/* ===== 变量与基础 ===== */
:root {
  --navy-950: #050D18;
  --navy-900: #071423;
  --navy-800: #0A1B2E;
  --navy-700: #0C2740;
  --navy-600: #133352;
  --gold: #C9A24B;
  --gold-light: #DDBE7C;
  --gold-dark: #A98334;
  --gold-pale: rgba(201, 162, 75, 0.12);
  --ink: #16202E;
  --muted: #5B6675;
  --bg: #FBF9F5;
  --white: #FFFFFF;
  --line: #EAE4D6;
  --shadow-sm: 0 6px 24px rgba(7, 20, 35, 0.06);
  --shadow-md: 0 16px 48px rgba(7, 20, 35, 0.10);
  --radius: 14px;
  --container: 1200px;
  --header-h: 72px;
  --font: "Noto Sans SC", -apple-system, BlinkMacSystemFont, "PingFang SC",
    "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg);
  line-height: 1.75;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img,
svg {
  display: block;
}

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

section {
  scroll-margin-top: calc(var(--header-h) - 10px);
}

.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== 通用按钮 ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 500;
  line-height: 1;
  letter-spacing: 0.5px;
  cursor: pointer;
  transition: transform 0.25s ease, box-shadow 0.25s ease,
    background 0.25s ease, color 0.25s ease, border-color 0.25s ease;
  white-space: nowrap;
}

.btn-gold {
  background: linear-gradient(135deg, var(--gold-light), var(--gold) 55%, var(--gold-dark));
  color: #1a1206;
  box-shadow: 0 8px 22px rgba(201, 162, 75, 0.32);
}

.btn-gold:hover {
  transform: translateY(-2px);
  box-shadow: 0 14px 30px rgba(201, 162, 75, 0.42);
}

.btn-ghost {
  border: 1px solid rgba(255, 255, 255, 0.35);
  color: #fff;
}

.btn-ghost:hover {
  border-color: var(--gold-light);
  color: var(--gold-light);
  transform: translateY(-2px);
}

.btn-lg {
  padding: 16px 36px;
  font-size: 16px;
}

/* ===== 顶部导航 ===== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--header-h);
  transition: background 0.35s ease, box-shadow 0.35s ease, height 0.35s ease;
  background: transparent;
}

.site-header.scrolled {
  background: rgba(7, 20, 35, 0.92);
  backdrop-filter: saturate(180%) blur(14px);
  box-shadow: 0 8px 30px rgba(5, 13, 24, 0.35);
  height: 62px;
}

.nav-inner {
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 11px;
  flex-shrink: 0;
}

.brand-mark {
  display: grid;
  place-items: center;
  line-height: 0;
}

.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
}

.brand-name {
  font-size: 19px;
  font-weight: 700;
  color: #fff;
  letter-spacing: 2px;
}

.brand-sub {
  font-size: 9px;
  letter-spacing: 2.6px;
  color: var(--gold-light);
  text-transform: uppercase;
  margin-top: 3px;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 30px;
}

.nav-link {
  position: relative;
  font-size: 15px;
  color: rgba(255, 255, 255, 0.82);
  padding: 6px 0;
  transition: color 0.25s ease;
}

.nav-link::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 0;
  height: 2px;
  background: var(--gold);
  transition: width 0.3s ease;
}

.nav-link:hover,
.nav-link.active {
  color: #fff;
}

.nav-link.active::after,
.nav-link:hover::after {
  width: 100%;
}

.nav-cta {
  padding: 10px 22px;
  font-size: 14px;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 42px;
  height: 42px;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.nav-toggle span {
  display: block;
  height: 2px;
  width: 100%;
  background: #fff;
  border-radius: 2px;
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.nav-toggle.open span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.nav-toggle.open span:nth-child(2) {
  opacity: 0;
}
.nav-toggle.open span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ===== Hero：左文右图 ===== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  background: linear-gradient(160deg, var(--navy-950), var(--navy-800) 55%, var(--navy-700));
  color: #fff;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.hero-bg::before {
  content: "";
  position: absolute;
  top: -20%;
  right: -10%;
  width: 640px;
  height: 640px;
  background: radial-gradient(circle, rgba(201, 162, 75, 0.22), transparent 62%);
}

.hero-bg::after {
  content: "";
  position: absolute;
  bottom: -30%;
  left: -15%;
  width: 720px;
  height: 720px;
  background: radial-gradient(circle, rgba(19, 51, 82, 0.75), transparent 65%);
}

.hero-bg .grid {
  position: absolute;
  inset: 0;
  background-image: linear-gradient(rgba(255, 255, 255, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.04) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse at center, #000 30%, transparent 75%);
}

