/* TankCoach — "clear water": white and pale aqua, deep teal, coral for warnings. */
:root {
  --teal-900: #134e4a;
  --teal-700: #0f766e;
  --teal-600: #0d9488;
  --teal-100: #ccfbf1;
  --aqua-50: #f0fbfc;
  --aqua-100: #e0f5f7;
  --ink: #0f2a2e;
  --ink-2: #3d5a5f;
  --line: #d5e8ea;
  --coral: #f2704f;
  --coral-50: #fff1ec;
  --amber: #c98a0b;
  --amber-50: #fff7e0;
  --ok: #138a5b;
  --ok-50: #e7f7ef;
  --bad: #c2412d;
  --bad-50: #fdecea;
  --white: #fff;
  --radius: 16px;
  --radius-s: 10px;
  --shadow: 0 1px 2px rgba(15, 42, 46, .06), 0 8px 24px rgba(15, 42, 46, .07);
  --font: "Inter", ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0; font-family: var(--font); color: var(--ink); background: var(--white);
  font-size: 17px; line-height: 1.6;
}
img, svg { max-width: 100%; }
a { color: var(--teal-700); text-underline-offset: 3px; }
a:hover { color: var(--teal-900); }
h1, h2, h3 { line-height: 1.2; letter-spacing: -0.015em; color: var(--ink); }
h1 { font-size: clamp(2rem, 4.6vw, 3.1rem); margin: 0 0 .5rem; font-weight: 800; }
h2 { font-size: clamp(1.5rem, 3vw, 2rem); margin: 0 0 .75rem; font-weight: 750; }
h3 { font-size: 1.15rem; margin: 0 0 .35rem; font-weight: 700; }
p { margin: 0 0 1rem; }
.muted { color: var(--ink-2); }
.wrap { width: min(1120px, 100% - 32px); margin-inline: auto; }
.narrow { width: min(760px, 100% - 32px); margin-inline: auto; }
.skip { position: absolute; left: -999px; }
.skip:focus { left: 16px; top: 8px; background: var(--white); padding: 8px 12px; z-index: 10; }

/* Header */
.site-header { position: sticky; top: 0; z-index: 5; background: rgba(255,255,255,.92); backdrop-filter: blur(8px); border-bottom: 1px solid var(--line); }
.header-row { display: flex; align-items: center; justify-content: space-between; height: 64px; gap: 16px; }
.brand { display: inline-flex; align-items: center; gap: 8px; font-weight: 800; font-size: 1.15rem; color: var(--ink); text-decoration: none; }
.nav { display: flex; align-items: center; gap: 22px; font-size: .95rem; }
.nav a { color: var(--ink-2); text-decoration: none; font-weight: 550; }
.nav a:hover { color: var(--teal-700); }
@media (max-width: 640px) {
  .nav a:not(.btn) { display: none; }
}

/* Buttons */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  background: var(--teal-700); color: var(--white) !important; border: 0; border-radius: 999px;
  padding: 12px 22px; font: inherit; font-weight: 650; text-decoration: none; cursor: pointer;
  transition: background .15s, transform .15s;
}
.btn:hover { background: var(--teal-900); }
.btn:active { transform: translateY(1px); }
.btn-small { padding: 8px 16px; font-size: .9rem; }
.btn-ghost { background: transparent; color: var(--teal-700) !important; box-shadow: inset 0 0 0 1.5px var(--teal-700); }
.btn-ghost:hover { background: var(--aqua-100); }
.linkish { background: none; border: 0; padding: 0; font: inherit; color: var(--teal-700); text-decoration: underline; cursor: pointer; }

/* Sections */
section { padding: 72px 0; }
.section-alt { background: var(--aqua-50); }
.eyebrow { display: inline-block; font-size: .8rem; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--teal-600); margin-bottom: .6rem; }
.lead { font-size: 1.2rem; color: var(--ink-2); max-width: 40ch; }
.section-head { max-width: 640px; margin-bottom: 32px; }

/* Water-plant divider (borrowed from the natural style): a fine line with a few blades. */
.plant-rule { display: block; width: 100%; height: 28px; color: var(--teal-600); opacity: .55; }

/* Hero */
.hero { padding: 56px 0 32px; background: linear-gradient(180deg, var(--aqua-50) 0%, var(--white) 100%); overflow: hidden; }
.hero-grid { display: grid; grid-template-columns: 1.1fr .9fr; gap: 48px; align-items: center; }
.hero .lead { margin-bottom: 1.6rem; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; }
.hero-note { margin-top: 14px; font-size: .9rem; color: var(--ink-2); }
@media (max-width: 860px) { .hero-grid { grid-template-columns: 1fr; } }

