/* ============================================================
   calix-pqc website — style.css
   Palette: deep space indigo + neon cyan/violet/teal accents
   ============================================================ */

:root {
  --bg:        #070a1f;
  --bg-2:      #0d1330;
  --card:      #121a3d;
  --card-2:    #161f47;
  --line:      #243056;
  --text:      #eaf1ff;
  --muted:     #93a5d4;
  --muted-2:   #6c7eb0;

  --cyan:      #2bd9ff;
  --violet:    #7c5cff;
  --teal:      #36f1cd;
  --pink:      #ff6bcb;
  --gold:      #ffd166;
  --green:     #4ade80;
  --orange:    #ff9f43;
  --red:       #ff6b6b;

  --grad-main: linear-gradient(120deg, #36f1cd 0%, #2bd9ff 45%, #7c5cff 100%);
  --grad-warm: linear-gradient(120deg, #ffd166 0%, #ff9f43 50%, #ff6b6b 100%);
  --grad-pink: linear-gradient(120deg, #7c5cff 0%, #ff6bcb 100%);

  --radius: 18px;
  --shadow: 0 18px 50px -20px rgba(43, 217, 255, .35);
  --maxw: 1180px;
  --font: "Segoe UI", system-ui, -apple-system, Roboto, Helvetica, Arial, sans-serif;
  --mono: "JetBrains Mono", "SF Mono", "Fira Code", Consolas, monospace;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; scroll-padding-top: 90px; }
body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  overflow-x: hidden;
}

/* Animated aurora background */
body::before {
  content: "";
  position: fixed; inset: 0; z-index: -2;
  background:
    radial-gradient(40% 50% at 15% 10%, rgba(124,92,255,.22), transparent 60%),
    radial-gradient(45% 55% at 85% 20%, rgba(43,217,255,.18), transparent 60%),
    radial-gradient(50% 50% at 50% 100%, rgba(54,241,205,.14), transparent 60%),
    var(--bg);
  animation: bgshift 18s ease-in-out infinite alternate;
}
@keyframes bgshift {
  0%   { filter: hue-rotate(0deg)   saturate(1); }
  100% { filter: hue-rotate(28deg)  saturate(1.25); }
}
/* drifting star particles */
body::after {
  content: "";
  position: fixed; inset: 0; z-index: -1; opacity: .5;
  background-image:
    radial-gradient(1.5px 1.5px at 20% 30%, #fff, transparent),
    radial-gradient(1.5px 1.5px at 70% 60%, #bfe9ff, transparent),
    radial-gradient(2px 2px   at 40% 80%, #d6c6ff, transparent),
    radial-gradient(1px 1px   at 90% 40%, #fff, transparent),
    radial-gradient(1.5px 1.5px at 55% 15%, #aef7e6, transparent);
  background-size: 600px 600px;
  animation: drift 60s linear infinite;
}
@keyframes drift { to { background-position: 600px 600px; } }

a { color: var(--cyan); text-decoration: none; }
.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 22px; }

.gradient-text {
  background: var(--grad-main);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent; color: transparent;
}

/* ---------- Header / Nav ---------- */
header {
  position: sticky; top: 0; z-index: 50;
  backdrop-filter: blur(14px);
  background: rgba(7,10,31,.72);
  border-bottom: 1px solid var(--line);
}
.nav {
  display: flex; align-items: center; gap: 18px;
  height: 68px;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 800; font-size: 1.15rem; letter-spacing: .3px; }
.brand img { width: 34px; height: 34px; }
.nav-links { display: flex; gap: 6px; margin-left: auto; align-items: center; }
.nav-links a {
  color: var(--muted); padding: 8px 14px; border-radius: 10px;
  font-size: .94rem; font-weight: 600; transition: .2s;
}
.nav-links a:hover { color: var(--text); background: rgba(124,92,255,.14); }

.lang-toggle {
  display: inline-flex; border: 1px solid var(--line); border-radius: 999px; overflow: hidden;
  background: var(--bg-2);
}
.lang-toggle button {
  background: none; border: none; color: var(--muted); cursor: pointer;
  padding: 7px 14px; font-weight: 700; font-size: .85rem; transition: .2s;
}
.lang-toggle button.active { background: var(--grad-main); color: #04122e; }

