/* ===== G6 Study Plan — Site-wide stylesheet (克制美学) ===== */
:root{
  --bg:#f4f5f7; --bg2:#ffffff; --ink:#1a1a2e; --muted:#6b7280;
  --rule:#e2e4e9; --accent:#1e40af; --accent2:#d97706;
  --heading:Georgia,'Noto Serif SC',serif;
  --body:-apple-system,BlinkMacSystemFont,'Segoe UI',sans-serif;
  --shadow:0 1px 4px rgba(0,0,0,.08);
  --radius:10px;
  --math:#2563eb; --sci:#059669; --eng:#7c3aed; --hist:#6d4c41;
  --geo:#0277bd; --anki:#e65100; --proj:#0891b2; --pei:#388e3c;
}
*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:var(--body);font-size:15.5px;line-height:1.75;color:var(--ink);background:var(--bg);-webkit-font-smoothing:antialiased}
a{color:var(--accent);text-decoration:none}
a:hover{opacity:.8}
img{max-width:100%;height:auto}

.wrap{max-width:1080px;margin:0 auto;padding:0 20px}

/* ===== Site nav ===== */
.site-nav{background:linear-gradient(135deg,#0a1628,#1a3a5c);color:#fff;position:sticky;top:0;z-index:999;box-shadow:0 2px 8px rgba(0,0,0,.2)}
.nav-inner{max-width:1080px;margin:0 auto;display:flex;align-items:center;gap:8px;padding:10px 20px;font-size:.85rem;flex-wrap:wrap}
.nav-logo{font-family:var(--heading);font-weight:700;font-size:1.2rem;color:#ffb300;margin-right:14px}
.nav-link{color:rgba(255,255,255,.85);padding:3px 9px;border-radius:5px;transition:background .15s,color .15s}
.nav-link:hover{background:rgba(255,255,255,.16);color:#fff;opacity:1}
.nav-sep{color:rgba(255,255,255,.3);font-size:.7rem}
.nav-current{color:rgba(255,255,255,.6);font-size:.8rem}
.nav-cta{margin-left:auto;background:#ffb300;color:#0a1628!important;font-weight:700;padding:4px 14px;border-radius:20px;font-size:.8rem}
.nav-cta:hover{background:#ffc43d;opacity:1}

/* ===== Hero ===== */
.hero{background:linear-gradient(135deg,#0a1628 0%,#1a3a5c 55%,#0d2137 100%);color:#fff;padding:56px 20px 46px;text-align:center}
.hero h1{font-family:var(--heading);font-size:2.6rem;font-weight:700;letter-spacing:3px;margin-bottom:6px}
.hero .lead{font-size:1.05rem;opacity:.82;max-width:640px;margin:6px auto 0}
.hero .lead-strong{font-size:1.12rem;opacity:.95;font-weight:600;margin-top:4px}
.hero .meta{font-size:.82rem;opacity:.55;margin-top:10px}
.hero .chips{display:flex;justify-content:center;gap:8px;flex-wrap:wrap;margin-top:18px}
.hero .chip{padding:5px 15px;border-radius:20px;font-size:.75rem;font-weight:600;background:rgba(255,255,255,.1);border:1px solid rgba(255,255,255,.22)}
.hero .chip.hot{background:#ffb300;color:#0a1628;border-color:#ffb300}
.hero .chip.grn{background:rgba(5,150,105,.3);border-color:rgba(5,150,105,.55)}
.hero .chip.blu{background:rgba(37,99,235,.3);border-color:rgba(37,99,235,.55)}
.hero .chip.ppl{background:rgba(124,58,237,.3);border-color:rgba(124,58,237,.55)}

/* ===== Sections ===== */
.section{padding:38px 0}
.section.alt{background:var(--bg2);border-block:1px solid var(--rule)}
h2{font-family:var(--heading);font-size:1.55rem;font-weight:700;color:var(--ink);margin-bottom:8px}
.sec-sub{color:var(--muted);font-size:.9rem;margin-bottom:22px;max-width:720px}
.sec-head{display:flex;align-items:baseline;gap:14px;margin-bottom:20px;padding-bottom:8px;border-bottom:3px solid var(--accent)}
.sec-head h2{margin:0}
.sec-head .en{font-family:var(--heading);font-style:italic;color:var(--muted);font-size:.8rem}

