/* TUNA55 — 时间轴叙事·洄游航线 | bg #0B2434 / accent #7FD8F7 | Croissant One + K2D
   所有类名 tn- 前缀（跨站零共享）。纯 CSS 交互，无 JS。 */

:root {
  --tn-bg: #0B2434;
  --tn-panel: #0F2C40;
  --tn-panel2: #123449;
  --tn-line: #1C4560;
  --tn-silver: #7FD8F7;
  --tn-silver2: #4FA8C9;
  --tn-deep: #2E6E88;
  --tn-ink: #D9E8F0;
  --tn-mute: #9DB6C4;
  --tn-glow: rgba(127, 216, 247, 0.32);
  --tn-red: #E05656;
  --tn-w: 1180px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--tn-bg);
  color: var(--tn-ink);
  font-family: "K2D", "Segoe UI", system-ui, sans-serif;
  font-size: 17px;
  line-height: 1.78;
  overflow-x: clip;
}

h1, h2, h3, .tn-logoword, .tn-btn, .tn-kicker, .tn-ft, .tn-nodenum, .tn-mnavt {
  font-family: "Croissant One", Georgia, serif;
  font-weight: 400;
  letter-spacing: 0.01em;
}

h1 { font-size: clamp(1.5rem, 3.8vw, 2.4rem); line-height: 1.3; color: #F0F9FE; margin: 0.4em 0; }
h2 { font-size: clamp(1.2rem, 2.5vw, 1.6rem); color: var(--tn-silver); margin: 1.6em 0 0.5em; line-height: 1.4; }
h3 { font-size: 1.05rem; color: #EAF7FD; margin: 0 0 0.35em; }
p { margin: 0.65em 0; }
a { color: var(--tn-silver); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; height: auto; display: block; }

.tn-main > section, .tn-headin, .tn-fgrid, .tn-paper { margin-inline: auto; }

/* ---------- 顶部 ---------- */

.tn-head {
  position: sticky;
  top: 0;
  z-index: 40;
  background: rgba(11, 36, 52, 0.95);
  border-bottom: 1px solid var(--tn-line);
  backdrop-filter: blur(6px);
}

.tn-headin {
  max-width: var(--tn-w);
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 10px 20px;
}

.tn-logo { display: inline-flex; align-items: center; gap: 10px; }
.tn-logoreel {
  display: inline-flex;
  gap: 3px;
  padding: 4px 6px;
  background: #081A27;
  border: 1px solid var(--tn-deep);
  border-radius: 8px;
  box-shadow: inset 0 0 10px rgba(127, 216, 247, 0.22);
}
.tn-logoreel b { font-size: 0.72rem; }
.tn-logoword { color: #F0F9FE; font-size: 1.15rem; }

.tn-nav { margin-left: auto; display: flex; gap: 16px; font-size: 0.88rem; }
.tn-nav a { color: var(--tn-mute); padding: 6px 2px; }
.tn-nav a:hover { color: var(--tn-silver); text-decoration: none; }
.tn-nav a.tn-on { color: var(--tn-silver); border-bottom: 2px solid var(--tn-silver); }

.tn-hact { display: flex; gap: 10px; margin-left: 4px; }

.tn-btn {
  display: inline-block;
  padding: 9px 18px;
  border-radius: 22px;
  border: 1px solid var(--tn-deep);
  font-size: 0.82rem;
  text-align: center;
  cursor: pointer;
  font-family: "K2D", sans-serif;
}
.tn-btn:hover { text-decoration: none; transform: translateY(-1px); }
.tn-btn-main {
  background: linear-gradient(120deg, var(--tn-silver), #A8E6FB);
  color: #0A2231;
  font-weight: 700;
  box-shadow: 0 0 18px var(--tn-glow);
}
.tn-btn-main:hover { filter: brightness(1.06); }
.tn-btn-ghost { background: transparent; color: var(--tn-silver); }
.tn-btn-ghost:hover { border-color: var(--tn-silver); }

