/* ============================================================
   明和设计教育官网 — 全局样式
   MingHe Education Official Website — Global Styles
   ============================================================ */

/* --------------------------------------------------
   CSS Variables / Design Tokens
   -------------------------------------------------- */
:root {
  /* Colors */
  --color-primary: #1E3A5F;
  --color-primary-dark: #152A45;
  --color-primary-light: #2A5080;
  --color-accent: #D4A853;
  --color-accent-light: #E8D5A0;
  --color-cta: #E8742A;
  --color-cta-hover: #D0651F;
  --color-cta-light: #F5A36A;
  --color-bg: #FAFBFB;
  --color-bg-alt: #F0F2F5;
  --color-text: #1D1D1F;
  --color-text-secondary: #6E6E73;
  --color-text-light: #999;
  --color-white: #FFFFFF;
  --color-border: #E5E7EB;
  --color-border-light: #F0F0F0;
  --color-success: #34C759;
  --color-star: #F5A623;

  /* Typography */
  --font-heading: 'Noto Serif SC', 'Source Han Serif SC', 'SimSun', serif;
  --font-body: 'Noto Sans SC', 'Source Han Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-mono: 'Inter', 'SF Mono', 'Consolas', monospace;

  /* Spacing scale */
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
  --space-2xl: 48px;
  --space-3xl: 64px;
  --space-4xl: 80px;
  --space-5xl: 120px;

  /* Container */
  --container-max: 1200px;
  --container-narrow: 960px;
  --container-padding: var(--space-lg);

  /* Border radius */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.12);
  --shadow-xl: 0 20px 60px rgba(0, 0, 0, 0.15);

  /* Transitions */
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);

  /* Navigation */
  --nav-height: 72px;
  --nav-height-scrolled: 64px;
}

/* --------------------------------------------------
   Reset & Base
   -------------------------------------------------- */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  font-size: 16px;
}

body {
  font-family: var(--font-body);
  font-weight: 400;
  font-size: 1rem;
  line-height: 1.75;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-fast);
}

ul, ol {
  list-style: none;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
  font-size: inherit;
}

input, textarea, select {
  font-family: inherit;
  font-size: inherit;
}

/* --------------------------------------------------
   Typography
   -------------------------------------------------- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.3;
  color: var(--color-text);
}

h1 { font-size: clamp(2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.5rem, 4vw, 2.5rem); }
h3 { font-size: clamp(1.125rem, 3vw, 1.5rem); }
h4 { font-size: 1.125rem; }

.section-label {
  display: inline-block;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: var(--space-md);
  position: relative;
}

.section-label::after {
  content: '';
  display: block;
  width: 40px;
  height: 3px;
  background: var(--color-accent);
  margin: var(--space-sm) auto 0;
  border-radius: 2px;
}

.section-title {
  margin-bottom: var(--space-md);
}

.section-subtitle {
  font-size: 1.1rem;
  color: var(--color-text-secondary);
  max-width: 600px;
  line-height: 1.8;
}

.text-center { text-align: center; }
.text-muted { color: var(--color-text-secondary); }

/* --------------------------------------------------
   Container & Section Layout
   -------------------------------------------------- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

.container--narrow {
  max-width: var(--container-narrow);
}

.section {
  padding: var(--space-5xl) 0;
  position: relative;
}

.section--alt {
  background-color: var(--color-bg-alt);
}

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

.section--primary .section-title,
.section--primary h2,
.section--primary h3 {
  color: var(--color-white);
}

.section--primary .text-muted {
  color: rgba(255, 255, 255, 0.7);
}

.section-header {
  text-align: center;
  margin-bottom: var(--space-4xl);
}

.section-header .section-subtitle {
  margin: 0 auto;
}

/* --------------------------------------------------
   Navigation Bar
   -------------------------------------------------- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--nav-height);
  display: flex;
  align-items: center;
  transition:
    background var(--transition-base),
    box-shadow var(--transition-base),
    height var(--transition-base);
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.nav--scrolled {
  background: rgba(255, 255, 255, 0.97);
  box-shadow: var(--shadow-sm);
  height: var(--nav-height-scrolled);
}

.nav--home-top {
  background: rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.nav--home-top .nav__link {
  color: var(--color-white);
}

.nav--home-top .nav__link:hover {
  color: var(--color-accent);
}

.nav--home-top .nav__logo {
  color: var(--color-white);
  border-color: rgba(255, 255, 255, 0.3);
  background: rgba(255, 255, 255, 0.1);
}