/* Phone mockup */
.phone {
  width: 300px; max-width: 100%; margin-inline: auto; border-radius: 42px; padding: 12px;
  background: #0b1f22; box-shadow: 0 30px 60px rgba(15,42,46,.25), inset 0 0 0 2px #22393c;
}
.screen { color: var(--ink); border-radius: 32px; background: var(--aqua-50); overflow: hidden; font-size: 13px; line-height: 1.45; }
.screen-top { display: flex; justify-content: space-between; padding: 12px 20px 4px; font-weight: 650; font-size: 11px; color: var(--ink-2); }
.screen-body { padding: 8px 14px 18px; display: grid; gap: 10px; }
.app-title { font-size: 18px; font-weight: 800; margin: 2px 4px 0; }
.app-sub { margin: 0 4px; color: var(--ink-2); font-size: 12px; }
.card { background: var(--white); border-radius: 14px; padding: 12px 14px; box-shadow: 0 1px 2px rgba(15,42,46,.06); }
.stages { display: flex; gap: 4px; margin: 6px 0 4px; }
.stages i { flex: 1; height: 6px; border-radius: 3px; background: var(--line); }
.stages i.done { background: var(--teal-600); }
.stages i.now { background: var(--coral); }
.stage-name { font-weight: 750; }
.reading { display: grid; grid-template-columns: repeat(3, 1fr); gap: 6px; text-align: center; }
.reading b { display: block; font-size: 16px; }
.reading small { color: var(--ink-2); font-size: 10.5px; }
.reading .warn b { color: var(--coral); }
.todo { list-style: none; padding: 0; margin: 4px 0 0; display: grid; gap: 6px; }
.todo li { display: flex; gap: 8px; align-items: flex-start; }
.todo li::before { content: ""; flex: none; width: 14px; height: 14px; margin-top: 2px; border-radius: 4px; border: 1.5px solid var(--teal-600); }
.todo li.done::before { background: var(--teal-600); box-shadow: inset 0 0 0 2px var(--white); }
.pill { display: inline-block; padding: 2px 8px; border-radius: 999px; font-size: 11px; font-weight: 700; }
.pill-coral { background: var(--coral-50); color: var(--coral); }

/* Situations */
.situations { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.situation { background: var(--white); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; }
.situation .who { font-size: .8rem; font-weight: 700; color: var(--teal-600); text-transform: uppercase; letter-spacing: .06em; }
.situation q { display: block; font-size: 1.05rem; font-weight: 650; margin: 8px 0 10px; quotes: "“" "”"; }
.situation p { font-size: .95rem; color: var(--ink-2); margin: 0; }
@media (max-width: 960px) { .situations { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 560px) { .situations { grid-template-columns: 1fr; } }

/* Tiles (calculators, guides) */
.tiles { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 18px; }
.tile {
  display: block; background: var(--white); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 22px; text-decoration: none; color: var(--ink); transition: border-color .15s, box-shadow .15s, transform .15s;
}
.tile:hover { border-color: var(--teal-600); box-shadow: var(--shadow); transform: translateY(-2px); color: var(--ink); }
.tile .icon { width: 40px; height: 40px; border-radius: 12px; display: grid; place-items: center; background: var(--teal-100); color: var(--teal-700); margin-bottom: 14px; }
.tile p { color: var(--ink-2); font-size: .95rem; margin: 0; }
.tile .go { display: inline-block; margin-top: 12px; font-weight: 650; color: var(--teal-700); font-size: .95rem; }
.guide-list { display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px 28px; padding: 0; list-style: none; margin: 0; counter-reset: g; }
.guide-list li { counter-increment: g; border-bottom: 1px solid var(--line); }
.guide-list a { display: flex; gap: 14px; padding: 14px 0; text-decoration: none; color: var(--ink); font-weight: 600; }
.guide-list a::before { content: counter(g, decimal-leading-zero); color: var(--teal-600); font-weight: 750; font-variant-numeric: tabular-nums; }
.guide-list a:hover { color: var(--teal-700); }
@media (max-width: 700px) { .guide-list { grid-template-columns: 1fr; } }

/* FAQ */
.faq { display: grid; gap: 10px; }
.faq details { background: var(--white); border: 1px solid var(--line); border-radius: var(--radius-s); padding: 0 18px; }
.faq summary { cursor: pointer; padding: 16px 0; font-weight: 650; list-style: none; display: flex; justify-content: space-between; gap: 16px; }
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after { content: "+"; color: var(--teal-600); font-size: 1.3rem; line-height: 1; }
.faq details[open] summary::after { content: "–"; }
.faq details > div { padding-bottom: 16px; color: var(--ink-2); }

/* App availability */
.app-cta { background: var(--teal-900); color: var(--white); border-radius: 24px; padding: 44px; display: grid; grid-template-columns: 1.3fr 1fr; gap: 32px; align-items: center; }
.app-cta h2 { color: var(--white); }
.app-cta p { color: #c7e6e3; }
.app-cta ul { margin: 0; padding-left: 1.1rem; color: #e1f3f1; }
.app-cta .btn { background: var(--white); color: var(--teal-900) !important; }
.app-cta .btn:hover { background: var(--teal-100); }
@media (max-width: 760px) { .app-cta { grid-template-columns: 1fr; padding: 28px; } }

