/* ==========================================================================
   Athabasca University Theme — 严格对齐 athabascau.ca 真实设计
   2026-10-12 v1

   真实设计系统 (从 athabascau.ca 提取):
   - 主色: black   #000 (主条, nav)
   - 强调: orange  #FF6B1A (Apply / Get started CTA)
   - 文字: dark grey #232323 on white
   - 字体: sans-serif (Athabasca 用 web font "Druk" 风格 + system sans)
   - 风格: 现代 clean, 大图 hero, 大字标题, 4 圆形功能卡
   ========================================================================== */

:root {
  --au-orange:        #FF6B1A;
  --au-orange-dark:   #e85a0a;
  --au-black:         #000000;
  --au-ink:           #232323;
  --au-grey-50:       #f7f7f7;
  --au-grey-100:      #ebebeb;
  --au-grey-200:      #c7c7c7;
  --au-grey-700:       #555;
  --au-white:         #ffffff;
  --au-blue:          #005CFA; /* link blue */

  --au-font-body:     "Inter", "Helvetica Neue", -apple-system, "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --au-font-heading:  var(--au-font-body);

  --au-s-xxs: .25rem; --au-s-xs: .5rem;  --au-s-s:  1rem;
  --au-s-m:  1.5rem; --au-s-l:  2rem;   --au-s-xl: 2.5rem;
  --au-s-xxl: 3rem;  --au-s-xxxl: 4rem;  --au-s-xxxxl: 5rem;

  --au-radius:        4px;
  --au-radius-pill:   999px;
  --au-t:             200ms ease;
  --au-container:     1280px;
}

*, *::before, *::after { box-sizing: border-box; }

body {
  margin: 0;
  font-family: var(--au-font-body);
  font-size: 16px;
  line-height: 1.6;
  color: var(--au-ink);
  background: var(--au-white);
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
a { color: var(--au-blue); text-decoration: none; transition: color var(--au-t); }
a:hover { color: var(--au-orange); text-decoration: underline; }

h1, h2, h3, h4, h5, h6 {
  margin: 0 0 var(--au-s-s);
  font-family: var(--au-font-heading);
  font-weight: 700;
  line-height: 1.2;
  color: var(--au-black);
}
h1 { font-size: clamp(2.25rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.75rem, 3vw, 2.5rem); }
h3 { font-size: 1.375rem; }
p { margin: 0 0 var(--au-s-s); }


/* ===== Site Header (AU 真实: 白色 utility + 黑色主条 + 橙色 Apply) ===== */
.site-header {
  background: var(--au-white);
  position: sticky;
  top: 0;
  z-index: 50;
}
.site-header__utility {
  background: var(--au-white);
  border-bottom: 1px solid var(--au-grey-100);
  font-size: 0.8125rem;
}
.site-header__utility-inner {
  max-width: var(--au-container);
  margin: 0 auto;
  padding: 0.4rem var(--au-s-s);
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: var(--au-s-m);
  flex-wrap: wrap;
}
.site-header__utility a {
  color: var(--au-grey-700);
  text-decoration: none;
}
.site-header__utility a:hover { color: var(--au-orange); }
.site-header__main {
  background: var(--au-black);
}
.site-header__main-inner {
  max-width: var(--au-container);
  margin: 0 auto;
  padding: 0 var(--au-s-s);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--au-s-s);
  flex-wrap: wrap;
}
.site-brand {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none;
  color: var(--au-white);
  padding: 0.75rem 0;
}
.site-brand__icon {
  width: 36px; height: 36px;
  background: var(--au-orange);
  border-radius: 50%;
  display: inline-flex; align-items: center; justify-content: center;
  color: var(--au-white);
  font-size: 1.125rem;
  font-weight: 700;
  flex-shrink: 0;
}
.site-brand__text {
  font-family: var(--au-font-heading);
  font-size: 1rem;
  font-weight: 700;
  color: var(--au-white);
  line-height: 1.1;
}
.site-brand__text small {
  display: block;
  font-size: 0.625rem;
  font-weight: 500;
  opacity: 0.7;
  text-transform: uppercase;
  letter-spacing: 0.1em;
}
.site-header__nav {
  display: flex;
  align-items: center;
  gap: 0.125rem;
}
.site-header__nav-item {
  padding: 0.75rem 0.875rem;
  color: var(--au-white) !important;
  text-decoration: none;
  font-weight: 500;
  font-size: 0.9375rem;
  border-radius: var(--au-radius);
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
}
.site-header__nav-item:hover {
  background: rgba(255,255,255,0.1);
  color: var(--au-white) !important;
  text-decoration: none;
}
.site-header__nav-item::after { content: "▾"; font-size: 0.7em; opacity: 0.5; }
.site-header__actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}
.site-header__action-help {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px; height: 36px;
  background: rgba(255,255,255,0.1);
  color: var(--au-white);
  border-radius: 50%;
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 700;
}
.site-header__action-apply {
  background: var(--au-orange);
  color: var(--au-white);
  padding: 0.5rem 1.25rem;
  border-radius: var(--au-radius);
  text-decoration: none;
  font-weight: 700;
  font-size: 0.875rem;
  border: 1.5px solid var(--au-orange);
}
.site-header__action-apply:hover { background: var(--au-orange-dark); color: var(--au-white); }
.site-header__action-search {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px; height: 36px;
  color: var(--au-white);
  border-radius: 50%;
  text-decoration: none;
  font-size: 1rem;
  background: var(--au-orange);
}
.site-header__action-search:hover { background: var(--au-orange-dark); }


