:root {
  --ink: #e8f4f8; --muted: #9dbccb; --line: rgba(160, 220, 235, .16);
  --card: rgba(8, 40, 62, .62); --glow: #7fe3e0; --warm: #ffb48a;
  --surface: #0d5f84; --deep: #031726; --abyss: #01070f;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0; color: var(--ink); line-height: 1.65;
  font: 17px/1.65 "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, serif;
  background: linear-gradient(180deg, var(--surface) 0, #08405f 22rem, var(--deep) 60rem, var(--abyss) 100%) fixed var(--deep);
  min-height: 100vh;
}
a { color: var(--glow); text-underline-offset: .2em; }
a:hover { color: #fff; }
h1, h2, h3, nav, .tag, .meta, .ruler, footer { font-family: "Avenir Next", "Segoe UI", system-ui, sans-serif; }
h1 { font-size: clamp(2.3rem, 6vw, 4.2rem); line-height: 1.05; margin: 0 0 1rem; letter-spacing: -.02em; }
h2 { font-size: clamp(1.5rem, 3vw, 2.1rem); line-height: 1.2; margin: 0 0 .8rem; }
h3 { font-size: 1.15rem; margin: 0 0 .3rem; }
p { margin: 0 0 1rem; }
.wrap { width: min(1080px, 100% - 2.5rem); margin-inline: auto; }

header.top { position: sticky; top: 0; z-index: 5; backdrop-filter: blur(10px); background: rgba(3, 23, 38, .55); border-bottom: 1px solid var(--line); }
header.top .wrap { display: flex; align-items: center; justify-content: space-between; gap: 1rem; padding: .8rem 0; flex-wrap: wrap; }
.brand { display: flex; align-items: center; gap: .6rem; color: var(--ink); text-decoration: none; font: 600 1.05rem "Avenir Next", "Segoe UI", system-ui, sans-serif; letter-spacing: .04em; }
.brand svg { width: 1.7rem; height: 1.7rem; color: var(--glow); }
nav { display: flex; gap: 1.3rem; font-size: .95rem; }
nav a { color: var(--muted); text-decoration: none; padding: .2rem 0; border-bottom: 2px solid transparent; }
nav a:hover, nav a[aria-current] { color: var(--ink); border-color: var(--glow); }

.hero { position: relative; overflow: hidden; padding: clamp(4rem, 12vw, 8rem) 0 clamp(5rem, 12vw, 8rem); }
.hero p.lead { font-size: 1.25rem; max-width: 36rem; color: #d3e8f0; }
.hero h1 span { background: linear-gradient(90deg, var(--glow), #b9f3ff 50%, var(--warm)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero .drift { position: absolute; right: -2rem; top: 12%; width: min(46vw, 430px); color: rgba(127, 227, 224, .2); animation: drift 14s ease-in-out infinite alternate; }
.btn { display: inline-block; margin-top: .6rem; padding: .7rem 1.3rem; border-radius: 999px; border: 1px solid var(--glow); color: var(--ink); text-decoration: none; font: 600 .95rem "Avenir Next", "Segoe UI", system-ui, sans-serif; transition: background .25s, color .25s; }
.btn:hover { background: var(--glow); color: #04263a; }
.wave { display: block; width: 100%; height: 70px; color: rgba(127, 227, 224, .14); }
.wave path { animation: sway 9s ease-in-out infinite alternate; }

.bubbles { position: absolute; inset: 0; pointer-events: none; }
.bubbles i { position: absolute; bottom: -3rem; border-radius: 50%; border: 1px solid rgba(190, 240, 250, .45); background: radial-gradient(circle at 30% 30%, rgba(255, 255, 255, .35), transparent 60%); animation: rise linear infinite; }
.bubbles i:nth-child(1) { left: 8%; width: 14px; height: 14px; animation-duration: 13s; }
.bubbles i:nth-child(2) { left: 22%; width: 8px; height: 8px; animation-duration: 9s; animation-delay: 3s; }
.bubbles i:nth-child(3) { left: 41%; width: 20px; height: 20px; animation-duration: 17s; animation-delay: 1s; }
.bubbles i:nth-child(4) { left: 58%; width: 10px; height: 10px; animation-duration: 11s; animation-delay: 6s; }
.bubbles i:nth-child(5) { left: 73%; width: 16px; height: 16px; animation-duration: 15s; animation-delay: 2s; }
.bubbles i:nth-child(6) { left: 90%; width: 7px; height: 7px; animation-duration: 10s; animation-delay: 5s; }
@keyframes rise { from { transform: translate(0, 0); opacity: 0; } 12% { opacity: 1; } to { transform: translate(24px, -110vh); opacity: 0; } }
@keyframes drift { from { transform: translate(0, 0) rotate(-4deg); } to { transform: translate(-28px, 26px) rotate(5deg); } }
@keyframes sway { from { transform: translateX(-30px); } to { transform: translateX(30px); } }