.nav--home-top .nav__logo:hover {
  border-color: var(--color-accent);
  background: rgba(255, 255, 255, 0.2);
}

.nav--home-top .nav__logo-img {
  border-color: var(--color-accent);
}

.nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-padding);
  height: 100%;
}

.nav__logo {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--color-primary);
  padding: 6px 14px 6px 6px;
  border: 2px solid rgba(30, 58, 95, 0.15);
  border-radius: 50px;
  background: rgba(255, 255, 255, 0.6);
  transition: border-color var(--transition-fast), background var(--transition-fast);
}

.nav__logo:hover {
  border-color: var(--color-primary);
  background: rgba(255, 255, 255, 0.9);
}

.nav__logo-img {
  height: 36px;
  width: 36px;
  display: block;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid var(--color-accent);
  flex-shrink: 0;
}

.nav__logo-text {
  white-space: nowrap;
}

.nav__links {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
}

.nav__link {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--color-text);
  position: relative;
  padding: var(--space-xs) 0;
  transition: color var(--transition-fast);
}

.nav__link:hover {
  color: var(--color-primary);
}

.nav__link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-accent);
  border-radius: 1px;
  transition: width var(--transition-base);
}

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

.nav__link--active {
  color: var(--color-primary);
  font-weight: 600;
}

.nav__cta {
  display: inline-flex;
  align-items: center;
  padding: 8px 20px;
  background: var(--color-cta);
  color: var(--color-white);
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  transition: background var(--transition-fast), transform var(--transition-fast);
}

.nav__cta:hover {
  background: var(--color-cta-hover);
  transform: translateY(-1px);
  color: var(--color-white);
}

/* Mobile menu toggle */
.nav__toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 8px;
  z-index: 1001;
}

.nav__toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

.nav--home-top .nav__toggle span {
  background: var(--color-white);
}

/* --------------------------------------------------
   Footer
   -------------------------------------------------- */
.footer {
  background: var(--color-primary-dark);
  color: rgba(255, 255, 255, 0.85);
  padding: var(--space-4xl) 0 var(--space-xl);
}

.footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-2xl);
  margin-bottom: var(--space-3xl);
}

.footer__brand-name {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-white);
  margin-bottom: var(--space-md);
}

.footer__brand-desc {
  font-size: 0.9rem;
  line-height: 1.8;
  margin-bottom: var(--space-lg);
  color: rgba(255, 255, 255, 0.65);
}

.footer__heading {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-white);
  margin-bottom: var(--space-lg);
  letter-spacing: 0.05em;
}

.footer__links li {
  margin-bottom: var(--space-sm);
}

.footer__links a {
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.65);
  transition: color var(--transition-fast);
}

.footer__links a:hover {
  color: var(--color-accent);
}

.footer__contact-item {
  display: flex;
  align-items: flex-start;
  gap: var(--space-sm);
  margin-bottom: var(--space-md);
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.65);
}

.footer__contact-item svg {
  flex-shrink: 0;
  margin-top: 4px;
  color: var(--color-accent);
}

.footer__bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: var(--space-lg);
  text-align: center;
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.45);
}

/* --------------------------------------------------
   Buttons
   -------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: 12px 28px;
  font-size: 0.9375rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  transition:
    background var(--transition-fast),
    color var(--transition-fast),
    transform var(--transition-fast),
    box-shadow var(--transition-fast);
  white-space: nowrap;
}

.btn:hover {
  transform: translateY(-2px);
}

.btn--primary {
  background: var(--color-cta);
  color: var(--color-white);
}

.btn--primary:hover {
  background: var(--color-cta-hover);
  box-shadow: 0 6px 20px rgba(232, 116, 42, 0.35);
  color: var(--color-white);
}

.btn--secondary {
  background: var(--color-white);
  color: var(--color-primary);
  border: 2px solid var(--color-white);
}

.btn--secondary:hover {
  background: transparent;
  color: var(--color-white);
}

.btn--outline {
  background: transparent;
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
}

.btn--outline:hover {
  background: var(--color-primary);
  color: var(--color-white);
}

.btn--outline-light {
  background: transparent;
  color: var(--color-white);
  border: 2px solid rgba(255, 255, 255, 0.3);
}

.btn--outline-light:hover {
  border-color: var(--color-white);
  background: rgba(255, 255, 255, 0.1);
  color: var(--color-white);
}

