/* =========================================================
   LIBWATER — design system "DEPTH"
   Concept: the page reads like looking straight down through
   clear water — pale surface light fading into deep abyssal ink.
   Signature element: the ripple badge (concentric rings around
   a catalogue number), standing in for a sensor/instrument
   reading rather than a library stamp.

   Palette
     --abyss   #041B2D  near-black deep-sea ink (dark sections, text)
     --deep    #0B4870  primary structural blue
     --current #1C82AE  primary accent / interactive blue
     --surface #6FD3E3  pale cyan accent (highlights, ripples)
     --foam    #F5FBFC  page background, cool near-white
     --mist    #E4F3F6  tinted section background
     --line    #CFE6EA  hairlines
     --ink     #0B2733  body text
     --ink-2   #4F7480  secondary text
     --amber   #C77F1E  missing-data flag

   Type
     Display: "Space Grotesk" — geometric, technical, contemporary
     Body:    "Inter"
     Data:    "IBM Plex Mono" — scores, catalogue numbers, units
   ========================================================= */

:root{
  --abyss:   #041B2D;
  --deep:    #0B4870;
  --current: #1C82AE;
  --surface: #6FD3E3;
  --foam:    #F5FBFC;
  --mist:    #E4F3F6;
  --line:    #CFE6EA;
  --ink:     #0B2733;
  --ink-2:   #4F7480;
  --ink-faint: #86A5AD;
  --amber:   #C77F1E;

  --display: "Space Grotesk", -apple-system, BlinkMacSystemFont, sans-serif;
  --sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, monospace;

  --radius: 10px;
  --radius-sm: 6px;
  --container: 1180px;
}

*{ box-sizing: border-box; }
html{ scroll-behavior: smooth; }
body{
  margin:0;
  background: var(--foam);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}
a{ color: inherit; text-decoration: none; }
img{ max-width:100%; display:block; }
button{ font-family: inherit; cursor:pointer; }
::selection{ background: var(--current); color: #fff; }

h1,h2,h3,h4{
  font-family: var(--display);
  color: var(--abyss);
  font-weight: 600;
  letter-spacing: -0.02em;
  margin: 0 0 .5em;
}
h1{ font-size: clamp(2.4rem, 5vw, 4rem); line-height: 1.02; font-weight: 600;}
h2{ font-size: clamp(1.5rem, 2.6vw, 2.15rem); }
h3{ font-size: 1.2rem; }
p{ margin: 0 0 1em; }

.container{ max-width: var(--container); margin: 0 auto; padding: 0 28px; }
.small-caps{
  font-family: var(--mono);
  font-size: .72rem;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--current);
}
.muted{ color: var(--ink-2); }
.center{ text-align:center; }

.skip-link{
  position:absolute; left:-999px; top:0; background:var(--abyss); color:#fff;
  padding:10px 16px; z-index:200;
}
.skip-link:focus{ left:12px; top:12px; }
:focus-visible{ outline: 2px solid var(--current); outline-offset: 2px; }

/* ---------- header ---------- */
.site-header{
  position: sticky; top:0; z-index: 100;
  background: rgba(245,251,252,.9);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.site-header .bar{
  display:flex; align-items:center; justify-content:space-between;
  height: 68px;
}
.wordmark{
  font-family: var(--display); font-weight: 600; font-size: 1.3rem; color: var(--abyss);
  display:flex; align-items:center; gap:10px; letter-spacing: -0.02em;
}
.wordmark .drop{
  width: 22px; height: 22px; border-radius: 50% 50% 50% 4px; transform: rotate(45deg);
  background: linear-gradient(160deg, var(--surface), var(--current));
  display:inline-block; flex-shrink:0;
}
.wordmark small{
  font-family: var(--mono); font-size: .56rem; letter-spacing:.1em;
  color: var(--ink-faint); font-weight:400; text-transform:uppercase;
  display:none;
}
@media (min-width: 560px){ .wordmark small{ display:inline; margin-left:2px; } }

nav.main-nav{ display:flex; gap: 26px; align-items:center; }
nav.main-nav a{
  font-size: .92rem; font-weight:500; color: var(--ink-2); position:relative; padding: 6px 0;
}
nav.main-nav a:hover, nav.main-nav a.active{ color: var(--abyss); }
nav.main-nav a.active::after{
  content:""; position:absolute; left:0; right:0; bottom:-2px; height:2px;
  background: linear-gradient(90deg, var(--current), var(--surface)); border-radius:2px;
}
.nav-toggle{ display:none; background:none; border:1px solid var(--line); border-radius:var(--radius-sm); padding:8px 10px; color:var(--abyss); }