.tn-burger { display: none; margin-left: auto; cursor: pointer; padding: 6px; }
.tn-burger span { display: block; width: 22px; height: 2px; background: var(--tn-silver); margin: 5px 0; border-radius: 2px; }

.tn-navtog { display: none; }
.tn-mnav { display: none; }

/* ---------- 航线 hero ---------- */

.tn-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(52px, 8vw, 100px) 20px clamp(72px, 9vw, 120px);
  background:
    radial-gradient(70% 90% at 78% 12%, #10314A 0%, transparent 62%),
    radial-gradient(50% 70% at 12% 90%, #0D2939 0%, transparent 60%),
    var(--tn-bg);
}

.tn-wsvg {
  position: absolute;
  left: 0; right: 0; bottom: 0;
  width: 100%;
  height: 130px;
}

.tn-fschool { position: absolute; inset: auto 0 44px 0; height: 40px; pointer-events: none; }
.tn-fish { position: absolute; font-size: 1.15rem; opacity: 0.85; filter: drop-shadow(0 0 6px var(--tn-glow)); }
.tn-f1 { left: 14%; animation: tn-bob 5.2s ease-in-out infinite; }
.tn-f2 { left: 47%; animation: tn-bob 6.4s ease-in-out 0.8s infinite; font-size: 0.85rem; opacity: 0.6; }
.tn-f3 { left: 76%; animation: tn-bob 4.6s ease-in-out 1.6s infinite; }

@keyframes tn-bob {
  0%, 100% { transform: translateY(0) rotate(-4deg); }
  50% { transform: translateY(-12px) rotate(4deg); }
}

.tn-heroin { position: relative; max-width: var(--tn-w); }
.tn-kicker {
  display: inline-block;
  color: #0A2231;
  background: var(--tn-silver);
  border-radius: 14px;
  font-size: 0.72rem;
  padding: 4px 12px;
  margin-bottom: 14px;
}
.tn-herop { max-width: 660px; color: #C4D8E4; }
.tn-heroact { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 26px; }

/* ---------- 洄游时间轴 ---------- */

.tn-route, .tn-seasonsec, .tn-faqsec { max-width: var(--tn-w); padding: clamp(34px, 5vw, 62px) 20px; }
.tn-routep, .tn-seasonp { color: var(--tn-mute); max-width: 660px; }

.tn-routein {
  list-style: none;
  position: relative;
  margin: 34px 0 0;
  padding: 0;
}
/* 中央波浪虚线（中奖线意象） */
.tn-routein::before {
  content: "";
  position: absolute;
  top: 0; bottom: 0;
  left: 50%;
  width: 3px;
  transform: translateX(-50%);
  background: repeating-linear-gradient(180deg, var(--tn-silver2) 0 12px, transparent 12px 24px);
  opacity: 0.55;
}

.tn-node { position: relative; width: 50%; padding: 12px 0; }
.tn-node:nth-child(odd) { left: 0; padding-right: 54px; text-align: right; }
.tn-node:nth-child(even) { left: 50%; padding-left: 54px; }

/* 铃铛浮标节点 */
.tn-nodeb {
  position: absolute;
  top: 34px;
  width: 18px; height: 18px;
  border-radius: 50%;
  background: #0A2231;
  border: 3px solid var(--tn-silver);
  box-shadow: 0 0 0 5px rgba(127, 216, 247, 0.15), 0 0 16px var(--tn-glow);
}
.tn-node:nth-child(odd) .tn-nodeb { right: -9px; }
.tn-node:nth-child(even) .tn-nodeb { left: -9px; }

