/* ===== RESET & BASE ===== */
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{font-size:100%;-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{font-family:Georgia,'Times New Roman',serif;font-weight:400;line-height:1.6;color:#1A1A1A;background:#FFFFFF;min-height:100vh}
img{max-width:100%;display:block}
ul,ol{list-style:none}
a{color:inherit;text-decoration:none}
button,input,textarea{font:inherit;color:inherit;border:none;background:none}
button{cursor:pointer}
:focus-visible{outline:3px solid #C8962E;outline-offset:2px;border-radius:2px}
:focus:not(:focus-visible){outline:none}
::selection{background:#1B4D3E;color:#FFFFFF}
@media(prefers-reduced-motion:reduce){
  *{animation-duration:0.01ms!important;animation-iteration-count:1!important;transition-duration:0.01ms!important;scroll-behavior:auto!important}
}

/* ===== CSS VARIABLES ===== */
:root{
  --clr-primary:#1B4D3E;
  --clr-primary-light:#2A7A5E;
  --clr-accent:#C8962E;
  --clr-accent-light:#DFB05C;
  --clr-white:#FFFFFF;
  --clr-gray-light:#F2F2F2;
  --clr-gray-mid:#CCCCCC;
  --clr-text:#1A1A1A;
  --clr-border:#BFA76A;
  --clr-gradient-start:#1B4D3E;
  --clr-gradient-end:#2A7A5E;
  --font-heading:Impact,'Arial Black',sans-serif;
  --font-body:Georgia,'Times New Roman',serif;
  --shadow-strong:8px 8px 0 rgba(27,77,62,0.25);
  --shadow-accent:6px 6px 0 rgba(200,150,46,0.3);
  --border-thick:4px solid var(--clr-border);
  --border-thick-primary:4px solid var(--clr-primary);
  --max-width:1200px;
  --header-height:80px;
  --nav-width:180px;
  --spacing-section:4rem;
  --transition-fast:0.2s ease;
  --transition-med:0.35s ease;
}

/* ===== SKIP LINK ===== */
.skip-link{
  position:absolute;top:-1000px;left:8px;z-index:10000;
  background:var(--clr-accent);color:var(--clr-white);
  padding:12px 24px;font-family:var(--font-heading);
  font-size:1rem;text-transform:uppercase;letter-spacing:0.05em;
  border:3px solid var(--clr-text);box-shadow:var(--shadow-strong)
}
.skip-link:focus{top:8px}

/* ===== PROGRESS BAR ===== */
.progress-bar{
  position:fixed;top:0;left:0;z-index:9999;
  width:100%;height:4px;background:var(--clr-gray-light);
  transform-origin:0 50%;transform:scaleX(0);
  transition:transform 0.1s linear;will-change:transform
}
.progress-bar::after{
  content:'';display:block;width:100%;height:100%;
  background:linear-gradient(90deg,var(--clr-primary),var(--clr-accent))
}

