:root {
  --ink: #142033;
  --muted: #5d6b82;
  --line: #dce8f5;
  --soft-line: #edf3fa;
  --paper: #ffffff;
  --mist: #f6fbff;
  --ice: #eef8ff;
  --blue: #1d62f0;
  --blue-strong: #0b49c9;
  --teal: #00a6b5;
  --teal-soft: #dff8f8;
  --red: #d83a52;
  --shadow: 0 18px 44px rgba(28, 73, 135, 0.12);
  --container: 1180px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--mist);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
  line-height: 1.7;
  overflow-x: hidden;
}

img {
  display: block;
  max-width: 100%;
}

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

p {
  margin: 0 0 18px;
}

.container {
  width: min(var(--container), calc(100% - 48px));
  margin: 0 auto;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.mobile-only {
  display: none;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255, 255, 255, 0.9);
  border-bottom: 1px solid rgba(220, 232, 245, 0.9);
  backdrop-filter: blur(16px);
}

.nav-shell {
  position: relative;
  width: min(1240px, calc(100% - 48px));
  min-height: 72px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 22px;
}

.brand {
  display: inline-flex;
  align-items: center;
  flex: 0 0 auto;
}

.brand img {
  width: 285px;
  height: auto;
}

.nav-links {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-links a {
  min-height: 40px;
  display: inline-flex;
  align-items: center;
  padding: 0 14px;
  color: #2f3d52;
  font-size: 15px;
  border-radius: 6px;
}

.nav-links a:hover,
.nav-links a:focus-visible {
  color: var(--blue);
  background: #edf5ff;
  outline: none;
}

.nav-phone {
  flex: 0 0 auto;
  min-height: 40px;
  display: inline-flex;
  align-items: center;
  padding: 0 16px;
  color: var(--blue-strong);
  font-weight: 700;
  border: 1px solid #cfe0f7;
  border-radius: 6px;
  background: #f7fbff;
}

.nav-toggle {
  display: none;
  width: 42px;
  height: 42px;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--paper);
  padding: 10px;
}

.nav-toggle span:not(.sr-only) {
  display: block;
  height: 2px;
  margin: 5px 0;
  background: var(--ink);
  border-radius: 2px;
}

.hero {
  position: relative;
  min-height: clamp(620px, calc(100vh - 250px), 760px);
  display: flex;
  align-items: center;
  overflow: hidden;
  background:
    linear-gradient(90deg, rgba(248, 252, 255, 0.99) 0%, rgba(248, 252, 255, 0.97) 48%, rgba(248, 252, 255, 0.9) 100%),
    url("assets/banner.jpg") center / cover no-repeat;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(29, 98, 240, 0.08) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 166, 181, 0.08) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: linear-gradient(90deg, #000 0%, rgba(0, 0, 0, 0.8) 55%, transparent 100%);
  pointer-events: none;
}

.hero::after {
  content: "";
  position: absolute;
  inset: auto 0 0;
  height: 96px;
  background: linear-gradient(180deg, transparent, var(--mist));
  pointer-events: none;
}

.hero-inner {
  position: relative;
  z-index: 1;
  padding: 64px 0 70px;
}

.eyebrow,
.section-kicker {
  margin: 0 0 12px;
  color: var(--teal);
  font-size: 14px;
  font-weight: 800;
  text-transform: uppercase;
}

.hero h1 {
  max-width: 1080px;
  margin: 0;
  font-size: 54px;
  line-height: 1.14;
  font-weight: 900;
  color: #0f1c31;
  overflow-wrap: anywhere;
}

.hero-lead {
  max-width: 680px;
  margin-top: 24px;
  color: #31415a;
  font-size: 20px;
  overflow-wrap: anywhere;
}

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

.btn {
  min-height: 46px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0 22px;
  border-radius: 6px;
  font-weight: 800;
  border: 1px solid transparent;
}

.btn-primary {
  color: #fff;
  background: var(--blue);
  box-shadow: 0 12px 24px rgba(29, 98, 240, 0.24);
}

.btn-primary:hover,
.btn-primary:focus-visible {
  background: var(--blue-strong);
  outline: none;
}

.btn-secondary {
  color: var(--blue-strong);
  background: rgba(255, 255, 255, 0.74);
  border-color: #bfd7f5;
}

.btn-secondary:hover,
.btn-secondary:focus-visible {
  border-color: var(--blue);
  background: #fff;
  outline: none;
}

.hero-stats {
  max-width: 760px;
  margin: 44px 0 0;
  padding: 22px 0 0;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 18px;
  border-top: 1px solid rgba(29, 98, 240, 0.18);
}

