/* ================================================================
   CalculateIA — Complete Design System
   ================================================================ */
@import url('https://fonts.googleapis.com/css2?family=Sora:wght@300;400;500;600;700&family=DM+Mono:ital,wght@0,400;0,500;1,400&display=swap');

/* ── CSS Variables ─────────────────────────────────────────────── */
:root {
  --primary:       #2563eb;
  --primary-dark:  #1e40af;
  --primary-light: #3b82f6;
  --primary-dim:   rgba(37,99,235,0.1);
  --secondary:     #0ea5e9;
  --accent:        #f59e0b;
  --green:         #10b981;
  --red:           #ef4444;
  --orange:        #f97316;
  --purple:        #8b5cf6;

  --bg:       #f8fafc;
  --bg2:      #f1f5f9;
  --surface:  #ffffff;
  --border:   #e2e8f0;
  --border-h: #cbd5e1;

  --text:  #0f172a;
  --text2: #475569;
  --text3: #94a3b8;

  --radius:    14px;
  --radius-sm: 8px;
  --radius-lg: 20px;

  --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
  --shadow:    0 2px 8px rgba(37,99,235,0.06), 0 1px 3px rgba(0,0,0,0.08);
  --shadow-lg: 0 4px 24px rgba(0,0,0,0.10), 0 12px 48px rgba(0,0,0,0.06);

  --header-h:  64px;
  --font:      'Sora', sans-serif;
  --mono:      'DM Mono', monospace;
  --ease:      0.18s ease;
}

[data-theme="dark"] {
  --bg:      #0f172a;
  --bg2:     #1e293b;
  --surface: #1e293b;
  --border:  #334155;
  --border-h:#475569;
  --text:    #f1f5f9;
  --text2:   #94a3b8;
  --text3:   #475569;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
  --shadow:    0 2px 8px rgba(0,0,0,0.3);
  --shadow-lg: 0 4px 24px rgba(0,0,0,0.4);
}

/* ── Reset ─────────────────────────────────────────────────────── */
*,*::before,*::after { box-sizing:border-box; margin:0; padding:0; }
html { scroll-behavior:smooth; scroll-padding-top:calc(var(--header-h) + 20px); font-size:16px; }
body { font-family:var(--font); background:var(--bg); color:var(--text); line-height:1.6; transition:background var(--ease),color var(--ease); }
a { color:inherit; text-decoration:none; }
button { font-family:var(--font); cursor:pointer; border:none; background:none; }
input,select,textarea { font-family:var(--font); }
img { display:block; max-width:100%; }

/* ── Typography ────────────────────────────────────────────────── */
h1,h2,h3,h4,h5 { font-weight:700; line-height:1.2; letter-spacing:-0.02em; }
h1 { font-size:clamp(1.8rem,4vw,3rem); }
h2 { font-size:clamp(1.4rem,3vw,2rem); }
h3 { font-size:1.2rem; }
h4 { font-size:1rem; }
p  { color:var(--text2); }

/* ── Layout ────────────────────────────────────────────────────── */
.container    { max-width:1200px; margin:0 auto; padding:0 20px; }
.container-sm { max-width:760px;  margin:0 auto; padding:0 20px; }
.section    { padding:60px 0; }
.section-sm { padding:36px 0; }

/* ── Header ────────────────────────────────────────────────────── */
.site-header {
  position:sticky; top:0; z-index:200; height:var(--header-h);
  background:rgba(248,250,252,0.92); backdrop-filter:blur(16px);
  border-bottom:1px solid var(--border); box-shadow:var(--shadow-sm);
  transition:background var(--ease);
}
[data-theme="dark"] .site-header { background:rgba(15,23,42,0.92); }
.header-inner { height:100%; display:flex; align-items:center; justify-content:space-between; }

.logo { display:flex; align-items:center; gap:10px; font-size:1.3rem; font-weight:700; letter-spacing:-0.03em; }
.logo-icon { width:34px; height:34px; background:var(--primary); border-radius:9px; display:flex; align-items:center; justify-content:center; font-size:16px; }
.logo em { color:var(--primary); font-style:normal; }