/* ===== HEADER ===== */
.site-header{
  position:relative;z-index:1000;
  background:var(--clr-primary);color:var(--clr-white);
  border-bottom:var(--border-thick);box-shadow:var(--shadow-strong)
}
.header-inner{
  display:grid;
  grid-template-columns:var(--nav-width) 1fr;
  grid-template-rows:auto;
  grid-template-areas:"nav brand";
  align-items:center;max-width:var(--max-width);
  margin:0 auto;padding:0.5rem 1.5rem;gap:1rem;
  min-height:var(--header-height)
}
.header-brand{
  grid-area:brand;text-align:center;
  display:flex;flex-direction:column;align-items:center;
  justify-content:center
}
.header-brand__name{
  font-family:var(--font-heading);font-size:2.8rem;
  text-transform:uppercase;letter-spacing:0.08em;
  color:var(--clr-white);line-height:1.1;
  text-shadow:3px 3px 0 rgba(0,0,0,0.2)
}
.header-brand__tagline{
  font-family:var(--font-body);font-size:0.85rem;
  color:var(--clr-accent);letter-spacing:0.15em;
  text-transform:uppercase;margin-top:2px
}
.header-nav{grid-area:nav}
.header-nav__list{
  display:flex;flex-direction:column;gap:0.25rem
}
.header-nav__link{
  display:flex;align-items:center;gap:0.75rem;
  padding:0.6rem 1rem 0.6rem 0.75rem;
  font-family:var(--font-heading);font-size:1rem;
  text-transform:uppercase;letter-spacing:0.06em;
  color:var(--clr-white);border-left:3px solid transparent;
  transition:all var(--transition-fast);position:relative
}
.header-nav__link:hover,
.header-nav__link:focus-visible{
  color:var(--clr-accent);border-left-color:var(--clr-accent);
  padding-left:1.25rem
}
.header-nav__link[aria-current="page"]{
  color:var(--clr-accent);border-left-color:var(--clr-accent);
  background:rgba(200,150,46,0.08)
}
.header-nav__icon{
  width:28px;height:28px;flex-shrink:0;
  color:currentColor;transition:transform var(--transition-fast)
}
.header-nav__link:hover .header-nav__icon,
.header-nav__link:focus-visible .header-nav__icon{
  transform:scale(1.15)
}
.header-nav__label{white-space:nowrap}
.nav-toggle{display:none;grid-area:toggle}

/* ===== MOBILE NAV ===== */
@media(max-width:767px){
  .header-inner{
    grid-template-columns:1fr auto;
    grid-template-areas:"brand toggle";
    padding:0.75rem 1rem;min-height:64px
  }
  .header-brand__name{font-size:2rem}
  .header-brand__tagline{font-size:0.75rem}
  .header-nav{
    grid-area:nav;position:fixed;top:64px;left:0;right:0;
    background:var(--clr-primary);border-bottom:var(--border-thick);
    max-height:0;overflow:hidden;transition:max-height var(--transition-med);
    box-shadow:0 8px 16px rgba(0,0,0,0.3);
    z-index:999
  }
  .header-nav[data-open]{
    max-height:80vh;overflow-y:auto
  }
  .header-nav__list{
    flex-direction:column;padding:0.75rem 1rem;gap:0
  }
  .header-nav__link{
    padding:0.75rem 1rem;border-left:none;
    border-bottom:1px solid rgba(255,255,255,0.08)
  }
  .header-nav__link:hover,
  .header-nav__link:focus-visible{
    padding-left:1.5rem;border-left:none
  }
  .header-nav__link[aria-current="page"]{
    border-left:none;background:rgba(200,150,46,0.12)
  }
  .header-nav__icon{width:24px;height:24px}
  .nav-toggle{
    display:flex;flex-direction:column;justify-content:center;
    align-items:center;gap:5px;width:44px;height:44px;
    padding:8px;border:2px solid var(--clr-accent);
    border-radius:4px;transition:all var(--transition-fast);
    background:transparent
  }
  .nav-toggle:hover,.nav-toggle:focus-visible{
    background:rgba(200,150,46,0.15)
  }
  .nav-toggle__line{
    display:block;width:24px;height:3px;
    background:var(--clr-white);border-radius:2px;
    transition:all var(--transition-fast);
    transform-origin:center
  }
  .nav-toggle[aria-expanded="true"] .nav-toggle__line:nth-child(1){
    transform:translateY(8px) rotate(45deg)
  }
  .nav-toggle[aria-expanded="true"] .nav-toggle__line:nth-child(2){
    opacity:0;transform:scaleX(0)
  }
  .nav-toggle[aria-expanded="true"] .nav-toggle__line:nth-child(3){
    transform:translateY(-8px) rotate(-45deg)
  }
}

/* ===== TABLET & DESKTOP ===== */
@media(min-width:768px){
  .site-header{border-bottom-width:6px}
  .header-inner{padding:0.75rem 2rem;gap:2rem}
  .header-nav__list{gap:0.15rem}
  .header-nav__link{
    font-size:0.95rem;padding:0.5rem 1rem 0.5rem 0.75rem
  }
  .header-nav__icon{width:30px;height:30px}
}
@media(min-width:1024px){
  .header-brand__name{font-size:3.2rem}
  .header-nav__link{
    font-size:1.05rem;padding:0.65rem 1.25rem 0.65rem 1rem
  }
  .header-nav__icon{width:32px;height:32px}
}