.hero-stats div {
  min-width: 0;
}

.hero-stats dt {
  color: var(--blue-strong);
  font-size: 30px;
  line-height: 1;
  font-weight: 900;
}

.hero-stats dd {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 14px;
}

.intro-section,
.cert-section {
  position: relative;
  padding: 68px 0;
  background: var(--paper);
}

.intro-section {
  background:
    linear-gradient(180deg, var(--mist), #fff 26%),
    repeating-linear-gradient(135deg, rgba(29, 98, 240, 0.05) 0 1px, transparent 1px 22px);
}

.feature-block {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 54px;
  align-items: center;
  padding: 44px 0;
}

.feature-block + .feature-block {
  border-top: 1px solid var(--soft-line);
}

.feature-media {
  margin: 0;
  position: relative;
}

.feature-media::before {
  content: "";
  position: absolute;
  inset: -14px 18px 18px -14px;
  border: 1px solid rgba(0, 166, 181, 0.26);
  border-radius: 8px;
  pointer-events: none;
}

.feature-media img {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: 8px;
  border: 1px solid var(--line);
  box-shadow: var(--shadow);
}

.feature-copy h2,
.section-head h2,
.about-layout h2 {
  margin: 0 0 20px;
  font-size: 34px;
  line-height: 1.24;
  color: #10213a;
}

.feature-copy p,
.about-layout p,
.section-head p {
  color: var(--muted);
  font-size: 17px;
}

.signal-list {
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
}

.signal-list li {
  position: relative;
  padding: 14px 0 14px 22px;
  color: #3a4a61;
  border-top: 1px solid var(--soft-line);
}

.signal-list li::before {
  content: "";
  position: absolute;
  top: 26px;
  left: 0;
  width: 8px;
  height: 8px;
  background: var(--teal);
  border-radius: 2px;
}

.course-section {
  padding: 86px 0;
  background:
    linear-gradient(180deg, #f6fbff, #eef8ff),
    linear-gradient(90deg, rgba(216, 58, 82, 0.06), transparent 34%, rgba(0, 166, 181, 0.08));
}

.section-head {
  max-width: 780px;
  margin: 0 auto 42px;
  text-align: center;
}

.section-head p {
  margin-bottom: 0;
}

.course-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 22px;
}

.course-card {
  position: relative;
  min-width: 0;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  color: var(--ink);
  background: rgba(255, 255, 255, 0.94);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: 0 10px 24px rgba(31, 68, 118, 0.08);
  transition: transform 180ms ease, box-shadow 180ms ease, border-color 180ms ease;
}

.course-card:hover,
.course-card:focus-visible {
  transform: translateY(-5px);
  border-color: rgba(29, 98, 240, 0.5);
  box-shadow: 0 18px 34px rgba(31, 68, 118, 0.16);
  outline: none;
}

.course-card img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-bottom: 1px solid var(--soft-line);
}

.course-visual {
  --c1: #e7f7ff;
  --c2: #bfe8ff;
  --c3: #1d62f0;
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  display: flex;
  align-items: flex-end;
  overflow: hidden;
  padding: 18px;
  background:
    linear-gradient(rgba(255, 255, 255, 0.18) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.18) 1px, transparent 1px),
    linear-gradient(135deg, var(--c1), var(--c2));
  background-size: 34px 34px, 34px 34px, 100% 100%;
  border-bottom: 1px solid var(--soft-line);
  isolation: isolate;
}

.course-visual::before {
  content: "";
  position: absolute;
  inset: -24% -14% auto auto;
  width: 72%;
  aspect-ratio: 1;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(255, 255, 255, 0.86), rgba(255, 255, 255, 0.18) 46%, transparent 68%);
  z-index: -1;
}

.course-visual::after {
  content: "";
  position: absolute;
  right: 22px;
  top: 20px;
  width: 86px;
  height: 86px;
  border: 1px solid rgba(255, 255, 255, 0.72);
  border-radius: 8px;
  background:
    linear-gradient(90deg, transparent 48%, rgba(255, 255, 255, 0.65) 49%, rgba(255, 255, 255, 0.65) 51%, transparent 52%),
    linear-gradient(0deg, transparent 48%, rgba(255, 255, 255, 0.65) 49%, rgba(255, 255, 255, 0.65) 51%, transparent 52%);
  box-shadow:
    -38px 38px 0 -20px rgba(255, 255, 255, 0.5),
    0 16px 36px rgba(17, 68, 136, 0.16);
}