.btn--lg {
  padding: 16px 36px;
  font-size: 1.05rem;
}

.btn--sm {
  padding: 8px 18px;
  font-size: 0.85rem;
}

/* --------------------------------------------------
   Cards
   -------------------------------------------------- */
.card {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition:
    transform var(--transition-base),
    box-shadow var(--transition-base);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.card__image {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  background: var(--color-bg-alt);
}

.card__body {
  padding: var(--space-lg);
}

.card__title {
  font-size: 1.25rem;
  margin-bottom: var(--space-sm);
}

.card__text {
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  line-height: 1.7;
}

/* --------------------------------------------------
   Hero Section
   -------------------------------------------------- */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  color: var(--color-white);
  overflow: hidden;
  background: var(--color-primary);
}

.hero__bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.55;
}

.hero__overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    180deg,
    rgba(21, 42, 69, 0.7) 0%,
    rgba(30, 58, 95, 0.6) 50%,
    rgba(21, 42, 69, 0.8) 100%
  );
}

.hero__content {
  position: relative;
  z-index: 1;
  max-width: 900px;
  padding: 0 var(--container-padding);
}

.hero__overline {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-accent);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  margin-bottom: var(--space-lg);
}

.hero__slogan {
  font-family: var(--font-heading);
  font-size: clamp(2.25rem, 6vw, 4rem);
  font-weight: 700;
  line-height: 1.25;
  margin-bottom: var(--space-lg);
  letter-spacing: 0.02em;
  color: var(--color-white);
}

.hero__highlight {
  color: var(--color-accent);
}

.hero__divider {
  width: 60px;
  height: 3px;
  background: var(--color-accent);
  border-radius: 2px;
  margin: 0 auto var(--space-xl);
}

.hero__sub {
  font-size: 1.05rem;
  color: rgba(255, 255, 255, 0.8);
  margin-bottom: var(--space-2xl);
  line-height: 1.8;
}

.hero__actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-md);
  flex-wrap: wrap;
}

/* --------------------------------------------------
   Scroll Animation
   -------------------------------------------------- */
.fade-up {
  opacity: 0;
  transform: translateY(30px);
  transition:
    opacity var(--transition-slow),
    transform var(--transition-slow);
}

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

/* Stagger children animation delay */
.stagger > * {
  opacity: 0;
  transform: translateY(20px);
  transition:
    opacity 0.5s cubic-bezier(0.4, 0, 0.2, 1),
    transform 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

.stagger.is-visible > *:nth-child(1) { transition-delay: 0.00s; opacity: 1; transform: translateY(0); }
.stagger.is-visible > *:nth-child(2) { transition-delay: 0.06s; opacity: 1; transform: translateY(0); }
.stagger.is-visible > *:nth-child(3) { transition-delay: 0.12s; opacity: 1; transform: translateY(0); }
.stagger.is-visible > *:nth-child(4) { transition-delay: 0.18s; opacity: 1; transform: translateY(0); }
.stagger.is-visible > *:nth-child(5) { transition-delay: 0.24s; opacity: 1; transform: translateY(0); }
.stagger.is-visible > *:nth-child(6) { transition-delay: 0.30s; opacity: 1; transform: translateY(0); }
.stagger.is-visible > *:nth-child(7) { transition-delay: 0.36s; opacity: 1; transform: translateY(0); }
.stagger.is-visible > *:nth-child(8) { transition-delay: 0.42s; opacity: 1; transform: translateY(0); }
.stagger.is-visible > *:nth-child(9) { transition-delay: 0.48s; opacity: 1; transform: translateY(0); }
.stagger.is-visible > *:nth-child(10) { transition-delay: 0.54s; opacity: 1; transform: translateY(0); }
.stagger.is-visible > *:nth-child(11) { transition-delay: 0.60s; opacity: 1; transform: translateY(0); }
.stagger.is-visible > *:nth-child(12) { transition-delay: 0.66s; opacity: 1; transform: translateY(0); }
.stagger.is-visible > *:nth-child(13) { transition-delay: 0.72s; opacity: 1; transform: translateY(0); }
.stagger.is-visible > *:nth-child(14) { transition-delay: 0.78s; opacity: 1; transform: translateY(0); }
.stagger.is-visible > *:nth-child(15) { transition-delay: 0.84s; opacity: 1; transform: translateY(0); }

