/* ============================================================
   郭清章老師 輔助教學網站 — 共用樣式表
   沉穩學術風：深藍 + 金色點綴
   若要調整全站配色，只需要修改本檔案最上方的 CSS 變數即可。
   ============================================================ */
:root{
  --navy-900:#0a1830;
  --navy-800:#0f2245;
  --navy-700:#173463;
  --navy-600:#234a86;
  --gold-500:#c8a648;
  --gold-400:#dcbf74;
  --ivory:#f7f5ef;
  --paper:#ffffff;
  --ink:#1c2130;
  --muted:#5c6577;
  --line:#e4e0d4;
  --radius:14px;
  --shadow:0 10px 30px rgba(10,24,48,.08);
  --shadow-lg:0 20px 50px rgba(10,24,48,.14);
}
*{box-sizing:border-box;}
html{scroll-behavior:smooth;}
body{
  margin:0;
  font-family:"Noto Sans TC","PingFang TC","Microsoft JhengHei",sans-serif;
  color:var(--ink);
  background:var(--ivory);
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
}
h1,h2,h3,h4{
  font-family:"Noto Serif TC","Georgia",serif;
  font-weight:700;
  margin:0 0 .5em;
  color:var(--navy-900);
  letter-spacing:.02em;
}
a{color:inherit;text-decoration:none;}
img{max-width:100%;display:block;}
.container{max-width:1120px;margin:0 auto;padding:0 24px;}
.eyebrow{
  display:inline-flex;align-items:center;gap:8px;
  font-size:.8rem;letter-spacing:.18em;font-weight:700;
  color:var(--gold-500);text-transform:uppercase;margin-bottom:14px;
}
.eyebrow::before{content:"";width:28px;height:2px;background:var(--gold-500);display:inline-block;}

/* Nav */
header.site-header{
  position:sticky;top:0;z-index:50;
  background:rgba(10,24,48,.96);
  backdrop-filter:saturate(140%) blur(6px);
  border-bottom:1px solid rgba(255,255,255,.08);
}
.nav-inner{
  display:flex;align-items:center;justify-content:space-between;
  padding:16px 24px;max-width:1120px;margin:0 auto;
}
.brand{display:flex;align-items:center;gap:12px;color:#fff;}
.brand-mark{
  width:40px;height:40px;border-radius:10px;
  background:linear-gradient(135deg,var(--gold-400),var(--gold-500));
  display:flex;align-items:center;justify-content:center;
  font-family:"Noto Serif TC",serif;font-weight:700;color:var(--navy-900);
  font-size:1.05rem;flex:none;
}
.brand-text .name{font-family:"Noto Serif TC",serif;font-weight:700;font-size:1.05rem;line-height:1.3;}
.brand-text .dept{font-size:.78rem;color:rgba(255,255,255,.65);}
nav.main-nav ul{list-style:none;display:flex;gap:6px;margin:0;padding:0;}
nav.main-nav a{
  color:rgba(255,255,255,.82);font-size:.92rem;padding:10px 14px;border-radius:8px;
  display:inline-block;transition:background .2s,color .2s;
}
nav.main-nav a:hover,nav.main-nav a.active{background:rgba(255,255,255,.1);color:#fff;}
.nav-toggle{display:none;background:none;border:0;color:#fff;font-size:1.4rem;cursor:pointer;}
@media (max-width:820px){
  nav.main-nav{position:absolute;top:100%;left:0;right:0;background:var(--navy-900);
    border-top:1px solid rgba(255,255,255,.08);display:none;}
  nav.main-nav.open{display:block;}
  nav.main-nav ul{flex-direction:column;padding:10px 24px 18px;gap:2px;}
  .nav-toggle{display:block;}
}

/* Hero */
.hero{
  position:relative;overflow:hidden;
  background:radial-gradient(1100px 500px at 85% -10%,rgba(220,191,116,.18),transparent 60%),
             linear-gradient(160deg,var(--navy-900),var(--navy-800) 55%,var(--navy-700));
  color:#fff;padding:96px 0 88px;
}
.hero::after{
  content:"";position:absolute;inset:0;pointer-events:none;
  background-image:
    linear-gradient(rgba(255,255,255,.045) 1px,transparent 1px),
    linear-gradient(90deg,rgba(255,255,255,.045) 1px,transparent 1px);
  background-size:44px 44px;
  mask-image:linear-gradient(180deg,transparent,rgba(0,0,0,.5) 40%,transparent);
}
.hero-inner{position:relative;z-index:1;max-width:760px;}
.hero h1{color:#fff;font-size:clamp(2.1rem,4.2vw,3.1rem);margin-bottom:.3em;}
.hero .role{color:var(--gold-400);font-size:1.15rem;font-weight:600;margin-bottom:18px;}
.hero p.lead{color:rgba(255,255,255,.82);font-size:1.05rem;max-width:640px;}
.hero-actions{display:flex;flex-wrap:wrap;gap:14px;margin-top:34px;}
.hero-years{display:flex;flex-wrap:wrap;gap:10px;margin-top:22px;}
.hero-years a{
  font-size:.82rem;font-weight:700;color:rgba(255,255,255,.8);
  border:1px solid rgba(255,255,255,.25);border-radius:999px;padding:7px 16px;
  transition:background .2s,color .2s;
}
.hero-years a:hover{background:rgba(255,255,255,.12);color:#fff;}