@media (max-width: 860px){
  nav.main-nav{
    position:fixed; inset: 68px 0 0 0; background:var(--foam); flex-direction:column;
    align-items:flex-start; padding: 24px 28px; gap: 18px; transform:translateX(100%);
    transition: transform .25s ease; overflow:auto;
  }
  nav.main-nav.open{ transform:translateX(0); }
  .nav-toggle{ display:block; }
}

/* ---------- hero ---------- */
.hero{
  position: relative;
  padding: 130px 0 90px;
  overflow: hidden;
  isolation: isolate;
  min-height: 88vh;
  display: flex;
  align-items: center;
}
.hero-video-bg{
  position: absolute; inset: 0; z-index: -2;
  width: 100%; height: 100%; object-fit: cover;
}
.hero::after{
  content:""; position:absolute; inset:0; z-index:-1; pointer-events:none;
  background: linear-gradient(180deg, rgba(4,27,45,.68) 0%, rgba(4,27,45,.5) 45%, rgba(4,27,45,.88) 100%);
}
.hero .container{ position:relative; z-index:1; }
.hero .eyebrow{ margin-bottom:18px; color: var(--surface); }
.hero h1{ max-width: 17ch; margin-bottom:.32em; color:#fff; }
.hero h1 em{ font-style:normal; color: var(--surface); }
.hero .lede{ max-width: 50ch; font-size: 1.18rem; color: rgba(255,255,255,.85); }

.search-box{
  margin-top: 32px; display:flex; gap:10px; max-width: 580px;
}
.search-box input{
  flex:1; border:1px solid rgba(255,255,255,.25); background:rgba(255,255,255,.1); backdrop-filter: blur(10px);
  border-radius: var(--radius); padding: 16px 20px; font-size: .98rem; color: #fff;
}
.search-box input::placeholder{ color: rgba(255,255,255,.6); }
.search-box input:focus{ border-color: var(--surface); background: rgba(255,255,255,.16); }
.btn{
  border:1px solid var(--abyss); background: var(--abyss); color:#fff;
  padding: 14px 24px; border-radius: var(--radius); font-size:.92rem; font-weight:600;
  white-space:nowrap; transition: transform .15s cubic-bezier(.2,.8,.2,1), background .15s ease, box-shadow .2s ease;
}
.btn:hover{ background: var(--current); border-color: var(--current); transform: translateY(-2px); box-shadow: 0 10px 24px -8px rgba(28,130,174,.5); }
.btn.ghost{ background:transparent; color:var(--abyss); border-color: var(--line); }
.btn.ghost:hover{ border-color: var(--current); color: var(--current); background:transparent; transform:none; box-shadow:none; }
.btn.sm{ padding: 9px 16px; font-size: .82rem; }

.hero-stats{
  display:flex; gap: 0; margin-top: 54px; flex-wrap:wrap;
  background: rgba(255,255,255,.08); backdrop-filter: blur(16px);
  border: 1px solid rgba(255,255,255,.18); border-radius: var(--radius);
  padding: 24px 0;
}
.hero-stats .stat{ flex:1; min-width:130px; padding: 0 24px; border-left: 1px solid rgba(255,255,255,.16); }
.hero-stats .stat:first-child{ border-left:none; }
.hero-stats .stat b{
  display:block; font-family: var(--display); font-size: 2.2rem; color: #fff; font-weight:600;
}
.hero-stats .stat span{ font-size:.78rem; color: rgba(255,255,255,.65); }

/* ---------- video banners (Explorer / Map / etc) ---------- */
.video-banner{
  position: relative; height: 280px; border-radius: var(--radius); overflow: hidden; margin: 26px 0; isolation: isolate;
}
.video-banner video{ position:absolute; inset:0; width:100%; height:100%; object-fit:cover; z-index:-1; }
.video-banner::after{ content:""; position:absolute; inset:0; background: linear-gradient(180deg, transparent 35%, rgba(4,27,45,.65)); }
.video-banner span{ position:absolute; left:22px; bottom:18px; color:#fff; font-family: var(--display); font-weight:600; font-size:1.2rem; z-index:1; }

