/* Eulingua — layout + flashy components. */

/* ---------- animated aurora backdrop ---------- */
.aurora { position: fixed; inset: 0; z-index: -1; overflow: hidden; filter: blur(70px); opacity: .55; pointer-events: none; }
.aurora span { position: absolute; width: 46vw; height: 46vw; border-radius: 50%; mix-blend-mode: screen; animation: drift 26s ease-in-out infinite; }
.aurora span:nth-child(1){ background: radial-gradient(circle, var(--accent), transparent 60%); top:-10vw; left:-6vw; }
.aurora span:nth-child(2){ background: radial-gradient(circle, var(--accent-2), transparent 60%); bottom:-14vw; right:-8vw; animation-delay:-9s; }
.aurora span:nth-child(3){ background: radial-gradient(circle, var(--accent-3), transparent 60%); top:30vh; left:42vw; animation-delay:-16s; }
@keyframes drift { 0%,100%{ transform: translate(0,0) scale(1);} 33%{ transform: translate(6vw,4vh) scale(1.15);} 66%{ transform: translate(-5vw,-3vh) scale(.9);} }

/* ---------- nav ---------- */
.nav {
  position: sticky; top: 0; z-index: 50;
  display: flex; align-items: center; gap: var(--pad-4);
  padding: var(--pad-2) var(--pad-4);
  background: var(--glass); backdrop-filter: blur(16px) saturate(140%);
  border-bottom: 1px solid var(--border-1);
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 800; font-size: 1.15rem; color: var(--text-1); }
.brand-mark { font-family: var(--font-mono); color: var(--accent); font-size: 1.3rem; }
.brand-name { background: linear-gradient(90deg, var(--accent), var(--accent-2)); -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; }
.nav-links { display: flex; gap: 4px; margin-left: auto; }
.nav-links a { padding: 7px 14px; border-radius: var(--radius-full); color: var(--text-2); font-weight: 500; font-size: .94rem; transition: var(--transition); }
.nav-links a:hover { color: var(--text-1); background: var(--surface-2); }
.nav-links a.active { color: var(--accent-fg); background: var(--accent); }
.nav-right { display: flex; align-items: center; gap: 8px; }
.theme-select { background: var(--surface-2); color: var(--text-2); border: 1px solid var(--border-1); border-radius: var(--radius-full); padding: 6px 10px; font: inherit; font-size: .85rem; cursor: pointer; }
.btn-icon { display: grid; place-items: center; width: 36px; height: 36px; border-radius: var(--radius-full); border: 1px solid var(--border-1); background: var(--surface-2); color: var(--text-2); cursor: pointer; transition: var(--transition); }
.btn-icon:hover { color: var(--accent); border-color: var(--accent); transform: rotate(35deg); }

/* ---------- layout ---------- */
.main { max-width: var(--maxw); margin: 0 auto; padding: var(--pad-5) var(--pad-4) 64px; }
.section-head { margin: 0 0 var(--pad-4); }
.section-head h1 { font-size: clamp(1.8rem, 4vw, 2.6rem); margin: 0 0 6px; }
.section-head p { color: var(--text-2); margin: 0; max-width: 60ch; }
.eyebrow { text-transform: uppercase; letter-spacing: .18em; font-size: .72rem; font-weight: 700; color: var(--accent); }

/* ---------- buttons ---------- */
.btn { display: inline-flex; align-items: center; gap: 8px; padding: 11px 20px; border-radius: var(--radius-full); border: 1px solid transparent; font: inherit; font-weight: 600; cursor: pointer; transition: var(--transition); }
.btn-primary { background: linear-gradient(95deg, var(--accent), var(--accent-2)); color: var(--accent-fg); box-shadow: var(--shadow-md); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: var(--shadow-lg); color: var(--accent-fg); }
.btn-ghost { background: var(--surface-2); color: var(--text-1); border-color: var(--border-1); }
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }

/* ---------- cards ---------- */
.card { background: var(--surface-1); border: 1px solid var(--border-1); border-radius: var(--radius-lg); padding: var(--pad-4); transition: var(--transition); }
.card:hover { border-color: var(--border-2); box-shadow: var(--shadow-md); }
.grid { display: grid; gap: var(--pad-3); }