.burger { display: none; background: none; border: none; cursor: pointer; flex-direction: column; gap: 5px; }
.burger span { width: 26px; height: 3px; border-radius: 3px; background: var(--text); transition: .3s; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 9px;
  padding: 13px 26px; border-radius: 12px; font-weight: 700; font-size: .98rem;
  cursor: pointer; border: none; transition: transform .18s, box-shadow .25s, filter .2s;
  white-space: nowrap;
}
.btn-primary { background: var(--grad-main); color: #04122e; box-shadow: var(--shadow); }
.btn-primary:hover { transform: translateY(-3px) scale(1.02); filter: brightness(1.08); }
.btn-ghost { background: rgba(124,92,255,.12); color: var(--text); border: 1px solid var(--line); }
.btn-ghost:hover { background: rgba(124,92,255,.24); transform: translateY(-3px); }

/* ---------- Hero ---------- */
.hero { padding: 70px 0 50px; }
.hero-grid { display: grid; grid-template-columns: 1.05fr .95fr; gap: 40px; align-items: center; }
.badge {
  display: inline-flex; align-items: center; gap: 8px;
  background: rgba(54,241,205,.12); color: var(--teal);
  border: 1px solid rgba(54,241,205,.35);
  padding: 7px 15px; border-radius: 999px; font-size: .8rem; font-weight: 700;
  letter-spacing: .5px; margin-bottom: 22px;
}
.badge .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--teal); animation: pulse 1.6s infinite; }
@keyframes pulse { 0%,100% { opacity: 1; box-shadow: 0 0 0 0 rgba(54,241,205,.5);} 50% { opacity:.5; box-shadow: 0 0 0 7px rgba(54,241,205,0);} }

.hero h1 { font-size: clamp(2.2rem, 5vw, 3.6rem); line-height: 1.08; font-weight: 900; letter-spacing: -1px; }
.hero p.lead { color: var(--muted); font-size: 1.12rem; margin: 20px 0 30px; max-width: 540px; }
.hero-cta { display: flex; gap: 14px; flex-wrap: wrap; }
.hero-art { position: relative; }
.hero-art img { width: 100%; height: auto; border-radius: 22px; filter: drop-shadow(0 30px 60px rgba(43,217,255,.25)); }
.float { animation: float 6s ease-in-out infinite; }
@keyframes float { 0%,100% { transform: translateY(0);} 50% { transform: translateY(-16px);} }

/* stat strip */
.stats { display: grid; grid-template-columns: repeat(4,1fr); gap: 16px; margin-top: 52px; }
.stat {
  background: linear-gradient(160deg, var(--card), var(--card-2));
  border: 1px solid var(--line); border-radius: var(--radius);
  padding: 22px; text-align: center; transition: .25s;
}
.stat:hover { transform: translateY(-6px); border-color: var(--cyan); box-shadow: var(--shadow); }
.stat .num { font-size: 1.9rem; font-weight: 900; }
.stat .lbl { color: var(--muted); font-size: .86rem; margin-top: 4px; }

/* ---------- Sections ---------- */
section { padding: 76px 0; position: relative; }
.section-head { text-align: center; max-width: 760px; margin: 0 auto 48px; }
.section-head .kicker { color: var(--teal); font-weight: 800; letter-spacing: 3px; font-size: .78rem; text-transform: uppercase; }
.section-head h2 { font-size: clamp(1.8rem, 4vw, 2.6rem); font-weight: 900; margin: 10px 0 14px; letter-spacing: -.5px; }
.section-head p { color: var(--muted); font-size: 1.05rem; }

/* feature cards */
.grid-3 { display: grid; grid-template-columns: repeat(3,1fr); gap: 22px; }
.grid-2 { display: grid; grid-template-columns: repeat(2,1fr); gap: 22px; }
.feature {
  background: linear-gradient(160deg, var(--card), var(--card-2));
  border: 1px solid var(--line); border-radius: var(--radius);
  padding: 28px; transition: .28s; position: relative; overflow: hidden;
}
.feature::before {
  content:""; position:absolute; inset:0; padding:1px; border-radius:var(--radius);
  background: var(--grad-main); -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor; mask-composite: exclude; opacity: 0; transition: .28s;
}
.feature:hover { transform: translateY(-8px); }
.feature:hover::before { opacity: 1; }
.feature .ic {
  width: 56px; height: 56px; border-radius: 14px; display: grid; place-items: center;
  font-size: 1.6rem; margin-bottom: 16px; background: rgba(43,217,255,.12);
}
.feature h3 { font-size: 1.2rem; margin-bottom: 8px; }
.feature p { color: var(--muted); font-size: .96rem; }

