/* =========================================================
   spellyr — minimal calculator design system
   Display/body: Signika  |  Data/numeric: JetBrains Mono
========================================================= */

:root{
  --bg:            #F7F5F0;
  --surface:       #FFFFFF;
  --ink:           #262420;
  --ink-soft:      #6B6659;
  --border:        #E2DED3;
  --border-strong: #CFC9BA;

  --rose:          #A94F6B;
  --rose-soft:     #F2E1E6;
  --teal:          #2E6E6C;
  --teal-soft:     #DFEBE9;

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;

  --font-display: 'Signika', sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  --max-width: 1120px;
}

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

html{ scroll-behavior: smooth; }

body{
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-display);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3{
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.2;
  margin: 0 0 0.5em;
  letter-spacing: -0.01em;
}

h1{ font-size: clamp(1.9rem, 3vw, 2.6rem); }
h2{ font-size: clamp(1.5rem, 2.4vw, 2rem); }
h3{ font-size: 1.05rem; font-weight: 600; }

p{ margin: 0 0 1em; color: var(--ink-soft); }

a{ color: var(--rose); text-decoration: none; }
a:hover{ text-decoration: underline; }

.wrap{
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}
.wrap-narrow{ max-width: 720px; }

.mono{ font-family: var(--font-mono); font-variant-numeric: tabular-nums; }
.muted{ color: var(--ink-soft); }

section{ padding: 72px 0; }
section + section{ border-top: 1px solid var(--border); }

.section-label{
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--rose);
  margin-bottom: 10px;
}
.section-intro{ max-width: 640px; font-size: 1.05rem; }

/* focus visibility */
a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
summary:focus-visible{
  outline: 2px solid var(--teal);
  outline-offset: 2px;
}

@media (prefers-reduced-motion: reduce){
  *{ animation: none !important; transition: none !important; }
  html{ scroll-behavior: auto; }
}

/* ---------------------------------------------------------
   Header
--------------------------------------------------------- */
.site-header{
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(247,245,240,0.92);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--border);
}

.header-inner{
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}

.brand{
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 1.15rem;
  color: var(--ink);
  letter-spacing: -0.02em;
}
.brand:hover{ text-decoration: none; }
.brand-dot{ color: var(--rose); }

.site-nav{
  display: flex;
  align-items: center;
  gap: 28px;
}
.site-nav a{
  color: var(--ink);
  font-size: 0.95rem;
  font-weight: 500;
}
.site-nav a:hover{ color: var(--rose); text-decoration: none; }
.site-nav a.is-active{ color: var(--rose); }

.nav-toggle{
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0;
}
.nav-toggle span{
  display: block;
  height: 2px;
  width: 100%;
  background: var(--ink);
  border-radius: 2px;
}

/* ---------------------------------------------------------
   Tool section
--------------------------------------------------------- */
.tool-section{ padding-top: 56px; }

.tool-card{
  margin-top: 32px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 8px;
  max-width: 720px;
}

.tool-tabs{
  display: flex;
  gap: 4px;
  padding: 6px;
  background: var(--bg);
  border-radius: var(--radius-md);
  margin-bottom: 24px;
}

.tool-tab{
  flex: 1;
  padding: 12px 16px;
  border: none;
  background: transparent;
  border-radius: var(--radius-sm);
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--ink-soft);
  cursor: pointer;
}
.tool-tab.is-active{
  background: var(--surface);
  color: var(--ink);
  box-shadow: 0 1px 2px rgba(38,36,32,0.08);
}

.tool-panel{
  display: none;
  padding: 8px 20px 24px;
}
.tool-panel.is-active{ display: block; }

.field-row{
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-bottom: 20px;
}

.field{ display: flex; flex-direction: column; gap: 6px; }
.field label{
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--ink-soft);
}

.field input,
.field select{
  font-family: var(--font-mono);
  font-size: 1rem;
  padding: 12px 14px;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-sm);
  background: var(--surface);
  color: var(--ink);
}
.field input:focus,
.field select:focus{
  border-color: var(--teal);
}

.btn-primary,
.btn-secondary{
  display: inline-block;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 0.98rem;
  padding: 13px 26px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  cursor: pointer;
}

.btn-primary{
  background: var(--rose);
  color: #fff;
}
.btn-primary:hover{ background: #953f59; text-decoration: none; }

.btn-secondary{
  background: transparent;
  border-color: var(--border-strong);
  color: var(--ink);
}
.btn-secondary:hover{ border-color: var(--teal); color: var(--teal); text-decoration: none; }

/* ---------------------------------------------------------
   Benefits
--------------------------------------------------------- */
.benefits-grid{
  margin-top: 32px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.benefit-card{
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 24px;
}

.benefit-index{
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--teal);
  background: var(--teal-soft);
  padding: 3px 8px;
  border-radius: 4px;
  margin-bottom: 14px;
}

