16px;
  font-weight: 700;
}

.hero-stats dd {
  margin: 4px 0 0;
  color: var(--muted);
  font-size: 14px;
}

/* ---------- Pain ---------- */
.pain-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.pain-item {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: baseline;
  column-gap: 10px;
  row-gap: 8px;
  min-width: 0;
  padding: 28px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}

.pain-no {
  display: block;
  margin-bottom: 0;
  color: var(--accent);
  font-size: 14px;
  font-weight: 800;
  letter-spacing: 0.06em;
}

.pain-item h3 {
  margin-bottom: 0;
  font-size: 19px;
  font-weight: 700;
}

.pain-item p {
  grid-column: 1 / -1;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.7;
}

/* ---------- About ---------- */
.about-card {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: clamp(24px, 4vw, 44px);
  min-width: 0;
  padding: clamp(32px, 5vw, 40px) clamp(20px, 5vw, 40px);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
}

.about-badge {
  position: relative;
  display: grid;
  width: 72px;
  height: 72px;
  place-items: center;
  background: #f1f3f7;
  border: 1px solid var(--line);
  border-radius: 20px;
}

.badge-word {
  color: var(--ink);
  font-size: 36px;
  font-weight: 800;
  line-height: 1;
}

.badge-dot {
  position: absolute;
  right: -4px;
  bottom: -4px;
  width: 16px;
  height: 16px;
  background: var(--accent);
  border: 3px solid var(--surface);
  border-radius: 50%;
}

.about-body .kicker {
  margin-bottom: 10px;
}

.about-name {
  font-size: 26px;
  font-weight: 800;
  color: var(--ink);
  letter-spacing: -0.01em;
}

.about-title {
  margin: 6px 0 18px;
  color: var(--accent);
  font-size: 15px;
  font-weight: 600;
}

.about-body h2 {
  margin-bottom: 16px;
  font-size: clamp(22px, 3vw, 30px);
  font-weight: 800;
  letter-spacing: -0.02em;
}

.about-body p {
  margin-bottom: 14px;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.75;
}

.about-points {
  margin: 20px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 12px;
}

.about-points li {
  position: relative;
  padding-left: 26px;
  color: var(--ink);
  font-size: 15px;
}

.about-points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent);
}

/* ---------- Services ---------- */
.service-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.service-grid-4 {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.service-card {
  min-width: 0;
  padding: 26px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
  transition: transform 160ms ease, box-shadow 160ms ease;
}

.service-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.service-card h3 {
  margin-bottom: 10px;
  font-size: 18px;
  font-weight: 700;
}

.service-card p {
  color: var(--muted);
  font-size: 15px;
  line-height: 1.7;
}

/* ---------- Deliverable templates ---------- */
.deliverable-section {
  background: var(--surface);
  max-width: none;
  padding-left: 0;
  padding-right: 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.deliverable-section > .section-head,
.deliverable-section > .tpl-grid {
  max-width: var(--maxw);
  margin-left: auto;
  margin-right: auto;
  padding-left: clamp(20px, 5vw, 40px);
  padding-right: clamp(20px, 5vw, 40px);
}

.tpl-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.tpl-card {
  min-width: 0;
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.tpl-top {
  padding: 20px 22px 14px;
  border-bottom: 1px solid var(--line);
}

.tpl-tag {
  display: inline-block;
  margin-bottom: 10px;
  padding: 3px 10px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent-dark);
  font-size: 12px;
  font-weight: 700;
}

.tpl-top h3 {
  font-size: 18px;
  font-weight: 700;
}

.tpl-body {
  padding: 18px 22px 22px;
  font-size: 15px;
}

.tpl-line {
  display: grid;
  grid-template-columns: 50px 1fr;
  align-items: start;
  gap: 10px;
  color: var(--muted);
  margin-bottom: 12px;
  line-height: 1.7;
}

.tpl-key {
  display: inline-block;
  width: fit-content;
  margin-right: 8px;
  padding: 2px 8px;
  border-radius: 6px;
  background: #eceef2;
  color: var(--ink);
  font-size: 12px;
  font-weight: 700;
}

.tpl-out {
  margin: 0 0 10px;
}

.tpl-output {
  display: grid;
  grid-template-columns: 50px 1fr;
  align-items: start;
  gap: 10px;
}

.tpl-list {
  margin: 0;
  padding-left: 0;
  color: var(--ink);
  display: grid;
  gap: 6px;
  list-style-position: inside;
}

