/* ═══════════════════════════════════════════
   CalcPro — Shared Design System
   style.css  |  v1.0
═══════════════════════════════════════════ */

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

:root {
  --black:        #0f0f0f;
  --white:        #fafafa;
  --gray-50:      #f9f9f7;
  --gray-100:     #f4f4f2;
  --gray-200:     #e8e8e5;
  --gray-300:     #d4d4d0;
  --gray-400:     #b0afa9;
  --gray-500:     #888780;
  --gray-600:     #6b6a65;
  --gray-800:     #2e2e2b;
  --accent:       #1a6b4a;
  --accent-light: #e8f4ef;
  --accent-mid:   #2d9968;
  --accent-dark:  #0f4a33;
  --pro:          #b86e00;
  --pro-light:    #fff7eb;
  --pro-dark:     #7a4900;
  --expert:       #8b1a1a;
  --expert-light: #fdf0f0;
  --expert-dark:  #5c1010;
  --font-display: 'DM Serif Display', Georgia, serif;
  --font-body:    'DM Sans', system-ui, -apple-system, sans-serif;
  --font-mono:    'JetBrains Mono', 'Fira Code', 'Courier New', monospace;
  --max:          1160px;
  --max-calc:     900px;
  --radius:       3px;
  --radius-md:    6px;
  --shadow-sm:    0 1px 3px rgba(0,0,0,0.06);
  --shadow-md:    0 4px 16px rgba(0,0,0,0.08);
}

html { scroll-behavior: smooth; font-size: 15px; }

body {
  font-family: var(--font-body);
  background: var(--white);
  color: var(--black);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ── TYPOGRAPHY ── */
h1, h2, h3, h4 { font-family: var(--font-display); letter-spacing: -0.02em; line-height: 1.15; }
h1 { font-size: clamp(1.8rem, 4vw, 2.8rem); }
h2 { font-size: clamp(1.4rem, 3vw, 2rem); }
h3 { font-size: 1.15rem; }
p  { color: var(--gray-600); }

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

code, kbd { font-family: var(--font-mono); font-size: 0.85em; background: var(--gray-100); padding: 0.1em 0.35em; border-radius: 2px; }

/* ── NAV ── */
.site-nav {
  position: sticky; top: 0; z-index: 200;
  background: var(--white);
  border-bottom: 1px solid var(--gray-200);
  padding: 0 2rem;
}
.nav-inner {
  max-width: var(--max);
  margin: 0 auto;
  display: flex; align-items: center;
  justify-content: space-between;
  height: 54px; gap: 1.5rem;
}
.nav-logo {
  font-family: var(--font-display);
  font-size: 1.2rem; color: var(--black);
  text-decoration: none; flex-shrink: 0;
  letter-spacing: -0.01em;
}
.nav-logo span { color: var(--accent); }
.nav-links {
  display: flex; align-items: center; gap: 1.75rem;
  flex: 1;
}
.nav-links a {
  font-size: 0.85rem; color: var(--gray-600);
  text-decoration: none; transition: color 0.15s;
  white-space: nowrap;
}
.nav-links a:hover { color: var(--black); text-decoration: none; }
.nav-right { display: flex; align-items: center; gap: 0.75rem; flex-shrink: 0; }
.nav-tier-badge {
  font-size: 0.65rem; font-weight: 500;
  letter-spacing: 0.08em; text-transform: uppercase;
  padding: 0.2rem 0.55rem; border-radius: 2px;
}
.tier-free   { background: var(--accent-light); color: var(--accent); }
.tier-pro    { background: var(--pro-light);    color: var(--pro); }
.tier-expert { background: var(--expert-light); color: var(--expert); }
.btn-unlock {
  font-size: 0.75rem; font-weight: 500;
  color: var(--white); background: var(--black);
  border: none; border-radius: var(--radius);
  padding: 0.4rem 0.9rem; cursor: pointer;
  font-family: var(--font-body); letter-spacing: 0.02em;
  transition: background 0.15s; text-decoration: none;
  display: inline-block;
}
.btn-unlock:hover { background: var(--accent); color: var(--white); text-decoration: none; }

/* ── BREADCRUMB ── */
.breadcrumb {
  max-width: var(--max-calc); margin: 0 auto;
  padding: 1rem 2rem 0;
  font-size: 0.75rem; color: var(--gray-400);
  display: flex; align-items: center; gap: 0.4rem;
  flex-wrap: wrap;
}
.breadcrumb a { color: var(--gray-400); text-decoration: none; }
.breadcrumb a:hover { color: var(--black); }
.breadcrumb-sep { color: var(--gray-300); }