.benefit-card p{ font-size: 0.94rem; margin-bottom: 0; }

/* ---------------------------------------------------------
   How to use
--------------------------------------------------------- */
.howto-list{
  list-style: none;
  margin: 32px 0 0;
  padding: 0;
  max-width: 720px;
}

.howto-list li{
  display: flex;
  gap: 20px;
  padding: 22px 0;
  border-top: 1px solid var(--border);
}
.howto-list li:last-child{ padding-bottom: 0; }

.howto-num{
  flex-shrink: 0;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--rose-soft);
  color: var(--rose);
  font-family: var(--font-mono);
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: center;
}

.howto-list h3{ margin-bottom: 4px; }
.howto-list p{ margin-bottom: 0; font-size: 0.95rem; }

/* ---------------------------------------------------------
   FAQ
--------------------------------------------------------- */
.faq-list{ margin-top: 32px; max-width: 760px; }

.faq-item{
  border-bottom: 1px solid var(--border);
  padding: 18px 0;
}

.faq-item summary{
  cursor: pointer;
  font-weight: 600;
  font-size: 1rem;
  color: var(--ink);
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.faq-item summary::-webkit-details-marker{ display: none; }

.faq-item summary::after{
  content: '+';
  font-family: var(--font-mono);
  font-size: 1.2rem;
  color: var(--rose);
  margin-left: 16px;
  flex-shrink: 0;
}
.faq-item[open] summary::after{ content: '\2212'; }

.faq-item p{
  margin: 14px 0 0;
  font-size: 0.95rem;
}

/* ---------------------------------------------------------
   Result page
--------------------------------------------------------- */
.result-section{ padding-top: 56px; }

.result-card{
  margin: 32px 0;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  display: flex;
  overflow: hidden;
}

.result-figure{
  flex: 0 0 220px;
  background: var(--rose);
  color: #fff;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 32px 20px;
  text-align: center;
}

.result-value{
  font-family: var(--font-mono);
  font-size: 2.6rem;
  font-weight: 600;
  line-height: 1;
}

.result-caption{
  margin-top: 10px;
  font-size: 0.82rem;
  opacity: 0.9;
}

.result-breakdown{
  flex: 1;
  padding: 24px 28px;
}

.breakdown-row{
  display: flex;
  justify-content: space-between;
  padding: 12px 0;
  border-bottom: 1px solid var(--border);
  font-size: 0.98rem;
}
.breakdown-row:last-child{ border-bottom: none; }

.result-note{ font-size: 0.9rem; }

/* ---------------------------------------------------------
   Conversions table
--------------------------------------------------------- */
.refresh-btn{ margin: 20px 0 32px; }

.conversions-heading{
  margin: 40px 0 16px;
  font-size: 1.2rem;
}
.conversions-heading:first-of-type{ margin-top: 0; }

.table-wrap{
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  margin-bottom: 8px;
}

.numbers-table{
  width: 100%;
  border-collapse: collapse;
}

.numbers-table thead th{
  text-align: left;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-soft);
  background: var(--bg);
  padding: 14px 20px;
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 68px;
}

.numbers-table td{
  padding: 12px 20px;
  border-bottom: 1px solid var(--border);
  font-size: 0.95rem;
}
.numbers-table tbody tr:last-child td{ border-bottom: none; }
.numbers-table tbody tr:hover{ background: var(--teal-soft); }

.numbers-table td:first-child{ width: 60px; }
.numbers-table td:nth-child(2){ width: 140px; }

/* ---------------------------------------------------------
   Footer
--------------------------------------------------------- */
.site-footer{
  border-top: 1px solid var(--border);
  padding: 48px 0 32px;
}

.footer-inner{ text-align: center; }

.footer-brand .brand-mark{
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 1.1rem;
  color: var(--ink);
}
.footer-brand p{ margin: 6px 0 0; font-size: 0.9rem; }

.footer-nav{
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 20px;
  margin: 24px 0;
}
.footer-nav a{ color: var(--ink); font-size: 0.9rem; }
.footer-nav a:hover{ color: var(--rose); }

.footer-note{
  font-size: 0.82rem;
  max-width: 520px;
  margin: 0 auto 6px;
}
.footer-copy{
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--ink-soft);
  margin: 0;
}

/* ---------------------------------------------------------
   Responsive
--------------------------------------------------------- */
@media (max-width: 900px){
  .benefits-grid{ grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 760px){
  .field-row{ grid-template-columns: 1fr; }
  .result-card{ flex-direction: column; }
  .result-figure{ flex-basis: auto; padding: 28px; }
  .numbers-table thead th{ position: static; }
}

@media (max-width: 680px){
  .nav-toggle{ display: flex; }

  .site-nav{
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    padding: 8px 24px 16px;
    display: none;
  }
  .site-nav.is-open{ display: flex; }
  .site-nav a{ padding: 12px 0; width: 100%; }

  .benefits-grid{ grid-template-columns: 1fr; }
  section{ padding: 48px 0; }
}