/* how-it-works */
.flow-img { width: 100%; border-radius: var(--radius); border: 1px solid var(--line); background: var(--bg-2); }
.steps { display: grid; grid-template-columns: repeat(4,1fr); gap: 18px; margin-top: 34px; }
.step { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; position: relative; }
.step .n { width: 34px; height: 34px; border-radius: 10px; background: var(--grad-main); color: #04122e; font-weight: 900; display: grid; place-items: center; margin-bottom: 12px; }
.step h4 { font-size: 1.02rem; margin-bottom: 6px; }
.step p { color: var(--muted); font-size: .9rem; }

/* spec table */
.spec { background: linear-gradient(160deg,var(--card),var(--card-2)); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.spec table { width: 100%; border-collapse: collapse; }
.spec th, .spec td { padding: 15px 22px; text-align: left; border-bottom: 1px solid var(--line); }
.spec th { color: var(--teal); font-size: .82rem; text-transform: uppercase; letter-spacing: 1px; }
.spec td:last-child { font-family: var(--mono); color: var(--cyan); font-weight: 600; }
.spec tr:last-child td { border-bottom: none; }
.spec tr:hover td { background: rgba(43,217,255,.05); }

/* ---------- Code / Integration tabs ---------- */
.tabs { display: flex; gap: 8px; flex-wrap: wrap; justify-content: center; margin-bottom: 26px; }
.tab {
  background: var(--card); border: 1px solid var(--line); color: var(--muted);
  padding: 10px 20px; border-radius: 999px; cursor: pointer; font-weight: 700; font-size: .9rem; transition: .2s;
  display: inline-flex; align-items: center; gap: 8px;
}
.tab:hover { color: var(--text); border-color: var(--cyan); }
.tab.active { background: var(--grad-main); color: #04122e; border-color: transparent; }

.code-wrap {
  background: #0a0f28; border: 1px solid var(--line); border-radius: var(--radius);
  overflow: hidden; box-shadow: var(--shadow);
}
.code-bar { display: flex; align-items: center; gap: 8px; padding: 12px 16px; border-bottom: 1px solid var(--line); background: #0c1230; }
.code-bar .dots { display: flex; gap: 6px; }
.code-bar .dots i { width: 12px; height: 12px; border-radius: 50%; display: inline-block; }
.code-bar .dots i:nth-child(1){background:#ff5f57;} .code-bar .dots i:nth-child(2){background:#febc2e;} .code-bar .dots i:nth-child(3){background:#28c840;}
.code-bar .fname { color: var(--muted); font-family: var(--mono); font-size: .82rem; margin-left: 6px; }
.code-bar .copy { margin-left: auto; background: rgba(124,92,255,.18); color: var(--text); border: 1px solid var(--line); padding: 6px 13px; border-radius: 8px; cursor: pointer; font-size: .8rem; font-weight: 700; transition: .2s; }
.code-bar .copy:hover { background: rgba(124,92,255,.4); }
.code-bar .copy.done { background: var(--green); color: #04220f; }
.code-panel { display: none; }
.code-panel.active { display: block; }
pre { margin: 0; padding: 22px; overflow-x: auto; font-family: var(--mono); font-size: .86rem; line-height: 1.7; }
pre code { color: #cfe0ff; white-space: pre; }
/* lightweight token coloring via spans added in HTML */
.t-key { color: #ff6bcb; } .t-fn { color: #36f1cd; } .t-str { color: #ffd166; }
.t-com { color: #6c7eb0; font-style: italic; } .t-num { color: #2bd9ff; } .t-type { color: #c6b3ff; }