/* ---------- hero (home) ---------- */
.hero { text-align: center; padding: 48px 0 40px; }
.hero h1 { font-size: clamp(2.4rem, 7vw, 4.6rem); margin: 0 0 10px; letter-spacing: -.03em; }
.hero .grad { background: linear-gradient(100deg, var(--accent), var(--accent-2) 45%, var(--accent-3)); background-size: 200% auto; -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent; animation: sheen 8s linear infinite; }
@keyframes sheen { to { background-position: 200% center; } }
.hero-sub { font-size: 1.2rem; color: var(--text-2); max-width: 56ch; margin: 0 auto 26px; }
.hero-cta { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.hero-langline { margin-top: 30px; display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; }

/* language pills / chips */
.lang-pill { display: inline-flex; align-items: center; gap: 6px; padding: 4px 12px; border-radius: var(--radius-full); font-size: .82rem; font-weight: 600; color: var(--lang-color, var(--accent)); background: color-mix(in srgb, var(--lang-color, var(--accent)) 14%, transparent); border: 1px solid color-mix(in srgb, var(--lang-color, var(--accent)) 36%, transparent); }
.lang-pill::before { content: ""; width: 8px; height: 8px; border-radius: 50%; background: var(--lang-color, var(--accent)); box-shadow: 0 0 8px var(--lang-color, var(--accent)); }

/* language cards grid */
.lang-cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px,1fr)); gap: var(--pad-3); margin-top: 40px; }
.lang-card { position: relative; display: block; padding: var(--pad-4); border-radius: var(--radius-lg); background: var(--surface-1); border: 1px solid var(--border-1); overflow: hidden; transition: var(--transition); }
.lang-card::after { content: ""; position: absolute; inset: 0 0 auto 0; height: 3px; background: var(--lang-color); }
.lang-card:hover { transform: translateY(-4px); border-color: var(--lang-color); box-shadow: 0 16px 40px -16px var(--lang-color); }
.lang-card h3 { margin: 6px 0 4px; color: var(--text-1); }
.lang-card .yr { font-family: var(--font-mono); color: var(--text-3); font-size: .8rem; }
.lang-card p { color: var(--text-2); font-size: .9rem; margin: 8px 0 0; }

/* home feature sections */
.home-sections { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px,1fr)); gap: var(--pad-3); margin-top: 48px; }
.home-sections .card h3 { margin: 0 0 6px; }
.home-sections .card .big { font-size: 2rem; font-weight: 800; background: linear-gradient(90deg,var(--accent),var(--accent-2)); -webkit-background-clip:text; background-clip:text; -webkit-text-fill-color:transparent; }

/* ---------- compare ---------- */
.topic-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px,1fr)); gap: var(--pad-3); }
.topic-card { display: block; padding: var(--pad-4); border-radius: var(--radius-lg); background: var(--surface-1); border: 1px solid var(--border-1); transition: var(--transition); }
.topic-card:hover { transform: translateY(-3px); border-color: var(--accent); box-shadow: var(--shadow-md); }
.topic-card .num { font-family: var(--font-mono); color: var(--accent); font-size: .8rem; }
.topic-card h3 { margin: 4px 0 6px; color: var(--text-1); }
.topic-card p { color: var(--text-2); font-size: .88rem; margin: 0; }

.compare-toolbar { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; margin-bottom: var(--pad-4); padding: var(--pad-2); background: var(--surface-1); border: 1px solid var(--border-1); border-radius: var(--radius-full); }
.lang-toggle { cursor: pointer; user-select: none; opacity: .45; filter: grayscale(.5); transition: var(--transition); }
.lang-toggle.on { opacity: 1; filter: none; }

.compare-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(340px, 1fr)); gap: var(--pad-3); align-items: start; }