/* ── PAGE WRAPPER ── */
.calc-page {
  max-width: var(--max-calc);
  margin: 0 auto;
  padding: 2rem 2rem 5rem;
}

/* ── PAGE HEADER ── */
.calc-page-header {
  display: flex; align-items: flex-start;
  justify-content: space-between;
  gap: 1rem; margin-bottom: 2rem;
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--gray-200);
  flex-wrap: wrap;
}
.calc-page-header-left { flex: 1; min-width: 200px; }
.calc-page-title { color: var(--black); margin-bottom: 0.3rem; }
.calc-page-desc { font-size: 0.875rem; color: var(--gray-600); line-height: 1.6; max-width: 560px; }
.calc-tier-pill {
  display: inline-flex; align-items: center; gap: 0.3rem;
  font-size: 0.65rem; font-weight: 500; letter-spacing: 0.08em;
  text-transform: uppercase; padding: 0.25rem 0.6rem;
  border-radius: 2px; flex-shrink: 0; margin-top: 0.25rem;
}

/* ── LAYOUT GRIDS ── */
.calc-grid-2   { display: grid; grid-template-columns: 1fr 1fr;     gap: 1.25rem; align-items: start; }
.calc-grid-wide{ display: grid; grid-template-columns: 1.05fr 0.95fr; gap: 1.25rem; align-items: start; }
.calc-grid-1   { display: grid; grid-template-columns: 1fr;         gap: 1.25rem; max-width: 540px; }

/* ── PANELS ── */
.panel {
  background: var(--gray-100);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-md);
  padding: 1.5rem;
}
.panel-title {
  font-size: 0.65rem; font-weight: 500;
  letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--gray-400); margin-bottom: 1.25rem;
}
.result-panel {
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  position: relative; overflow: hidden;
}
.result-panel::before {
  content: ''; position: absolute;
  top: 0; left: 0; right: 0; height: 2px;
  background: linear-gradient(90deg, var(--accent), var(--accent-mid));
}
.result-panel.pro-accent::before   { background: linear-gradient(90deg, var(--pro), #e09020); }
.result-panel.expert-accent::before{ background: linear-gradient(90deg, var(--expert), #c44040); }

/* ── FORM ELEMENTS ── */
.field { margin-bottom: 1rem; }
.field:last-child { margin-bottom: 0; }
.field > label {
  display: block; font-size: 0.68rem; font-weight: 500;
  letter-spacing: 0.07em; text-transform: uppercase;
  color: var(--gray-600); margin-bottom: 0.35rem;
}
.field input,
.field select,
.field textarea {
  width: 100%; padding: 0.6rem 0.8rem;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  background: var(--white);
  font-family: var(--font-body); font-size: 0.9rem;
  color: var(--black); outline: none;
  transition: border-color 0.15s, box-shadow 0.15s;
  appearance: none; -webkit-appearance: none;
}
.field input:focus,
.field select:focus,
.field textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(26,107,74,0.08);
}
.field select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%236b6a65' stroke-width='1.5' fill='none' stroke-linecap='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.75rem center;
  padding-right: 2.2rem;
}
.field textarea { resize: vertical; min-height: 90px; line-height: 1.5; font-size: 0.875rem; }
.field-hint { font-size: 0.72rem; color: var(--gray-400); margin-top: 0.3rem; }
.field-row   { display: grid; grid-template-columns: 1fr 1fr;     gap: 0.75rem; margin-bottom: 1rem; }
.field-row-3 { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 0.75rem; margin-bottom: 1rem; }
.field-row   > .field,
.field-row-3 > .field { margin-bottom: 0; }

/* Input with prefix/suffix */
.input-wrap { position: relative; }
.input-prefix, .input-suffix {
  position: absolute; top: 50%; transform: translateY(-50%);
  font-size: 0.85rem; color: var(--gray-500); pointer-events: none;
  font-weight: 500;
}
.input-prefix { left: 0.75rem; }
.input-suffix { right: 0.75rem; }
.input-wrap input.has-prefix { padding-left: 1.6rem; }
.input-wrap input.has-suffix { padding-right: 1.6rem; }

/* Range sliders */
.range-field label { display: flex; justify-content: space-between; align-items: center; }
.range-field label span { font-size: 0.85rem; font-weight: 500; color: var(--black); font-family: var(--font-mono); }
.field input[type="range"] {
  padding: 0; height: 4px; border: none; box-shadow: none;
  accent-color: var(--accent); cursor: pointer;
  background: var(--gray-200); border-radius: 2px;
}
.field input[type="range"]:focus { box-shadow: none; border-color: transparent; }