.nav { display:flex; align-items:center; gap:4px; }
.nav a { padding:7px 14px; border-radius:var(--radius-sm); font-size:0.875rem; font-weight:500; color:var(--text2); transition:all var(--ease); }
.nav a:hover,.nav a.active { color:var(--primary); background:var(--primary-dim); }

.header-actions { display:flex; align-items:center; gap:8px; }
.btn-dark-toggle {
  width:36px; height:36px; border-radius:8px; border:1px solid var(--border);
  background:var(--surface); display:flex; align-items:center; justify-content:center;
  font-size:16px; transition:all var(--ease); cursor:pointer;
}
.btn-dark-toggle:hover { border-color:var(--primary); }
.hamburger { display:none; flex-direction:column; gap:5px; padding:8px; cursor:pointer; }
.hamburger span { width:22px; height:2px; background:var(--text); border-radius:2px; display:block; transition:all 0.2s; }

/* ── Buttons ───────────────────────────────────────────────────── */
.btn {
  display:inline-flex; align-items:center; justify-content:center; gap:8px;
  padding:11px 24px; border-radius:var(--radius-sm);
  font-size:0.9rem; font-weight:600; letter-spacing:-0.01em;
  transition:all var(--ease); cursor:pointer; border:none;
}
.btn-primary { background:var(--primary); color:#fff; box-shadow:0 2px 8px rgba(37,99,235,0.3); }
.btn-primary:hover { background:var(--primary-dark); transform:translateY(-1px); box-shadow:0 4px 16px rgba(37,99,235,0.4); }
.btn-primary:active { transform:translateY(0); }
.btn-secondary { background:var(--surface); color:var(--text); border:1.5px solid var(--border); }
.btn-secondary:hover { border-color:var(--primary); color:var(--primary); background:var(--primary-dim); }
.btn-ghost { color:var(--text2); }
.btn-ghost:hover { color:var(--primary); }
.btn-sm  { padding:7px 16px; font-size:0.8rem; }
.btn-lg  { padding:14px 28px; font-size:1rem; }
.btn-full { width:100%; }

/* ── Cards ─────────────────────────────────────────────────────── */
.card {
  background:var(--surface); border:1px solid var(--border);
  border-radius:var(--radius); padding:24px;
  box-shadow:var(--shadow); transition:all var(--ease);
}

/* Calculator card */
.calc-card {
  display:flex; flex-direction:column; gap:10px; padding:20px;
  background:var(--surface); border:1px solid var(--border);
  border-radius:var(--radius); box-shadow:var(--shadow);
  transition:all var(--ease); text-decoration:none; cursor:pointer;
}
.calc-card:hover { transform:translateY(-3px); box-shadow:var(--shadow-lg); border-color:var(--primary); }
.calc-card-icon {
  width:48px; height:48px; border-radius:12px; background:var(--primary-dim);
  display:flex; align-items:center; justify-content:center; font-size:22px; flex-shrink:0;
}
.calc-card-name  { font-size:1rem; font-weight:600; color:var(--text); }
.calc-card-desc  { font-size:0.82rem; color:var(--text2); line-height:1.5; flex:1; }
.calc-card-link  { font-size:0.8rem; color:var(--primary); font-weight:600; }
.calc-grid { display:grid; grid-template-columns:repeat(auto-fill,minmax(220px,1fr)); gap:16px; }

/* ── Form Controls ─────────────────────────────────────────────── */
.form-group  { display:flex; flex-direction:column; gap:6px; }
.form-label  { font-size:0.82rem; font-weight:600; color:var(--text2); }
.inputs-grid { display:flex; flex-direction:column; gap:18px; }

.form-input {
  width:100%; padding:11px 14px; font-size:0.95rem;
  border:1.5px solid var(--border); border-radius:var(--radius-sm);
  background:var(--surface); color:var(--text);
  transition:all var(--ease); outline:none;
}
.form-input:focus { border-color:var(--primary); box-shadow:0 0 0 3px var(--primary-dim); }
.form-input::placeholder { color:var(--text3); }