/* --------------------------------------------------
   Home: Intro Stats
   -------------------------------------------------- */
.intro-stats {
  display: flex;
  justify-content: center;
  gap: var(--space-3xl);
  flex-wrap: wrap;
  margin-top: var(--space-2xl);
}

.intro-stat {
  text-align: center;
}

.intro-stat__number {
  font-family: var(--font-heading);
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1.2;
}

.intro-stat__label {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  margin-top: var(--space-xs);
}

/* --------------------------------------------------
   Home: Course Cards
   -------------------------------------------------- */
.course-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-xl);
  max-width: 1100px;
  margin: 0 auto;
}

.course-card {
  background: var(--color-white);
  border-radius: var(--radius-lg);
  padding: var(--space-2xl);
  text-align: center;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--color-border-light);
  transition:
    transform var(--transition-base),
    box-shadow var(--transition-base);
  position: relative;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.course-card .btn {
  margin-top: auto;
}

.course-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
}

.course-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
}

.course-card--elite::before {
  background: var(--color-primary);
}

.course-card--fast::before {
  background: var(--color-primary);
}

.course-card--full::before {
  background: var(--color-accent);
}

.course-card__icon {
  width: 64px;
  height: 64px;
  margin: 0 auto var(--space-lg);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.75rem;
}

.course-card--elite .course-card__icon {
  background: rgba(30, 58, 95, 0.08);
  color: var(--color-primary);
}

.course-card--fast .course-card__icon {
  background: rgba(30, 58, 95, 0.08);
  color: var(--color-primary);
}

.course-card--full .course-card__icon {
  background: rgba(212, 168, 83, 0.12);
  color: var(--color-accent);
}

.course-card__title {
  font-size: 1.5rem;
  margin-bottom: var(--space-sm);
}

.course-card__subtitle {
  font-size: 0.95rem;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-lg);
  line-height: 1.6;
}

.course-card__features {
  text-align: left;
  margin-bottom: var(--space-xl);
}

.course-card__features li {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  padding: 6px 0;
  padding-left: 24px;
  position: relative;
}

.course-card__features li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 14px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-accent);
}

/* --------------------------------------------------
   Learning Path
   -------------------------------------------------- */
.learning-path {
  display: flex;
  align-items: stretch;
  justify-content: center;
  gap: var(--space-xl);
  flex-wrap: wrap;
}

.learning-path__step {
  flex: 1;
  min-width: 200px;
  max-width: 240px;
  text-align: center;
  position: relative;
  padding: var(--space-xl) var(--space-lg);
  background: var(--color-white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  transition:
    transform var(--transition-base),
    box-shadow var(--transition-base);
  display: flex;
  flex-direction: column;
}

.learning-path__step-desc {
  flex: 1;
}

.learning-path__step:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.learning-path__step:not(:last-child)::after {
  content: '→';
  position: absolute;
  right: -28px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 1.5rem;
  color: var(--color-accent);
  font-weight: 700;
}

.learning-path__step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--color-primary);
  color: var(--color-white);
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: var(--space-md);
}

.learning-path__step-title {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: var(--space-xs);
}

.learning-path__step-desc {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

.learning-path__step-duration {
  display: inline-block;
  margin-top: var(--space-sm);
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-cta);
  background: rgba(232, 116, 42, 0.08);
  padding: 2px 12px;
  border-radius: 20px;
}

/* --------------------------------------------------
   Advantages Grid
   -------------------------------------------------- */
.advantages {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-lg);
}

.advantage-item {
  display: flex;
  gap: var(--space-md);
  padding: var(--space-lg);
  background: var(--color-white);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  transition:
    transform var(--transition-base),
    box-shadow var(--transition-base);
}

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

.advantage-item__icon {
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  background: rgba(30, 58, 95, 0.06);
  color: var(--color-primary);
}

.advantage-item__title {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.advantage-item__desc {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* --------------------------------------------------
   Teachers Preview Grid
   -------------------------------------------------- */
.teachers-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-lg);
}

.teacher-card {
  text-align: center;
  padding: var(--space-xl) var(--space-lg);
  background: var(--color-white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  transition:
    transform var(--transition-base),
    box-shadow var(--transition-base);
}

.teacher-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.teacher-card__avatar {
  width: 100px;
  height: 100px;
  border-radius: 50%;
  background: var(--color-bg-alt);
  margin: 0 auto var(--space-md);
  overflow: hidden;
  border: 3px solid var(--color-border-light);
}