/* Segmented control */
.seg-control { display: flex; border: 1px solid var(--gray-200); border-radius: var(--radius); overflow: hidden; }
.seg-control button {
  flex: 1; padding: 0.5rem 0.5rem;
  border: none; border-right: 1px solid var(--gray-200);
  background: transparent; font-family: var(--font-body);
  font-size: 0.78rem; font-weight: 500; cursor: pointer;
  color: var(--gray-600); transition: all 0.12s;
  letter-spacing: 0.03em; white-space: nowrap;
}
.seg-control button:last-child { border-right: none; }
.seg-control button.active { background: var(--black); color: var(--white); }
.seg-control button:hover:not(.active) { background: var(--gray-100); color: var(--black); }

/* ── RUN BUTTON ── */
.btn-calc {
  width: 100%; margin-top: 1.25rem;
  padding: 0.72rem; background: var(--black);
  color: var(--white); border: none;
  border-radius: var(--radius);
  font-family: var(--font-body); font-size: 0.875rem;
  font-weight: 500; cursor: pointer; letter-spacing: 0.02em;
  transition: background 0.15s, transform 0.1s;
}
.btn-calc:hover  { background: var(--accent); }
.btn-calc:active { transform: scale(0.99); }

/* ── RESULTS ── */
.result-main {
  display: flex; justify-content: space-between;
  align-items: flex-end; margin-bottom: 1.25rem;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--gray-200);
  gap: 0.5rem; flex-wrap: wrap;
}
.result-label-group {}
.result-label {
  font-size: 0.65rem; text-transform: uppercase;
  letter-spacing: 0.1em; color: var(--gray-400);
  font-weight: 500; margin-bottom: 0.1rem;
}
.result-sublabel { font-size: 0.75rem; color: var(--gray-500); }
.result-value {
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  color: var(--accent); line-height: 1;
  text-align: right; flex-shrink: 0;
}
.result-value.neutral { color: var(--black); }
.result-value.warn    { color: var(--pro); }
.result-value.danger  { color: var(--expert); }

.result-rows {}
.result-row {
  display: flex; justify-content: space-between;
  align-items: center; padding: 0.5rem 0;
  border-bottom: 1px solid var(--gray-100);
  font-size: 0.83rem; gap: 0.5rem;
}
.result-row:last-child { border-bottom: none; }
.result-row-label { color: var(--gray-600); flex: 1; }
.result-row-val   { font-weight: 500; color: var(--black); text-align: right; }
.result-row-val.accent { color: var(--accent); }
.result-row-val.warn   { color: var(--pro); }
.result-row-val.danger { color: var(--expert); }
.result-row-val.muted  { color: var(--gray-400); font-weight: 400; }

/* Multi-result boxes */
.result-boxes {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(130px,1fr));
  gap: 0.75rem; margin-bottom: 1.25rem;
}
.result-box {
  background: var(--gray-100); border: 1px solid var(--gray-200);
  border-radius: var(--radius); padding: 0.85rem 1rem;
}
.result-box-label { font-size: 0.65rem; text-transform: uppercase; letter-spacing: 0.08em; color: var(--gray-400); font-weight: 500; margin-bottom: 0.25rem; }
.result-box-val   { font-family: var(--font-display); font-size: 1.35rem; color: var(--black); line-height: 1.1; }
.result-box-val.accent { color: var(--accent); }
.result-box-val.warn   { color: var(--pro); }
.result-box-val.danger { color: var(--expert); }

/* Empty state */
.empty-state {
  text-align: center; padding: 2.5rem 1rem;
  color: var(--gray-400); font-size: 0.875rem;
}
.empty-icon { font-size: 2rem; margin-bottom: 0.6rem; opacity: 0.5; }

/* ── DATA TABLE ── */
.table-wrap { margin-top: 1.75rem; overflow-x: auto; }
.table-title {
  font-size: 0.65rem; font-weight: 500; letter-spacing: 0.1em;
  text-transform: uppercase; color: var(--gray-400); margin-bottom: 0.65rem;
}
.data-table { width: 100%; border-collapse: collapse; font-size: 0.8rem; }
.data-table th {
  text-align: left; padding: 0.45rem 0.75rem;
  font-size: 0.62rem; font-weight: 500; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--gray-400);
  border-bottom: 1px solid var(--gray-200);
  white-space: nowrap;
}
.data-table td { padding: 0.45rem 0.75rem; border-bottom: 1px solid var(--gray-100); color: var(--black); }
.data-table tr:last-child td { border-bottom: none; }
.data-table tr:hover td { background: var(--gray-100); }
.data-table td.accent { color: var(--accent); font-weight: 500; }
.data-table td.muted  { color: var(--gray-400); }
.data-table td.warn   { color: var(--pro); }
.data-table td.bold   { font-weight: 500; }
.table-note { font-size: 0.72rem; color: var(--gray-400); margin-top: 0.5rem; }
.table-scroll { max-height: 400px; overflow-y: auto; }