.form-select {
  width:100%; padding:11px 14px; font-size:0.95rem;
  border:1.5px solid var(--border); border-radius:var(--radius-sm);
  background:var(--surface); color:var(--text);
  outline:none; cursor:pointer; transition:all var(--ease); appearance:auto;
}
.form-select:focus { border-color:var(--primary); box-shadow:0 0 0 3px var(--primary-dim); }

.input-wrap { position:relative; }
.input-prefix { position:absolute; left:12px; top:50%; transform:translateY(-50%); color:var(--text3); font-size:0.9rem; pointer-events:none; z-index:1; }
.input-suffix { position:absolute; right:12px; top:50%; transform:translateY(-50%); color:var(--text3); font-size:0.85rem; pointer-events:none; z-index:1; }
.input-wrap .form-input.has-prefix { padding-left:28px; }
.input-wrap .form-input.has-suffix { padding-right:44px; }

/* Range slider */
input[type=range] {
  width:100%; -webkit-appearance:none; height:5px;
  border-radius:999px; background:var(--border); outline:none; cursor:pointer;
}
input[type=range]::-webkit-slider-thumb {
  -webkit-appearance:none; width:18px; height:18px; border-radius:50%;
  background:var(--primary); box-shadow:0 2px 6px rgba(37,99,235,0.4);
}

/* ── NL Date Input ─────────────────────────────────────────────── */
.nl-date-wrap { position:relative; }
.nl-date-input {
  width:100%; padding:11px 40px 11px 14px; font-family:var(--mono); font-size:0.9rem;
  border:1.5px solid var(--border); border-radius:var(--radius-sm);
  background:var(--surface); color:var(--text);
  transition:all var(--ease); outline:none;
}
.nl-date-input:focus { border-color:var(--primary); box-shadow:0 0 0 3px var(--primary-dim); }
.nl-date-input::placeholder { font-family:var(--font); font-size:0.85rem; color:var(--text3); }
.nl-date-icon { position:absolute; right:12px; top:50%; transform:translateY(-50%); font-size:14px; pointer-events:none; }

.nl-parsed-badge {
  display:none; align-items:center; gap:7px; margin-top:6px;
  padding:6px 12px; background:rgba(16,185,129,0.08);
  border:1px solid rgba(16,185,129,0.25); border-radius:6px;
  font-size:0.8rem; color:var(--green);
}
.nl-parsed-badge.show { display:flex; animation:popIn 0.15s ease; }
.nl-parsed-dot { width:6px; height:6px; border-radius:50%; background:var(--green); box-shadow:0 0 6px var(--green); flex-shrink:0; }

.nl-suggestions {
  position:absolute; bottom:calc(100% + 6px); left:0; right:0; z-index:100;
  background:var(--surface); border:1px solid var(--border-h);
  border-radius:var(--radius-sm); padding:8px;
  box-shadow:var(--shadow-lg); display:none;
  max-height:220px; overflow-y:auto; animation:popUp 0.16s ease;
}
.nl-suggestions.show { display:block; }
.nl-sug-label { font-size:0.7rem; letter-spacing:0.12em; text-transform:uppercase; color:var(--text3); padding:0 4px; margin-bottom:6px; }
.nl-sug-item {
  display:flex; align-items:center; justify-content:space-between;
  padding:8px 10px; border-radius:6px; cursor:pointer;
  border:1px solid transparent; transition:all var(--ease);
}
.nl-sug-item:hover { border-color:var(--primary); background:var(--primary-dim); }
.nl-sug-date { font-size:0.875rem; font-weight:500; color:var(--text); }
.nl-sug-note { font-size:0.75rem; color:var(--text3); }
.nl-sug-pick { font-size:0.72rem; color:var(--primary); font-weight:600; background:var(--primary-dim); border-radius:999px; padding:2px 9px; flex-shrink:0; margin-left:8px; }