/* ---------- code cards ---------- */
.codecard { display: flex; flex-direction: column; border: 1px solid var(--border-1); border-radius: var(--radius-lg); overflow: hidden; background: var(--surface-1); box-shadow: var(--shadow-sm); }
.codecard-head { display: flex; align-items: center; justify-content: space-between; padding: 10px 14px; border-bottom: 1px solid var(--border-1); background: var(--surface-2); }
.codecard-body { overflow: auto; }
.codecard-body pre, pre.chroma { margin: 0; padding: 16px; font-size: .85rem; line-height: 1.55; overflow: auto; background: #1e1e2e; }
.codecard-note { padding: 12px 14px; font-size: .86rem; color: var(--text-2); border-top: 1px solid var(--border-1); background: var(--surface-1); }
.codecard-note :first-child { margin-top: 0; } .codecard-note :last-child { margin-bottom: 0; }
.run-btn { font: inherit; font-size: .8rem; font-weight: 600; padding: 4px 12px; border-radius: var(--radius-full); border: 1px solid var(--success); color: var(--success); background: transparent; cursor: pointer; transition: var(--transition); }
.run-btn:hover { background: var(--success); color: var(--surface-0); }
.run-btn[disabled] { opacity: .5; cursor: progress; }
.run-output { margin: 0; padding: 12px 14px; background: #11111b; color: #cdd6f4; font-family: var(--font-mono); font-size: .82rem; white-space: pre-wrap; border-top: 1px solid var(--border-2); max-height: 220px; overflow: auto; }
.run-output.err { color: var(--danger); }

/* ---------- quiz ---------- */
.quiz-setup { max-width: 720px; }
.lang-checks { display: flex; flex-wrap: wrap; gap: 8px; margin: var(--pad-3) 0; }
.lang-check { cursor: pointer; }
.lang-check input { display: none; }
.lang-check .lang-pill { opacity: .5; transition: var(--transition); }
.lang-check input:checked + .lang-pill { opacity: 1; box-shadow: 0 0 0 2px var(--lang-color); }
.quiz-stage { max-width: 760px; margin: 0 auto; }
.quiz-progress { height: 6px; border-radius: var(--radius-full); background: var(--surface-3); overflow: hidden; margin-bottom: var(--pad-4); }
.quiz-progress > i { display: block; height: 100%; background: linear-gradient(90deg,var(--accent),var(--accent-2)); width: 0; transition: width .4s var(--ease-spring); }
.quiz-card { background: var(--surface-1); border: 1px solid var(--border-1); border-radius: var(--radius-lg); padding: var(--pad-4); box-shadow: var(--shadow-md); }
.quiz-meta { display: flex; gap: 8px; align-items: center; margin-bottom: var(--pad-3); font-size: .8rem; color: var(--text-3); }
.quiz-prompt { font-size: 1.1rem; margin-bottom: var(--pad-3); }
.choices { display: grid; gap: 10px; }
.choice { text-align: left; padding: 14px 16px; border-radius: var(--radius-md); border: 1px solid var(--border-1); background: var(--surface-2); color: var(--text-1); font: inherit; cursor: pointer; transition: var(--transition); }
.choice:hover { border-color: var(--accent); transform: translateX(3px); }
.choice.correct { border-color: var(--success); background: color-mix(in srgb, var(--success) 18%, transparent); }
.choice.wrong { border-color: var(--danger); background: color-mix(in srgb, var(--danger) 18%, transparent); }
.choice.dim { opacity: .5; }
.fill-input { width: 100%; padding: 14px 16px; border-radius: var(--radius-md); border: 1px solid var(--border-1); background: var(--surface-2); color: var(--text-1); font: inherit; font-family: var(--font-mono); }
.quiz-feedback { margin-top: var(--pad-3); padding: var(--pad-3); border-radius: var(--radius-md); background: var(--surface-2); border-left: 3px solid var(--accent); }
.quiz-feedback.ok { border-left-color: var(--success); }
.quiz-feedback.no { border-left-color: var(--danger); }
.hint-btn { background: none; border: none; color: var(--accent); cursor: pointer; font: inherit; font-size: .85rem; }
.quiz-actions { display: flex; justify-content: space-between; align-items: center; margin-top: var(--pad-4); }
.stats-panel { margin-top: var(--pad-5); display: grid; grid-template-columns: repeat(auto-fit,minmax(220px,1fr)); gap: var(--pad-3); }
.bar { height: 8px; border-radius: var(--radius-full); background: var(--surface-3); overflow: hidden; margin-top: 6px; }
.bar > i { display: block; height: 100%; background: linear-gradient(90deg,var(--danger),var(--warning),var(--success)); }
.weak-tag { display: inline-block; padding: 3px 10px; border-radius: var(--radius-full); background: color-mix(in srgb, var(--warning) 18%, transparent); color: var(--warning); font-size: .8rem; margin: 3px; }