/* ── GAUGE / PROGRESS ── */
.gauge-bar { height: 8px; border-radius: 4px; overflow: hidden; margin: 0.6rem 0 0.3rem; }
.gauge-fill { height: 100%; border-radius: 4px; transition: width 0.4s ease; }
.gauge-labels { display: flex; justify-content: space-between; font-size: 0.65rem; color: var(--gray-400); }

.bmi-gauge { height: 10px; border-radius: 5px; background: linear-gradient(90deg,#60a5fa 0%,#4ade80 26%,#facc15 55%,#fb923c 75%,#f87171 100%); position: relative; margin: 1rem 0 0.4rem; }
.bmi-marker { position: absolute; top: -5px; width: 20px; height: 20px; border-radius: 50%; background: var(--black); border: 2px solid var(--white); box-shadow: 0 1px 4px rgba(0,0,0,0.25); transform: translateX(-50%); transition: left 0.4s ease; }
.bmi-labels { display: flex; justify-content: space-between; font-size: 0.62rem; color: var(--gray-400); }

/* ── INFO BOX ── */
.info-box {
  background: var(--accent-light); border: 1px solid #9fe1cb;
  border-radius: var(--radius); padding: 0.85rem 1rem;
  font-size: 0.82rem; color: var(--accent-dark);
  margin-top: 1rem; line-height: 1.6;
}
.info-box.warn   { background: var(--pro-light); border-color: #fac775; color: var(--pro-dark); }
.info-box.danger { background: var(--expert-light); border-color: #f7c1c1; color: var(--expert-dark); }

/* ── GATE / LOCK OVERLAY ── */
.gate-wrap { position: relative; }
.gate-overlay {
  position: absolute; inset: 0;
  background: rgba(250,250,250,0.9);
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  border-radius: var(--radius-md);
  backdrop-filter: blur(4px);
  z-index: 50; text-align: center; padding: 2rem;
}
.gate-lock { font-size: 2.2rem; margin-bottom: 0.75rem; }
.gate-title { font-family: var(--font-display); font-size: 1.25rem; color: var(--black); margin-bottom: 0.35rem; }
.gate-sub   { font-size: 0.82rem; color: var(--gray-600); margin-bottom: 1.25rem; line-height: 1.6; }
.gate-btn {
  background: var(--black); color: var(--white);
  border: none; padding: 0.65rem 1.5rem;
  border-radius: var(--radius); cursor: pointer;
  font-family: var(--font-body); font-size: 0.85rem;
  font-weight: 500; transition: background 0.15s;
}
.gate-btn:hover { background: var(--accent); }

/* ── MODAL ── */
.modal-overlay {
  position: fixed; inset: 0;
  background: rgba(15,15,15,0.65);
  display: flex; align-items: center; justify-content: center;
  z-index: 1000; opacity: 0; pointer-events: none;
  transition: opacity 0.2s; padding: 1rem;
}
.modal-overlay.open { opacity: 1; pointer-events: all; }
.modal {
  background: var(--white); border-radius: var(--radius-md);
  padding: 2.25rem; max-width: 420px; width: 100%;
  transform: translateY(12px); transition: transform 0.2s;
  border: 1px solid var(--gray-200); box-shadow: var(--shadow-md);
}
.modal-overlay.open .modal { transform: translateY(0); }
.modal-title { font-family: var(--font-display); font-size: 1.4rem; color: var(--black); margin-bottom: 0.4rem; }
.modal-desc  { font-size: 0.83rem; color: var(--gray-600); margin-bottom: 1.5rem; line-height: 1.65; }
.modal-input {
  width: 100%; padding: 0.7rem 0.9rem;
  border: 1px solid var(--gray-200); border-radius: var(--radius);
  font-family: var(--font-mono); font-size: 0.9rem;
  letter-spacing: 0.04em; outline: none; margin-bottom: 0.85rem;
  transition: border-color 0.15s; color: var(--black);
}
.modal-input:focus { border-color: var(--accent); }
.modal-actions { display: flex; gap: 0.65rem; }
.modal-cancel {
  flex: 1; padding: 0.68rem;
  background: transparent; border: 1px solid var(--gray-200);
  border-radius: var(--radius); cursor: pointer;
  font-family: var(--font-body); font-size: 0.83rem;
  color: var(--gray-600); transition: all 0.15s;
}
.modal-cancel:hover { border-color: var(--black); color: var(--black); }
.modal-submit {
  flex: 2; padding: 0.68rem; background: var(--black);
  border: none; border-radius: var(--radius); cursor: pointer;
  font-family: var(--font-body); font-size: 0.83rem;
  color: var(--white); font-weight: 500; transition: background 0.15s;
}
.modal-submit:hover { background: var(--accent); }
.modal-msg { font-size: 0.78rem; margin-top: 0.75rem; text-align: center; min-height: 1.2em; }
.modal-msg.error   { color: var(--expert); }
.modal-msg.success { color: var(--accent); }