section { padding: 3rem 0; }
.intro { max-width: 44rem; }
.grid { display: grid; gap: 1.2rem; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); margin-top: 1.5rem; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: 18px; padding: 1.4rem; transition: transform .3s, border-color .3s, box-shadow .3s; }
.card:hover { transform: translateY(-5px); border-color: rgba(127, 227, 224, .55); box-shadow: 0 14px 40px rgba(0, 0, 0, .35), 0 0 30px rgba(127, 227, 224, .08); }
.card svg.icon { width: 3.4rem; height: 3.4rem; color: var(--glow); margin-bottom: .6rem; transition: transform .5s; }
.card:hover svg.icon { transform: translateX(6px) rotate(-4deg); }
.card em.sci { display: block; color: var(--muted); font-size: .93rem; margin-bottom: .7rem; }
.card p { font-size: .98rem; margin-bottom: .7rem; }
.tag { display: inline-block; font-size: .72rem; letter-spacing: .09em; text-transform: uppercase; padding: .2rem .6rem; border-radius: 999px; border: 1px solid var(--line); color: var(--muted); margin: 0 .3rem .3rem 0; }
.tag.warn { color: var(--warm); border-color: rgba(255, 180, 138, .4); }
.meta { font-size: .86rem; color: var(--muted); }

.facts { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 1rem; margin: 2rem 0 0; padding: 0; list-style: none; }
.facts li { border-left: 2px solid var(--glow); padding: .2rem 0 .2rem 1rem; }
.facts b { display: block; font: 600 1.7rem "Avenir Next", "Segoe UI", system-ui, sans-serif; color: #fff; }
.facts span { color: var(--muted); font-size: .92rem; }

.zone { display: grid; grid-template-columns: 7.5rem 1fr; gap: 1.5rem; padding: 3.5rem 0; border-top: 1px dashed var(--line); }
.ruler { font-size: .85rem; color: var(--muted); letter-spacing: .06em; position: sticky; top: 5rem; align-self: start; }
.ruler b { display: block; font-size: 1.5rem; color: var(--ink); letter-spacing: 0; }
.zone ul { padding-left: 1.1rem; margin: 0; }
.zone li { margin-bottom: .4rem; }
.zone li::marker { color: var(--glow); }
.zone.dark h2 { text-shadow: 0 0 22px rgba(127, 227, 224, .45); }

.place { display: grid; grid-template-columns: 1fr 1fr; gap: 2rem; align-items: start; padding: 2.5rem 0; border-top: 1px solid var(--line); }
.place aside { background: var(--card); border: 1px solid var(--line); border-radius: 18px; padding: 1.2rem 1.4rem; font-size: .96rem; }
.place aside dt { color: var(--muted); font: .8rem "Avenir Next", "Segoe UI", system-ui, sans-serif; text-transform: uppercase; letter-spacing: .08em; margin-top: .7rem; }
.place aside dd { margin: 0; }

.sources li { margin-bottom: .5rem; }
footer { border-top: 1px solid var(--line); margin-top: 3rem; padding: 2rem 0 3rem; color: var(--muted); font-size: .88rem; }
footer .wrap { display: flex; justify-content: space-between; gap: 1rem; flex-wrap: wrap; }

@media (max-width: 720px) {
  .zone, .place { grid-template-columns: 1fr; gap: .8rem; }
  .ruler { position: static; }
  .hero .drift { opacity: .5; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
  html { scroll-behavior: auto; }
}