.teacher-card__avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.teacher-card__avatar-placeholder {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.5rem;
  color: var(--color-primary);
  background: linear-gradient(135deg, rgba(30,58,95,0.06), rgba(212,168,83,0.1));
}

.teacher-card__name {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.teacher-card__role {
  font-size: 0.85rem;
  color: var(--color-accent);
  font-weight: 500;
  margin-bottom: var(--space-sm);
}

.teacher-card__exp {
  font-size: 0.8rem;
  color: var(--color-text-light);
}

/* --------------------------------------------------
   Environment Preview
   -------------------------------------------------- */
.env-preview {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-xl);
}

.env-preview__card {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  aspect-ratio: 4 / 3;
  cursor: pointer;
}

.env-preview__card img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  background: var(--color-bg-alt);
  transition: transform var(--transition-slow);
}

.env-preview__card:hover img {
  transform: scale(1.05);
}

.env-preview__label {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: var(--space-lg);
  background: linear-gradient(transparent, rgba(0, 0, 0, 0.7));
  color: var(--color-white);
  font-weight: 600;
  font-size: 1.1rem;
}

/* --------------------------------------------------
   CTA Banner
   -------------------------------------------------- */
.cta-banner {
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
  color: var(--color-white);
  text-align: center;
  padding: var(--space-4xl) 0;
}

.cta-banner__title {
  font-family: var(--font-heading);
  font-size: clamp(1.5rem, 4vw, 2.25rem);
  font-weight: 700;
  color: var(--color-white);
  margin-bottom: var(--space-md);
}

.cta-banner__sub {
  font-size: 1.1rem;
  color: rgba(255, 255, 255, 0.8);
  margin-bottom: var(--space-xl);
}

.cta-banner__actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-md);
  flex-wrap: wrap;
}

.cta-banner__phone {
  font-family: var(--font-mono);
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--color-accent-light);
  letter-spacing: 0.05em;
}

.cta-banner--inline {
  text-align: center;
  margin-top: var(--space-3xl);
  padding: var(--space-3xl);
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
  border-radius: var(--radius-xl);
}

/* --------------------------------------------------
   Page Hero (Sub Pages)
   -------------------------------------------------- */
.page-hero {
  position: relative;
  padding: calc(var(--nav-height) + var(--space-4xl)) 0 var(--space-4xl);
  background: var(--color-primary);
  color: var(--color-white);
  text-align: center;
  overflow: hidden;
}

.page-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse at 30% 50%, rgba(212,168,83,0.15) 0%, transparent 60%),
    radial-gradient(ellipse at 70% 20%, rgba(30,58,95,0.3) 0%, transparent 60%);
}

.page-hero__title {
  font-family: var(--font-heading);
  font-size: clamp(1.75rem, 4vw, 2.75rem);
  font-weight: 700;
  color: var(--color-white);
  margin-bottom: var(--space-md);
  position: relative;
}

.page-hero__sub {
  font-size: 1.1rem;
  color: rgba(255, 255, 255, 0.8);
  max-width: 600px;
  margin: 0 auto;
  position: relative;
}

/* --------------------------------------------------
   Courses: Comparison Table
   -------------------------------------------------- */
.compare-table-wrap {
  overflow-x: auto;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}

.compare-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--color-white);
  font-size: 0.9375rem;
}

.compare-table thead th {
  background: var(--color-primary);
  color: var(--color-white);
  padding: var(--space-lg);
  font-weight: 600;
  text-align: center;
}

.compare-table thead th:first-child {
  text-align: left;
  background: var(--color-primary-dark);
}

.compare-table tbody td {
  padding: var(--space-md) var(--space-lg);
  text-align: center;
  border-bottom: 1px solid var(--color-border-light);
}

.compare-table tbody td:first-child {
  text-align: left;
  font-weight: 500;
  color: var(--color-text-secondary);
}

.compare-table tbody tr:nth-child(even) td {
  background: var(--color-bg);
}

.compare-table .check {
  color: var(--color-success);
  font-weight: 700;
}

/* --------------------------------------------------
   Courses: Learning Timeline
   -------------------------------------------------- */
.timeline {
  position: relative;
  padding-left: 0;
}

.timeline__item {
  display: flex;
  gap: var(--space-xl);
  margin-bottom: var(--space-2xl);
  position: relative;
}