/* ===== FOOTER ===== */
.site-footer{
  background:var(--clr-primary);color:var(--clr-white);
  border-top:var(--border-thick);box-shadow:0 -8px 0 rgba(27,77,62,0.15);
  margin-top:var(--spacing-section)
}
.footer-inner{
  max-width:var(--max-width);margin:0 auto;
  padding:3rem 1.5rem 2rem;
  display:grid;grid-template-columns:1fr 1fr;
  gap:2rem 3rem
}
.footer-brand{grid-column:1/2}
.footer-brand__name{
  font-family:var(--font-heading);font-size:2rem;
  text-transform:uppercase;letter-spacing:0.06em;
  color:var(--clr-white);display:block;line-height:1.2
}
.footer-brand__desc{
  font-family:var(--font-body);font-size:0.9rem;
  color:var(--clr-accent);margin-top:0.25rem;
  letter-spacing:0.04em
}
.footer-nav{grid-column:2/3;text-align:right}
.footer-nav__list{display:flex;flex-direction:column;gap:0.5rem;align-items:flex-end}
.footer-nav__link{
  font-family:var(--font-heading);font-size:0.95rem;
  text-transform:uppercase;letter-spacing:0.06em;
  color:var(--clr-white);padding:0.25rem 0;
  border-bottom:2px solid transparent;
  transition:all var(--transition-fast)
}
.footer-nav__link:hover,.footer-nav__link:focus-visible{
  color:var(--clr-accent);border-bottom-color:var(--clr-accent)
}
.footer-contact{
  grid-column:1/3;display:flex;flex-wrap:wrap;gap:0.75rem 2rem;
  font-family:var(--font-body);font-size:0.9rem;
  color:rgba(255,255,255,0.85);border-top:1px solid rgba(255,255,255,0.12);
  padding-top:1.25rem;margin-top:0.5rem
}
.footer-contact__item{position:relative;padding-left:0}
.footer-meta{
  grid-column:1/3;display:flex;flex-wrap:wrap;
  justify-content:space-between;align-items:center;gap:1rem;
  font-size:0.78rem;color:rgba(255,255,255,0.6);
  border-top:1px solid rgba(255,255,255,0.1);
  padding-top:1.25rem;margin-top:0.5rem
}
.footer-note{max-width:480px;text-align:right;font-style:italic}
.footer-icp{font-family:var(--font-heading);letter-spacing:0.04em}
@media(max-width:767px){
  .footer-inner{grid-template-columns:1fr;padding:2rem 1.25rem 1.5rem;gap:1.5rem}
  .footer-brand,.footer-nav{grid-column:1/2;text-align:center}
  .footer-nav__list{align-items:center}
  .footer-contact{grid-column:1/2;flex-direction:column;align-items:center;text-align:center;gap:0.5rem}
  .footer-meta{grid-column:1/2;flex-direction:column;text-align:center}
  .footer-note{text-align:center}
  .footer-brand__name{font-size:1.6rem}
}
@media(min-width:768px)and(max-width:1023px){
  .footer-inner{gap:2rem}
  .footer-contact{gap:1rem}
}

/* ===== CONTAINER & SECTION ===== */
.container{max-width:var(--max-width);margin:0 auto;padding:0 1.5rem}
.section{padding:var(--spacing-section) 0}
.section__title{
  font-family:var(--font-heading);font-size:2.5rem;
  text-transform:uppercase;letter-spacing:0.04em;
  color:var(--clr-primary);margin-bottom:1.5rem;
  position:relative;display:inline-block
}
.section__title::after{
  content:'';display:block;width:60%;height:4px;
  background:var(--clr-accent);margin-top:0.25rem
}

