:root {
  --ink: #0c3446;
  --copy: #3f5d69;
  --mute: #7a929c;
  --teal: #0a8fae;
  --gold: #c98a12;
  --line: rgba(10, 143, 174, .16);
  --paper: #f5f9fc;
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(60% 40% at 100% 0%, rgba(70, 190, 220, .14), transparent 70%),
    radial-gradient(50% 35% at 0% 30%, rgba(140, 150, 245, .08), transparent 70%),
    var(--paper);
  font: 15px/1.7 "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", system-ui, sans-serif;
}
a { color: inherit; text-decoration: none; }
img { display: block; max-width: 100%; }

.fbs-bar {
  position: sticky; top: 0; z-index: 10;
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
  padding: 12px max(16px, env(safe-area-inset-right)) 12px max(16px, env(safe-area-inset-left));
  background: rgba(255, 255, 255, .82);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}
.fbs-brand img { height: 28px; width: auto; filter: invert(1) hue-rotate(180deg) saturate(1.3); }
.fbs-back { color: var(--teal); font-size: 14px; font-weight: 600; letter-spacing: .04em; }
.fbs-back:hover { color: var(--gold); }

.fbs-main { width: min(1200px, 100%); margin: 0 auto; padding: clamp(32px, 5vw, 64px) max(16px, env(safe-area-inset-right)) 48px max(16px, env(safe-area-inset-left)); }
.fbs-head { margin-bottom: clamp(24px, 4vw, 44px); text-align: center; }
.fbs-kicker { margin: 0 0 10px; color: var(--teal); font-size: 13px; font-weight: 700; letter-spacing: .2em; }
.fbs-kicker i { display: inline-block; width: 4px; height: 4px; margin: 0 .9em; border-radius: 50%; background: currentColor; vertical-align: middle; }
.fbs-head h1 {
  margin: 0;
  font-size: clamp(26px, 4.2vw, 46px);
  line-height: 1.3;
  letter-spacing: .02em;
  background: linear-gradient(100deg, #0c3446 0%, #007f9b 55%, #4f86de 100%);
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
}
.fbs-meta { margin: 12px 0 0; color: var(--copy); font-size: 14px; text-wrap: balance; }

.fbs-deck { display: grid; gap: clamp(14px, 2vw, 24px); }
.fbs-slide { margin: 0; border-radius: clamp(10px, 1.4vw, 18px); overflow: hidden; background: #fff; box-shadow: 0 18px 40px -26px rgba(6, 80, 110, .55), 0 0 0 1px var(--line); }
.fbs-slide img { width: 100%; height: auto; }
.fbs-slide figcaption { padding: 8px 14px; color: var(--mute); font-size: 12px; letter-spacing: .12em; text-align: right; border-top: 1px solid var(--line); }
.fbs-empty { margin: 0; padding: 48px 16px; color: var(--mute); text-align: center; border: 1px dashed var(--line); border-radius: 16px; background: rgba(255, 255, 255, .6); }

.fbs-foot-cta { margin: clamp(28px, 4vw, 48px) 0 0; text-align: center; }
.fbs-btn { display: inline-block; padding: 12px 26px; border-radius: 999px; color: #fff; font-weight: 700; letter-spacing: .08em; background: linear-gradient(120deg, #04445f 0%, #05577d 45%, #0a8fae 100%); box-shadow: 0 14px 30px -16px rgba(5, 87, 125, .85); }
.fbs-btn:hover { filter: brightness(1.08); }

.fbs-footer { padding: 24px max(16px, env(safe-area-inset-right)) calc(24px + env(safe-area-inset-bottom)) max(16px, env(safe-area-inset-left)); border-top: 1px solid var(--line); color: var(--mute); font-size: 12px; text-align: center; }
.fbs-footer p { margin: 0; }