/* ═══ 北民大新生指南 - Neo-Brutalism 共享样式 ═══
 * 统一设计语言：纯色块 + 粗黑边框 + 硬偏移阴影
 * v3: 2026-07-30 Neo-Brutalism 全项目统一
 */

/* ── Google Fonts ── */
@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@400;500;600;700;800;900&display=swap');

/* ── Neo-Brutalism Design Tokens ── */
:root {
  --blue: #2563eb;
  --yellow: #facc15;
  --coral: #fb5c4a;
  --green: #22c55e;
  --purple: #8b5cf6;
  --orange: #f97316;
  --pink: #ec4899;
  --cyan: #06b6d4;
  --ink: #1a1a2e;
  --ink-dim: #5c5c7a;
  --bg: #faf7f2;
  --font: 'Noto Sans SC', -apple-system, 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --bd: 2.5px solid #1a1a2e;
  --shadow: 5px 5px 0 #1a1a2e;
  --shadow-sm: 3px 3px 0 #1a1a2e;
  --shadow-xs: 2px 2px 0 #1a1a2e;
  --radius: 14px;
  --radius-sm: 10px;
  --radius-xs: 6px;
}

/* ── Reset & Base ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; -webkit-tap-highlight-color: transparent; scroll-behavior: smooth; }
body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--ink);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
  min-height: 100vh;
  /* 微妙点阵纹理 */
  background-image: radial-gradient(circle, rgba(26,26,46,0.06) 1px, transparent 1px);
  background-size: 24px 24px;
}
a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }

/* ── Page Wrapper ── */
.page-content-wrapper {
  max-width: 480px;
  margin: 0 auto;
  padding: 0 16px 6rem;
  position: relative;
  z-index: 1;
  min-height: 100vh;
  animation: page-fade-in 0.4s ease-out;
}
@keyframes page-fade-in {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ══════════════════════════════════════════
   HERO — 纯色块 + 硬阴影
   ══════════════════════════════════════════ */
.hero-section {
  position: relative;
  margin: 0 -16px;
  padding: 32px 24px 40px;
  background: #2563eb;
  border-radius: 0 0 28px 28px;
  overflow: hidden;
  color: #fff;
  box-shadow: none;
}
.hero-section::before { content: none; }
.hero-section::after {
  content: '+';
  position: absolute;
  bottom: 20px;
  left: 20px;
  font-size: 28px;
  font-weight: 900;
  color: rgba(255,255,255,0.18);
  animation: float-y 4s ease-in-out infinite 1s;
}
@keyframes float-y {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-12px); }
}
.hero-breadcrumb {
  font-size: 12px;
  font-weight: 700;
  opacity: 0.75;
  margin-bottom: 14px;
  position: relative;
  z-index: 1;
}
.hero-breadcrumb a { color: #fff; opacity: 0.85; }
.hero-breadcrumb a:hover { opacity: 1; }
.hero-title {
  font-size: clamp(1.75rem, 8vw, 2.2rem);
  font-weight: 900;
  line-height: 1.2;
  margin-bottom: 8px;
  position: relative;
  z-index: 1;
}
.hero-sub {
  font-size: 0.95rem;
  font-weight: 600;
  opacity: 0.9;
  line-height: 1.7;
  position: relative;
  z-index: 1;
}

/* ══════════════════════════════════════════
   SECTION HEADER — 黄色荧光笔效果
   ══════════════════════════════════════════ */
.section-hd {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
}
.section-hd-title {
  font-size: 24px;
  font-weight: 900;
  color: var(--ink);
  position: relative;
  display: inline-block;
}
.section-hd-title::after {
  content: '';
  position: absolute;
  bottom: 2px;
  left: -2px;
  right: -2px;
  height: 10px;
  background: rgba(250,204,21,0.5);
  z-index: -1;
  border-radius: 2px;
  transform: rotate(-1deg);
}
.section-hd-tag {
  font-size: 11px;
  font-weight: 900;
  color: var(--ink);
  background: var(--yellow);
  padding: 5px 12px;
  border-radius: var(--radius-xs);
  border: 2px solid var(--ink);
  box-shadow: var(--shadow-xs);
}