/* ── FOOTER ── */
.site-footer {
  border-top: 1px solid var(--gray-200);
  padding: 2rem 2rem; margin-top: 4rem;
  background: var(--white);
}
.footer-inner {
  max-width: var(--max); margin: 0 auto;
  display: flex; align-items: center;
  justify-content: space-between;
  flex-wrap: wrap; gap: 1rem;
}
.footer-logo { font-family: var(--font-display); font-size: 1.05rem; color: var(--black); }
.footer-logo span { color: var(--accent); }
.footer-copy { font-size: 0.75rem; color: var(--gray-400); }
.footer-links { display: flex; gap: 1.5rem; flex-wrap: wrap; }
.footer-links a { font-size: 0.75rem; color: var(--gray-400); text-decoration: none; transition: color 0.15s; }
.footer-links a:hover { color: var(--black); }

/* ── SEO ARTICLE SECTION ── */
.calc-article {
  margin-top: 3rem; padding-top: 2rem;
  border-top: 1px solid var(--gray-200);
  max-width: 720px;
}
.calc-article h2 { font-size: 1.3rem; margin-bottom: 0.75rem; color: var(--black); }
.calc-article h3 { font-size: 1.05rem; margin: 1.5rem 0 0.5rem; color: var(--black); font-family: var(--font-display); }
.calc-article p  { font-size: 0.875rem; color: var(--gray-600); line-height: 1.75; margin-bottom: 0.75rem; }
.calc-article ul { padding-left: 1.25rem; margin-bottom: 0.75rem; }
.calc-article li { font-size: 0.875rem; color: var(--gray-600); line-height: 1.75; margin-bottom: 0.25rem; }

/* ── HUB — CATEGORY CARDS ── */
.hub-section { padding: 4.5rem 2rem; }
.hub-section-inner { max-width: var(--max); margin: 0 auto; }
.section-eyebrow {
  font-size: 0.68rem; font-weight: 500; letter-spacing: 0.12em;
  text-transform: uppercase; color: var(--accent);
  margin-bottom: 0.6rem;
  display: flex; align-items: center; gap: 0.4rem;
}
.section-eyebrow::before { content:''; display:inline-block; width:14px; height:1px; background:var(--accent); }
.section-title { font-family: var(--font-display); font-size: clamp(1.6rem,3vw,2.2rem); letter-spacing:-0.02em; color: var(--black); margin-bottom: 0.4rem; }
.section-sub   { font-size: 0.875rem; color: var(--gray-600); max-width: 540px; }

.calc-card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 1px; background: var(--gray-200);
  border: 1px solid var(--gray-200); border-radius: var(--radius-md);
  overflow: hidden;
}
.calc-card-item {
  background: var(--white); padding: 1.1rem 1.2rem;
  cursor: pointer; transition: background 0.12s;
  text-decoration: none; display: block;
  border: none; text-align: left; font-family: var(--font-body);
  width: 100%;
}
.calc-card-item:hover { background: var(--accent-light); text-decoration: none; }
.calc-card-item.locked:hover { background: var(--gray-50); }
.card-top { display: flex; align-items: flex-start; justify-content: space-between; margin-bottom: 0.4rem; }
.card-icon { font-size: 1rem; line-height: 1; }
.card-arrow { font-size: 0.8rem; color: var(--accent); opacity: 0; transition: all 0.15s; }
.calc-card-item:hover:not(.locked) .card-arrow { opacity: 1; transform: translate(2px,-2px); }
.card-name { font-size: 0.875rem; font-weight: 500; color: var(--black); margin-bottom: 0.2rem; line-height: 1.3; }
.card-desc { font-size: 0.73rem; color: var(--gray-600); line-height: 1.5; }
.card-badge {
  display: inline-block; font-size: 0.58rem; font-weight: 500;
  letter-spacing: 0.08em; text-transform: uppercase;
  padding: 0.12rem 0.38rem; border-radius: 2px; margin-top: 0.5rem;
}
.badge-free   { background: var(--accent-light); color: var(--accent); }
.badge-pro    { background: var(--pro-light); color: var(--pro); }
.badge-expert { background: var(--expert-light); color: var(--expert); }
.lock-icon { opacity: 0.35; font-size: 0.72rem; }