/* ---------- scroll reveal ---------- */
.reveal{ opacity:0; transform: translateY(24px); transition: opacity .7s cubic-bezier(.2,.8,.2,1), transform .7s cubic-bezier(.2,.8,.2,1); }
.reveal.in{ opacity:1; transform: translateY(0); }

/* ---------- section framing ---------- */
section.block{ padding: 60px 0; }
section.block.tinted{ background: var(--mist); border-top:1px solid var(--line); border-bottom:1px solid var(--line); }
.block-head{ display:flex; align-items:flex-end; justify-content:space-between; gap: 20px; margin-bottom: 32px; flex-wrap:wrap;}
.block-head p{ margin:0; max-width:50ch; color: var(--ink-2); }

/* ---------- ranking access cards ---------- */
.rank-grid{ display:grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
@media (max-width: 900px){ .rank-grid{ grid-template-columns: repeat(2,1fr);} }
@media (max-width: 600px){ .rank-grid{ grid-template-columns: 1fr;} }

.rank-card{
  border:1px solid var(--line); background:#fff; border-radius: var(--radius);
  padding: 24px; display:flex; flex-direction:column; gap: 10px;
  transition: border-color .15s, transform .15s, box-shadow .15s;
}
.rank-card:hover{ border-color: var(--current); transform: translateY(-5px) scale(1.01); box-shadow: 0 20px 40px -20px rgba(11,72,112,.4); }
.rank-card .tag{ font-family: var(--mono); font-size:.66rem; letter-spacing:.12em; color: var(--current); text-transform:uppercase; }
.rank-card h3{ margin:0; font-size:1.14rem; }
.rank-card p{ font-size:.88rem; margin:0; color: var(--ink-2); }
.rank-card .leader{ margin-top: 6px; font-size:.85rem; color: var(--ink); }
.rank-card .leader b{ color: var(--current); }

/* ---------- ripple badge (signature element) ---------- */
.call-number{
  font-family: var(--mono); font-size: .72rem; letter-spacing:.04em; font-weight:500;
  color: var(--deep); border-radius: 999px;
  padding: 4px 12px 4px 10px; display:inline-flex; align-items:center; gap:6px;
  background: var(--mist); border: 1px solid var(--line);
}
.call-number::before{
  content:""; width:8px; height:8px; border-radius:50%;
  background: var(--current);
  box-shadow: 0 0 0 3px rgba(28,130,174,.18), 0 0 0 6px rgba(28,130,174,.1);
}

/* ---------- toolbar / filters ---------- */
.toolbar{
  display:flex; gap: 12px; flex-wrap:wrap; align-items:center; margin-bottom: 26px;
  padding: 14px; background:#fff; border:1px solid var(--line); border-radius: var(--radius);
}
.toolbar input[type=search]{
  flex:1; min-width:180px; border:1px solid var(--line); border-radius: var(--radius-sm);
  padding: 10px 12px; font-size:.9rem;
}
.toolbar select{
  border:1px solid var(--line); border-radius: var(--radius-sm); padding: 10px 10px; font-size:.85rem; background:#fff; color:var(--ink-2);
}
.result-count{ font-size:.8rem; color: var(--ink-faint); margin-bottom:16px; }

.water-grid{ display:grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
@media (max-width: 980px){ .water-grid{ grid-template-columns: repeat(2,1fr);} }
@media (max-width: 620px){ .water-grid{ grid-template-columns: 1fr;} }

.water-card{
  border:1px solid var(--line); background:#fff; border-radius: var(--radius); padding: 18px;
  display:flex; flex-direction:column; gap:8px; transition: box-shadow .15s, border-color .15s, transform .15s;
}
.water-card:hover{ border-color: var(--current); box-shadow: 0 18px 36px -22px rgba(11,72,112,.45); transform: translateY(-4px) scale(1.008); }
.water-card .top-row{ display:flex; justify-content:space-between; align-items:flex-start; gap:8px; }
.water-card h3{ margin:0; font-size: 1.08rem; }
.water-card .country{ font-size:.8rem; color: var(--ink-2); }
.score-pill{
  font-family: var(--mono); font-weight:600; font-size:.8rem; color:#fff;
  background: linear-gradient(135deg, var(--current), var(--deep)); border-radius: 999px; padding: 4px 11px; white-space:nowrap;
}
.profile-line{ font-size:.82rem; color: var(--current); font-family: var(--mono); }
.water-card .note{ font-size: .84rem; color: var(--ink-2); }