.nl-token-pills { display:flex; flex-wrap:wrap; gap:5px; margin-top:6px; }
.nl-token { font-size:0.72rem; padding:2px 9px; border-radius:999px; border:1px solid; font-family:var(--mono); }
.nl-token-day   { border-color:rgba(245,158,11,0.4); color:#b45309; background:rgba(245,158,11,0.08); }
.nl-token-month { border-color:rgba(37,99,235,0.4);  color:var(--primary); background:var(--primary-dim); }
.nl-token-year  { border-color:rgba(139,92,246,0.4); color:#7c3aed; background:rgba(139,92,246,0.08); }
.nl-token-other { border-color:var(--border); color:var(--text3); }
[data-theme="dark"] .nl-token-day  { color:#fbbf24; }
[data-theme="dark"] .nl-token-month{ color:#60a5fa; }
[data-theme="dark"] .nl-token-year { color:#a78bfa; }

/* ── Calculator Page Layout ─────────────────────────────────────── */
.calc-page { padding:36px 0 120px; }
.calc-page-header { margin-bottom:28px; }
.calc-breadcrumb {
  display:flex; align-items:center; gap:6px;
  font-size:0.78rem; color:var(--text3); margin-bottom:12px;
}
.calc-breadcrumb a:hover { color:var(--primary); }
.calc-page-title { font-size:1.7rem; font-weight:700; margin-bottom:6px; }
.calc-page-desc  { font-size:0.9rem; color:var(--text2); max-width:600px; }

.calc-layout {
  display:grid; grid-template-columns:1fr 1fr; gap:24px; align-items:start;
}
.calc-inputs-panel {
  background:var(--surface); border:1px solid var(--border);
  border-radius:var(--radius); padding:28px; box-shadow:var(--shadow);
}
.calc-results-panel { position:sticky; top:calc(var(--header-h) + 16px); }
.calc-layout-single { max-width:600px; }

/* ── Result Panel ───────────────────────────────────────────────── */
.result-panel {
  display:none; background:var(--surface); border:1px solid var(--border);
  border-radius:var(--radius); overflow:hidden; box-shadow:var(--shadow);
}
.result-panel.show { display:block; animation:fadeUp 0.3s ease; }
.result-header {
  background:linear-gradient(135deg, var(--primary), var(--primary-dark));
  padding:20px 24px; color:#fff;
}
.result-header h3  { color:#fff; font-size:0.82rem; font-weight:500; opacity:0.85; margin-bottom:4px; }
.result-main-val   { font-size:2.2rem; font-weight:700; letter-spacing:-0.04em; font-family:var(--mono); }
.result-sub-val    { font-size:0.9rem; opacity:0.8; margin-top:4px; }
.result-body       { padding:20px 24px; }

.result-grid { display:grid; grid-template-columns:repeat(auto-fit,minmax(130px,1fr)); gap:12px; }
.result-tile { background:var(--bg2); border-radius:var(--radius-sm); padding:14px; }
.result-tile-val   { font-family:var(--mono); font-size:1.1rem; font-weight:600; color:var(--primary); margin-bottom:4px; }
.result-tile-label { font-size:0.72rem; color:var(--text3); text-transform:uppercase; letter-spacing:0.08em; }
.result-actions { display:flex; gap:8px; margin-top:16px; flex-wrap:wrap; }

/* ── Action Bar ─────────────────────────────────────────────────── */
.action-bar {
  position:sticky; bottom:0; z-index:50;
  background:rgba(248,250,252,0.92); backdrop-filter:blur(16px);
  border-top:1px solid var(--border); padding:12px 20px;
  display:flex; gap:12px; align-items:center; justify-content:center;
  box-shadow:0 -4px 20px rgba(0,0,0,0.08);
}
[data-theme="dark"] .action-bar { background:rgba(15,23,42,0.92); }
.action-bar .btn { min-width:140px; }

/* ── Tabs ───────────────────────────────────────────────────────── */
.tabs { display:flex; gap:4px; background:var(--bg2); padding:4px; border-radius:var(--radius-sm); margin-bottom:20px; }
.tab-btn { flex:1; padding:8px; border-radius:6px; font-size:0.85rem; font-weight:500; color:var(--text2); transition:all var(--ease); }
.tab-btn.active { background:var(--surface); color:var(--primary); box-shadow:var(--shadow-sm); }
.tab-pane { display:none; }
.tab-pane.active { display:block; }