/* ── FILTER TABS ── */
.filter-tabs {
  display: flex; width: fit-content;
  border: 1px solid var(--gray-200); border-radius: var(--radius);
  overflow: hidden; background: var(--white); margin-bottom: 2rem;
}
.filter-tab {
  padding: 0.48rem 1.1rem; font-size: 0.75rem; font-weight: 500;
  letter-spacing: 0.04em; text-transform: uppercase; cursor: pointer;
  border: none; border-right: 1px solid var(--gray-200);
  background: transparent; font-family: var(--font-body);
  color: var(--gray-600); transition: all 0.15s;
}
.filter-tab:last-child { border-right: none; }
.filter-tab.active { background: var(--black); color: var(--white); }
.filter-tab:hover:not(.active) { background: var(--gray-100); color: var(--black); }

/* ── UNIT CONVERTER TABS ── */
.unit-cat-tabs { display: flex; flex-wrap: wrap; gap: 0.4rem; margin-bottom: 1.1rem; }
.unit-cat-btn {
  font-size: 0.72rem; padding: 0.28rem 0.65rem;
  border: 1px solid var(--gray-200); border-radius: 2px;
  cursor: pointer; background: none; font-family: var(--font-body);
  color: var(--gray-600); transition: all 0.15s;
}
.unit-cat-btn.active { background: var(--black); color: var(--white); border-color: var(--black); }
.unit-cat-btn:hover:not(.active) { border-color: var(--black); color: var(--black); }

/* ── SCIENTIFIC CALCULATOR ── */
.sci-display {
  background: var(--black); color: var(--white);
  border-radius: var(--radius); padding: 1rem 1.25rem;
  margin-bottom: 0.85rem; min-height: 80px;
  display: flex; flex-direction: column; justify-content: flex-end; align-items: flex-end;
}
.sci-expression { font-size: 0.8rem; color: var(--gray-500); font-family: var(--font-mono); min-height: 1.2em; }
.sci-main { font-size: 2rem; font-family: var(--font-mono); word-break: break-all; }
.sci-grid { display: grid; grid-template-columns: repeat(5, 1fr); gap: 0.4rem; }
.sci-btn {
  padding: 0.7rem 0.3rem; border: 1px solid var(--gray-200);
  border-radius: var(--radius); background: var(--white);
  font-family: var(--font-mono); font-size: 0.85rem;
  cursor: pointer; color: var(--black); transition: all 0.12s;
  text-align: center;
}
.sci-btn:hover  { background: var(--gray-100); }
.sci-btn:active { background: var(--gray-200); transform: scale(0.97); }
.sci-btn.op  { background: var(--gray-100); font-weight: 500; }
.sci-btn.fn  { background: var(--gray-50); color: var(--gray-600); font-size: 0.75rem; }
.sci-btn.eq  { background: var(--black); color: var(--white); border-color: var(--black); }
.sci-btn.eq:hover { background: var(--accent); border-color: var(--accent); }
.sci-btn.clr { background: var(--expert-light); color: var(--expert); border-color: #f7c1c1; }

/* ── FORMULA CARDS (Physics) ── */
.formula-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px,1fr)); gap: 0.75rem; margin-bottom: 1.5rem; }
.formula-card {
  border: 1px solid var(--gray-200); border-radius: var(--radius-md);
  padding: 1rem 1.1rem; cursor: pointer; transition: all 0.15s; background: var(--white);
}
.formula-card:hover, .formula-card.selected { border-color: var(--accent); background: var(--accent-light); }
.formula-name { font-size: 0.85rem; font-weight: 500; color: var(--black); margin-bottom: 0.2rem; }
.formula-eq   { font-size: 0.78rem; color: var(--gray-600); font-family: var(--font-mono); }

/* ── RESPONSIVE ── */
@media (max-width: 700px) {
  .calc-grid-2, .calc-grid-wide { grid-template-columns: 1fr; }
  .field-row, .field-row-3 { grid-template-columns: 1fr; }
  .hub-section { padding: 2.5rem 1rem; }
  .calc-page { padding: 1.5rem 1rem 4rem; }
  .nav-links { display: none; }
  .result-boxes { grid-template-columns: 1fr 1fr; }
  .sci-grid { grid-template-columns: repeat(4,1fr); }
}
@media (max-width: 400px) {
  .result-boxes { grid-template-columns: 1fr; }
}