/* ══════════════════════════════════════════
   FLOATING BUTTON — Neo-Brutalism
   ══════════════════════════════════════════ */
#float-btn {
  position: fixed;
  bottom: 24px;
  right: 16px;
  z-index: 40;
  width: 56px;
  height: 56px;
  border-radius: 16px;
  background: var(--blue);
  color: #fff;
  border: var(--bd);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow);
  transition: transform 0.15s, box-shadow 0.15s;
  animation: none;
}
#float-btn:hover {
  transform: translate(-2px, -2px);
  box-shadow: 7px 7px 0 var(--ink);
}
#float-btn:active {
  transform: translate(2px, 2px);
  box-shadow: 1px 1px 0 var(--ink);
}
#float-btn svg { width: 24px; height: 24px; }
#float-btn .float-btn-icon { width: 24px; height: 24px; }

/* ══════════════════════════════════════════
   FOOTER
   ══════════════════════════════════════════ */
.site-footer {
  text-align: center;
  padding: 20px 16px;
  font-size: 12px;
  font-weight: 600;
  color: var(--ink-dim);
  background: none;
  border-top: 2.5px solid var(--ink);
}

/* ══════════════════════════════════════════
   QR CODE MODAL — 硬阴影 + 无毛玻璃
   ══════════════════════════════════════════ */
#qrcode-modal {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 100;
  align-items: center;
  justify-content: center;
}
#qrcode-modal.modal-visible { display: flex; }
#qrcode-modal .modal-overlay {
  position: absolute;
  inset: 0;
  background: rgba(26,26,46,0.5);
}
#qrcode-modal .modal-content {
  position: relative;
  background: #fff;
  border: var(--bd);
  border-radius: 20px;
  padding: 36px 28px;
  text-align: center;
  max-width: 300px;
  width: 90%;
  box-shadow: 8px 8px 0 var(--ink);
  animation: modal-pop 0.3s ease-out;
}
@keyframes modal-pop {
  from { opacity: 0; transform: scale(0.92) translateY(16px); }
  to { opacity: 1; transform: scale(1) translateY(0); }
}
#qrcode-modal .modal-title {
  font-family: var(--font);
  font-size: 22px;
  font-weight: 900;
  color: var(--ink);
  margin: 0 0 8px;
}
#qrcode-modal .modal-hint {
  font-family: var(--font);
  font-size: 13px;
  font-weight: 600;
  color: var(--ink-dim);
  margin: 0 0 20px;
}
#qrcode-modal .qr-placeholder {
  width: 180px;
  height: 180px;
  margin: 0 auto 20px;
  background: var(--bg);
  border: 2px dashed rgba(26,26,46,0.25);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--ink-dim);
  font-size: 13px;
  font-weight: 600;
}
#qrcode-modal .modal-close-btn {
  display: inline-block;
  background: #fff;
  color: var(--ink);
  font-family: var(--font);
  font-size: 14px;
  font-weight: 900;
  padding: 11px 28px;
  border: var(--bd);
  border-radius: var(--radius-sm);
  cursor: pointer;
  box-shadow: var(--shadow-sm);
  transition: transform 0.15s, box-shadow 0.15s;
}
#qrcode-modal .modal-close-btn:hover {
  transform: translate(-1px, -1px);
  box-shadow: 4px 4px 0 var(--ink);
}
#qrcode-modal .modal-close-btn:active {
  transform: translate(1px, 1px);
  box-shadow: 1px 1px 0 var(--ink);
}

/* ── Mobile ── */
@media (max-width: 640px) {
  .page-content-wrapper {
    padding: 0 12px 5rem;
  }
  .hero-section {
    padding: 28px 20px 36px;
  }
  .hero-title {
    font-size: clamp(1.5rem, 7vw, 1.8rem);
  }
}