/* ===== Hero (AU 真实: 全屏实景 + 暗蒙版 + 大字 + 橙色 CTA) ===== */
.home-hero {
  position: relative;
  min-height: 540px;
  background: var(--au-black);
  overflow: hidden;
}
.home-hero__image {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  z-index: 0;
}
.home-hero__overlay {
  position: relative;
  z-index: 2;
  background: linear-gradient(90deg, rgba(0,0,0,0.6) 0%, rgba(0,0,0,0.3) 60%, transparent 100%);
  color: var(--au-white);
  padding: var(--au-s-xxxxl) var(--au-s-s);
  min-height: 540px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: flex-start;
  max-width: var(--au-container);
  margin: 0 auto;
}
.home-hero__title {
  font-family: var(--au-font-heading);
  font-size: clamp(2.25rem, 5vw, 3.5rem);
  font-weight: 700;
  line-height: 1.1;
  color: var(--au-white);
  margin: 0 0 var(--au-s-s);
  max-width: 28rem;
}
.home-hero__title-mark {
  display: inline-block;
  width: 6px;
  height: 1em;
  background: var(--au-orange);
  vertical-align: middle;
  margin: 0 0.5rem;
}
.home-hero__sub {
  font-size: 1.0625rem;
  color: rgba(255,255,255,0.92);
  margin: 0 0 var(--au-s-l);
  max-width: 32rem;
  line-height: 1.5;
}
.home-hero__actions { display: flex; gap: var(--au-s-s); flex-wrap: wrap; }


/* ===== Buttons (AU 真实: 圆角小, 黑/橙实心) ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.7rem 1.5rem;
  font-family: var(--au-font-body);
  font-size: 0.9375rem;
  font-weight: 700;
  border-radius: var(--au-radius);
  border: 1.5px solid transparent;
  cursor: pointer;
  transition: all var(--au-t);
  text-decoration: none;
  line-height: 1.2;
}
.btn--primary {
  background: var(--au-orange);
  color: var(--au-white);
  border-color: var(--au-orange);
}
.btn--primary:hover { background: var(--au-orange-dark); border-color: var(--au-orange-dark); color: var(--au-white); text-decoration: none; }
.btn--secondary {
  background: var(--au-black);
  color: var(--au-white);
  border-color: var(--au-black);
}
.btn--secondary:hover { background: var(--au-grey-700); border-color: var(--au-grey-700); color: var(--au-white); text-decoration: none; }
.btn--outline {
  background: transparent;
  color: var(--au-black);
  border-color: var(--au-black);
}
.btn--outline:hover { background: var(--au-black); color: var(--au-white); text-decoration: none; }
.btn--white {
  background: var(--au-white);
  color: var(--au-black);
  border-color: var(--au-white);
}
.btn--white:hover { background: var(--au-grey-50); color: var(--au-black); text-decoration: none; }