/* ---------- Downloads ---------- */
.dl-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 20px; }
.dl-card {
  background: linear-gradient(160deg,var(--card),var(--card-2));
  border: 1px solid var(--line); border-radius: var(--radius); padding: 24px;
  display: flex; flex-direction: column; gap: 12px; transition: .26s; position: relative; overflow: hidden;
}
.dl-card:hover { transform: translateY(-7px); border-color: var(--cyan); box-shadow: var(--shadow); }
.dl-top { display: flex; align-items: center; gap: 14px; }
.dl-ic { width: 50px; height: 50px; border-radius: 13px; display: grid; place-items: center; font-size: 1.5rem; flex-shrink: 0; }
.dl-ic.green{background:rgba(74,222,128,.15);} .dl-ic.blue{background:rgba(43,217,255,.15);}
.dl-ic.purple{background:rgba(124,92,255,.15);} .dl-ic.cyan{background:rgba(43,217,255,.15);}
.dl-ic.teal{background:rgba(54,241,205,.15);} .dl-ic.gold{background:rgba(255,209,102,.15);}
.dl-ic.pink{background:rgba(255,107,203,.15);} .dl-ic.orange{background:rgba(255,159,67,.15);}
.dl-ic.slate{background:rgba(147,165,212,.15);}
.dl-card h3 { font-size: 1.12rem; }
.dl-card .size { font-family: var(--mono); font-size: .8rem; color: var(--teal); }
.dl-card p { color: var(--muted); font-size: .9rem; flex: 1; }
.dl-card .btn { width: 100%; justify-content: center; margin-top: 6px; }

/* ---------- Security callout ---------- */
.callout { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.do, .dont { border-radius: var(--radius); padding: 26px; border: 1px solid var(--line); }
.do { background: rgba(74,222,128,.07); border-color: rgba(74,222,128,.3); }
.dont { background: rgba(255,107,107,.07); border-color: rgba(255,107,107,.3); }
.do h3 { color: var(--green); } .dont h3 { color: var(--red); }
.do ul, .dont ul { list-style: none; margin-top: 14px; display: grid; gap: 10px; }
.do li, .dont li { padding-left: 28px; position: relative; color: var(--muted); font-size: .95rem; }
.do li::before { content: "✓"; position: absolute; left: 0; color: var(--green); font-weight: 900; }
.dont li::before { content: "✗"; position: absolute; left: 0; color: var(--red); font-weight: 900; }

/* ---------- Footer ---------- */
footer { border-top: 1px solid var(--line); padding: 50px 0 36px; background: var(--bg-2); }
.foot-grid { display: flex; justify-content: space-between; gap: 30px; flex-wrap: wrap; align-items: flex-start; }
.foot-grid .brand { margin-bottom: 12px; }
footer p { color: var(--muted-2); font-size: .9rem; max-width: 380px; }
.foot-links { display: flex; gap: 40px; flex-wrap: wrap; }
.foot-col h5 { font-size: .8rem; text-transform: uppercase; letter-spacing: 1.5px; color: var(--muted); margin-bottom: 12px; }
.foot-col a { display: block; color: var(--muted-2); font-size: .92rem; padding: 4px 0; transition: .2s; }
.foot-col a:hover { color: var(--cyan); }
.copyright { text-align: center; margin-top: 36px; color: var(--muted-2); font-size: .85rem; border-top: 1px solid var(--line); padding-top: 24px; }

/* ---------- Scroll reveal ---------- */
.reveal { opacity: 0; transform: translateY(36px); transition: opacity .7s ease, transform .7s cubic-bezier(.2,.7,.3,1); }
.reveal.in { opacity: 1; transform: none; }

/* lang visibility */
[data-lang-en] { display: none; }
body.en [data-lang-vi] { display: none; }
body.en [data-lang-en] { display: revert; }

/* ---------- Responsive ---------- */
@media (max-width: 920px) {
  .hero-grid { grid-template-columns: 1fr; text-align: center; }
  .hero p.lead { margin-left: auto; margin-right: auto; }
  .hero-cta { justify-content: center; }
  .hero-art { order: -1; max-width: 420px; margin: 0 auto; }
  .grid-3, .dl-grid { grid-template-columns: repeat(2,1fr); }
  .steps { grid-template-columns: repeat(2,1fr); }
  .stats { grid-template-columns: repeat(2,1fr); }
}
@media (max-width: 640px) {
  .nav-links { position: fixed; top: 68px; left: 0; right: 0; flex-direction: column;
    background: var(--bg-2); border-bottom: 1px solid var(--line); padding: 14px;
    transform: translateY(-130%); transition: transform .3s; align-items: stretch; }
  .nav-links.open { transform: none; }
  .nav-links a { padding: 12px; }
  .lang-toggle { align-self: center; }
  .burger { display: flex; margin-left: auto; }
  .grid-3, .grid-2, .dl-grid, .steps, .stats, .callout { grid-template-columns: 1fr; }
  section { padding: 56px 0; }
  .hero { padding: 44px 0 30px; }
}
@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; }
  .reveal { opacity: 1; transform: none; }
}