.tn-nodecard {
  position: relative;
  background: linear-gradient(165deg, var(--tn-panel2), var(--tn-panel));
  border: 1px solid var(--tn-line);
  border-radius: 12px;
  padding: 20px 22px 26px;
  transition: box-shadow 0.2s, transform 0.2s, border-color 0.2s;
}
.tn-nodecard:hover {
  border-color: var(--tn-silver2);
  box-shadow: 0 8px 30px rgba(127, 216, 247, 0.16);
  transform: translateY(-3px);
}
.tn-nodenum {
  display: inline-block;
  color: #07202E;
  background: var(--tn-silver);
  border-radius: 9px;
  padding: 2px 10px;
  font-size: 0.74rem;
  margin-bottom: 10px;
}
.tn-nodecard h3 a { color: #EAF7FD; }
.tn-nodelnk { font-size: 0.8rem; letter-spacing: 0.05em; }

/* ---------- 季节表（机柜灯箱） ---------- */

.tn-season {
  margin: 26px 0 0;
  border: 1px solid var(--tn-line);
  border-top: 4px solid var(--tn-silver2);
  border-radius: 12px;
  background: var(--tn-panel);
  box-shadow: inset 0 10px 24px rgba(127, 216, 247, 0.07);
  padding: 6px 6px 12px;
}
.tn-seasoncap { font-size: 0.78rem; color: var(--tn-mute); padding: 8px 12px 2px; }
.tn-tablewrap { overflow-x: auto; }
.tn-seatable { width: 100%; border-collapse: collapse; min-width: 560px; }
.tn-seatable th {
  font-family: "Croissant One", serif;
  font-weight: 400;
  color: #07202E;
  background: linear-gradient(120deg, var(--tn-silver), #9FE1F9);
  padding: 10px 14px;
  text-align: left;
  font-size: 0.86rem;
}
.tn-seatable td { padding: 10px 14px; border-bottom: 1px dashed var(--tn-line); color: var(--tn-ink); font-size: 0.92rem; vertical-align: top; }
.tn-seatable tr:last-child td { border-bottom: 0; }
.tn-seatable td:first-child { color: var(--tn-silver); white-space: nowrap; }

/* ---------- 关于 / 优势 / 精选 ---------- */

.tn-why { max-width: var(--tn-w); padding: clamp(30px, 4.5vw, 56px) 20px; }
.tn-whygrid { display: grid; grid-template-columns: 1.5fr 1fr; gap: 34px; align-items: start; }
.tn-about h2:first-child { margin-top: 0; }
.tn-whyside {
  background: var(--tn-panel);
  border: 1px solid var(--tn-line);
  border-radius: 12px;
  padding: 20px 22px;
}
.tn-whyside h3 { color: var(--tn-silver); }
.tn-advlist { list-style: none; margin: 0; padding: 0; }
.tn-advlist li { display: flex; flex-direction: column; padding: 12px 0; border-bottom: 1px dashed var(--tn-line); }
.tn-advlist li:last-child { border-bottom: 0; }
.tn-advlist b { color: #EAF7FD; }
.tn-advlist span { color: var(--tn-mute); font-size: 0.92rem; }

.tn-picks { margin-top: 14px; }
.tn-pickrow { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; margin-top: 20px; }
.tn-pick {
  background: var(--tn-panel);
  border: 1px solid var(--tn-line);
  border-radius: 10px;
  padding: 16px 18px;
}
.tn-pick a b { color: #EAF7FD; font-size: 0.98rem; }
.tn-pick p { color: var(--tn-mute); font-size: 0.88rem; }

/* ---------- FAQ / 信任 ---------- */

.tn-q {
  border: 1px solid var(--tn-line);
  border-left: 4px solid var(--tn-silver2);
  border-radius: 8px;
  background: var(--tn-panel);
  padding: 12px 18px;
  margin: 10px 0;
}
.tn-q summary { cursor: pointer; color: #EAF7FD; font-weight: 600; }
.tn-q summary:hover { color: var(--tn-silver); }
.tn-q p { color: var(--tn-mute); }

