/* style.css — Kalkgo design system v2 (matrix-unified with KalkgoID).
   Giữ nguyên mọi class cũ để 16 trang công cụ + index + pro/privacy/terms không vỡ. */
:root{
  --bg:#f4f7f5; --card:#ffffff; --ink:#14231c; --muted:#5f6f66; --line:#e2eae5;
  --brand:#0b6e4f; --brand2:#07452f; --brand-soft:#e7f4ec;
  --accent:#ffb020; --accent2:#f59e0b; --danger:#b3261e;
  --radius:18px;
  --shadow-sm:0 1px 3px rgba(11,110,79,.08);
  --shadow-md:0 8px 28px rgba(11,110,79,.10);
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;font-family:"Segoe UI",system-ui,-apple-system,Roboto,"Helvetica Neue",Arial,sans-serif;background:var(--bg);color:var(--ink);line-height:1.7;font-size:16.5px;-webkit-font-smoothing:antialiased}
a{color:var(--brand);text-decoration:none}
a:hover{text-decoration:underline}
.wrap{max-width:1060px;margin:0 auto;padding:0 20px}
/* ===== header ===== */
header.site{background:rgba(7,69,47,.96);backdrop-filter:blur(12px);color:#fff;position:sticky;top:0;z-index:50;box-shadow:0 2px 16px rgba(0,0,0,.12)}
header.site .wrap{display:flex;align-items:center;justify-content:space-between;padding:15px 20px;gap:12px;flex-wrap:wrap}
.logo{font-weight:800;font-size:20px;color:#fff;letter-spacing:.2px}
.logo span{background:linear-gradient(135deg,var(--accent),var(--accent2));-webkit-background-clip:text;background-clip:text;color:transparent}
nav.main a{color:#dcefe6;margin-left:20px;font-size:15px;font-weight:500;transition:.2s}
nav.main a:hover{color:#fff;text-decoration:none}
/* ===== hero ===== */
.hero{background:radial-gradient(1100px 480px at 20% -10%,rgba(255,176,32,.16),transparent 60%),radial-gradient(900px 420px at 90% 110%,rgba(16,185,129,.22),transparent 55%),linear-gradient(135deg,#0c7a57 0%,#07452f 70%,#053a27 100%);color:#fff;padding:56px 0 46px;position:relative;overflow:hidden}
.hero::after{content:"";position:absolute;inset:0;background:radial-gradient(2px 2px at 12% 30%,rgba(255,255,255,.25),transparent 50%),radial-gradient(2px 2px at 78% 18%,rgba(255,255,255,.18),transparent 50%),radial-gradient(1.5px 1.5px at 55% 75%,rgba(255,255,255,.2),transparent 50%);pointer-events:none}
.hero .wrap{position:relative;z-index:1}
.hero h1{margin:0 0 12px;font-size:32px;line-height:1.28;letter-spacing:-.5px;font-weight:800}
.hero p{margin:0;max-width:760px;color:#d7ece4;font-size:16.5px}
.pill{display:inline-flex;align-items:center;gap:8px;background:rgba(255,255,255,.14);border:1px solid rgba(255,255,255,.25);color:#fff;border-radius:999px;padding:6px 16px;font-size:12.5px;font-weight:700;letter-spacing:1.5px;margin-bottom:16px;backdrop-filter:blur(6px)}
.pill i{width:7px;height:7px;border-radius:50%;background:#4ade80;box-shadow:0 0 10px #4ade80;animation:pulse 2s infinite;font-style:normal}
@keyframes pulse{50%{opacity:.5}}
.trust{display:flex;gap:18px;flex-wrap:wrap;margin-top:18px;font-size:13.5px;color:#cde9db;font-weight:600}
.scroll-cta{display:inline-block;margin-top:22px;background:rgba(255,255,255,.14);border:1px solid rgba(255,255,255,.3);color:#fff;font-weight:700;font-size:15px;padding:12px 28px;border-radius:999px;backdrop-filter:blur(6px);transition:.25s}
.scroll-cta:hover{background:var(--accent);border-color:var(--accent);color:#3a2a00;text-decoration:none;transform:translateY(-2px)}
/* ===== main ===== */
main{padding:0 0 48px}
main>.wrap{padding-top:26px}
.breadcrumb{font-size:13.5px;color:var(--muted);margin:2px 0 4px}
.tag{display:inline-block;background:#e7f4ec;color:var(--brand);border-radius:999px;padding:3px 12px;font-size:12.5px;font-weight:700;margin-bottom:10px;letter-spacing:.5px}
/* ===== calculator card ===== */
.card{background:var(--card);border:1px solid var(--line);border-radius:20px;padding:30px;margin:22px 0;box-shadow:var(--shadow-md);position:relative;overflow:hidden}
.card::before{content:"";position:absolute;top:0;left:0;right:0;height:5px;background:linear-gradient(90deg,var(--brand),#10b981,var(--accent))}
.card h2{margin-top:0;font-size:21px;color:var(--brand2);letter-spacing:-.3px}
/* ===== form ===== */
form.calc{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:14px;margin-top:8px}
.field label{display:block;font-weight:700;font-size:14.5px;margin-bottom:7px}
.field input,.field select{width:100%;padding:13px 14px;border:2px solid var(--line);border-radius:12px;font-size:16.5px;background:#fbfdfc;transition:.2s;color:var(--ink);font-family:inherit}
.field input:focus,.field select:focus{outline:none;border-color:var(--brand);box-shadow:0 0 0 4px rgba(11,110,79,.12);background:#fff}
.field .hint{font-size:13px;color:var(--muted);margin-top:6px;display:block}