/* Calculator pages */
.page-head { padding: 48px 0 8px; background: linear-gradient(180deg, var(--aqua-50), var(--white)); }
.crumbs { font-size: .85rem; color: var(--ink-2); margin-bottom: 10px; }
.crumbs a { color: var(--ink-2); }
.calc { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; align-items: start; margin: 24px 0 8px; }
@media (max-width: 820px) { .calc { grid-template-columns: 1fr; } }
.panel { background: var(--white); border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; box-shadow: var(--shadow); }
.field { display: grid; gap: 6px; margin-bottom: 16px; }
.field label, .legend { font-weight: 650; font-size: .95rem; }
.field input, .field select {
  font: inherit; padding: 11px 12px; border: 1.5px solid var(--line); border-radius: var(--radius-s); background: var(--white); color: var(--ink); width: 100%;
}
.field input:focus, .field select:focus { outline: none; border-color: var(--teal-600); box-shadow: 0 0 0 3px var(--teal-100); }
.row3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.row2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; }
.seg { display: inline-flex; background: var(--aqua-100); border-radius: 999px; padding: 4px; gap: 4px; margin-bottom: 16px; }
.seg label { cursor: pointer; }
.seg input { position: absolute; opacity: 0; pointer-events: none; }
.seg span { display: inline-block; padding: 6px 14px; border-radius: 999px; font-weight: 600; font-size: .9rem; color: var(--ink-2); }
.seg input:checked + span { background: var(--white); color: var(--teal-900); box-shadow: 0 1px 2px rgba(15,42,46,.12); }
.seg input:focus-visible + span { outline: 2px solid var(--teal-600); }
.result { background: var(--teal-900); color: var(--white); border-radius: var(--radius); padding: 26px; }
.result .big { font-size: 2.6rem; font-weight: 800; letter-spacing: -0.02em; line-height: 1.1; }
.result .unit { font-size: 1.1rem; font-weight: 600; color: #a7e3dc; }
.result dl { display: grid; grid-template-columns: 1fr auto; gap: 6px 16px; margin: 18px 0 0; padding-top: 16px; border-top: 1px solid rgba(255,255,255,.15); }
.result dt { color: #c7e6e3; }
.result dd { margin: 0; font-weight: 700; text-align: right; font-variant-numeric: tabular-nums; }
.result .hint { margin: 16px 0 0; font-size: .92rem; color: #c7e6e3; }
.result .err { color: #ffd2c6; }
.verdict { border-radius: var(--radius-s); padding: 12px 14px; margin-top: 10px; }
.verdict.ok { background: var(--ok-50); color: var(--ok); }
.verdict.warn { background: var(--amber-50); color: var(--amber); }
.verdict.bad { background: var(--bad-50); color: var(--bad); }

/* Article prose */
.prose { font-size: 1.05rem; }
.prose h2 { margin-top: 2.2rem; }
.prose h3 { margin-top: 1.6rem; }
.prose ul, .prose ol { padding-left: 1.3rem; }
.prose li { margin-bottom: .35rem; }
.prose table { width: 100%; border-collapse: collapse; margin: 1rem 0 1.5rem; font-size: .95rem; }
.prose th, .prose td { text-align: left; padding: 10px 12px; border-bottom: 1px solid var(--line); }
.prose th { background: var(--aqua-50); }
.answer { background: var(--aqua-50); border-left: 4px solid var(--teal-600); border-radius: 0 var(--radius-s) var(--radius-s) 0; padding: 16px 20px; margin: 0 0 1.5rem; font-size: 1.08rem; }
.note { background: var(--amber-50); border-radius: var(--radius-s); padding: 14px 18px; font-size: .95rem; }

/* Footer */
.site-footer { background: var(--aqua-50); border-top: 1px solid var(--line); padding: 48px 0 24px; margin-top: 48px; font-size: .95rem; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 32px; }
.footer-grid a { display: block; color: var(--ink-2); text-decoration: none; margin-bottom: 6px; }
.footer-grid a:hover { color: var(--teal-700); }
.footer-h { font-size: .8rem; text-transform: uppercase; letter-spacing: .08em; color: var(--ink-2); margin-bottom: 10px; }
.fine { margin-top: 32px; padding-top: 18px; border-top: 1px solid var(--line); font-size: .85rem; color: var(--ink-2); }
.fine p { margin-bottom: 6px; }
@media (max-width: 640px) { .footer-grid { grid-template-columns: 1fr 1fr; } .footer-grid > div:first-child { grid-column: 1 / -1; } }

/* Consent banner */
.consent {
  position: fixed; left: 16px; right: 16px; bottom: 16px; z-index: 20; max-width: 560px; margin-inline: auto;
  background: var(--white); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow);
  padding: 16px 18px; display: flex; gap: 16px; align-items: center; font-size: .92rem;
}
.consent[hidden] { display: none; }
.consent p { margin: 0; }
.consent-actions { display: flex; gap: 8px; flex: none; }
@media (max-width: 520px) { .consent { flex-direction: column; align-items: stretch; } .consent-actions { justify-content: flex-end; } }