.tn-trust {
  max-width: var(--tn-w);
  margin: 30px 20px 60px;
  padding: clamp(24px, 4vw, 40px);
  background: linear-gradient(180deg, #0C2A3A, #0A2331);
  border: 1px solid var(--tn-deep);
  border-radius: 14px;
}
.tn-trustlnk { display: inline-block; margin-top: 8px; font-size: 0.9rem; }

/* ---------- 文章纸面 ---------- */

.tn-paper { max-width: 900px; padding: 34px 20px 70px; }

.tn-strip {
  display: flex;
  justify-content: center;
  gap: 28px;
  padding: 10px 0;
  border-bottom: 1px solid var(--tn-line);
  background: #08202F;
  color: var(--tn-silver);
  font-size: 1rem;
  letter-spacing: 0.3em;
}

.tn-crumbs { font-size: 0.8rem; color: var(--tn-mute); margin-bottom: 18px; }
.tn-edulead { font-size: 1.08rem; color: #C4D8E4; }

.tn-fig { margin: 26px 0; border: 1px solid var(--tn-line); border-radius: 10px; background: #08202F; padding: 8px; }
.tn-fig img { width: 100%; border-radius: 6px; }
.tn-fig figcaption { font-size: 0.8rem; color: var(--tn-mute); padding: 8px 6px 4px; }

.tn-navpage h2, .tn-edu h2 { margin-top: 1.7em; }

.tn-steps { list-style: none; counter-reset: tnstep; margin: 18px 0; padding: 0; }
.tn-steps li {
  counter-increment: tnstep;
  position: relative;
  padding: 14px 0 14px 52px;
  border-bottom: 1px dashed var(--tn-line);
}
.tn-steps li::before {
  content: counter(tnstep);
  position: absolute;
  left: 0;
  top: 18px;
  width: 34px; height: 34px;
  border-radius: 50%;
  background: #08202F;
  border: 2px solid var(--tn-silver2);
  color: var(--tn-silver);
  font-family: "Croissant One", serif;
  font-size: 0.9rem;
  display: grid;
  place-items: center;
}
.tn-steps b { display: block; color: #EAF7FD; }
.tn-steps span { color: var(--tn-mute); font-size: 0.94rem; }

.tn-navlist li { padding: 7px 0 7px 22px; position: relative; color: var(--tn-mute); }
.tn-navlist li::before { content: "⌖"; position: absolute; left: 0; color: var(--tn-silver2); }
.tn-navp { color: var(--tn-mute); }

.tn-note {
  border: 1px dashed var(--tn-deep);
  border-radius: 8px;
  background: #0C2A3A;
  padding: 14px 18px;
  color: #CFE8F4;
}

.tn-navaside {
  margin-top: 34px;
  padding: 18px 20px;
  background: var(--tn-panel);
  border: 1px solid var(--tn-line);
  border-radius: 10px;
  display: flex;
  flex-direction: column;
  gap: 7px;
}
.tn-asidet {
  margin: 8px 0 2px;
  color: var(--tn-silver);
  font-family: "Croissant One", serif;
  font-size: 0.78rem;
  letter-spacing: 0.1em;
}

.tn-resp {
  margin-top: 30px;
  padding: 12px 16px;
  border-left: 4px solid var(--tn-silver2);
  border-radius: 0 8px 8px 0;
  background: #08202F;
  color: var(--tn-mute);
  font-size: 0.86rem;
}

/* ---------- 404 ---------- */

.tn-404 { max-width: 640px; margin-inline: auto; text-align: center; padding: 90px 20px; }
.tn-404buoy { font-size: 1.6rem; letter-spacing: 0.25em; }
.tn-404act { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; margin-top: 24px; }