.btn{grid-column:1/-1;background:linear-gradient(135deg,#0d8a5f,#0b6e4f);color:#fff;border:0;border-radius:12px;padding:15px 20px;font-size:16.5px;font-weight:800;cursor:pointer;transition:.25s;box-shadow:0 8px 20px rgba(11,110,79,.28);font-family:inherit}
.btn:hover{transform:translateY(-2px);box-shadow:0 12px 28px rgba(11,110,79,.36)}
.btn:active{transform:translateY(0)}
/* ===== result ===== */
.result{margin-top:20px;border-top:2px dashed var(--line);padding-top:18px;display:none}
.result.show{display:block;animation:fadeUp .45s ease}
@keyframes fadeUp{from{opacity:0;transform:translateY(10px)}to{opacity:1;transform:none}}
.result h3{color:var(--brand2);margin:4px 0 10px}
table.kv{width:100%;border-collapse:collapse;margin:10px 0}
table.kv th,table.kv td{border:1px solid var(--line);padding:10px 12px;text-align:left;font-size:15px}
table.kv th{background:#eef5f1;color:var(--brand2)}
table.kv td.num,table.kv th.num{text-align:right;font-variant-numeric:tabular-nums}
.big{font-size:22px;font-weight:800;color:var(--brand2);font-variant-numeric:tabular-nums}
.result .hint{font-size:13.5px;color:var(--muted)}
.pos{color:var(--brand);font-weight:700}.neg{color:var(--danger);font-weight:700}
/* ===== content ===== */
h1.page{font-size:27px;line-height:1.35;margin:8px 0 6px}
.lead{color:var(--muted);font-size:17px;margin:0 0 8px}
main h2{font-size:21px;margin:30px 0 10px;letter-spacing:-.2px}
main h2:not(.card h2){position:relative;padding-bottom:10px}
main h2:not(.card h2)::after{content:"";position:absolute;left:0;bottom:0;width:52px;height:4px;border-radius:4px;background:linear-gradient(90deg,var(--brand),var(--accent))}
main p{color:#33473c}
.note{background:#fff8e6;border:1px solid #f0d98c;border-radius:12px;padding:14px 18px;font-size:15px}
/* ===== faq ===== */
.faq details{border:1px solid var(--line);border-radius:14px;padding:14px 18px;margin:10px 0;background:#fff;transition:.2s}
.faq details:hover{border-color:#bcd8c6}
.faq details[open]{border-color:#9fd0b4;box-shadow:var(--shadow-sm)}
.faq summary{font-weight:700;cursor:pointer;font-size:15.5px;list-style:none;display:flex;justify-content:space-between;align-items:center;gap:10px}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";font-size:22px;color:var(--brand);font-weight:400;flex-shrink:0}
.faq details[open] summary::after{content:"–";color:var(--accent2)}
.faq p{margin:10px 0 0;color:var(--muted);font-size:15px}
/* ===== misc ===== */
.disclaimer{font-size:13.5px;color:#8a6d1c;background:#fff8e6;border:1px solid #f0d98c;border-radius:12px;padding:14px 18px;margin-top:28px}
/* ===== index grid ===== */
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:16px;margin:24px 0}
.tool-card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:24px;display:block;transition:.25s;position:relative;overflow:hidden}
.tool-card::before{content:"";position:absolute;top:0;left:0;right:0;height:4px;background:linear-gradient(90deg,var(--brand),var(--accent));opacity:0;transition:.25s}
.tool-card:hover{border-color:#bcd8c6;text-decoration:none;box-shadow:var(--shadow-md);transform:translateY(-4px)}
.tool-card:hover::before{opacity:1}
.tool-card h3{margin:0 0 8px;font-size:18px;color:var(--ink)}
.tool-card p{margin:0;color:var(--muted);font-size:14.5px}
/* ===== footer ===== */
footer.site{background:#0a2e21;color:#a9c8b8;margin-top:36px}
footer.site .wrap{padding:28px 20px;font-size:14px}
footer.site a{color:#e8f3ee}
/* ===== hero hook ===== */
.hero .hook{color:#ffd98a;font-size:17.5px;font-weight:700;margin:0 0 12px;max-width:760px;line-height:1.6}
/* ===== filter chips ===== */
.chips{display:flex;gap:10px;flex-wrap:wrap;margin:16px 0 6px}
.chip{border:2px solid var(--line);background:#fff;color:var(--ink);border-radius:999px;padding:8px 20px;font-size:15px;font-weight:700;cursor:pointer;font-family:inherit;transition:.2s}
.chip:hover{border-color:var(--brand)}
.chip.active{background:var(--brand);border-color:var(--brand);color:#fff}
.tool-card.hidden{display:none}
/* ===== country switcher ===== */
.locale{display:inline-flex;gap:2px;background:rgba(255,255,255,.12);border:1px solid rgba(255,255,255,.25);border-radius:999px;padding:3px;align-self:center}
.locale a{color:#dcefe6;font-size:13px;font-weight:700;padding:4px 12px;border-radius:999px;transition:.2s}
.locale a:hover{color:#fff;text-decoration:none}
.locale a.cur{background:var(--accent);color:#3a2a00}
@media (max-width:640px){.hero{padding:44px 0 38px}.hero h1{font-size:25px}.hero .hook{font-size:16px}.chip{padding:7px 16px;font-size:14px}.card{padding:22px 18px}h1.page{font-size:23px}body{font-size:16px}.btn{grid-column:1/-1}}