.hero-grid {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 56px;
  align-items: center;
  padding-top: 100px;
  padding-bottom: 80px;
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 14px;
  letter-spacing: 4px;
  color: var(--gold-light);
  margin-bottom: 22px;
}

.hero-eyebrow::before {
  content: "";
  width: 32px;
  height: 1px;
  background: var(--gold);
}

.hero-title {
  font-size: clamp(44px, 7vw, 76px);
  font-weight: 700;
  letter-spacing: 6px;
  line-height: 1.08;
  margin-bottom: 24px;
  background: linear-gradient(180deg, #fff 30%, var(--gold-light));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-lead {
  max-width: 560px;
  font-size: clamp(16px, 2vw, 18px);
  color: rgba(255, 255, 255, 0.78);
  line-height: 1.9;
  margin-bottom: 36px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 52px;
}

.hero-stats {
  display: flex;
  gap: 44px;
  flex-wrap: wrap;
  border-top: 1px solid rgba(255, 255, 255, 0.12);
  padding-top: 30px;
}

.hero-stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.hero-stat-num {
  font-size: clamp(28px, 3.6vw, 40px);
  font-weight: 700;
  color: var(--gold-light);
  line-height: 1;
}

.hero-stat-label {
  font-size: 14px;
  color: rgba(255, 255, 255, 0.62);
  letter-spacing: 1px;
}

/* 阶梯图卡片 */
.hero-visual {
  display: flex;
  justify-content: center;
}

.ladder-card {
  position: relative;
  width: 100%;
  max-width: 360px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 20px;
  padding: 28px 28px 40px;
  backdrop-filter: blur(8px);
}

.ladder-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 28px;
}

.ladder-title {
  font-size: 15px;
  font-weight: 600;
  color: #fff;
  letter-spacing: 1px;
}

.ladder-badge {
  font-size: 10px;
  letter-spacing: 2px;
  color: var(--gold-light);
  border: 1px solid rgba(201, 162, 75, 0.4);
  padding: 3px 10px;
  border-radius: 999px;
}

.ladder-chart {
  position: relative;
  display: flex;
  align-items: flex-end;
  gap: 16px;
  height: 220px;
  padding: 0 6px;
}

.ladder-bar {
  flex: 1;
  height: var(--h);
  border-radius: 10px 10px 0 0;
  background: linear-gradient(180deg, var(--gold-light), var(--gold-dark));
  position: relative;
  box-shadow: 0 8px 24px rgba(201, 162, 75, 0.3);
}

.ladder-bar:nth-child(1) { opacity: 0.55; }
.ladder-bar:nth-child(2) { opacity: 0.7; }
.ladder-bar:nth-child(3) { opacity: 0.85; }
.ladder-bar:nth-child(4) { opacity: 1; }

.ladder-value {
  position: absolute;
  bottom: -30px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 12px;
  color: rgba(255, 255, 255, 0.7);
  white-space: nowrap;
  letter-spacing: 1px;
}

.ladder-line {
  position: absolute;
  left: 20px;
  right: 20px;
  bottom: 46px;
  height: 140px;
  width: calc(100% - 40px);
  pointer-events: none;
}

.hero-scroll {
  position: absolute;
  left: 50%;
  bottom: 28px;
  transform: translateX(-50%);
  width: 26px;
  height: 42px;
  border: 1.5px solid rgba(255, 255, 255, 0.35);
  border-radius: 14px;
  display: flex;
  justify-content: center;
  padding-top: 8px;
  z-index: 2;
}

.hero-scroll span {
  width: 2px;
  height: 8px;
  background: var(--gold-light);
  border-radius: 2px;
  animation: scroll-dot 1.6s ease-in-out infinite;
}

@keyframes scroll-dot {
  0% { transform: translateY(0); opacity: 1; }
  70% { transform: translateY(12px); opacity: 0; }
  100% { transform: translateY(0); opacity: 0; }
}

/* ===== 通用 Section ===== */
.section {
  padding: 104px 0;
}

.section-about,
.section-client,
.section-courses {
  background: var(--bg);
}

.section-growth {
  background: var(--white);
}

.section-head {
  max-width: 720px;
  margin: 0 auto 60px;
  text-align: center;
}

.section-eyebrow {
  display: inline-block;
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 3px;
  color: var(--gold-dark);
  text-transform: uppercase;
  margin-bottom: 14px;
}

.section-title {
  font-size: clamp(28px, 4.4vw, 40px);
  font-weight: 700;
  color: var(--navy-800);
  line-height: 1.3;
  margin-bottom: 16px;
  letter-spacing: 1px;
}

.section-desc {
  font-size: 16px;
  color: var(--muted);
}

/* ===== 关于我们 ===== */
.about-grid {
  display: grid;
  grid-template-columns: 1.25fr 1fr;
  gap: 56px;
  align-items: start;
}