.tpl-list li {
  line-height: 1.6;
}

.tpl-check {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 10px;
}

.tpl-check li {
  position: relative;
  padding-left: 26px;
  line-height: 1.6;
}

.tpl-check li::before {
  content: "✓";
  position: absolute;
  left: 0;
  top: 0;
  color: var(--accent);
  font-weight: 800;
}

.tpl-table {
  display: grid;
  gap: 0;
  border: 1px solid var(--line);
  border-radius: 10px;
  overflow: hidden;
}

.tpl-row {
  display: grid;
  grid-template-columns: 1.6fr 1fr 0.7fr;
  gap: 8px;
  padding: 11px 14px;
  border-top: 1px solid var(--line);
  font-size: 14px;
}

.tpl-row:first-child {
  border-top: 0;
}

.tpl-row-head {
  background: #eceef2;
  color: var(--ink);
  font-weight: 700;
}

.tpl-row span:nth-child(2),
.tpl-row span:nth-child(3) {
  color: var(--muted);
}

.tpl-footer {
  max-width: var(--maxw);
  margin: 28px auto 0;
  padding: 0 clamp(20px, 5vw, 40px);
  color: var(--muted);
  font-size: 14px;
  text-align: center;
  line-height: 1.7;
}

/* ---------- Fit (适合/不适合) ---------- */
.fit-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.fit-card {
  min-width: 0;
  padding: 28px;
  background: var(--surface);
  border: 2px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}

.fit-yes {
  border-color: var(--accent);
}

.fit-no {
  border-color: #d1d5db;
}

.fit-card h3 {
  margin-bottom: 16px;
  font-size: 19px;
  font-weight: 800;
}

.fit-yes h3 {
  color: var(--accent);
}

.fit-no h3 {
  color: var(--muted);
}

.fit-card ul {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 12px;
}

.fit-card li {
  position: relative;
  padding-left: 24px;
  color: var(--ink);
  font-size: 15px;
  line-height: 1.65;
}

.fit-yes li::before {
  content: "✓";
  position: absolute;
  left: 0;
  top: 0;
  color: var(--accent);
  font-weight: 800;
  font-size: 16px;
}

.fit-no li::before {
  content: "✗";
  position: absolute;
  left: 0;
  top: 0;
  color: var(--muted);
  font-weight: 800;
  font-size: 16px;
}

/* ---------- Scenes ---------- */
.scene-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}

.scene-card {
  min-width: 0;
  padding: 24px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}

.scene-card h3 {
  margin-bottom: 8px;
  font-size: 17px;
  font-weight: 700;
}

.scene-card p {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.65;
}

/* ---------- Method ---------- */
.method-steps {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: none;
}

.method-steps li {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: start;
  gap: 14px;
  min-width: 0;
  padding: 26px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-sm);
}

.method-steps li > div {
  display: contents;
}

.method-no {
  display: grid;
  width: 36px;
  height: 36px;
  place-items: center;
  border-radius: 10px;
  background: var(--accent-soft);
  color: var(--accent-dark);
  font-weight: 800;
}

.method-steps strong {
  display: block;
  align-self: center;
  margin-bottom: 0;
  font-size: 17px;
}

.method-steps p {
  grid-column: 1 / -1;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.65;
}

/* ---------- FAQ ---------- */
.faq-list {
  display: grid;
  gap: 12px;
}

details {
  min-width: 0;
  padding: 20px 22px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

summary {
  cursor: pointer;
  font-size: 17px;
  font-weight: 700;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

summary::-webkit-details-marker {
  display: none;
}

summary::after {
  content: "+";
  color: var(--accent);
  font-size: 22px;
  font-weight: 400;
  transition: transform 180ms ease;
}

details[open] summary::after {
  transform: rotate(45deg);
}

details p {
  margin-top: 14px;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.75;
}

/* ---------- Contact ---------- */
.contact-card {
  min-width: 0;
  padding: clamp(32px, 5vw, 60px);
  background: var(--ink);
  border-radius: var(--radius-lg);
  color: #fff;
}

.contact-card .kicker {
  color: #93a4ff;
}

.contact-card h2 {
  font-size: clamp(24px, 3.4vw, 34px);
  line-height: 1.25;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.contact-desc {
  max-width: 660px;
  margin-top: 18px;
  color: #b9c0cc;
  font-size: 16px;
  line-height: 1.75;
}

.contact-methods {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.contact-chip {
  display: inline-flex;
  align-items: baseline;
  gap: 10px;
  min-width: 0;
  padding: 14px 20px;
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.06);
  color: #fff;
  font: inherit;
  cursor: pointer;
  transition: background 160ms ease, transform 160ms ease;
}