/* ── Info Box ───────────────────────────────────────────────────── */
.info-box { background:var(--primary-dim); border:1px solid rgba(37,99,235,0.2); border-radius:var(--radius-sm); padding:12px 16px; font-size:0.85rem; color:var(--primary); }
.info-box.success { background:rgba(16,185,129,0.08); border-color:rgba(16,185,129,0.25); color:var(--green); }
.info-box.warning { background:rgba(245,158,11,0.08); border-color:rgba(245,158,11,0.25); color:#92400e; }
[data-theme="dark"] .info-box.warning { color:#fbbf24; }

/* ── Hero ───────────────────────────────────────────────────────── */
.hero {
  padding:72px 0 56px; background:linear-gradient(160deg,var(--bg) 0%,var(--bg2) 100%);
  position:relative; overflow:hidden;
}
.hero::before {
  content:''; position:absolute; top:-100px; right:-200px;
  width:600px; height:600px; border-radius:50%;
  background:radial-gradient(circle,var(--primary-dim) 0%,transparent 70%);
  pointer-events:none;
}
.hero-badge { display:inline-flex; align-items:center; gap:7px; background:var(--primary-dim); border:1px solid rgba(37,99,235,0.2); border-radius:999px; padding:5px 14px; font-size:0.8rem; color:var(--primary); font-weight:500; margin-bottom:18px; }
.hero h1 { margin-bottom:14px; }
.hero h1 span { color:var(--primary); }
.hero p { font-size:1.05rem; max-width:520px; margin-bottom:28px; }
.hero-actions { display:flex; gap:12px; flex-wrap:wrap; }
.section-eyebrow { font-size:0.72rem; letter-spacing:0.2em; text-transform:uppercase; color:var(--primary); font-weight:600; margin-bottom:8px; }
.section-header { text-align:center; margin-bottom:36px; }
.section-header h2 { margin-bottom:8px; }
.section-header p  { max-width:520px; margin:0 auto; }

/* ── Badge ──────────────────────────────────────────────────────── */
.badge { display:inline-flex; align-items:center; padding:3px 10px; border-radius:999px; font-size:0.75rem; font-weight:600; }
.badge-blue   { background:var(--primary-dim); color:var(--primary); }
.badge-green  { background:rgba(16,185,129,0.1); color:var(--green); }
.badge-orange { background:rgba(249,115,22,0.1); color:var(--orange); }

/* ── Copy btn ───────────────────────────────────────────────────── */
.btn-copy { position:relative; }
.btn-copy .copy-tip { display:none; position:absolute; top:-32px; left:50%; transform:translateX(-50%); background:var(--text); color:var(--bg); font-size:0.72rem; padding:4px 8px; border-radius:4px; white-space:nowrap; }
.btn-copy.copied .copy-tip { display:block; }

/* ── Scroll to top ──────────────────────────────────────────────── */
.scroll-top {
  position:fixed; bottom:24px; right:24px; z-index:100;
  width:40px; height:40px; border-radius:10px; background:var(--primary); color:#fff;
  display:none; align-items:center; justify-content:center; font-size:18px;
  box-shadow:0 4px 14px rgba(37,99,235,0.4); transition:all var(--ease); cursor:pointer;
}
.scroll-top.show { display:flex; }
.scroll-top:hover { transform:translateY(-2px); }

/* ── Footer ─────────────────────────────────────────────────────── */
.site-footer { background:var(--bg2); border-top:1px solid var(--border); padding:48px 0 28px; }
.footer-grid { display:grid; grid-template-columns:2fr 1fr 1fr 1fr; gap:40px; margin-bottom:36px; }
.footer-brand p { font-size:0.875rem; color:var(--text2); margin-top:10px; max-width:260px; }
.footer-col h4  { font-size:0.78rem; font-weight:700; text-transform:uppercase; letter-spacing:0.1em; color:var(--text3); margin-bottom:12px; }
.footer-col ul  { list-style:none; display:flex; flex-direction:column; gap:8px; }
.footer-col ul li a { font-size:0.875rem; color:var(--text2); transition:color var(--ease); }
.footer-col ul li a:hover { color:var(--primary); }
.footer-bottom { border-top:1px solid var(--border); padding-top:20px; display:flex; justify-content:space-between; font-size:0.8rem; color:var(--text3); }