/* ===== Sections ===== */
.section {
  width: 100%;
  padding: var(--au-s-xxxxl) var(--au-s-s);
}
.section--white { background: var(--au-white); }
.section--grey { background: var(--au-grey-50); }
.section--dark { background: var(--au-black); color: var(--au-white); }
.section--dark h1, .section--dark h2, .section--dark h3 { color: var(--au-white); }
.section__container { max-width: var(--au-container); margin: 0 auto; }
.section__head { margin-bottom: var(--au-s-xl); }
.section__head--center { text-align: center; }
.section__title {
  font-size: clamp(1.5rem, 3vw, 2.25rem);
  font-weight: 700;
  color: var(--au-black);
  margin: 0 0 var(--au-s-s);
}
.section--dark .section__title { color: var(--au-white); }
.section__sub {
  font-size: 1.0625rem;
  color: var(--au-grey-700);
  max-width: 48rem;
  margin: 0;
}
.section--dark .section__sub { color: rgba(255,255,255,0.88); }


/* ===== 4 圆形功能卡 (AU 真实) ===== */
.quick-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--au-s-m);
  max-width: var(--au-container);
  margin: -3rem auto 0;
  padding: 0 var(--au-s-s);
  position: relative;
  z-index: 5;
}
.quick-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  background: var(--au-white);
  padding: var(--au-s-l) var(--au-s-m);
  text-decoration: none;
  color: var(--au-ink);
  border: 1px solid var(--au-grey-100);
  border-radius: var(--au-radius);
  transition: all var(--au-t);
}
.quick-card:hover {
  border-color: var(--au-orange);
  transform: translateY(-4px);
  color: var(--au-ink);
  text-decoration: none;
  box-shadow: 0 4px 12px rgba(255, 107, 26, 0.15);
}
.quick-card__icon {
  width: 56px; height: 56px;
  border: 2px solid var(--au-grey-200);
  border-radius: 50%;
  display: inline-flex; align-items: center; justify-content: center;
  color: var(--au-blue);
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: var(--au-s-s);
}
.quick-card:hover .quick-card__icon { border-color: var(--au-orange); color: var(--au-orange); }
.quick-card__title {
  font-family: var(--au-font-heading);
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--au-blue);
  margin: 0 0 0.5rem;
  text-decoration: underline;
  text-underline-offset: 4px;
}
.quick-card:hover .quick-card__title { color: var(--au-orange); }
.quick-card__body {
  font-size: 0.875rem;
  color: var(--au-grey-700);
  line-height: 1.5;
  margin: 0;
}


/* ===== Stats bar (AU 真实: 浅灰 + 大数字) ===== */
.stats-bar {
  background: var(--au-grey-50);
  padding: var(--au-s-xxl) var(--au-s-s);
}
.stats-bar__inner {
  max-width: var(--au-container);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--au-s-xl);
  align-items: center;
}
.stats-bar__image {
  border-radius: var(--au-radius);
  overflow: hidden;
  max-width: 280px;
  aspect-ratio: 1/1;
}
.stats-bar__image img {
  width: 100%; height: 100%; object-fit: cover;
}
.stats-bar__stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--au-s-l);
}
.stat__num {
  font-family: var(--au-font-heading);
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--au-orange);
  line-height: 1;
  margin: 0 0 0.25rem;
}
.stat__label {
  font-size: 0.875rem;
  color: var(--au-grey-700);
  margin: 0;
  font-weight: 600;
}