/* ── ANIMATIONS ── */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(14px); }
  to   { opacity: 1; transform: translateY(0); }
}
.calc-page { animation: fadeUp 0.3s ease both; }
.anim-delay-1 { animation-delay: 0.05s; }
.anim-delay-2 { animation-delay: 0.1s;  }
.anim-delay-3 { animation-delay: 0.15s; }

/* ── PRINT ── */
@media print {
  .site-nav, .btn-calc, .gate-overlay, .site-footer { display: none; }
  .result-panel { border: 1px solid #ccc; }
}

/* ═══════════════════════════════════════════
   MODAL v2 — Two-tab Buy + Key
═══════════════════════════════════════════ */
.modal-overlay {
  position: fixed; inset: 0; background: rgba(0,0,0,0.55);
  display: flex; align-items: center; justify-content: center;
  z-index: 1000; opacity: 0; pointer-events: none;
  transition: opacity 0.18s ease; padding: 1rem;
}
.modal-overlay.open { opacity: 1; pointer-events: all; }
.modal {
  background: var(--white); border-radius: var(--radius-md);
  width: 100%; max-width: 480px; overflow: hidden;
  box-shadow: 0 20px 60px rgba(0,0,0,0.18);
  transform: translateY(12px); transition: transform 0.18s ease;
}
.modal-overlay.open .modal { transform: translateY(0); }

.modal-header {
  display: flex; align-items: center; justify-content: space-between;
  padding: 1.1rem 1.4rem; border-bottom: 1px solid var(--gray-100);
}
.modal-logo { font-family: var(--font-display); font-size: 1rem; color: var(--black); }
.modal-logo span { color: var(--accent); }
.modal-close {
  background: none; border: none; cursor: pointer; font-size: 1rem;
  color: var(--gray-400); padding: 0.2rem; line-height: 1;
  transition: color 0.15s;
}
.modal-close:hover { color: var(--black); }

.modal-tabs {
  display: flex; border-bottom: 1px solid var(--gray-100);
}
.modal-tab {
  flex: 1; padding: 0.75rem; border: none; background: var(--gray-100);
  font-family: var(--font-body); font-size: 0.82rem; font-weight: 500;
  cursor: pointer; color: var(--gray-500); transition: all 0.15s;
  border-bottom: 2px solid transparent;
}
.modal-tab:first-child { border-right: 1px solid var(--gray-200); }
.modal-tab.active {
  background: var(--white); color: var(--black);
  border-bottom-color: var(--black);
}

/* Buy pane */
#modal-pane-buy { padding: 1.25rem 1.4rem 1.4rem; }
.modal-buy-intro { font-size: 0.82rem; color: var(--gray-500); margin-bottom: 1rem; }

.modal-plans { display: flex; flex-direction: column; gap: 0.75rem; }
.modal-plan-card {
  border: 1.5px solid var(--gray-200); border-radius: var(--radius);
  padding: 1rem 1.1rem; transition: border-color 0.15s, box-shadow 0.15s;
}
.modal-plan-card.modal-plan-active {
  border-color: var(--black);
  box-shadow: 0 0 0 3px rgba(15,15,15,0.06);
}
.modal-plan-header {
  display: flex; align-items: flex-start; justify-content: space-between;
  margin-bottom: 0.75rem;
}
.modal-plan-name { font-size: 0.82rem; font-weight: 600; letter-spacing: 0.03em; margin-bottom: 0.2rem; }
.modal-plan-features { font-size: 0.73rem; color: var(--gray-500); line-height: 1.5; }
.modal-plan-price {
  font-family: var(--font-display); font-size: 1.6rem;
  color: var(--black); line-height: 1; flex-shrink: 0; margin-left: 0.75rem;
}
.modal-plan-btn {
  display: block; width: 100%; padding: 0.65rem;
  border-radius: var(--radius); border: 1.5px solid;
  font-family: var(--font-body); font-size: 0.82rem; font-weight: 500;
  cursor: pointer; transition: all 0.15s; letter-spacing: 0.02em; margin-top: 0.75rem;
}
.modal-plan-btn:hover { opacity: 0.85; transform: translateY(-1px); }
.pro-btn { background: var(--black); color: #fff; border-color: var(--black); }
.pro-btn:hover { background: var(--accent); border-color: var(--accent); }
.expert-btn { background: var(--expert); color: #fff; border-color: var(--expert); }
.expert-btn:hover { background: #b91c1c; border-color: #b91c1c; }
.modal-plan-featured { border-color: var(--expert) !important; position: relative; }
.modal-plan-badge {
  position: absolute; top: -1px; right: 14px;
  background: var(--expert); color: #fff;
  font-size: 0.58rem; font-weight: 500; letter-spacing: 0.08em; text-transform: uppercase;
  padding: 0.18rem 0.55rem; border-radius: 0 0 3px 3px;
}
.modal-bottom-row {
  margin-top: 1rem; padding-top: 0.85rem;
  border-top: 1px solid var(--gray-100);
  display: flex; flex-direction: column; gap: 0.35rem;
}
.modal-guarantee { font-size: 0.7rem; color: var(--gray-400); }
.modal-guarantee a { color: var(--gray-500); }
.modal-bottom-links { font-size: 0.7rem; }
.modal-bottom-links a { color: var(--accent); text-decoration: none; }
.modal-bottom-links a:hover { text-decoration: underline; }