.btn{
  display:inline-flex;align-items:center;gap:8px;
  padding:13px 24px;border-radius:999px;font-weight:700;font-size:.95rem;
  border:1px solid transparent;cursor:pointer;transition:transform .15s,box-shadow .15s,background .15s;
}
.btn-gold{background:linear-gradient(135deg,var(--gold-400),var(--gold-500));color:var(--navy-900);}
.btn-gold:hover{transform:translateY(-2px);box-shadow:0 12px 24px rgba(200,166,72,.35);}
.btn-outline{background:transparent;border-color:rgba(255,255,255,.35);color:#fff;}
.btn-outline:hover{background:rgba(255,255,255,.1);}
.btn-outline-navy{background:transparent;border-color:var(--navy-700);color:var(--navy-800);}
.btn-outline-navy:hover{background:var(--navy-800);color:#fff;}

/* Sections */
section{padding:88px 0;}
section.alt{background:var(--paper);}
.section-head{max-width:640px;margin-bottom:48px;}
.section-head p{color:var(--muted);}

/* About */
.about-grid{display:grid;grid-template-columns:1.3fr 1fr;gap:48px;align-items:start;}
.about-card{
  background:var(--paper);border:1px solid var(--line);border-radius:var(--radius);
  padding:28px;box-shadow:var(--shadow);
}
.about-card h3{font-size:1rem;color:var(--navy-800);margin-bottom:14px;}
.fact-list{list-style:none;margin:0;padding:0;display:grid;gap:12px;}
.fact-list li{display:flex;gap:10px;font-size:.94rem;color:var(--ink);}
.fact-list b{color:var(--navy-800);min-width:74px;flex:none;}
@media (max-width:900px){.about-grid{grid-template-columns:1fr;}}

/* Cards grid */
.card-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:26px;}
@media (max-width:900px){.card-grid{grid-template-columns:repeat(2,1fr);}}
@media (max-width:620px){.card-grid{grid-template-columns:1fr;}}
.course-card{
  background:var(--paper);border:1px solid var(--line);border-radius:var(--radius);
  padding:26px;box-shadow:var(--shadow);transition:transform .18s,box-shadow .18s;
  display:flex;flex-direction:column;gap:12px;
}
.course-card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg);}
.course-tag{
  align-self:flex-start;font-size:.72rem;font-weight:700;letter-spacing:.06em;
  color:var(--navy-800);background:#eef1f7;border-radius:999px;padding:4px 12px;
}
.course-card h3{font-size:1.08rem;margin:0;}
.course-card p{color:var(--muted);font-size:.92rem;margin:0;flex:1;}
.course-card .card-link{font-weight:700;color:var(--navy-800);font-size:.9rem;}
.course-card .card-link:hover{color:var(--gold-500);}

/* Archive banner */
.banner{
  background:linear-gradient(120deg,var(--navy-800),var(--navy-700));
  color:#fff;border-radius:20px;padding:44px;display:flex;flex-wrap:wrap;
  align-items:center;justify-content:space-between;gap:24px;
}
.banner h2{color:#fff;margin-bottom:6px;}
.banner p{color:rgba(255,255,255,.75);margin:0;max-width:520px;}

/* Resource feature cards */
.feature-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:22px;}
@media (max-width:900px){.feature-grid{grid-template-columns:repeat(2,1fr);}}
@media (max-width:560px){.feature-grid{grid-template-columns:1fr;}}
.feature{
  background:var(--paper);border:1px solid var(--line);border-radius:var(--radius);
  padding:24px;text-align:left;box-shadow:var(--shadow);
}
.feature .icon{
  width:46px;height:46px;border-radius:12px;margin-bottom:16px;
  background:linear-gradient(135deg,var(--navy-800),var(--navy-600));
  color:var(--gold-400);display:flex;align-items:center;justify-content:center;
  font-family:"Noto Serif TC",serif;font-weight:700;font-size:1.2rem;
}
.feature h3{font-size:1rem;margin-bottom:8px;}
.feature p{color:var(--muted);font-size:.9rem;margin:0;}

