* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body { font-family: "Noto Sans TC", Arial, sans-serif; line-height: 1.7; color: #1f2937; background: #ffffff; }
.container { width: min(1120px, 92%); margin: 0 auto; }
.narrow { max-width: 850px; }
.top-header { background: rgba(255,255,255,.95); border-bottom: 1px solid #e5e7eb; position: sticky; top: 0; z-index: 20; backdrop-filter: blur(12px); }
.nav-container { display: flex; justify-content: space-between; align-items: center; padding: 16px 0; gap: 16px; }
.logo { display: flex; align-items: center; gap: 12px; text-decoration: none; color: inherit; }
.logo-mark { background: #1e3a8a; color: white; font-weight: bold; padding: 10px 12px; border-radius: 10px; letter-spacing: .5px; }
.logo h1 { font-size: 20px; }
.logo p { font-size: 12px; color: #6b7280; }
nav { display: flex; gap: 18px; }
nav a { text-decoration: none; color: #374151; font-size: 15px; }
nav a:hover { color: #1e3a8a; }
.menu-toggle { display: none; border: 0; background: #f3f4f6; padding: 8px 11px; border-radius: 8px; font-size: 20px; }
.hero { background: linear-gradient(120deg, #eff6ff, #ffffff); padding: 90px 0; }
.hero-grid { display: grid; grid-template-columns: 1.6fr .9fr; gap: 36px; align-items: center; }
.tag { color: #1e40af; font-weight: 700; margin-bottom: 12px; }
.hero h2 { font-size: clamp(32px, 4vw, 46px); line-height: 1.25; margin-bottom: 18px; }
.hero-text { font-size: 18px; color: #4b5563; margin-bottom: 28px; }
.hero-buttons { display: flex; gap: 12px; flex-wrap: wrap; }
.hero-card { background: #fff; border: 1px solid #e5e7eb; border-radius: 22px; padding: 28px; box-shadow: 0 18px 40px rgba(30,58,138,.08); }
.hero-card h3 { margin-bottom: 12px; color: #111827; }
.hero-card p { padding: 7px 0; border-bottom: 1px solid #f3f4f6; color: #4b5563; }
.btn { display: inline-block; padding: 11px 18px; border-radius: 9px; text-decoration: none; font-weight: 700; border: 1px solid transparent; cursor: pointer; }
.btn.primary { background: #1e3a8a; color: white; }
.btn.secondary { background: white; color: #1e3a8a; border-color: #1e3a8a; }
.section { padding: 70px 0; }
.section.light { background: #f9fafb; }
.section-title { margin-bottom: 28px; }
.section-title h2, .section h2 { font-size: 30px; margin-bottom: 6px; }
.section-title p { color: #6b7280; }
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 20px; }
.card { background: white; border: 1px solid #e5e7eb; border-radius: 16px; padding: 22px; box-shadow: 0 8px 20px rgba(0,0,0,.04); }
.card h3 { margin-bottom: 10px; color: #111827; }
.card p { color: #4b5563; margin-bottom: 12px; }
.card a, .paper-item a { color: #1e40af; font-weight: 700; text-decoration: none; }
.filter-box { margin-bottom: 24px; }
.filter-box input { width: 100%; padding: 13px 15px; border: 1px solid #d1d5db; border-radius: 10px; font-size: 16px; }
.paper-list { display: grid; gap: 16px; }
.paper-item { padding: 20px; border: 1px solid #e5e7eb; border-radius: 16px; background: white; }
.paper-meta { font-size: 14px; color: #6b7280; margin: 6px 0 10px; }
.paper-category { display: inline-block; background: #dbeafe; color: #1e40af; padding: 3px 9px; border-radius: 999px; font-size: 13px; margin-bottom: 8px; }
.upload-box { background: white; border-radius: 18px; padding: 36px; border: 1px solid #e5e7eb; }
.upload-box .btn { margin-top: 16px; margin-right: 8px; }
.note { color: #6b7280; font-size: 14px; margin-top: 14px; }
footer { background: #111827; color: #d1d5db; text-align: center; padding: 24px; }
@media (max-width: 820px) {
  .nav-container { align-items: flex-start; flex-direction: column; }
  .menu-toggle { display: block; position: absolute; right: 4%; top: 18px; }
  nav { display: none; flex-wrap: wrap; gap: 12px; }
  nav.open { display: flex; }
  .hero-grid { grid-template-columns: 1fr; }
}