@import url('https://api.fontshare.com/v2/css?f[]=general-sans@600,700&display=swap');
@import url('https://fonts.googleapis.com/css2?family=DM+Sans:wght@400;500&family=JetBrains+Mono:wght@400&display=swap');

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --primary:       #6366F1;
  --primary-hover: #4F46E5;
  --secondary:     #20970B;
  --neutral:       #9C9C9C;
  --bg:            #FAFAFA;
  --surface:       #FFFFFF;
  --text-primary:  #0A0A0A;
  --text-secondary:#6B6B6B;
  --border:        #E8E8EC;
  --success:       #10B981;
  --warning:       #F59E0B;
  --error:         #EF4444;

  --font-display: 'General Sans', sans-serif;
  --font-body:    'DM Sans', sans-serif;
  --font-mono:    'JetBrains Mono', monospace;

  --radius-chip:  4px;
  --radius-btn:   6px;
  --radius-card:  12px;
  --radius-pill:  9999px;
}

html { font-size: 15px; }

body {
  background: var(--bg);
  color: var(--text-primary);
  font-family: var(--font-body);
  line-height: 1.6;
  min-height: 100vh;
}

/* ── NAV ── */
nav {
  position: sticky;
  top: 0;
  z-index: 100;
  height: 56px;
  background: rgba(255,255,255,0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  padding: 0 24px;
  gap: 32px;
}
.nav-logo {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--text-primary);
  text-decoration: none;
}
.nav-logo span { color: var(--secondary); }
.nav-links { display: flex; gap: 4px; margin-left: auto; }
.nav-link {
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 500;
  color: var(--text-secondary);
  text-decoration: none;
  padding: 6px 12px;
  border-radius: var(--radius-btn);
  transition: background 150ms, color 150ms;
}
.nav-link:hover { background: #F0F0F4; color: var(--text-primary); }
.nav-link.active { color: var(--primary); }

/* ── LAYOUT ── */
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ── HERO ── */
.hero {
  padding: 64px 0 48px;
  border-bottom: 1px solid var(--border);
}
.hero-label {
  display: inline-block;
  font-family: var(--font-body);
  font-size: 11px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--primary);
  background: rgba(99,102,241,0.08);
  padding: 4px 12px;
  border-radius: var(--radius-pill);
  margin-bottom: 20px;
}
.hero h1 {
  font-family: var(--font-display);
  font-size: 60px;
  font-weight: 700;
  letter-spacing: -0.04em;
  line-height: 1.05;
  color: var(--text-primary);
  max-width: 680px;
  margin-bottom: 16px;
}
.hero p {
  font-size: 17px;
  color: var(--text-secondary);
  max-width: 560px;
  line-height: 1.65;
}
.hero-note {
  margin-top: 12px;
  font-size: 12px;
  font-family: var(--font-mono);
  color: var(--neutral);
}

/* ── SECTION ── */
.section { padding: 48px 0; }
.section + .section { border-top: 1px solid var(--border); }
.section-header {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 24px;
}
.section-num {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--neutral);
  letter-spacing: 0.04em;
}
.section-title {
  font-family: var(--font-display);
  font-size: 13px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-primary);
}

/* ── GRID ── */
.g2 { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.g3 { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 20px; }
.g4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px; }

/* ── CARD ── */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  padding: 24px;
  transition: box-shadow 200ms, transform 200ms;
}
.card:hover {
  box-shadow: 0 8px 30px rgba(0,0,0,0.08);
  transform: translateY(-2px);
}
.card-flat {
  background: #F5F5F8;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 16px 20px;
}
.card-accent {
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--primary);
  border-radius: 8px;
  padding: 20px 24px;
}

/* ── INPUTS ── */
.field { display: flex; flex-direction: column; gap: 6px; }
.field label {
  font-size: 12px;
  font-weight: 500;
  color: var(--text-secondary);
  font-family: var(--font-body);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
input[type=number] {
  width: 100%;
  font-family: var(--font-mono);
  font-size: 20px;
  font-weight: 400;
  padding: 10px 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius-btn);
  background: var(--surface);
  color: var(--text-primary);
  outline: none;
  transition: border-color 150ms, box-shadow 150ms;
  -moz-appearance: textfield;
}
input[type=number]::-webkit-inner-spin-button,
input[type=number]::-webkit-outer-spin-button { opacity: 1; }
input[type=number]:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(99,102,241,0.12);
}