/* ---------- v2: more picture, less text ---------- */
:root { --display: "Bricolage Grotesque", var(--font); }
h1, h2, .big, .stage-day { font-family: var(--display); }
h1 { font-weight: 800; letter-spacing: -0.03em; }
h2 { font-weight: 800; letter-spacing: -0.02em; }
.center { text-align: center; margin-inline: auto; }
.row-head { display: flex; justify-content: space-between; align-items: end; max-width: none; gap: 16px; }
.go { font-weight: 650; text-decoration: none; }
.sr { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }

/* Hero: an aquarium scene */
.hero { position: relative; padding: 88px 0 96px; background: #0b4f55; color: var(--white); min-height: 620px; }
.scene { position: absolute; inset: 0; width: 100%; height: 100%; }
.hero-grid { position: relative; }
.hero h1 { color: var(--white); font-size: clamp(2.6rem, 6.4vw, 4.6rem); line-height: 1.02; max-width: 11ch; text-shadow: 0 2px 30px rgba(4,40,44,.35); }
.hero .lead { color: #d6f4f1; font-size: 1.25rem; max-width: 30ch; }
.eyebrow-light { color: #9ff0e4; }
.btn-light { background: var(--white); color: var(--teal-900) !important; }
.btn-light:hover { background: var(--teal-100); }
.btn-outline-light { background: transparent; color: var(--white) !important; box-shadow: inset 0 0 0 1.5px rgba(255,255,255,.8); }
.btn-outline-light:hover { background: rgba(255,255,255,.12); }
.hero .phone { transform: rotate(3deg); }
@media (max-width: 860px) { .hero { padding: 56px 0 64px; } .hero .phone { transform: none; margin-top: 24px; } }

.sway { transform-box: fill-box; transform-origin: 50% 100%; animation: sway 6s ease-in-out infinite; }
.s2 { animation-duration: 7.5s; animation-delay: -2s; }
.s3 { animation-duration: 5.5s; animation-delay: -4s; }
@keyframes sway { 0%,100% { transform: rotate(-3deg); } 50% { transform: rotate(3deg); } }
.fish { animation: swim 26s linear infinite; }
.f1 { animation-duration: 30s; }
.f2 { animation-duration: 22s; animation-delay: -6s; }
.f3 { animation-duration: 22s; animation-delay: -7.2s; }
.f4 { animation-duration: 36s; animation-delay: -20s; animation-direction: reverse; }
@keyframes swim { from { transform: translateX(-120px); } to { transform: translateX(1560px); } }
.f4 > g { transform: translate(0px, 420px) scaleX(-1); }
.b { animation: rise 7s ease-in infinite; }
.b2 { animation-delay: -2s; } .b3 { animation-delay: -4.5s; } .b4 { animation-delay: -1s; animation-duration: 9s; } .b5 { animation-delay: -5s; animation-duration: 9s; }
@keyframes rise { from { transform: translateY(0); opacity: .8; } to { transform: translateY(-680px); opacity: 0; } }
@media (prefers-reduced-motion: reduce) { .sway, .fish, .b { animation: none; } }

/* Phone UI details */
.ring-card { display: flex; gap: 12px; align-items: center; }
.ring { width: 64px; height: 64px; flex: none; }
.ring-bg { fill: none; stroke: var(--aqua-100); stroke-width: 9; }
.ring-fg { fill: none; stroke: var(--coral); stroke-width: 9; stroke-linecap: round; transform: rotate(-90deg); transform-origin: 40px 40px; }
.ring-n { font: 800 17px var(--display); fill: var(--ink); }
.ring-s { font: 600 9px var(--font); fill: var(--ink-2); }
.bars { display: grid; gap: 8px; }
.bars > div { display: grid; grid-template-columns: 34px 1fr 34px; align-items: center; gap: 8px; font-size: 12px; }
.bars span { font-weight: 700; color: var(--ink-2); }
.bars i { height: 8px; border-radius: 4px; background: linear-gradient(90deg, var(--teal-600) calc(var(--v) * 100%), var(--aqua-100) 0); }
.bars .hot i { background: linear-gradient(90deg, var(--coral) calc(var(--v) * 100%), var(--aqua-100) 0); }
.bars b { text-align: right; }
.bars .hot b { color: var(--coral); }
.alert-card { border-left: 4px solid var(--coral); }
.alert-row { display: flex; gap: 8px; align-items: center; margin-top: 6px; font-weight: 650; }
.muted-row { color: var(--ink-2); font-weight: 500; padding-left: 26px; }