.timeline__marker {
  flex-shrink: 0;
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: var(--color-primary);
  color: var(--color-white);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.25rem;
  position: relative;
  z-index: 1;
}

.timeline__item:not(:last-child) .timeline__marker::after {
  content: '';
  position: absolute;
  top: 56px;
  left: 50%;
  transform: translateX(-50%);
  width: 2px;
  height: calc(100% + var(--space-2xl) - 56px);
  background: linear-gradient(to bottom, var(--color-accent), var(--color-border));
}

.timeline__content {
  flex: 1;
  background: var(--color-white);
  border-radius: var(--radius-md);
  padding: var(--space-lg) var(--space-xl);
  box-shadow: var(--shadow-sm);
  border-left: 4px solid var(--color-accent);
}

.timeline__content h4 {
  margin-bottom: var(--space-xs);
  font-size: 1.1rem;
}

.timeline__duration {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-cta);
  background: rgba(232, 116, 42, 0.08);
  padding: 2px 12px;
  border-radius: 20px;
  margin-bottom: var(--space-sm);
}

.timeline__content ul {
  list-style: disc;
  padding-left: 20px;
  font-size: 0.9rem;
  color: var(--color-text-secondary);
}

.timeline__content ul li {
  margin-bottom: 4px;
}

/* --------------------------------------------------
   Software Grid
   -------------------------------------------------- */
.software-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: var(--space-lg);
  text-align: center;
}

.software-item {
  padding: var(--space-lg);
  background: var(--color-white);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-base);
}

.software-item:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

.software-item__icon {
  width: 64px;
  height: 64px;
  margin: 0 auto var(--space-md);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-primary);
  background: rgba(30, 58, 95, 0.06);
}

.software-item__name {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.software-item__use {
  font-size: 0.8rem;
  color: var(--color-text-light);
}

/* --------------------------------------------------
   FAQ
   -------------------------------------------------- */
.faq-list {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  background: var(--color-white);
  border-radius: var(--radius-md);
  margin-bottom: var(--space-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.faq-item__question {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-lg) var(--space-xl);
  font-size: 1rem;
  font-weight: 600;
  text-align: left;
  color: var(--color-text);
  transition: background var(--transition-fast);
}

.faq-item__question:hover {
  background: var(--color-bg);
}

.faq-item__question svg {
  flex-shrink: 0;
  transition: transform var(--transition-fast);
}

.faq-item.is-open .faq-item__question svg {
  transform: rotate(45deg);
}

.faq-item__answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-base), padding var(--transition-base);
}

.faq-item.is-open .faq-item__answer {
  max-height: 300px;
}

.faq-item__answer-inner {
  padding: 0 var(--space-xl) var(--space-xl);
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  line-height: 1.8;
}

/* --------------------------------------------------
   Contact Page
   -------------------------------------------------- */
.contact-layout {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: var(--space-2xl);
}

.contact-form {
  background: var(--color-white);
  padding: var(--space-2xl);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}

.form-group {
  margin-bottom: var(--space-lg);
}

.form-group label {
  display: block;
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: var(--space-xs);
  color: var(--color-text);
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 12px 16px;
  border: 2px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: 0.9375rem;
  color: var(--color-text);
  background: var(--color-bg);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
  outline: none;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(30, 58, 95, 0.1);
}

.form-group textarea {
  min-height: 120px;
  resize: vertical;
}

.form-submit {
  width: 100%;
  padding: 14px;
  font-size: 1rem;
  font-weight: 600;
}

.contact-info-cards {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.contact-info-card {
  background: var(--color-white);
  padding: var(--space-lg);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  display: flex;
  gap: var(--space-md);
  align-items: flex-start;
}

.contact-info-card__icon {
  flex-shrink: 0;
  width: 44px;
  height: 44px;
  border-radius: var(--radius-sm);
  background: rgba(30, 58, 95, 0.06);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-primary);
}

.contact-info-card__label {
  font-size: 0.8rem;
  color: var(--color-text-light);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 4px;
}

.contact-info-card__value {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--color-text);
}

.contact-map {
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  margin-top: var(--space-2xl);
}

.contact-map img {
  width: 100%;
  aspect-ratio: 16 / 7;
  object-fit: cover;
  background: var(--color-bg-alt);
}

/* --------------------------------------------------
   Works Gallery
   -------------------------------------------------- */
.works-filters {
  display: flex;
  justify-content: center;
  gap: var(--space-sm);
  margin-bottom: var(--space-2xl);
  flex-wrap: wrap;
}