/* ── DATA DISPLAY ── */
.data-label {
  font-size: 11px;
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--neutral);
  margin-bottom: 6px;
  font-family: var(--font-body);
}
.data-val {
  font-family: var(--font-mono);
  font-size: 20px;
  color: var(--text-primary);
  line-height: 1.2;
  word-break: break-all;
}
.data-val-lg {
  font-family: var(--font-mono);
  font-size: 28px;
  font-weight: 400;
  color: var(--text-primary);
  line-height: 1.1;
  word-break: break-all;
}
.data-formula {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--neutral);
  margin-top: 4px;
}
.data-check {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--success);
  margin-top: 4px;
}

/* ── KEY CARDS ── */
.key-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 16px; }
.key-card {
  background: var(--text-primary);
  border-radius: 8px;
  padding: 16px 20px;
}
.key-card .data-label { color: rgba(255,255,255,0.45); }
.key-card .data-val { color: rgba(255,255,255,0.95); font-size: 22px; }
.key-card .data-check { color: rgba(255,255,255,0.4); }

/* ── ENCRYPTION FLOW ── */
.flow-row {
  display: flex;
  align-items: center;
  gap: 12px;
}
.flow-row > .card-flat { flex: 1; }
.flow-arrow {
  font-family: var(--font-mono);
  font-size: 16px;
  color: var(--neutral);
  flex-shrink: 0;
}
.flow-cipher { border-left: 3px solid var(--primary); }
.flow-product { border-left: 3px solid var(--text-primary); background: #F0F0FA; }

/* ── RESULT PANEL ── */
.result-panel {
  border: 1px solid var(--border);
  border-radius: var(--radius-card);
  padding: 28px 32px;
  background: var(--surface);
  transition: border-color 200ms;
}
.result-panel.ok  { border-color: var(--success); box-shadow: 0 0 0 3px rgba(16,185,129,0.08); }
.result-panel.fail { border-color: var(--error);  box-shadow: 0 0 0 3px rgba(239,68,68,0.08); }

.result-row { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; margin-bottom: 12px; }
.result-eq {
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--text-primary);
}
.result-desc { font-size: 14px; color: var(--text-secondary); line-height: 1.6; }

/* ── CHIPS / BADGES ── */
.chip {
  display: inline-flex;
  align-items: center;
  font-size: 12px;
  font-weight: 500;
  padding: 4px 12px;
  border-radius: var(--radius-pill);
  font-family: var(--font-body);
  white-space: nowrap;
}
.chip-ok   { background: rgba(16,185,129,0.1);  color: #059669; }
.chip-fail { background: rgba(239,68,68,0.1);   color: var(--error); }
.chip-warn { background: rgba(245,158,11,0.1);  color: #D97706; }
.chip-info { background: rgba(99,102,241,0.1);  color: var(--primary); }

/* ── PROP BOX ── */
.prop-box {
  background: rgba(99,102,241,0.05);
  border: 1px solid rgba(99,102,241,0.2);
  border-radius: 8px;
  padding: 16px 20px;
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--primary);
  margin-bottom: 20px;
}

/* ── FOOTER ── */
footer {
  border-top: 1px solid var(--border);
  padding: 24px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 32px;
}
footer span { font-size: 13px; color: var(--neutral); font-family: var(--font-body); }
footer a    { color: var(--primary); text-decoration: none; }
footer a:hover { text-decoration: underline; }

/* ── DIVIDER ── */
.divider { border: none; border-top: 1px solid var(--border); margin: 0; }

/* ── WARN ── */
#warn-msg { display: none; margin-top: 12px; }

/* ── RESPONSIVE ── */
@media (max-width: 768px) {
  .hero h1 { font-size: 40px; }
  .g2, .g3, .g4 { grid-template-columns: 1fr; }
  nav { padding: 0 16px; }
  .container { padding: 0 16px; }
}