/* Nitrogen-cycle chart */
.cycle-section { padding-top: 80px; }
.cycle-viz { display: grid; grid-template-columns: 1fr 300px; gap: 20px; align-items: stretch; }
@media (max-width: 900px) { .cycle-viz { grid-template-columns: 1fr; } }
.chart-card { background: var(--white); border: 1px solid var(--line); border-radius: 20px; padding: 18px 18px 8px; box-shadow: var(--shadow); }
.chart-svg { width: 100%; height: auto; display: block; overflow: visible; }
.legend { display: flex; gap: 18px; font-size: .88rem; font-weight: 650; margin: 0 4px 6px; }
.lg::before { content: ""; display: inline-block; width: 12px; height: 12px; border-radius: 4px; margin-right: 6px; vertical-align: -1px; background: currentColor; }
.c-ammonia { color: #f2704f; } .c-nitrite { color: #e0a100; } .c-nitrate { color: #0d9488; }
.curve { fill: none; stroke: currentColor; stroke-width: 3.5; stroke-linecap: round; }
.area { fill: currentColor; opacity: .1; stroke: none; }
.band { fill: transparent; transition: fill .2s; }
.band.on { fill: #e9f8f8; }
.band-label { font: 650 11.5px var(--font); fill: #8aa6a9; }
.axis { stroke: var(--line); stroke-width: 1.5; }
.tick { font: 500 11px var(--font); fill: #8aa6a9; }
.marker-line { stroke: var(--ink); stroke-width: 1.5; stroke-dasharray: 3 4; }
.dot { fill: var(--white); stroke: currentColor; stroke-width: 3.5; }
.slider { display: block; padding: 6px 4px 10px; }
.slider input { width: 100%; accent-color: var(--teal-700); height: 28px; cursor: pointer; }
.stage-card { background: var(--teal-900); color: var(--white); border-radius: 20px; padding: 26px; display: flex; flex-direction: column; gap: 10px; }
.stage-card h3 { color: var(--white); font-size: 1.4rem; margin: 0; }
.stage-card p { color: #c7e6e3; margin: 0; flex: 1; }
.stage-card .go { color: #9ff0e4; }
.stage-day { font-size: 3rem; font-weight: 800; line-height: 1; }
.pips { display: flex; gap: 5px; }
.pips i { flex: 1; height: 7px; border-radius: 4px; background: rgba(255,255,255,.18); }
.pips i.done { background: #5eead4; }
.pips i.now { background: var(--coral); }

/* Calculator tiles with pictures */
.calc-tiles { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
@media (max-width: 960px) { .calc-tiles { grid-template-columns: repeat(2, 1fr); } }
.ctile { display: block; border-radius: 20px; padding: 18px 20px 22px; text-decoration: none; color: var(--ink); background: var(--aqua-50); border: 1px solid var(--line); transition: transform .15s, box-shadow .15s; }
.ctile:hover { transform: translateY(-3px); box-shadow: var(--shadow); color: var(--ink); }
.ctile svg { width: 100%; height: 120px; display: block; margin-bottom: 8px; }
.ctile h3 { font-family: var(--display); font-size: 1.25rem; margin: 0; }
.ctile span { color: var(--ink-2); font-size: .92rem; }
.t-stock { background: #fff6f2; } .t-cycle { background: #f1fbf8; } .t-water { background: #eef8fb; }

/* Quotes */
.quotes { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
@media (max-width: 960px) { .quotes { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 520px) { .quotes { grid-template-columns: 1fr; } }
.quote { margin: 0; background: var(--white); border-radius: 20px; padding: 22px; box-shadow: var(--shadow); }
.quote blockquote { margin: 14px 0 10px; font-family: var(--display); font-size: 1.2rem; font-weight: 600; line-height: 1.3; }
.quote figcaption { color: var(--teal-600); font-weight: 700; font-size: .82rem; text-transform: uppercase; letter-spacing: .06em; }
.avatar { width: 48px; height: 48px; border-radius: 16px; display: grid; place-items: center; font-size: 24px; }
.a1 { background: #ffe7df; } .a2 { background: #e0f2fe; } .a3 { background: #fef3c7; } .a4 { background: #dcfce7; }

/* Guide cards */
.guide-cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
@media (max-width: 860px) { .guide-cards { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 520px) { .guide-cards { grid-template-columns: 1fr; } }
.gcard { position: relative; display: flex; flex-direction: column; justify-content: flex-end; min-height: 150px; padding: 20px; border-radius: 20px; text-decoration: none; color: var(--white); overflow: hidden; transition: transform .15s; }
.gcard:hover { transform: translateY(-3px); color: var(--white); }
.gcard h3 { color: inherit; font-family: var(--display); font-size: 1.3rem; margin: 0; max-width: 16ch; position: relative; }
.gicon { position: absolute; right: 16px; top: 8px; font: 800 64px/1 var(--display); opacity: .22; }
.g1 { background: linear-gradient(135deg, #0f766e, #14b8a6); }
.g2 { background: linear-gradient(135deg, #f2704f, #f59e78); }
.g3 { background: linear-gradient(135deg, #1d4ed8, #60a5fa); }
.g4 { background: linear-gradient(135deg, #b45309, #f59e0b); }
.g5 { background: linear-gradient(135deg, #475569, #94a3b8); }
.g6 { background: linear-gradient(135deg, #134e4a, #0d9488); }