.about-copy p {
  font-size: 16px;
  color: var(--muted);
  margin-bottom: 18px;
}

.about-copy strong {
  color: var(--navy-800);
  font-weight: 600;
}

.about-points {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.about-point {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  padding: 20px 22px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}

.about-point:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-sm);
  border-color: var(--gold-light);
}

.about-point-icon {
  flex-shrink: 0;
  width: 46px;
  height: 46px;
  display: grid;
  place-items: center;
  border-radius: 12px;
  color: var(--gold-dark);
  background: var(--gold-pale);
}

.about-point h3 {
  font-size: 17px;
  font-weight: 600;
  color: var(--navy-800);
  margin-bottom: 4px;
}

.about-point p {
  font-size: 14px;
  color: var(--muted);
}

/* ===== 培养体系：垂直时间轴 ===== */
.timeline {
  position: relative;
  max-width: 760px;
  margin: 0 auto;
  padding-left: 48px;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 18px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: linear-gradient(180deg, var(--gold), rgba(201, 162, 75, 0.15));
}

.timeline-item {
  position: relative;
  padding: 18px 24px;
  margin-bottom: 24px;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}

.timeline-item:last-child {
  margin-bottom: 0;
}

.timeline-item:hover {
  transform: translateX(4px);
  box-shadow: var(--shadow-sm);
  border-color: var(--gold-light);
}

.timeline-dot {
  position: absolute;
  left: -48px;
  top: 20px;
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: #fff;
  border: 2px solid var(--gold);
  color: var(--gold-dark);
  display: grid;
  place-items: center;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0;
}

.timeline-body h3 {
  font-size: 18px;
  font-weight: 600;
  color: var(--navy-800);
  margin-bottom: 6px;
}

.timeline-body p {
  font-size: 14px;
  color: var(--muted);
}

/* ===== 高端客户经营：图文交错 ===== */
.client-flow {
  display: flex;
  flex-direction: column;
  gap: 44px;
}

.client-row {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 48px;
  align-items: center;
}

.client-row.reverse .client-media {
  order: 2;
}
.client-row.reverse .client-text {
  order: 1;
}

.client-media {
  position: relative;
  height: 220px;
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.media-a { background: linear-gradient(135deg, #0C2740, #133352); }
.media-b { background: linear-gradient(135deg, #0A1B2E, #0C2740); }
.media-c { background: linear-gradient(135deg, #133352, #0A1B2E); }
.media-d { background: linear-gradient(135deg, #071423, #0C2740); }

.client-step {
  position: absolute;
  top: 18px;
  left: 20px;
  font-size: 11px;
  letter-spacing: 3px;
  color: var(--gold-light);
}

.client-icon-big {
  display: grid;
  place-items: center;
  width: 92px;
  height: 92px;
  border-radius: 50%;
  color: var(--gold-light);
  background: rgba(201, 162, 75, 0.12);
  border: 1px solid rgba(201, 162, 75, 0.3);
}

.client-text h3 {
  font-size: 24px;
  font-weight: 600;
  color: var(--navy-800);
  margin-bottom: 12px;
}

.client-text p {
  font-size: 15px;
  color: var(--muted);
  margin-bottom: 16px;
}

.client-tags {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  list-style: none;
}

.client-tags li {
  font-size: 13px;
  color: var(--gold-dark);
  background: var(--gold-pale);
  padding: 5px 14px;
  border-radius: 999px;
}

/* ===== 课程体系：列表 ===== */
.course-list {
  display: flex;
  flex-direction: column;
  max-width: 880px;
  margin: 0 auto;
}

.course-row {
  display: flex;
  align-items: center;
  gap: 26px;
  padding: 24px 28px;
  border-bottom: 1px solid var(--line);
  transition: background 0.25s ease, transform 0.25s ease, box-shadow 0.25s ease;
}

.course-row:first-child {
  border-top: 1px solid var(--line);
}

.course-row:hover {
  background: #fff;
  transform: translateX(4px);
  box-shadow: var(--shadow-sm);
}

.course-index {
  flex-shrink: 0;
  font-size: 28px;
  font-weight: 700;
  color: var(--gold);
  line-height: 1;
  width: 52px;
}

.course-info {
  flex: 1;
}

.course-info h3 {
  font-size: 18px;
  font-weight: 600;
  color: var(--navy-800);
  margin-bottom: 4px;
}

.course-info p {
  font-size: 14px;
  color: var(--muted);
}

.course-tag {
  flex-shrink: 0;
  font-size: 12px;
  letter-spacing: 2px;
  color: var(--gold-dark);
  background: var(--gold-pale);
  padding: 5px 14px;
  border-radius: 999px;
}