/* ---------- features matrix ---------- */
.matrix-tools { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: var(--pad-3); }
.matrix-cat { margin: var(--pad-5) 0 var(--pad-3); display: flex; align-items: center; gap: 10px; }
.matrix-cat h2 { margin: 0; font-size: 1.4rem; }
.matrix-wrap { overflow-x: auto; border: 1px solid var(--border-1); border-radius: var(--radius-lg); }
table.matrix { border-collapse: collapse; width: 100%; min-width: 760px; font-size: .85rem; }
table.matrix th, table.matrix td { padding: 12px 14px; text-align: left; border-bottom: 1px solid var(--border-1); vertical-align: top; }
table.matrix thead th { position: sticky; top: 0; background: var(--surface-2); z-index: 1; }
table.matrix th.feat { width: 220px; }
table.matrix tr:hover td { background: var(--surface-2); }
.support { display: inline-block; padding: 2px 9px; border-radius: var(--radius-full); font-size: .72rem; font-weight: 700; }
.support-yes { color: var(--success); background: color-mix(in srgb,var(--success) 16%,transparent); }
.support-partial { color: var(--warning); background: color-mix(in srgb,var(--warning) 16%,transparent); }
.support-via-lib { color: var(--accent-2); background: color-mix(in srgb,var(--accent-2) 16%,transparent); }
.support-no { color: var(--text-3); background: var(--surface-3); }
.feat-note { color: var(--text-2); display: block; margin-top: 4px; }

/* ---------- history + article ---------- */
.article-list { display: grid; gap: var(--pad-3); }
.article-card { padding: var(--pad-4); border-radius: var(--radius-lg); background: var(--surface-1); border: 1px solid var(--border-1); transition: var(--transition); }
.article-card:hover { border-color: var(--accent); transform: translateY(-2px); }
.article-card h3 { margin: 0 0 6px; }
.article-card .langs { margin-top: 10px; display: flex; gap: 6px; flex-wrap: wrap; }
.article { max-width: 760px; margin: 0 auto; font-size: 1.05rem; }
.article h1 { font-family: var(--font-display); font-size: clamp(2rem,5vw,3rem); }
.article h2, .article h3 { margin-top: 1.8em; }
.article p { color: var(--text-1); } .article blockquote { border-left: 3px solid var(--accent); margin: 1.4em 0; padding: 4px 0 4px 18px; color: var(--text-2); font-style: italic; }
.article pre.chroma { border-radius: var(--radius-md); margin: 1.4em 0; }
.article a { text-decoration: underline; text-underline-offset: 3px; }

/* language profile */
.lang-hero { display: flex; align-items: center; gap: 18px; padding: var(--pad-4); border-radius: var(--radius-lg); background: var(--surface-1); border: 1px solid var(--border-1); border-left: 5px solid var(--lang-color); margin-bottom: var(--pad-4); }
.lang-hero h1 { margin: 0; } .lang-hero .tag { color: var(--text-2); }
.fact-grid { display: grid; grid-template-columns: repeat(auto-fit,minmax(160px,1fr)); gap: var(--pad-2); margin: var(--pad-3) 0; }
.fact { padding: var(--pad-2) var(--pad-3); background: var(--surface-2); border-radius: var(--radius-md); }
.fact b { display: block; color: var(--text-3); font-size: .72rem; text-transform: uppercase; letter-spacing: .08em; }

/* ---------- footer ---------- */
.footer { max-width: var(--maxw); margin: 40px auto 0; padding: var(--pad-5) var(--pad-4); border-top: 1px solid var(--border-1); color: var(--text-3); }
.footer-quote { font-family: var(--font-display); font-size: 1.15rem; color: var(--text-2); border: 0; margin: 0 0 var(--pad-4); }
.footer-quote cite { display: block; margin-top: 8px; font-size: .85rem; color: var(--text-3); font-style: normal; }
.footer-row { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 8px; font-size: .82rem; }

.reveal { opacity: 0; transform: translateY(14px); transition: opacity .6s var(--transition), transform .6s var(--ease-spring); }
.reveal.in { opacity: 1; transform: none; }