/* ---------- 页脚 ---------- */

.tn-foot { border-top: 1px solid var(--tn-line); background: #08202F; }
.tn-fgrid {
  max-width: var(--tn-w);
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr 1fr;
  gap: 26px;
  padding: 44px 20px 26px;
}
.tn-fbrand p { color: var(--tn-mute); font-size: 0.86rem; }
.tn-ft {
  margin: 0 0 10px;
  color: var(--tn-silver);
  font-size: 0.78rem;
  letter-spacing: 0.12em;
}
.tn-fcol { display: flex; flex-direction: column; gap: 7px; font-size: 0.88rem; }
.tn-fcol a { color: var(--tn-mute); }
.tn-fcol a:hover { color: var(--tn-silver); }
.tn-18 {
  display: inline-block;
  margin-top: 10px;
  width: fit-content;
  border: 2px solid var(--tn-red);
  border-radius: 10px;
  color: var(--tn-red);
  font-weight: 700;
  padding: 1px 8px;
}
.tn-fbot {
  max-width: var(--tn-w);
  margin: 0 auto;
  padding: 16px 20px 26px;
  border-top: 1px solid var(--tn-line);
  color: var(--tn-mute);
  font-size: 0.8rem;
}

/* ---------- 悬浮条（唯一外链） ---------- */

.tn-float {
  position: fixed;
  left: 0; right: 0; bottom: 14px;
  z-index: 60;
  display: flex;
  justify-content: center;
  pointer-events: none;
}
.tn-floatin {
  pointer-events: auto;
  display: flex;
  align-items: center;
  gap: 14px;
  background: rgba(8, 32, 47, 0.96);
  border: 1px solid var(--tn-deep);
  border-radius: 40px;
  box-shadow: 0 6px 30px rgba(0, 0, 0, 0.55), 0 0 20px rgba(127, 216, 247, 0.15);
  padding: 9px 16px;
}
.tn-chip b { margin: 0 5px; font-size: 0.95rem; }
.tn-enter { animation: tn-breathe 1.8s ease-in-out infinite; }

@keyframes tn-breathe {
  0%, 100% { box-shadow: 0 0 8px var(--tn-glow); }
  50% { box-shadow: 0 0 24px var(--tn-glow); }
}

@media (prefers-reduced-motion: reduce) {
  .tn-fish, .tn-enter { animation: none; }
}

/* ---------- 响应式 ---------- */

@media (max-width: 1024px) {
  .tn-whygrid { grid-template-columns: 1fr; }
  .tn-pickrow { grid-template-columns: 1fr 1fr; }
  .tn-fgrid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 767px) {
  .tn-nav, .tn-hact { display: none; }
  .tn-burger { display: block; }
  .tn-navtog:checked ~ .tn-mnav {
    display: flex;
    flex-direction: column;
    gap: 4px;
    padding: 10px 22px 20px;
    border-top: 1px solid var(--tn-line);
    background: #0A2331;
  }
  .tn-mnav a { color: var(--tn-ink); padding: 8px 0; border-bottom: 1px dashed var(--tn-line); }
  .tn-mnav a:hover { color: var(--tn-silver); }
  .tn-mnavt {
    margin: 14px 0 4px;
    color: var(--tn-silver);
    font-size: 0.74rem;
    letter-spacing: 0.12em;
  }
  /* 时间轴改单列，线靠左 */
  .tn-routein::before { left: 10px; transform: none; }
  .tn-node, .tn-node:nth-child(odd), .tn-node:nth-child(even) {
    width: 100%;
    left: 0;
    padding: 10px 0 10px 40px;
    text-align: left;
  }
  .tn-node:nth-child(odd) .tn-nodeb, .tn-node:nth-child(even) .tn-nodeb { left: 2px; right: auto; }
  .tn-pickrow { grid-template-columns: 1fr; }
  .tn-fish { display: none; }
  .tn-trust { margin-inline: 20px; }
}

@media (min-width: 768px) and (max-width: 1439px) {
  .tn-hero { padding-top: 68px; }
  .tn-whygrid { gap: 24px; }
}