/* ===== 核心优势：2x2 ===== */
.section-advantage {
  position: relative;
  background: linear-gradient(160deg, var(--navy-800), var(--navy-900));
  color: #fff;
  overflow: hidden;
}

.section-advantage::before {
  content: "";
  position: absolute;
  top: -30%;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 400px;
  background: radial-gradient(ellipse, rgba(201, 162, 75, 0.16), transparent 65%);
}

.section-advantage .section-title {
  color: #fff;
}

.advantage-grid {
  position: relative;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
  max-width: 880px;
  margin: 0 auto;
}

.advantage-item {
  padding: 40px 36px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.03);
  transition: transform 0.25s ease, background 0.25s ease, border-color 0.25s ease;
}

.advantage-item:hover {
  transform: translateY(-5px);
  border-color: var(--gold);
  background: rgba(255, 255, 255, 0.06);
}

.advantage-num {
  display: block;
  font-size: 30px;
  font-weight: 700;
  color: var(--gold-light);
  letter-spacing: 2px;
  margin-bottom: 14px;
}

.advantage-item h3 {
  font-size: 20px;
  font-weight: 600;
  margin-bottom: 8px;
}

.advantage-item p {
  font-size: 15px;
  color: rgba(255, 255, 255, 0.62);
}

/* ===== 联系我们 ===== */
.contact-card {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 40px;
  align-items: center;
  padding: 56px 60px;
  background: linear-gradient(160deg, var(--navy-800), var(--navy-900));
  border-radius: 20px;
  color: #fff;
  box-shadow: var(--shadow-md);
}

.contact-card .section-eyebrow {
  color: var(--gold-light);
}

.contact-card .section-title {
  color: #fff;
}

.contact-desc {
  color: rgba(255, 255, 255, 0.72);
  margin-bottom: 30px;
}

.contact-person {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 16px;
}

.contact-person-label {
  font-size: 13px;
  letter-spacing: 2px;
  color: var(--gold-light);
  border: 1px solid rgba(201, 162, 75, 0.5);
  padding: 4px 12px;
  border-radius: 999px;
}

.contact-person-name {
  font-size: 20px;
  font-weight: 600;
}

.contact-phone {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-size: 26px;
  font-weight: 700;
  color: var(--gold-light);
  letter-spacing: 1px;
  transition: color 0.25s ease;
}

.contact-phone:hover {
  color: #fff;
}

.contact-cta {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
  text-align: center;
}

.contact-note {
  font-size: 13px;
  color: rgba(255, 255, 255, 0.55);
}

/* ===== 页脚 ===== */
.site-footer {
  background: var(--navy-950);
  color: rgba(255, 255, 255, 0.7);
  padding: 40px 0;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 11px;
}

.footer-copy {
  font-size: 14px;
}

/* ===== 滚动淡入动画 ===== */
.reveal {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

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

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }
  .hero-visual {
    display: none;
  }
  .client-row {
    grid-template-columns: 1fr;
    gap: 24px;
  }
  .client-row.reverse .client-media {
    order: 1;
  }
  .client-row.reverse .client-text {
    order: 2;
  }
  .client-media {
    height: 180px;
  }
}

@media (max-width: 900px) {
  .site-nav {
    position: fixed;
    top: 0;
    right: 0;
    height: 100vh;
    width: min(320px, 82vw);
    flex-direction: column;
    align-items: flex-start;
    justify-content: center;
    gap: 26px;
    padding: 0 40px;
    background: rgba(7, 20, 35, 0.98);
    backdrop-filter: blur(16px);
    transform: translateX(100%);
    transition: transform 0.35s ease;
  }
  .site-nav.open {
    transform: translateX(0);
  }
  .nav-link {
    font-size: 18px;
  }
  .nav-cta {
    display: none;
  }
  .nav-toggle {
    display: flex;
  }

  .about-grid {
    grid-template-columns: 1fr;
    gap: 36px;
  }

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

  .contact-card {
    grid-template-columns: 1fr;
    padding: 40px 28px;
  }
}

@media (max-width: 600px) {
  .section {
    padding: 72px 0;
  }
  .section-head {
    margin-bottom: 42px;
  }
  .hero-grid {
    padding-top: 80px;
  }
  .hero-stats {
    gap: 28px;
  }
  .timeline {
    padding-left: 40px;
  }
  .timeline-dot {
    left: -40px;
    width: 32px;
    height: 32px;
    font-size: 12px;
  }
  .course-row {
    flex-wrap: wrap;
    gap: 14px;
  }
  .course-index {
    width: auto;
    font-size: 22px;
  }
  .footer-inner {
    flex-direction: column;
    text-align: center;
  }
  .contact-phone {
    font-size: 22px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }
  .hero-scroll span {
    animation: none;
  }
}