/* App CTA features */
.features { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.features div { background: rgba(255,255,255,.08); border-radius: 16px; padding: 16px; font-weight: 650; display: flex; flex-direction: column; gap: 6px; }
.features b { font-size: 1.4rem; }

/* Volume calculator v2 */
.page-head h1 { font-size: clamp(2rem, 4.4vw, 3rem); }
.presets { display: flex; flex-wrap: wrap; gap: 8px; margin: 20px 0 4px; }
.presets button { font: inherit; font-weight: 650; font-size: .92rem; padding: 8px 16px; border-radius: 999px; border: 1.5px solid var(--line); background: var(--white); color: var(--ink-2); cursor: pointer; }
.presets button:hover { border-color: var(--teal-600); color: var(--teal-700); }
.presets button.on { background: var(--teal-700); border-color: var(--teal-700); color: var(--white); }
.calc-visual { grid-template-columns: 300px 1fr; }
@media (max-width: 820px) { .calc-visual { grid-template-columns: 1fr; } }
.calc-visual .seg { margin-right: 6px; }
.viz-card { background: linear-gradient(180deg, var(--aqua-50), #fff); border: 1px solid var(--line); border-radius: 20px; padding: 18px 20px 20px; box-shadow: var(--shadow); }
#tank-drawing { width: 100%; height: auto; max-height: 320px; display: block; }
#tank-drawing .glass-back { fill: #eef9fa; stroke: #b9dfe2; stroke-width: 1.5; }
#tank-drawing .glass-front { fill: rgba(255,255,255,.08); stroke: #0f766e; stroke-width: 2.5; }
#tank-drawing .glass-edge, #tank-drawing .glass-rim { fill: none; stroke: #0f766e; stroke-width: 2.5; }
#tank-drawing .water { fill: #2aa8a8; opacity: .85; }
#tank-drawing .water.side { fill: #1b8f90; }
#tank-drawing .water-top { fill: #8fe0e0; opacity: .9; }
#tank-drawing .sand { fill: #e8d5a8; }
#tank-drawing .dim { font: 650 13px var(--font); fill: var(--ink-2); }
.stats { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 10px; margin-top: 10px; }
@media (max-width: 560px) { .stats { grid-template-columns: 1fr 1fr; } }
.stat { background: var(--white); border: 1px solid var(--line); border-radius: 14px; padding: 12px 14px; display: flex; flex-direction: column; }
.stat b { font: 800 1.5rem/1.1 var(--display); color: var(--teal-900); }
.stat span { font-size: .82rem; color: var(--ink-2); }
.stat.main { background: var(--teal-900); border-color: var(--teal-900); }
.stat.main b { color: var(--white); font-size: 2.4rem; }
.stat.main span { color: #a7e3dc; }
.formula { display: flex; flex-wrap: wrap; align-items: center; justify-content: center; gap: 10px; background: var(--aqua-50); border-radius: 20px; padding: 20px; }
.formula div { background: var(--white); border-radius: 14px; padding: 10px 16px; text-align: center; box-shadow: 0 1px 2px rgba(15,42,46,.06); }
.formula b { display: block; font: 800 1.3rem var(--display); color: var(--teal-900); }
.formula span { font-size: .8rem; color: var(--ink-2); }
.formula i { font-style: normal; font-weight: 800; color: var(--teal-600); font-size: 1.3rem; }

/* v3: Floniks illustrations */
.hero { background: #0f766e; min-height: 600px; display: flex; align-items: center; }
.hero-img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; object-position: 70% 50%; }
.hero::before { content: ""; position: absolute; inset: 0; z-index: 1; background: linear-gradient(90deg, rgba(6,52,56,.55) 0%, rgba(6,52,56,.25) 45%, rgba(6,52,56,0) 70%); }
.hero-grid { z-index: 2; grid-template-columns: 1fr; width: min(1120px, 100% - 32px); }
.hero h1 { max-width: 12ch; }
@media (max-width: 760px) { .hero { min-height: 520px; align-items: flex-start; } .hero-img { object-position: 78% 50%; } .hero::before { background: linear-gradient(180deg, rgba(6,52,56,.6) 0%, rgba(6,52,56,.2) 60%, rgba(6,52,56,0) 100%); } }
.ctile img { width: 100%; height: auto; aspect-ratio: 4 / 3; object-fit: cover; border-radius: 14px; display: block; margin-bottom: 12px; }
.ctile { padding: 12px 12px 18px; background: var(--white); }
.ctile h3, .ctile span { padding: 0 6px; display: block; }
img.avatar { width: 72px; height: 72px; border-radius: 50%; object-fit: cover; }
.gcard { min-height: 0; padding: 0; justify-content: flex-start; background: var(--white) !important; color: var(--ink); border: 1px solid var(--line); }
.gcard:hover { color: var(--ink); box-shadow: var(--shadow); }
.gcard img { width: 100%; aspect-ratio: 16 / 9; object-fit: cover; display: block; }
.gcard h3 { padding: 14px 18px 18px; font-size: 1.15rem; max-width: none; }
.app-cta { grid-template-columns: 1fr 1fr; overflow: hidden; }
.app-phone { display: grid; grid-template-columns: 1fr 260px; gap: 20px; align-items: center; }
.app-phone .features { grid-template-columns: 1fr; }
.app-phone .phone { width: 260px; transform: rotate(4deg); margin: -20px 0 -80px; }
@media (max-width: 960px) { .app-cta { grid-template-columns: 1fr; } }
@media (max-width: 560px) { .app-phone { grid-template-columns: 1fr; } .app-phone .phone { margin: 0 auto -60px; } }