/* Archive accordion (courses.html) */
.year-block{
  border:1px solid var(--line);border-radius:var(--radius);background:var(--paper);
  margin-bottom:20px;overflow:hidden;box-shadow:var(--shadow);
}
.year-block summary{
  list-style:none;cursor:pointer;padding:22px 26px;display:flex;
  align-items:center;justify-content:space-between;gap:16px;
}
.year-block summary::-webkit-details-marker{display:none;}
.year-block summary .yt{display:flex;flex-direction:column;gap:4px;}
.year-block summary .yt span.badge{
  font-size:.72rem;font-weight:700;color:var(--gold-500);letter-spacing:.08em;
}
.year-block summary .yt h2{font-size:1.2rem;margin:0;}
.year-block summary .chev{
  width:32px;height:32px;border-radius:50%;background:#eef1f7;color:var(--navy-800);
  display:flex;align-items:center;justify-content:center;font-size:1.1rem;flex:none;
  transition:transform .2s;
}
.year-block[open] summary .chev{transform:rotate(45deg);}
.year-body{padding:0 26px 28px;border-top:1px solid var(--line);}
.year-body .desc{color:var(--muted);font-size:.9rem;margin:18px 0 6px;}
.course-list{display:grid;grid-template-columns:repeat(2,1fr);gap:18px;margin-top:14px;}
@media (max-width:700px){.course-list{grid-template-columns:1fr;}}
.course-block{background:var(--ivory);border:1px solid var(--line);border-radius:10px;padding:18px 20px;}
.course-block h3{font-size:.98rem;margin-bottom:10px;color:var(--navy-800);}
.course-block ul{margin:0;padding-left:0;list-style:none;display:grid;gap:8px;}
.course-block li a{font-size:.87rem;color:var(--navy-700);display:flex;align-items:center;gap:8px;}
.course-block li a::before{content:"›";color:var(--gold-500);font-weight:700;}
.course-block li a:hover{color:var(--gold-500);}
.course-block .empty-note{font-size:.85rem;color:var(--muted);font-style:italic;}

/* Resources page detail cards */
.resource-section{margin-bottom:56px;}
.resource-section h2{font-size:1.3rem;}
.resource-section .tagline{color:var(--muted);margin-bottom:24px;max-width:640px;}
.doc-list{display:grid;grid-template-columns:repeat(2,1fr);gap:16px;}
@media (max-width:700px){.doc-list{grid-template-columns:1fr;}}
.doc-item{
  display:flex;align-items:center;gap:14px;background:var(--paper);
  border:1px solid var(--line);border-radius:12px;padding:16px 18px;box-shadow:var(--shadow);
}
.doc-item .doc-icon{
  width:38px;height:38px;border-radius:9px;flex:none;
  background:#eef1f7;color:var(--navy-800);display:flex;align-items:center;justify-content:center;
  font-family:"Noto Serif TC",serif;font-weight:700;
}
.doc-item a{font-weight:700;font-size:.94rem;color:var(--navy-800);}
.doc-item a:hover{color:var(--gold-500);}

/* Contact */
.contact-grid{display:grid;grid-template-columns:1fr 1fr;gap:40px;}
@media (max-width:800px){.contact-grid{grid-template-columns:1fr;}}
.contact-list{list-style:none;margin:0;padding:0;display:grid;gap:22px;}
.contact-list li{display:flex;gap:16px;}
.contact-list .ic{
  width:42px;height:42px;border-radius:10px;background:#eef1f7;color:var(--navy-800);
  display:flex;align-items:center;justify-content:center;flex:none;font-weight:700;
}
.contact-list b{display:block;color:var(--navy-800);font-size:.85rem;margin-bottom:2px;}
.map-card{
  border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow);
  background:linear-gradient(135deg,#eef1f7,#e4e9f2);min-height:260px;
  display:flex;align-items:center;justify-content:center;color:var(--muted);text-align:center;padding:24px;
}

/* Breadcrumb / page header for sub pages */
.page-hero{background:linear-gradient(160deg,var(--navy-900),var(--navy-700));color:#fff;padding:64px 0 56px;}
.page-hero .eyebrow{color:var(--gold-400);}
.page-hero h1{color:#fff;font-size:clamp(1.8rem,3.4vw,2.5rem);}
.page-hero p{color:rgba(255,255,255,.78);max-width:600px;}
.breadcrumb{font-size:.85rem;color:rgba(255,255,255,.6);margin-bottom:18px;}
.breadcrumb a{color:rgba(255,255,255,.85);}
.breadcrumb a:hover{color:var(--gold-400);}

/* Footer */
footer.site-footer{background:var(--navy-900);color:rgba(255,255,255,.6);padding:36px 0;}
.footer-inner{display:flex;flex-wrap:wrap;gap:16px;align-items:center;justify-content:space-between;font-size:.85rem;}
.footer-inner a:hover{color:var(--gold-400);}
.back-top{display:inline-flex;align-items:center;gap:6px;color:rgba(255,255,255,.6);font-size:.85rem;}
.back-top:hover{color:var(--gold-400);}

.note-callout{
  border-left:3px solid var(--gold-500);background:#fbf7ea;color:#6b5a1e;
  padding:14px 18px;border-radius:0 10px 10px 0;font-size:.88rem;margin-top:18px;
}