/* ---------- water detail ---------- */
.water-hero{ padding: 48px 0 32px; border-bottom:1px solid var(--line); background: linear-gradient(180deg, var(--mist), var(--foam)); }
.water-hero .top{ display:flex; justify-content:space-between; align-items:flex-start; gap: 24px; flex-wrap:wrap; }
.water-hero .score-block{ text-align:right; }
.water-hero .score-block .num{ font-family:var(--display); font-size:3.2rem; color:var(--abyss); line-height:1; font-weight:600; }
.water-hero .score-block .lbl{ font-size:.72rem; color:var(--ink-2); text-transform:uppercase; letter-spacing:.1em; font-family:var(--mono);}
.chips{ display:flex; gap:8px; flex-wrap:wrap; margin-top:14px; }
.chip{
  font-size:.76rem; border:1px solid var(--line); border-radius:999px; padding:5px 12px; color: var(--ink-2); background:#fff;
}
.chip.teal{ color: var(--deep); border-color: rgba(28,130,174,.3); background: var(--mist); }

.detail-grid{ display:grid; grid-template-columns: 1.3fr .9fr; gap: 44px; padding: 44px 0; }
@media (max-width: 880px){ .detail-grid{ grid-template-columns: 1fr; } }

.comp-table{ width:100%; border-collapse: collapse; font-size:.92rem; }
.comp-table th{ text-align:left; font-family:var(--mono); font-size:.68rem; letter-spacing:.08em; text-transform:uppercase; color:var(--ink-faint); font-weight:500; padding: 8px 0; border-bottom:1px solid var(--line);}
.comp-table td{ padding: 11px 0; border-bottom:1px solid var(--line); }
.comp-table td.val{ font-family:var(--mono); text-align:right; color:var(--abyss); font-weight:500; }
.comp-table td.na{ color: var(--ink-faint); font-style:italic; }
.bar-track{ height:6px; background:var(--mist); border-radius:3px; overflow:hidden; margin-top:6px; }
.bar-fill{ height:100%; background: linear-gradient(90deg, var(--current), var(--surface)); border-radius:3px; }

.rankings-mini{ display:flex; flex-direction:column; gap:10px; }
.rankings-mini .row{ display:flex; justify-content:space-between; align-items:center; border:1px solid var(--line); border-radius:var(--radius-sm); padding:11px 14px; background:#fff; }
.rankings-mini .row:hover{ border-color: var(--current); }
.rankings-mini .row .name{ font-size:.86rem; }
.rankings-mini .row .rank{ font-family:var(--mono); font-size:.82rem; color:var(--current); }

.history-block{ background: var(--mist); border:1px solid var(--line); border-radius: var(--radius); padding:24px; margin-top: 8px;}
.history-block h4{ margin-top:0; }
.data-note{
  font-size:.78rem; color:var(--ink-faint); border-left:2px solid var(--line); padding-left:12px; margin-top:20px;
}

/* ---------- ranking table page ---------- */
.tabs{ display:flex; gap:4px; flex-wrap:wrap; margin-bottom: 26px; border-bottom:1px solid var(--line); }
.tabs button, .tabs a{
  background:none; border:none; padding: 10px 16px; font-size:.86rem; font-weight:500; color: var(--ink-faint);
  border-bottom: 2px solid transparent; margin-bottom:-1px; display:inline-block;
}
.tabs button.active, .tabs a.active{ color: var(--abyss); border-color: var(--current); }
.rank-weights{ font-size:.8rem; color: var(--ink-faint); margin-bottom: 22px; }

table.rank-table{ width:100%; border-collapse:collapse; font-size:.9rem; }
table.rank-table th{
  text-align:left; padding:10px 12px; font-family:var(--mono); font-size:.68rem; letter-spacing:.08em;
  text-transform:uppercase; color:var(--ink-faint); border-bottom:1px solid var(--line); font-weight:500;
}
table.rank-table td{ padding:12px; border-bottom:1px solid var(--line); }
table.rank-table tr:hover td{ background: var(--mist); }
table.rank-table td.rank-num{ font-family:var(--mono); color:var(--current); width:40px; font-weight:600; }
table.rank-table td.score{ font-family:var(--mono); text-align:right; font-weight:500; }
table.rank-table td.name a{ color: var(--abyss); font-weight:600; }
table.rank-table td.name .cc{ display:block; font-size:.76rem; color:var(--ink-faint); font-weight:400; }