.course-visual span {
  position: relative;
  z-index: 1;
  max-width: 100%;
  display: inline-flex;
  align-items: center;
  min-height: 34px;
  padding: 0 12px;
  color: #0d2c4f;
  font-size: 17px;
  line-height: 1.2;
  font-weight: 900;
  background: rgba(255, 255, 255, 0.78);
  border: 1px solid rgba(255, 255, 255, 0.9);
  border-radius: 6px;
  box-shadow: 0 12px 28px rgba(26, 83, 148, 0.14);
  overflow-wrap: anywhere;
}

.course-visual-01 {
  --c1: #e0f7ff;
  --c2: #7ed2ff;
  --c3: #0b74d1;
}

.course-visual-02 {
  --c1: #e9fbf7;
  --c2: #9adfd3;
  --c3: #0f9d8c;
}

.course-visual-03 {
  --c1: #eaf0ff;
  --c2: #8eb3ff;
  --c3: #315fe4;
}

.course-visual-04 {
  --c1: #eef7ff;
  --c2: #9cc8e8;
  --c3: #27618e;
}

.course-visual-05 {
  --c1: #ecfdf4;
  --c2: #9ee6bd;
  --c3: #0f9b65;
}

.course-visual-06 {
  --c1: #f0f4ff;
  --c2: #a8b9ff;
  --c3: #5167d8;
}

.course-visual-07 {
  --c1: #f2fbff;
  --c2: #83d6ef;
  --c3: #0984ac;
}

.course-visual-08 {
  --c1: #f1f8ff;
  --c2: #95b9d7;
  --c3: #335b78;
}

.course-visual-09 {
  --c1: #fff7ec;
  --c2: #f3c27e;
  --c3: #bd6b16;
}

.course-visual-10 {
  --c1: #edf8ff;
  --c2: #7fc4e8;
  --c3: #0a659b;
}

.course-visual-11 {
  --c1: #f7f1ff;
  --c2: #c4a7ff;
  --c3: #7652d6;
}

.course-visual-12 {
  --c1: #fff0f5;
  --c2: #f3a7bf;
  --c3: #d24c77;
}

.course-visual-03::after,
.course-visual-07::after,
.course-visual-10::after {
  border-radius: 50%;
  background:
    linear-gradient(90deg, transparent 45%, rgba(255, 255, 255, 0.66) 46%, rgba(255, 255, 255, 0.66) 54%, transparent 55%),
    radial-gradient(circle, transparent 40%, rgba(255, 255, 255, 0.62) 42%, transparent 44%);
}

.course-visual-08::after,
.course-visual-11::after {
  border-radius: 4px;
  background:
    linear-gradient(rgba(255, 255, 255, 0.66) 0 0) 18px 22px / 50px 5px no-repeat,
    linear-gradient(rgba(255, 255, 255, 0.66) 0 0) 18px 38px / 42px 5px no-repeat,
    linear-gradient(rgba(255, 255, 255, 0.66) 0 0) 18px 54px / 58px 5px no-repeat;
}

.course-visual-12::after {
  border-radius: 8px;
  background:
    linear-gradient(90deg, rgba(255, 255, 255, 0.72) 0 12px, transparent 12px 24px) 12px 14px / 72px 12px repeat-x,
    linear-gradient(rgba(255, 255, 255, 0.72) 0 0) 18px 54px / 52px 5px no-repeat;
}

.course-no {
  position: absolute;
  top: 12px;
  left: 12px;
  z-index: 1;
  min-width: 42px;
  height: 28px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 13px;
  font-weight: 900;
  background: linear-gradient(135deg, var(--blue), var(--teal));
  border-radius: 4px;
  box-shadow: 0 8px 16px rgba(20, 61, 126, 0.18);
}

.course-body {
  flex: 1;
  display: flex;
  flex-direction: column;
  padding: 18px 18px 20px;
}

.course-body h3 {
  margin: 0;
  min-height: 58px;
  color: #152238;
  font-size: 18px;
  line-height: 1.42;
  overflow-wrap: anywhere;
}

.course-body p {
  margin: 14px 0 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.55;
  overflow-wrap: anywhere;
}

.cert-section {
  background:
    linear-gradient(180deg, #fff, #f8fcff),
    linear-gradient(90deg, transparent, rgba(0, 166, 181, 0.08));
}

.cert-section .section-head {
  margin-bottom: 0;
}

.feature-copy a {
  color: var(--blue-strong);
  border-bottom: 2px solid rgba(29, 98, 240, 0.18);
}

.feature-copy a:hover,
.feature-copy a:focus-visible {
  color: var(--red);
  border-color: rgba(216, 58, 82, 0.28);
  outline: none;
}

.about-section {
  padding: 86px 0;
  background:
    linear-gradient(180deg, #f8fcff, #eff8ff),
    repeating-linear-gradient(0deg, rgba(29, 98, 240, 0.05) 0 1px, transparent 1px 36px);
  border-top: 1px solid var(--soft-line);
}

