:root {
  --b-ink: #111827;
  --b-muted: #667085;
  --b-line: rgba(15, 23, 42, 0.1);
  --b-paper: rgba(255, 255, 255, 0.74);
  --b-soft: #f8fafc;
  --b-warm: #fff7ed;
}

body {
  background: linear-gradient(135deg, #f8fbff 0%, #fffaf5 48%, #eef6ff 100%);
  color: var(--b-ink);
}

.b-main { min-height: 100vh; }

.b-page {
  width: min(1180px, calc(100% - 48px));
  margin: 0 auto;
}

.b-hero { padding: 150px 0 54px; }

.b-hero-grid {
  display: grid;
  grid-template-columns: minmax(280px, 0.85fr) minmax(280px, 1fr);
  gap: 54px;
  align-items: end;
}

.b-eyebrow {
  margin-bottom: 18px;
  color: #7c8aa0;
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.b-hero h1 {
  font-size: clamp(54px, 8vw, 104px);
  line-height: 0.92;
  letter-spacing: 0;
}

.b-hero-copy {
  max-width: 620px;
  color: #475569;
  font-size: 18px;
  line-height: 2;
}

.b-nav-wrap {
  position: sticky;
  top: 0;
  z-index: 30;
  padding: 12px 0 18px;
  background: rgba(255, 255, 255, 0.72);
  border-top: 1px solid rgba(255,255,255,0.75);
  border-bottom: 1px solid var(--b-line);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
}

.b-year-nav {
  display: flex;
  gap: 10px;
  overflow-x: auto;
  padding: 4px 0 8px;
  scrollbar-width: thin;
}

.b-year-btn {
  flex: 0 0 auto;
  border: 1px solid var(--b-line);
  background: #fff;
  border-radius: 999px;
  padding: 9px 18px;
  color: #1f2937;
  font-size: 14px;
  cursor: pointer;
  transition: background 0.25s ease, color 0.25s ease, transform 0.25s ease;
}

.b-year-btn:hover, .b-year-btn.active {
  background: #111;
  color: #fff;
  transform: translateY(-1px);
}

.b-nav-note {
  color: #8492a6;
  font-size: 13px;
}

.b-timeline { padding: 48px 0 100px; }

.b-year-section {
  display: none;
  margin-bottom: 76px;
}

.b-year-section.visible { display: block; }

.b-year-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 22px;
}

.b-year-head p {
  font-size: clamp(42px, 7vw, 76px);
  font-weight: 800;
  line-height: 1;
}

.b-year-head span {
  color: #94a3b8;
  font-size: 14px;
}

.b-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  grid-auto-flow: dense;
  gap: 18px;
}

.b-card {
  min-height: 360px;
  border: 1px solid rgba(15,23,42,0.08);
  border-radius: 24px;
  background: var(--b-paper);
  overflow: hidden;
  cursor: pointer;
  box-shadow: 0 18px 44px rgba(15,23,42,0.06);
  transition: transform 0.25s ease, box-shadow 0.25s ease, border-color 0.25s ease;
}

.b-card:hover, .b-card:focus-visible {
  transform: translateY(-5px);
  border-color: rgba(17, 24, 39, 0.2);
  box-shadow: 0 24px 60px rgba(15,23,42,0.12);
  outline: none;
}

.b-card-wide { grid-column: span 2; }

.b-card-media {
  position: relative;
  height: 190px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: radial-gradient(circle at 20% 20%, rgba(14,165,233,0.22), transparent 30%), radial-gradient(circle at 80% 30%, rgba(251,146,60,0.24), transparent 28%), linear-gradient(135deg, #eef6ff, #fff7ed);
  color: rgba(15,23,42,0.22);
  font-size: 52px;
  font-weight: 800;
  letter-spacing: 0.04em;
}

.b-card-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.b-card-body { padding: 22px 22px 26px; }

.b-card-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  color: #94a3b8;
  font-size: 12px;
  margin-bottom: 14px;
}

.b-card-meta span {
  color: #0f766e;
  background: rgba(20,184,166,0.1);
  border-radius: 999px;
  padding: 5px 10px;
}

.b-card h3 {
  font-size: 22px;
  line-height: 1.35;
  margin-bottom: 10px;
}

.b-card p:last-child {
  color: #64748b;
  font-size: 14px;
  line-height: 1.8;
}

.b-modal-backdrop {
  position: fixed;
  inset: 0;
  z-index: 10020;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 28px;
  background: rgba(15,23,42,0.48);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.b-modal-backdrop.open { display: flex; }

.b-modal {
  width: min(820px, 100%);
  max-height: min(760px, 92vh);
  overflow: auto;
  border-radius: 28px;
  background: #fff;
  box-shadow: 0 30px 90px rgba(0,0,0,0.24);
  position: relative;
}

.b-modal-close {
  position: absolute;
  top: 16px;
  right: 16px;
  width: 38px;
  height: 38px;
  border: 0;
  border-radius: 999px;
  background: rgba(255,255,255,0.9);
  cursor: pointer;
  font-size: 18px;
  z-index: 2;
}

.b-modal-cover {
  height: 310px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: radial-gradient(circle at 25% 25%, rgba(14,165,233,0.22), transparent 32%), radial-gradient(circle at 75% 35%, rgba(251,146,60,0.24), transparent 30%), linear-gradient(135deg, #f8fafc, #fff7ed);
  color: rgba(15,23,42,0.18);
  font-size: 64px;
  font-weight: 800;
}

.b-modal-cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.b-modal-content { padding: 34px 42px 44px; }

.b-modal-meta {
  color: #64748b;
  font-size: 13px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 10px;
}

.b-modal h2 {
  font-size: clamp(28px, 5vw, 46px);
  line-height: 1.1;
  margin-bottom: 24px;
}

.b-modal-content p {
  color: #475569;
  font-size: 16px;
  line-height: 1.95;
  margin-bottom: 16px;
}

@media (max-width: 960px) {
  .b-hero-grid { grid-template-columns: 1fr; gap: 24px; }
  .b-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 640px) {
  .b-page { width: min(100% - 28px, 1180px); }
  .b-hero { padding: 116px 0 38px; }
  .b-hero-copy { font-size: 15px; line-height: 1.8; }
  .b-grid { display: block; }
  .b-card-wide { grid-column: auto; }
  .b-card { min-height: auto; margin-bottom: 16px; border-radius: 20px; }
  .b-card-media { height: 170px; }
  .b-year-head { align-items: flex-start; flex-direction: column; gap: 8px; }
  .b-modal-backdrop { padding: 14px; }
  .b-modal { border-radius: 22px; }
  .b-modal-cover { height: 220px; }
  .b-modal-content { padding: 26px 22px 32px; }
}

.xhs-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;

  background: none;      /* ❌ 去掉灰色 */
  width: auto;
  height: auto;
  padding: 0;
}

/* 控制图片大小 */
.xhs-btn img {
  width: 26px;   /* ⭐ 比原本大一点 */
  height: 26px;

  filter: brightness(0); /* 黑色 */

  transition: 0.3s;
}

/* hover */
.xhs-btn:hover img {
  filter: brightness(0) invert(1);
  transform: scale(1.1); /* ⭐ 微微放大 */
}