/* Stocking */
.stock-list { list-style: none; padding: 0; margin: 4px 0 10px; display: grid; gap: 6px; }
.stock-list li { display: flex; align-items: center; gap: 10px; background: var(--aqua-50); border-radius: 10px; padding: 8px 10px; font-weight: 600; }
.stock-list .count { font: 800 1rem var(--display); color: var(--teal-700); min-width: 2.2em; }
.stock-list button { margin-left: auto; border: 0; background: none; font-size: 1.3rem; line-height: 1; color: var(--ink-2); cursor: pointer; }
.verdict-head { display: flex; gap: 14px; align-items: center; margin-bottom: 18px; }
.verdict-head b { display: block; font: 800 1.7rem/1.1 var(--display); }
.verdict-head span { color: var(--ink-2); font-size: .92rem; }
.vbadge { width: 56px; height: 56px; border-radius: 18px; display: grid; place-items: center; font: 800 1.6rem var(--display); background: var(--aqua-100); color: var(--ink-2); flex: none; }
.vbadge.ok { background: var(--ok); color: #fff; } .vbadge.warn { background: #e0a100; color: #fff; } .vbadge.bad { background: var(--bad); color: #fff; }
.gauge { position: relative; height: 16px; border-radius: 8px; background: linear-gradient(90deg, var(--ok-50) 0 70.8%, var(--amber-50) 70.8% 83.3%, var(--bad-50) 83.3%); overflow: visible; }
.gauge-fill { height: 100%; border-radius: 8px; transition: width .3s; }
.gauge-fill.ok { background: var(--ok); } .gauge-fill.warn { background: #e0a100; } .gauge-fill.bad { background: var(--bad); }
.gauge-mark { position: absolute; top: -4px; bottom: -4px; width: 2px; background: var(--ink); opacity: .25; transform: translateX(-1px); }
.gauge-mark:nth-child(2) { left: 70.8% !important; } .gauge-mark:nth-child(3) { left: 83.3% !important; }
.gauge-legend { display: flex; justify-content: space-between; font-size: .85rem; color: var(--ink-2); margin: 6px 0 16px; font-weight: 600; }
.checks { list-style: none; padding: 0; margin: 0; display: grid; gap: 8px; }
.checks li { display: flex; gap: 10px; align-items: flex-start; padding: 10px 12px; border-radius: 12px; font-size: .95rem; }
.checks li i { flex: none; width: 22px; height: 22px; border-radius: 50%; display: grid; place-items: center; font-style: normal; font-weight: 800; font-size: .8rem; color: #fff; }
.checks .ok { background: var(--ok-50); } .checks .ok i { background: var(--ok); }
.checks .warn { background: var(--amber-50); } .checks .warn i { background: #e0a100; }
.checks .bad { background: var(--bad-50); } .checks .bad i { background: var(--bad); }

/* Cycle timeline */
.finish { margin-bottom: 18px; }
.finish .kicker { display: block; color: var(--teal-600); font-weight: 700; font-size: .9rem; }
.finish .big { display: block; font: 800 3rem/1.05 var(--display); color: var(--teal-900); margin: 4px 0; }
.finish span:last-child { color: var(--ink-2); }
.timeline { position: relative; display: flex; gap: 4px; margin: 34px 0 18px; }
.tl-seg { min-width: 0; background: var(--aqua-100); border-radius: 10px; padding: 8px 8px 6px; display: flex; flex-direction: column; }
.tl-seg span { font: 800 1rem var(--display); color: var(--teal-700); }
.tl-seg small { font-size: .72rem; color: var(--ink-2); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.tl-seg.on { background: var(--teal-700); } .tl-seg.on span, .tl-seg.on small { color: #fff; }
.tl-seg.s5 { background: var(--ok-50); } .tl-seg.s5.on { background: var(--ok); }
.tl-now { position: absolute; top: -30px; bottom: -6px; transform: translateX(-50%); display: flex; flex-direction: column; align-items: center; pointer-events: none; }
.tl-now b { order: -1; font-size: .75rem; background: var(--coral); color: #fff; padding: 2px 8px; border-radius: 999px; }
.tl-now i { flex: 1; width: 3px; background: var(--coral); border-radius: 2px; }
.today-card { background: var(--teal-900); color: #fff; border-radius: 16px; padding: 18px 20px; }
.today-card ul { margin: 10px 0 0; padding: 0; list-style: none; display: grid; gap: 8px; color: #d6f4f1; }
.today-card li { display: flex; gap: 10px; }
.today-card li::before { content: ""; flex: none; width: 16px; height: 16px; margin-top: 4px; border-radius: 5px; border: 2px solid #5eead4; }