.about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.6fr) minmax(300px, 0.7fr);
  gap: 54px;
  align-items: start;
}

.contact-panel {
  padding: 28px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.contact-panel h3 {
  margin: 0 0 18px;
  font-size: 22px;
}

.contact-panel p {
  margin: 0 0 12px;
  color: #3b4b61;
  font-size: 15px;
}

.contact-panel a {
  color: var(--blue-strong);
  font-weight: 700;
}

.site-footer {
  padding: 42px 0;
  background: #ffffff;
  border-top: 1px solid var(--line);
}

.footer-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr) 112px;
  gap: 34px;
  align-items: center;
}

.site-footer h2 {
  margin: 0 0 10px;
  font-size: 22px;
}

.site-footer p {
  margin: 0 0 8px;
  color: var(--muted);
  font-size: 14px;
}

.site-footer a {
  color: var(--blue-strong);
}

.qr {
  width: 112px;
  height: 112px;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 6px;
  background: #fff;
}

.back-top {
  position: fixed;
  right: 22px;
  bottom: 22px;
  z-index: 10;
  width: 44px;
  height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 22px;
  font-weight: 900;
  background: var(--blue);
  border-radius: 6px;
  box-shadow: 0 12px 28px rgba(29, 98, 240, 0.28);
  opacity: 0;
  pointer-events: none;
  transform: translateY(8px);
  transition: opacity 180ms ease, transform 180ms ease;
}

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

.reveal {
  opacity: 1;
  transform: none;
}

.reveal.is-visible {
  opacity: 1;
  transform: translateY(0);
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .course-card,
  .reveal,
  .back-top {
    transition: none;
  }

  .reveal {
    opacity: 1;
    transform: none;
  }
}

@media (max-width: 1100px) {
  .brand img {
    width: 235px;
  }

  .nav-links a {
    padding: 0 10px;
  }

  .hero h1 {
    font-size: 46px;
  }

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

@media (max-width: 880px) {
  .nav-shell {
    width: min(100% - 32px, 1240px);
    min-height: auto;
    padding: 10px 0 12px;
    flex-wrap: wrap;
    gap: 10px 14px;
  }

  .brand img {
    width: 220px;
  }

  .nav-toggle {
    display: none !important;
  }

  .nav-links {
    position: static;
    width: 100%;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 6px;
    margin-left: 0;
    padding: 0;
    background: transparent;
    border: 0;
    box-shadow: none;
  }

  .nav-links.is-open {
    display: flex;
  }

  .nav-links a {
    min-height: 32px;
    justify-content: center;
    padding: 0 10px;
    font-size: 14px;
    background: #f7fbff;
    border: 1px solid #e2edf9;
  }

  .nav-phone {
    display: none;
  }

  .hero {
    min-height: auto;
  }

  .hero-inner {
    padding: 78px 0 62px;
  }

  .hero h1 {
    font-size: 38px;
  }

  .hero-lead {
    font-size: 18px;
  }

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

  .feature-block,
  .feature-block-reverse,
  .about-layout {
    grid-template-columns: 1fr;
    gap: 30px;
  }

  .feature-block-reverse .feature-media {
    order: -1;
  }

  .course-grid {
    grid-template-columns: 1fr;
  }

  .course-body h3,
  .course-body p {
    max-width: min(100%, 320px);
  }

  .footer-layout {
    grid-template-columns: 1fr;
    align-items: start;
  }
}

@media (max-width: 560px) {
  .container {
    width: min(calc(100% - 32px), var(--container));
  }

  .brand img {
    width: 188px;
  }

  .hero {
    background-position: 62% center;
  }

  .hero-inner {
    padding: 58px 0 54px;
  }

  .hero h1 {
    font-size: 28px;
  }

  .mobile-only {
    display: block;
  }

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

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

  .btn {
    width: 100%;
  }

  .hero-stats {
    gap: 16px;
  }

  .hero-stats dt {
    font-size: 25px;
  }

  .intro-section,
  .course-section,
  .cert-section,
  .about-section {
    padding: 56px 0;
  }

  .feature-block {
    padding: 36px 0;
  }

  .feature-copy h2,
  .section-head h2,
  .about-layout h2 {
    font-size: 27px;
  }

  .feature-copy p,
  .about-layout p,
  .section-head p {
    font-size: 16px;
  }

  .feature-media::before {
    inset: -9px 11px 11px -9px;
  }

  .course-grid {
    grid-template-columns: 1fr;
  }

  .course-body h3 {
    min-height: 0;
  }

  .contact-panel {
    padding: 22px;
  }

  .back-top {
    right: 14px;
    bottom: 14px;
  }
}