/* ===== Program Grid (4-col cards) ===== */
.program-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--au-s-m);
}
.program-card {
  display: block;
  background: var(--au-white);
  text-decoration: none;
  color: var(--au-ink);
  border: 1px solid var(--au-grey-100);
  border-top: 4px solid var(--au-orange);
  padding: var(--au-s-l);
  transition: all var(--au-t);
}
.program-card:hover { transform: translateY(-4px); box-shadow: 0 4px 12px rgba(0,0,0,0.08); color: var(--au-ink); text-decoration: none; }
.program-card__icon {
  width: 48px; height: 48px;
  background: var(--au-orange);
  color: var(--au-white);
  border-radius: 50%;
  display: inline-flex; align-items: center; justify-content: center;
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: var(--au-s-s);
}
.program-card__title {
  font-family: var(--au-font-heading);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--au-black);
  margin: 0 0 0.5rem;
  line-height: 1.3;
}
.program-card__body {
  font-size: 0.9375rem;
  color: var(--au-grey-700);
  line-height: 1.5;
  margin: 0 0 var(--au-s-s);
}
.program-card__cta {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--au-blue);
  text-decoration: underline;
  text-underline-offset: 3px;
}
.program-card__cta:hover { color: var(--au-orange); }


/* ===== Story / Testimonial ===== */
.story-block {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--au-s-xl);
  align-items: center;
}
.story-block--reverse .story-block__media { order: 2; }
.story-block__media img {
  width: 100%;
  aspect-ratio: 4/3;
  object-fit: cover;
  border-radius: var(--au-radius);
}
.story-block__title {
  font-family: var(--au-font-heading);
  font-size: clamp(1.5rem, 3vw, 2.25rem);
  font-weight: 700;
  color: var(--au-black);
  margin: 0 0 var(--au-s-m);
  line-height: 1.2;
}
.story-block__body {
  font-size: 1.0625rem;
  color: var(--au-grey-700);
  line-height: 1.7;
  margin: 0 0 var(--au-s-l);
}
.story-block__cta {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 700;
  color: var(--au-blue);
  text-decoration: underline;
  text-underline-offset: 3px;
}


/* ===== News cards (3-col) ===== */
.news-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--au-s-m);
}
.news-card {
  display: flex;
  flex-direction: column;
  text-decoration: none;
  color: var(--au-ink);
  background: var(--au-white);
  border: 1px solid var(--au-grey-100);
  border-radius: var(--au-radius);
  overflow: hidden;
  transition: all var(--au-t);
}
.news-card:hover { transform: translateY(-2px); box-shadow: 0 4px 12px rgba(0,0,0,0.06); color: var(--au-ink); }
.news-card__media {
  width: 100%;
  aspect-ratio: 16/10;
  object-fit: cover;
  background: var(--au-grey-100);
}
.news-card__body { padding: var(--au-s-m); }
.news-card__date {
  display: inline-block;
  font-size: 0.75rem;
  color: var(--au-grey-700);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin: 0 0 0.5rem;
}
.news-card__title {
  font-family: var(--au-font-heading);
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--au-black);
  line-height: 1.3;
  margin: 0 0 var(--au-s-s);
}
.news-card__cta {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--au-blue);
  text-decoration: underline;
  text-underline-offset: 3px;
  margin-top: auto;
}


/* ===== Page Hero (内页) ===== */
.page-hero {
  background: var(--au-grey-50);
  padding: var(--au-s-xl) var(--au-s-s);
  border-bottom: 1px solid var(--au-grey-100);
}
.page-hero__container { max-width: var(--au-container); margin: 0 auto; }
.page-hero__breadcrumb {
  font-size: 0.875rem;
  color: var(--au-grey-700);
  margin: 0 0 var(--au-s-s);
}
.page-hero__breadcrumb a { color: var(--au-blue); }
.page-hero__title {
  font-family: var(--au-font-heading);
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  font-weight: 700;
  color: var(--au-black);
  margin: 0 0 var(--au-s-s);
}
.page-hero__sub {
  font-size: 1.0625rem;
  color: var(--au-grey-700);
  max-width: 48rem;
  margin: 0;
}