.works-filter {
  padding: 8px 24px;
  font-size: 0.9rem;
  font-weight: 500;
  border-radius: 50px;
  color: var(--color-text-secondary);
  background: var(--color-white);
  border: 2px solid var(--color-border);
  transition: all var(--transition-fast);
}

.works-filter:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.works-filter--active {
  background: var(--color-primary);
  color: var(--color-white);
  border-color: var(--color-primary);
}

.works-gallery {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-md);
}

.works-item {
  position: relative;
  border-radius: var(--radius-sm);
  overflow: hidden;
  cursor: pointer;
  aspect-ratio: 4 / 3;
  border: 3px solid var(--color-border-light);
  transition: border-color var(--transition-fast), transform var(--transition-base), box-shadow var(--transition-base);
}

.works-item:hover {
  border-color: var(--color-accent);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.works-item__img {
  width: 100%;
  height: 100%;
  display: block;
  object-fit: cover;
  object-position: center 80%;
  background: var(--color-bg-alt);
}

/* Pagination */
.works-pagination {
  display: flex;
  justify-content: center;
  gap: var(--space-sm);
  margin-top: var(--space-xl);
}

.works-pagination__btn {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  background: var(--color-white);
  border: 2px solid var(--color-border);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.works-pagination__btn:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.works-pagination__btn--active {
  background: var(--color-primary);
  color: var(--color-white);
  border-color: var(--color-primary);
}

.works-item__img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  background: var(--color-bg-alt);
  transition: transform var(--transition-slow);
}

.works-item:hover .works-item__img {
  transform: scale(1.05);
}

.works-item__overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(transparent 50%, rgba(0,0,0,0.7));
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  padding: var(--space-lg);
  opacity: 0;
  transition: opacity var(--transition-base);
}

.works-item:hover .works-item__overlay {
  opacity: 1;
}

.works-item__name {
  color: var(--color-white);
  font-weight: 600;
  font-size: 0.95rem;
}

.works-item__meta {
  color: rgba(255,255,255,0.75);
  font-size: 0.8rem;
  margin-top: 4px;
}

/* --------------------------------------------------
   Lightbox
   -------------------------------------------------- */
.lightbox {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.92);
  z-index: 2000;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-base);
}

.lightbox.is-open {
  opacity: 1;
  pointer-events: auto;
}

.lightbox__close {
  position: absolute;
  top: 24px;
  right: 24px;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: rgba(255,255,255,0.15);
  color: var(--color-white);
  font-size: 1.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background var(--transition-fast);
}

.lightbox__close:hover {
  background: rgba(255,255,255,0.3);
}

.lightbox__img {
  max-width: 90vw;
  max-height: 85vh;
  border-radius: var(--radius-sm);
  object-fit: contain;
}

.lightbox__caption {
  position: absolute;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  color: rgba(255,255,255,0.85);
  font-size: 0.95rem;
  text-align: center;
  background: rgba(0,0,0,0.5);
  padding: 8px 24px;
  border-radius: 50px;
}

/* --------------------------------------------------
   404 / Empty State
   -------------------------------------------------- */
.empty-state {
  text-align: center;
  padding: var(--space-4xl) 0;
  color: var(--color-text-secondary);
}

/* --------------------------------------------------
   Responsive: Tablet (<=1024px)
   -------------------------------------------------- */
@media (max-width: 1024px) {
  :root {
    --nav-height: 64px;
    --nav-height-scrolled: 56px;
  }

  .section {
    padding: var(--space-3xl) 0;
  }

  .section-header {
    margin-bottom: var(--space-2xl);
  }

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

  .course-cards {
    grid-template-columns: 1fr;
    max-width: 500px;
  }

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

  .env-preview {
    grid-template-columns: 1fr;
  }

  .contact-layout {
    grid-template-columns: 1fr;
  }

  .learning-path__step:not(:last-child)::after {
    display: none;
  }
}

/* --------------------------------------------------
   Responsive: Mobile (<=768px)
   -------------------------------------------------- */
@media (max-width: 768px) {
  :root {
    --nav-height: 60px;
    --nav-height-scrolled: 52px;
    --container-padding: var(--space-md);
  }