/* ---------- custom ranking ---------- */
.sliders{ display:grid; grid-template-columns: 1fr 1fr; gap: 18px 30px; margin: 30px 0 36px; }
@media (max-width:700px){ .sliders{ grid-template-columns: 1fr; } }
.slider-row label{ display:flex; justify-content:space-between; font-size:.86rem; margin-bottom:6px; }
.slider-row label .v{ font-family:var(--mono); color:var(--current); font-weight:600; }
.slider-row input[type=range]{ width:100%; accent-color: var(--current); }
.total-badge{ font-family:var(--mono); font-size:.85rem; padding:9px 16px; border-radius:var(--radius); display:inline-block; border:1px solid var(--line); }
.total-badge.ok{ color: var(--deep); border-color: rgba(28,130,174,.4); background: var(--mist); }
.total-badge.bad{ color: var(--amber); border-color: rgba(199,127,30,.4); }

/* ---------- compare ---------- */
.compare-picker{ display:flex; gap:10px; flex-wrap:wrap; margin-bottom: 26px; }
.compare-picker select{ border:1px solid var(--line); border-radius:var(--radius-sm); padding:10px 12px; font-size:.88rem; }
.compare-table-wrap{ overflow-x:auto; }
table.compare-table{ border-collapse:collapse; width:100%; min-width: 640px; font-size:.88rem; }
table.compare-table th, table.compare-table td{ padding:10px 14px; border-bottom:1px solid var(--line); white-space:nowrap; }
table.compare-table th.crit{ text-align:left; font-family:var(--mono); font-size:.7rem; text-transform:uppercase; letter-spacing:.08em; color:var(--ink-faint); font-weight:500; }
table.compare-table td{ text-align:center; font-family: var(--mono); }
table.compare-table th.wname{ font-family: var(--sans); text-align:center; }
table.compare-table th.wname .rm{ display:block; font-family:var(--sans); font-size:.72rem; color:var(--current); margin-top:4px; cursor:pointer; }

/* ---------- about ---------- */
.about-hero{
  position: relative; isolation: isolate; overflow: hidden;
  padding: 100px 0 70px;
  color: #cfe7ee;
}
.about-hero video{ position:absolute; inset:0; z-index:-2; width:100%; height:100%; object-fit:cover; }
.about-hero::before{
  content:""; position:absolute; inset:0; z-index:-1;
  background: linear-gradient(160deg, rgba(4,27,45,.85), rgba(11,72,112,.72) 130%);
}
.about-hero h1{ color:#fff; max-width: 18ch; }
.about-hero .lede{ color:#bfe0ea; max-width:56ch; font-size:1.15rem; }
.prose{ max-width: 68ch; font-size:1.02rem; }
.prose h2{ margin-top: 2.2em; }
.prose blockquote{
  font-family: var(--display); font-weight:600; font-size:1.5rem; color:var(--abyss);
  border-left: 3px solid var(--current); padding-left:20px; margin: 1.6em 0;
}

/* ---------- footer ---------- */
footer.site-footer{ border-top:1px solid var(--line); padding: 44px 0; margin-top: 40px; background: var(--mist); }
footer .cols{ display:flex; justify-content:space-between; flex-wrap:wrap; gap:20px; }
footer .small{ font-size:.8rem; color: var(--ink-2); }

/* ---------- misc ---------- */
.empty-state{ text-align:center; padding: 60px 20px; color: var(--ink-faint); }
.badge-missing{ font-size:.68rem; color: var(--amber); font-family: var(--mono); font-weight:500; }

/* ---------- photo banners ---------- */
.photo-banner{
  height: 220px; border-radius: var(--radius); background-size: cover; background-position: center;
  margin: 26px 0; position: relative; overflow: hidden;
}
.photo-banner::after{
  content:""; position:absolute; inset:0;
  background: linear-gradient(180deg, transparent 40%, rgba(4,27,45,.55));
}
.photo-banner span{
  position:absolute; left:20px; bottom:16px; color:#fff; font-family: var(--display); font-weight:600; font-size:1.1rem; z-index:1;
}
.photo-accent{
  width:100%; border-radius: var(--radius); margin-bottom: 22px; display:block; max-height:220px; object-fit:cover;
}