.contact-chip:hover {
  background: rgba(255, 255, 255, 0.12);
  transform: translateY(-1px);
}

.chip-label {
  font-size: 13px;
  font-weight: 700;
  color: #93a4ff;
}

.chip-value {
  font-size: 17px;
  font-weight: 700;
}

.chip-hint {
  font-size: 12px;
  color: #b9c0cc;
}

/* ---------- Footer ---------- */
.site-footer {
  max-width: var(--maxw);
  width: 100%;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding: 30px clamp(20px, 5vw, 40px) 44px;
  color: var(--muted);
  font-size: 14px;
  border-top: 1px solid var(--line);
}

/* ---------- Toast ---------- */
.toast {
  position: fixed;
  left: 50%;
  bottom: 34px;
  transform: translateX(-50%) translateY(12px);
  padding: 12px 22px;
  border-radius: 999px;
  background: var(--ink);
  color: #fff;
  font-weight: 600;
  font-size: 15px;
  box-shadow: 0 16px 40px rgba(17, 24, 39, 0.28);
  opacity: 0;
  pointer-events: none;
  transition: opacity 220ms ease, transform 220ms ease;
  z-index: 40;
}

.toast.is-visible {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  .service-grid,
  .service-grid-4,
  .scene-grid,
  .method-steps {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 640px) {
  .pain-grid,
  .tpl-grid,
  .fit-grid,
  .service-grid,
  .service-grid-4,
  .scene-grid,
  .method-steps,
  .hero-stats {
    grid-template-columns: 1fr;
  }

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

  .hero-stats {
    gap: 20px;
  }

  .hero h1 {
    font-size: clamp(34px, 10.2vw, 42px);
    letter-spacing: -0.035em;
  }

  .hero-subtitle {
    font-size: 16px;
    line-height: 1.75;
  }

  .hero-actions {
    flex-direction: column;
    width: 100%;
  }

  .hero-actions .button {
    width: 100%;
  }

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

  .brand-logo {
    height: 26px;
    max-width: min(150px, calc(100vw - 116px));
    object-fit: contain;
    object-position: left center;
  }

  .nav-cta {
    flex: 0 0 auto;
    margin-left: auto;
    padding: 7px 12px;
    font-size: 13px;
  }

  .site-header {
    gap: 12px;
    padding: 0 16px;
  }

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

  .deliverable-section > .section-head,
  .deliverable-section > .tpl-grid,
  .tpl-footer {
    padding-left: 16px;
    padding-right: 16px;
  }

  .section-head h2 {
    font-size: clamp(24px, 7vw, 30px);
    letter-spacing: -0.01em;
  }

  .pain-item,
  .service-card,
  .fit-card,
  .scene-card,
  .method-steps li,
  details {
    padding: 22px;
  }

  .tpl-table {
    gap: 10px;
    border: 0;
    border-radius: 0;
    overflow: visible;
  }

  .tpl-row-head {
    display: none;
  }

  .tpl-row:not(.tpl-row-head) {
    grid-template-columns: 1fr 1fr;
    gap: 10px;
    padding: 14px;
    border: 1px solid var(--line);
    border-radius: 12px;
    background: var(--surface);
  }

  .tpl-row:not(.tpl-row-head):first-child {
    border-top: 1px solid var(--line);
  }

  .tpl-row:not(.tpl-row-head) span:first-child {
    grid-column: 1 / -1;
    font-size: 15px;
    font-weight: 700;
    color: var(--ink);
  }

  .tpl-row:not(.tpl-row-head) span:nth-child(2),
  .tpl-row:not(.tpl-row-head) span:nth-child(3) {
    display: grid;
    gap: 2px;
    padding: 8px 10px;
    border-radius: 10px;
    background: #f3f6fb;
    color: var(--ink);
    font-size: 14px;
    font-weight: 700;
  }

  .tpl-row:not(.tpl-row-head) span:nth-child(2)::before {
    content: "是否适合 AI";
    color: var(--muted);
    font-size: 11px;
    font-weight: 600;
  }

  .tpl-row:not(.tpl-row-head) span:nth-child(3)::before {
    content: "优先级";
    color: var(--muted);
    font-size: 11px;
    font-weight: 600;
  }

  .contact-methods {
    flex-direction: column;
  }

  .contact-chip {
    width: 100%;
    justify-content: flex-start;
    flex-wrap: wrap;
  }

  .site-footer {
    flex-direction: column;
  }
}