/* Water change */
.chips { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 18px; }
.chips input { position: absolute; opacity: 0; pointer-events: none; }
.chips span { display: grid; place-items: center; width: 52px; height: 52px; border-radius: 50%; background: var(--c); font-weight: 800; color: #3b1c12; cursor: pointer; box-shadow: inset 0 0 0 2px rgba(0,0,0,.06); transition: transform .12s; }
.chips input:checked + span { transform: scale(1.12); box-shadow: 0 0 0 3px #fff, 0 0 0 5px var(--teal-700); }
.chips input:focus-visible + span { outline: 2px solid var(--teal-700); outline-offset: 3px; }
.tubes { display: flex; justify-content: center; align-items: flex-end; gap: 28px; padding: 8px 0 4px; }
.tube { margin: 0; text-align: center; }
.tube .glass { width: 54px; height: 170px; border: 3px solid #b9dfe2; border-top: 0; border-radius: 0 0 27px 27px; background: #f6fbfb; display: flex; align-items: flex-end; overflow: hidden; margin: 0 auto 8px; }
.tube .liquid { width: 100%; transition: height .4s, background .4s; }
.tube figcaption { font-size: .85rem; color: var(--ink-2); }
.tube figcaption b { font: 800 1.4rem var(--display); color: var(--ink); }
.tubes .arrow { font: 800 2rem var(--display); color: var(--teal-600); align-self: center; }
.wc-reason { margin-top: 12px; }
.stat.main.ok { background: var(--ok); border-color: var(--ok); } .stat.main.warn { background: #b07d00; border-color: #b07d00; }

/* Calculators index */
.calc-tiles.big { grid-template-columns: repeat(2, 1fr); }
@media (max-width: 640px) { .calc-tiles.big { grid-template-columns: 1fr; } }

/* Guides */
.guide-head { padding: 40px 0 0; background: linear-gradient(180deg, var(--aqua-50), #fff 70%); }
.guide-head h1 { font-size: clamp(2rem, 4.6vw, 3.1rem); margin-bottom: 20px; }
.guide-cover img { width: 100%; height: auto; aspect-ratio: 16 / 7; object-fit: cover; border-radius: 24px; display: block; }
.guide .prose { margin-top: 32px; }
.prose .steps { list-style: none; padding: 0; counter-reset: s; display: grid; gap: 12px; }
.prose .steps li { counter-increment: s; display: grid; grid-template-columns: 40px 1fr; gap: 12px; align-items: start; background: var(--aqua-50); border-radius: 14px; padding: 14px; margin: 0; }
.prose .steps li::before { content: counter(s); width: 40px; height: 40px; border-radius: 12px; background: var(--teal-700); color: #fff; display: grid; place-items: center; font: 800 1.1rem var(--display); }
.prose .cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 10px; margin: 1rem 0 1.5rem; }
.prose .cards div { background: var(--white); border: 1px solid var(--line); border-radius: 14px; padding: 14px; }
.prose .cards b { display: block; font: 800 1.4rem var(--display); color: var(--teal-900); }
.prose .cards span { font-size: .9rem; color: var(--ink-2); }
.prose .cards .hot b { color: var(--bad); } .prose .cards .ok b { color: var(--ok); }
.calc-cta { display: flex; justify-content: space-between; align-items: center; gap: 16px; flex-wrap: wrap; background: var(--teal-900); color: #fff !important; text-decoration: none; border-radius: 18px; padding: 20px 24px; margin: 2rem 0; }
.calc-cta span { font: 700 1.15rem var(--display); }
.calc-cta b { color: #9ff0e4; }
.gear { background: var(--aqua-50); border-radius: 18px; padding: 6px 22px 14px; margin: 2rem 0; }
.gear h2 { font-size: 1.3rem; margin-top: 1rem !important; }
.gear ul { list-style: none; padding: 0; display: grid; gap: 10px; }
.gear li { display: flex; flex-direction: column; background: #fff; border-radius: 12px; padding: 12px 14px; margin: 0; }
.gear li a { font-weight: 700; }
.gear li span { font-size: .9rem; color: var(--ink-2); }
.fine-print { font-size: .82rem; color: var(--ink-2); margin: 0; }
.updated { font-size: .85rem; margin-top: 2rem; }
.tag { display: inline-block; font-size: .78rem; font-weight: 700; padding: 2px 8px; border-radius: 999px; }
.tag.ok { background: var(--ok-50); color: var(--ok); } .tag.warn { background: var(--amber-50); color: #9a6a00; } .tag.bad { background: var(--bad-50); color: var(--bad); }