  .section {
    padding: var(--space-2xl) 0;
  }

  .section-header {
    margin-bottom: var(--space-xl);
  }

  /* Mobile nav */
  .nav__links {
    position: fixed;
    top: 0;
    right: -100%;
    width: 300px;
    height: 100vh;
    flex-direction: column;
    align-items: stretch;
    padding: 0;
    background: var(--color-bg);
    box-shadow: var(--shadow-xl);
    gap: 0;
    transition: right var(--transition-base);
    z-index: 1000;
    overflow-y: auto;
  }

  .nav__links.is-open {
    right: 0;
  }

  /* 顶部主题色装饰条 */
  .nav__links::before {
    content: '';
    display: block;
    height: 6px;
    flex-shrink: 0;
    background: linear-gradient(90deg, var(--color-primary), var(--color-primary-light), var(--color-accent));
  }

  /* 菜单内链接 — 全宽卡片式 */
  .nav__links .nav__link {
    display: flex;
    align-items: center;
    font-size: 1rem;
    font-weight: 500;
    color: var(--color-text);
    padding: 16px var(--space-xl);
    background: var(--color-white);
    border-bottom: 1px solid var(--color-border-light);
    transition: background var(--transition-fast), color var(--transition-fast);
    position: relative;
  }

  /* 右箭头 */
  .nav__links .nav__link::after {
    content: '\203A';
    position: absolute;
    right: var(--space-xl);
    top: 50%;
    transform: translateY(-50%);
    font-size: 1.5rem;
    font-weight: 300;
    color: var(--color-text-light);
    width: auto;
    height: auto;
    background: none;
    bottom: auto;
    left: auto;
    transition: color var(--transition-fast), transform var(--transition-fast);
  }

  .nav__links .nav__link:hover,
  .nav__links .nav__link:active {
    background: rgba(30, 58, 95, 0.04);
    color: var(--color-primary);
  }

  .nav__links .nav__link:hover::after {
    color: var(--color-primary);
    transform: translateY(-50%) translateX(3px);
  }

  /* 当前页高亮 */
  .nav__links .nav__link--active {
    color: var(--color-primary);
    font-weight: 600;
    background: linear-gradient(90deg, rgba(30,58,95,0.06), rgba(30,58,95,0.01));
    border-left: 3px solid var(--color-accent);
  }

  .nav__links .nav__link--active::after {
    color: var(--color-accent);
  }

  .nav__toggle {
    display: flex;
    transition: opacity var(--transition-fast), visibility var(--transition-fast);
  }

  /* 菜单打开后隐藏汉堡图标 */
  .nav__links.is-open ~ .nav__toggle {
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
  }

  /* 遮罩层带主题色 */
  .nav__overlay {
    background: rgba(21, 42, 69, 0.5);
  }

  .nav__cta {
    margin-top: var(--space-md);
    width: 100%;
    justify-content: center;
  }

  .hero__actions {
    flex-direction: column;
    gap: var(--space-sm);
  }

  .hero__actions .btn {
    width: 100%;
  }

  .intro-stats {
    gap: var(--space-xl);
  }

  .intro-stat__number {
    font-size: 2rem;
  }

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

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

  .works-gallery {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-sm);
  }

  /* 教学环境 — 手机端文字在上图片在下 */
  .env-row {
    grid-template-columns: 1fr !important;
    gap: var(--space-lg) !important;
  }

  .scene-gallery {
    grid-template-columns: 1fr !important;
    gap: var(--space-md) !important;
  }

  .learning-path {
    flex-direction: column;
    align-items: center;
  }

  .learning-path__step {
    max-width: 100%;
  }

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

  .cta-banner__actions {
    flex-direction: column;
  }

  .cta-banner__actions .btn {
    width: 100%;
  }
}

/* --------------------------------------------------
   Utility Classes
   -------------------------------------------------- */
.text-center { text-align: center; }
.mt-sm { margin-top: var(--space-sm); }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mt-xl { margin-top: var(--space-xl); }
.mt-2xl { margin-top: var(--space-2xl); }
.mt-3xl { margin-top: var(--space-3xl); }
.mb-md { margin-bottom: var(--space-md); }
.mb-lg { margin-bottom: var(--space-lg); }
.mb-xl { margin-bottom: var(--space-xl); }
.mb-2xl { margin-bottom: var(--space-2xl); }

.hidden {
  display: none !important;
}

/* Mobile menu overlay */
.nav__overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  z-index: 999;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-base);
}

.nav__overlay.is-open {
  opacity: 1;
  pointer-events: auto;
}