/* ── Chart ──────────────────────────────────────────────────────── */
.chart-wrap { width:100%; }
.chart-wrap canvas { max-width:100%; display:block; }

/* ── Calculator-specific: simple/scientific keypad ─────────────── */
.keypad {
  display:grid; gap:1px; background:var(--border);
  border-radius:var(--radius-sm); overflow:hidden; margin-top:16px;
}
.key {
  padding:17px 8px; font-family:var(--mono); font-size:1rem; font-weight:500;
  background:var(--surface); color:var(--text); border:none; cursor:pointer;
  transition:background var(--ease); text-align:center;
}
.key:hover  { background:var(--bg2); }
.key:active { background:var(--primary-dim); }
.key.op   { color:var(--primary); font-weight:700; }
.key.fn   { color:var(--secondary); font-size:0.82rem; }
.key.eq   { background:var(--primary); color:#fff; }
.key.eq:hover { background:var(--primary-dark); }
.key.clr  { color:var(--red); }
.key.span2 { grid-column:span 2; }
.key.span3 { grid-column:span 3; }
.calc-display {
  background:var(--bg2); padding:16px 20px; border-radius:var(--radius-sm);
  font-family:var(--mono); font-size:2rem; text-align:right; color:var(--text);
  border:1px solid var(--border); word-break:break-all; min-height:68px;
}
.calc-display .expr { font-size:0.8rem; color:var(--text3); min-height:20px; margin-bottom:4px; }

/* ── Utilities ──────────────────────────────────────────────────── */
.hidden       { display:none !important; }
.mt-8  { margin-top:8px; }
.mt-12 { margin-top:12px; }
.mt-16 { margin-top:16px; }
.mt-20 { margin-top:20px; }
.mt-24 { margin-top:24px; }
.text-center   { text-align:center; }
.text-primary  { color:var(--primary); }
.text-muted    { color:var(--text2); }
.font-mono     { font-family:var(--mono); }
.text-sm  { font-size:0.875rem; }
.text-xs  { font-size:0.75rem; }
hr { border:none; border-top:1px solid var(--border); margin:20px 0; }

/* ── Animations ─────────────────────────────────────────────────── */
@keyframes fadeUp { from{opacity:0;transform:translateY(12px)} to{opacity:1;transform:translateY(0)} }
@keyframes popIn  { from{opacity:0;transform:scale(0.95)}      to{opacity:1;transform:scale(1)} }
@keyframes popUp  { from{opacity:0;transform:translateY(6px)}  to{opacity:1;transform:translateY(0)} }
.anim-fade-up { animation:fadeUp 0.5s ease forwards; }
.anim-d1 { animation-delay:0.1s; opacity:0; }
.anim-d2 { animation-delay:0.2s; opacity:0; }
.anim-d3 { animation-delay:0.3s; opacity:0; }

/* ── Responsive ─────────────────────────────────────────────────── */
@media(max-width:768px){
  .hamburger { display:flex; }
  .nav {
    display:none; position:absolute; top:var(--header-h); left:0; right:0;
    background:var(--surface); border-bottom:1px solid var(--border);
    padding:12px; flex-direction:column; gap:4px; box-shadow:var(--shadow);
  }
  .nav.open { display:flex; }
  .calc-layout { grid-template-columns:1fr; }
  .calc-results-panel { position:static; }
  .footer-grid { grid-template-columns:1fr 1fr; }
  .hero { padding:44px 0 36px; }
  .section { padding:40px 0; }
}
@media(max-width:480px){
  .footer-grid  { grid-template-columns:1fr; }
  .footer-bottom{ flex-direction:column; gap:8px; text-align:center; }
  .result-grid  { grid-template-columns:1fr 1fr; }
  .action-bar .btn { min-width:0; flex:1; }
  .calc-page { padding:24px 0 100px; }
}