/* ===== BUTTONS ===== */
.btn{
  display:inline-flex;align-items:center;justify-content:center;
  gap:0.5rem;padding:0.75rem 1.75rem;
  font-family:var(--font-heading);font-size:0.95rem;
  text-transform:uppercase;letter-spacing:0.06em;
  border:3px solid var(--clr-primary);transition:all var(--transition-fast);
  cursor:pointer;min-height:48px;white-space:nowrap
}
.btn-primary{
  background:var(--clr-accent);color:var(--clr-text);
  border-color:var(--clr-accent);box-shadow:var(--shadow-accent)
}
.btn-primary:hover,.btn-primary:focus-visible{
  background:var(--clr-accent-light);transform:translate(-2px,-2px);
  box-shadow:8px 8px 0 rgba(200,150,46,0.25)
}
.btn-outline{
  background:transparent;color:var(--clr-primary);
  border-color:var(--clr-primary);box-shadow:3px 3px 0 var(--clr-primary)
}
.btn-outline:hover,.btn-outline:focus-visible{
  background:var(--clr-primary);color:var(--clr-white);
  transform:translate(-2px,-2px);box-shadow:6px 6px 0 rgba(27,77,62,0.3)
}

/* ===== BREADCRUMB ===== */
.breadcrumb{
  display:flex;flex-wrap:wrap;gap:0.35rem 0.5rem;
  font-family:var(--font-body);font-size:0.85rem;
  color:rgba(26,26,26,0.55);padding:0.75rem 0;
  border-bottom:1px solid var(--clr-gray-light);margin-bottom:1.5rem
}
.breadcrumb a{color:var(--clr-primary);border-bottom:1px solid transparent;transition:border var(--transition-fast)}
.breadcrumb a:hover,.breadcrumb a:focus-visible{border-bottom-color:var(--clr-accent);color:var(--clr-accent)}
.breadcrumb .breadcrumb__sep{color:var(--clr-border);margin:0 0.15rem}

/* ===== CARD ===== */
.card{
  background:var(--clr-white);border:var(--border-thick);
  box-shadow:var(--shadow-strong);padding:1.5rem;
  transition:all var(--transition-med)
}
.card:hover{box-shadow:12px 12px 0 rgba(27,77,62,0.2);transform:translate(-2px,-2px)}
.card__title{
  font-family:var(--font-heading);font-size:1.4rem;
  text-transform:uppercase;letter-spacing:0.04em;
  color:var(--clr-primary);margin-bottom:0.75rem;
  line-height:1.2
}
.card__body{font-family:var(--font-body);font-size:0.95rem;color:rgba(26,26,26,0.8);line-height:1.6}
.card-grid{
  display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));
  gap:1.5rem
}

/* ===== FRAME / 框景 ===== */
.frame-viewport{
  position:relative;padding:2rem;border:6px solid var(--clr-border);
  box-shadow:inset 0 0 0 2px var(--clr-primary),var(--shadow-strong);
  background:var(--clr-white);overflow:hidden
}
.frame-viewport::before{
  content:'';position:absolute;top:-6px;left:-6px;right:-6px;bottom:-6px;
  border:2px solid var(--clr-accent);pointer-events:none
}
.frame-viewport__inner{position:relative;z-index:1}

/* ===== TAG ===== */
.tag{
  display:inline-block;padding:0.25rem 0.75rem;
  background:var(--clr-accent);color:var(--clr-text);
  font-family:var(--font-heading);font-size:0.75rem;
  text-transform:uppercase;letter-spacing:0.08em;
  border:2px solid var(--clr-primary)
}

/* ===== STAT ===== */
.stat{text-align:center;padding:1rem}
.stat__value{
  font-family:var(--font-heading);font-size:3rem;
  color:var(--clr-primary);line-height:1;
  letter-spacing:0.02em
}
.stat__label{
  font-family:var(--font-body);font-size:0.85rem;
  color:rgba(26,26,26,0.65);text-transform:uppercase;
  letter-spacing:0.08em;margin-top:0.25rem;display:block
}