/* Key pane */
#modal-pane-key { padding: 1.25rem 1.4rem 1.4rem; }
.modal-key-intro { font-size: 0.82rem; color: var(--gray-500); margin-bottom: 0.85rem; }
.modal-input {
  display: block; width: 100%; padding: 0.65rem 0.85rem;
  border: 1.5px solid var(--gray-200); border-radius: var(--radius);
  font-family: var(--font-mono); font-size: 0.9rem; color: var(--black);
  outline: none; transition: border-color 0.15s; margin-bottom: 0.85rem;
  letter-spacing: 0.04em;
}
.modal-input:focus { border-color: var(--accent); }
.modal-actions { display: flex; gap: 0.6rem; margin-bottom: 0.75rem; }
.modal-cancel {
  flex: 1; padding: 0.65rem; border: 1px solid var(--gray-200);
  border-radius: var(--radius); background: transparent; cursor: pointer;
  font-family: var(--font-body); font-size: 0.82rem; color: var(--gray-600);
  transition: border-color 0.15s;
}
.modal-cancel:hover { border-color: var(--gray-400); }
.modal-submit {
  flex: 2; padding: 0.65rem; border: none; border-radius: var(--radius);
  background: var(--black); color: var(--white); cursor: pointer;
  font-family: var(--font-body); font-size: 0.82rem; font-weight: 500;
  transition: background 0.15s;
}
.modal-submit:hover { background: var(--accent); }
.modal-msg { font-size: 0.78rem; min-height: 1.2rem; }
.modal-msg.success { color: var(--accent-dark); }
.modal-msg.error   { color: #dc2626; }
.modal-key-footer { font-size: 0.73rem; color: var(--gray-400); margin-top: 0.85rem; }
.modal-key-footer a { color: var(--gray-500); }
.modal-link-btn {
  background: none; border: none; cursor: pointer; padding: 0;
  font-family: var(--font-body); font-size: 0.73rem;
  color: var(--black); font-weight: 500; text-decoration: underline;
}

/* Gate overlay v2 */
.gate-overlay {
  position: absolute; inset: 0; background: rgba(255,255,255,0.94);
  backdrop-filter: blur(6px); display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  padding: 2rem; z-index: 10; border-radius: var(--radius-md);
}
.gate-box {
  background: var(--white); border: 1px solid var(--gray-200);
  border-radius: var(--radius-md); padding: 2rem 2rem 1.5rem;
  max-width: 380px; width: 100%; text-align: center;
  box-shadow: 0 8px 32px rgba(0,0,0,0.08);
}
.gate-lock  { font-size: 2rem; margin-bottom: 0.75rem; }
.gate-title { font-family: var(--font-display); font-size: 1.3rem; margin-bottom: 0.5rem; color: var(--black); }
.gate-sub   { font-size: 0.83rem; color: var(--gray-600); margin-bottom: 1.5rem; line-height: 1.65; }
.gate-sub strong { color: var(--black); }
.gate-actions { display: flex; flex-direction: column; gap: 0.6rem; margin-bottom: 1rem; }
.gate-btn-buy {
  padding: 0.78rem 1.2rem; background: var(--black); color: var(--white);
  border: none; border-radius: var(--radius); font-family: var(--font-body);
  font-size: 0.9rem; font-weight: 500; cursor: pointer; transition: background 0.15s;
  letter-spacing: 0.02em;
}
.gate-btn-buy:hover { background: var(--accent); }
.gate-btn-key {
  padding: 0.6rem 1.2rem; background: transparent; color: var(--gray-600);
  border: 1px solid var(--gray-200); border-radius: var(--radius);
  font-family: var(--font-body); font-size: 0.83rem; cursor: pointer;
  transition: border-color 0.15s, color 0.15s;
}
.gate-btn-key:hover { border-color: var(--gray-500); color: var(--black); }
.gate-footer { font-size: 0.7rem; color: var(--gray-400); }
.gate-footer a { color: var(--accent); text-decoration: none; }
.gate-footer a:hover { text-decoration: underline; }