/* ===== Month grid ===== */
.month-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(320px,1fr));gap:18px}
.month-card{background:var(--bg2);border:1px solid var(--rule);border-radius:12px;overflow:hidden;display:flex;flex-direction:column;transition:transform .2s,box-shadow .2s}
.month-card:hover{transform:translateY(-3px);box-shadow:0 8px 24px rgba(0,0,0,.09)}
.card-hd{display:flex;align-items:center;justify-content:space-between;padding:16px 18px;color:#fff}
.card-hd h2{font-family:var(--heading);font-size:1.35rem;color:#fff;margin:0;letter-spacing:1px}
.card-hd .tag{font-size:.72rem;font-weight:700;padding:3px 12px;border-radius:20px;background:rgba(255,255,255,.2)}
.card-hd .tag.hot{background:#ffb300;color:#0a1628}
.m-sep{background:linear-gradient(135deg,#2563eb,#7c3aed)}
.m-oct{background:linear-gradient(135deg,#d97706,#dc2626)}
.m-nov{background:linear-gradient(135deg,#059669,#2563eb)}
.m-dec{background:linear-gradient(135deg,#6338a8,#0d9488)}
.m-anki{background:linear-gradient(135deg,#e65100,#0891b2)}
.card-bd{padding:16px 18px;display:flex;flex-direction:column;flex:1}
.stat-row{display:flex;gap:22px;margin-bottom:14px}
.stat .num{font-size:1.35rem;font-weight:800;color:var(--accent);font-family:var(--heading)}
.stat .label{font-size:.72rem;color:var(--muted)}
.week-list{display:flex;flex-direction:column;gap:2px;margin:6px 0 14px}
.week-item{display:flex;align-items:center;gap:8px;padding:7px 10px;border-radius:6px;color:var(--ink);font-size:.86rem;transition:background .15s}
.week-item:hover{background:#eef2ff;color:var(--accent);opacity:1}
.week-item .dot{width:7px;height:7px;border-radius:50%;background:var(--accent);flex-shrink:0}
.week-item .sub{color:var(--muted);font-size:.76rem;margin-left:auto}
.enter-btn{display:block;text-align:center;padding:11px;margin-top:auto;background:#f0f4ff;color:var(--accent);font-weight:700;border-radius:8px;font-size:.88rem;transition:background .15s,color .15s}
.enter-btn:hover{background:var(--accent);color:#fff;opacity:1}
.enter-btn.anki{background:#fff3e6;color:var(--anki)}
.enter-btn.anki:hover{background:var(--anki);color:#fff}

/* ===== Method legend ===== */
.method-legend{display:grid;grid-template-columns:repeat(auto-fill,minmax(210px,1fr));gap:12px}
.method-cell{display:flex;align-items:center;gap:10px;padding:12px 14px;background:var(--bg2);border:1px solid var(--rule);border-radius:8px;font-size:.86rem}
.method-cell .m-dot{width:11px;height:11px;border-radius:50%;flex-shrink:0}
.method-cell .m-name{font-weight:700}
.method-cell .m-en{color:var(--muted);font-size:.74rem;display:block}

/* ===== CTA banner ===== */
.cta-banner{background:linear-gradient(135deg,#1a3a5c,#2563eb);color:#fff;border-radius:14px;padding:30px;text-align:center;margin-top:8px}
.cta-banner h3{font-family:var(--heading);font-size:1.35rem;margin-bottom:6px;color:#fff}
.cta-banner p{opacity:.85;font-size:.9rem;max-width:560px;margin:0 auto 16px}
.cta-btn{display:inline-block;background:#ffb300;color:#0a1628;font-weight:700;padding:10px 26px;border-radius:24px;font-size:.92rem}
.cta-btn:hover{background:#ffc43d;opacity:1}

/* ===== Footer ===== */
.site-footer{background:#0a1628;color:rgba(255,255,255,.6);padding:26px 0;margin-top:20px;text-align:center;font-size:.8rem}
.site-footer .links{display:flex;justify-content:center;gap:18px;flex-wrap:wrap;margin-bottom:8px}
.site-footer .links a{color:rgba(255,255,255,.75)}
.site-footer .links a:hover{color:#ffb300}

/* ===== Anki center ===== */
.anki-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:14px}
.anki-card{display:flex;flex-direction:column;gap:8px;background:var(--bg2);border:1px solid var(--rule);border-radius:10px;padding:16px}
.anki-card .subj{font-size:.72rem;font-weight:700;text-transform:uppercase;letter-spacing:1px}
.anki-card h3{font-size:1rem;font-weight:700;color:var(--ink)}
.anki-card .dl{background:var(--accent);color:#fff;text-align:center;padding:9px;border-radius:7px;font-size:.85rem;font-weight:600;margin-top:auto}
.anki-card .dl:hover{background:#1e40af;opacity:1}
.group-label{font-family:var(--heading);font-weight:700;font-size:1.1rem;color:var(--ink);margin:24px 0 10px;padding-bottom:6px;border-bottom:2px solid var(--rule);display:flex;align-items:center;gap:10px}

/* ===== Responsive ===== */
@media(max-width:700px){
  .hero h1{font-size:1.9rem}
  .month-grid,.method-legend,.anki-grid{grid-template-columns:1fr}
  .nav-inner{gap:6px;font-size:.78rem;padding:8px 12px}
  .sec-head{flex-direction:column;gap:2px}
}