/* ===== PATH / 技能树 ===== */
.path{display:flex;flex-direction:column;gap:0;position:relative;padding-left:2.5rem}
.path::before{
  content:'';position:absolute;left:12px;top:0;bottom:0;
  width:3px;background:var(--clr-border)
}
.path__step{
  position:relative;padding:1rem 0 1rem 1.5rem;
  border-left:3px solid var(--clr-primary);margin-bottom:0.5rem;
  background:var(--clr-white);box-shadow:4px 4px 0 rgba(27,77,62,0.1);
  transition:all var(--transition-fast)
}
.path__step:hover{box-shadow:6px 6px 0 rgba(27,77,62,0.18);transform:translate(-1px,-1px)}
.path__step::before{
  content:'';position:absolute;left:-17px;top:1.4rem;
  width:14px;height:14px;border-radius:50%;
  background:var(--clr-accent);border:3px solid var(--clr-primary)
}
.path__step__title{
  font-family:var(--font-heading);font-size:1.1rem;
  text-transform:uppercase;letter-spacing:0.04em;
  color:var(--clr-primary);margin-bottom:0.25rem
}
.path__step__desc{font-size:0.9rem;color:rgba(26,26,26,0.7)}

/* ===== DIAGONAL BG ===== */
.diagonal-bg{
  position:relative;overflow:hidden
}
.diagonal-bg::after{
  content:'';position:absolute;top:-50%;right:-30%;
  width:60%;height:150%;background:linear-gradient(135deg,transparent 30%,rgba(27,77,62,0.06) 50%,transparent 70%);
  pointer-events:none;transform:rotate(12deg);z-index:0
}
.diagonal-bg>*{position:relative;z-index:1}

/* ===== UTILITY ===== */
.text-accent{color:var(--clr-accent)}
.text-primary{color:var(--clr-primary)}
.text-center{text-align:center}
.mt-1{margin-top:1rem}
.mt-2{margin-top:2rem}
.mb-1{margin-bottom:1rem}
.mb-2{margin-bottom:2rem}
.py-section{padding:var(--spacing-section) 0}
.visually-hidden{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}

/* ===== RESPONSIVE ADJUSTMENTS ===== */
@media(max-width:767px){
  :root{--spacing-section:2.5rem}
  .section__title{font-size:1.8rem}
  .card{padding:1rem}
  .card-grid{grid-template-columns:1fr}
  .frame-viewport{padding:1.25rem;border-width:4px}
  .stat__value{font-size:2.2rem}
  .path{padding-left:2rem}
  .path__step{padding:0.75rem 0 0.75rem 1rem}
  .path__step::before{left:-15px;top:1.1rem;width:12px;height:12px}
}
@media(min-width:768px)and(max-width:1023px){
  .card-grid{grid-template-columns:repeat(2,1fr)}
  .section__title{font-size:2.2rem}
}
@media(min-width:1024px){
  .card-grid{gap:2rem}
}

/* ===== PRINT ===== */
@media print{
  .site-header,.site-footer,.progress-bar,.nav-toggle{display:none!important}
  body{color:#000;background:#fff}
  a{text-decoration:underline}
}

/* ===== REDUCED MOTION OVERRIDES ===== */
@media(prefers-reduced-motion:reduce){
  .card:hover{transform:none;box-shadow:var(--shadow-strong)}
  .btn-primary:hover,.btn-primary:focus-visible{transform:none}
  .btn-outline:hover,.btn-outline:focus-visible{transform:none}
  .header-nav__link:hover{padding-left:0.75rem}
  .header-nav__link:hover .header-nav__icon{transform:none}
  .path__step:hover{transform:none}
  .progress-bar{transition:none}
  .header-nav{transition:none}
  .nav-toggle__line{transition:none}
  .header-nav__link{transition:none}
}

/* ===== ACCESSIBILITY ===== */
@media(prefers-contrast:more){
  .header-nav__link[aria-current="page"]{outline:2px solid var(--clr-accent)}
  .btn{border-width:3px}
  .card{border-width:4px}
}

/* ===== SCROLL MARGIN FOR SKIP TARGET ===== */
#main-content{scroll-margin-top:96px}
@media(max-width:767px){#main-content{scroll-margin-top:72px}}