/* ===== Content (prose) ===== */
.page-content {
  max-width: var(--au-container);
  margin: 0 auto;
  padding: var(--au-s-xxxxl) var(--au-s-s);
}
.prose {
  max-width: 56rem;
  font-size: 1.0625rem;
  line-height: 1.7;
  color: var(--au-ink);
}
.prose h2 {
  font-size: 1.625rem;
  color: var(--au-black);
  margin: var(--au-s-xl) 0 var(--au-s-s);
  border-bottom: 3px solid var(--au-orange);
  padding-bottom: 0.5rem;
  display: inline-block;
}
.prose h3 { font-size: 1.25rem; color: var(--au-black); margin: var(--au-s-l) 0 var(--au-s-xs); }
.prose a { color: var(--au-blue); text-decoration: underline; }
.prose blockquote {
  border-left: 4px solid var(--au-orange);
  padding: 0.5rem var(--au-s-m);
  margin: var(--au-s-m) 0;
  background: var(--au-grey-50);
  font-style: italic;
}


/* ===== Footer (AU 真实: 黑底 + 4 列) ===== */
.site-footer {
  background: var(--au-black);
  color: var(--au-white);
  padding: var(--au-s-xxxxl) var(--au-s-s) var(--au-s-l);
}
.site-footer__grid {
  max-width: var(--au-container);
  margin: 0 auto var(--au-s-xl);
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--au-s-l);
}
.site-footer__col h4 {
  font-family: var(--au-font-body);
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--au-white);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin: 0 0 var(--au-s-s);
}
.site-footer__col p {
  font-size: 0.875rem;
  color: rgba(255,255,255,0.85);
  margin: 0 0 var(--au-s-xs);
  line-height: 1.5;
}
.site-footer__col ul { list-style: none; padding: 0; margin: 0; }
.site-footer__col li { margin: 0 0 var(--au-s-xs); }
.site-footer__col a {
  color: rgba(255,255,255,0.85);
  text-decoration: none;
  font-size: 0.875rem;
}
.site-footer__col a:hover { color: var(--au-orange); text-decoration: underline; }
.site-footer__network {
  max-width: var(--au-container);
  margin: 0 auto var(--au-s-l);
  padding: var(--au-s-m) 0;
  border-top: 1px solid rgba(255,255,255,0.15);
  border-bottom: 1px solid rgba(255,255,255,0.15);
}
.site-footer__network-label {
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  color: rgba(255,255,255,0.6);
  letter-spacing: 0.1em;
  margin: 0 0 var(--au-s-xs);
}
.site-footer__network ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-wrap: wrap;
  gap: var(--au-s-xs) var(--au-s-m);
}
.site-footer__network a {
  color: rgba(255,255,255,0.85);
  text-decoration: none;
  font-size: 0.8125rem;
}
.site-footer__network a:hover { color: var(--au-orange); text-decoration: underline; }
.site-footer__bottom {
  max-width: var(--au-container);
  margin: 0 auto;
  padding-top: var(--au-s-l);
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: var(--au-s-s);
  font-size: 0.8125rem;
  color: rgba(255,255,255,0.7);
}
.site-footer__bottom a { color: rgba(255,255,255,0.85); text-decoration: underline; }


/* ===== Responsive ===== */
@media (max-width: 1024px) {
  .site-header__nav { gap: 0; }
  .site-header__nav-item { padding: 0.5rem 0.5rem; font-size: 0.875rem; }
  .quick-grid { grid-template-columns: repeat(2, 1fr); }
  .program-grid { grid-template-columns: repeat(2, 1fr); }
  .news-grid { grid-template-columns: repeat(2, 1fr); }
  .stats-bar__inner { grid-template-columns: 1fr; }
  .story-block { grid-template-columns: 1fr; }
  .story-block--reverse .story-block__media { order: 0; }
  .site-footer__grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 640px) {
  .site-header__top-inner { flex-direction: column; align-items: flex-start; }
  .site-header__main-inner { padding: 0.5rem var(--au-s-s); }
  .quick-grid, .program-grid, .news-grid, .site-footer__grid { grid-template-columns: 1fr; }
  .stats-bar__stats { grid-template-columns: 1fr; }
  .section { padding: var(--au-s-xl) var(--au-s-s); }
  .home-hero__title { font-size: 1.875rem; }
}