/* ==========================================================================
   Sales Tax / VAT Calculator — styles
   Design tokens, layout, components. No external libraries or fonts.
   ========================================================================== */

/* ---------- Tokens ---------- */
:root {
  --accent: #2a63e8;
  --accent-strong: #1f56d6;
  --accent-soft: rgba(42, 99, 232, 0.12);
  --accent-ring: rgba(42, 99, 232, 0.45);
  --on-accent: #ffffff;

  --bg: #f4f6fb;
  --bg-elevated: #ffffff;
  --surface: #ffffff;
  --surface-2: #f7f9fc;
  --border: #e2e7f0;
  --border-strong: #cfd7e6;

  --text: #101725;
  --text-muted: #5b6577;
  --text-faint: #64707f;

  --danger: #c62f3c;
  --danger-soft: rgba(198, 47, 60, 0.1);
  --success: #14804a;

  --radius-lg: 18px;
  --radius-md: 12px;
  --radius-sm: 9px;
  --shadow-sm: 0 1px 2px rgba(16, 23, 37, 0.05);
  --shadow-md: 0 10px 30px -12px rgba(16, 23, 37, 0.22), 0 2px 6px rgba(16, 23, 37, 0.04);
  --focus: 0 0 0 3px var(--accent-ring);

  --container: 1080px;
  --font: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial,
          "Noto Sans", sans-serif, "Apple Color Emoji", "Segoe UI Emoji";
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
}

html[data-theme="dark"] {
  --accent: #6f9dff;
  --accent-strong: #8fb2ff;
  --accent-soft: rgba(111, 157, 255, 0.16);
  --accent-ring: rgba(111, 157, 255, 0.45);
  --on-accent: #0b1020;

  --bg: #0b1020;
  --bg-elevated: #121a2e;
  --surface: #121a2e;
  --surface-2: #0f1729;
  --border: #22304d;
  --border-strong: #31436a;

  --text: #e9edf7;
  --text-muted: #a6b0c4;
  --text-faint: #93a0b8;

  --danger: #ff8b95;
  --danger-soft: rgba(255, 139, 149, 0.14);
  --success: #57d39a;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 18px 40px -18px rgba(0, 0, 0, 0.75), 0 2px 8px rgba(0, 0, 0, 0.35);
}

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

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  font-family: var(--font);
  font-size: clamp(15px, 0.95rem + 0.15vw, 16.5px);
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  transition: background-color .25s ease, color .25s ease;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

main { flex: 1 0 auto; }

h1, h2, h3, h4 { line-height: 1.25; margin: 0 0 .5rem; letter-spacing: -0.015em; }
h1 { font-size: clamp(1.6rem, 1.15rem + 2vw, 2.35rem); }
h2 { font-size: clamp(1.25rem, 1.05rem + .8vw, 1.55rem); }
h3 { font-size: 1.05rem; }
p  { margin: 0 0 1rem; }
a  { color: var(--accent-strong); text-underline-offset: 2px; }
a:hover { text-decoration-thickness: 2px; }

code {
  font-family: var(--mono);
  font-size: .92em;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: .08em .35em;
}

.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: clamp(16px, 4vw, 28px);
}

.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}

.skip-link {
  position: absolute; left: 12px; top: -60px; z-index: 100;
  background: var(--accent); color: var(--on-accent); padding: .6rem .9rem;
  border-radius: 0 0 var(--radius-sm) var(--radius-sm);
  text-decoration: none; font-weight: 600; transition: top .18s ease;
}
.skip-link:focus { top: 0; }

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* Inputs sit inside a group that paints its own ring */
.input-group input:focus-visible,
.input-group select:focus-visible { outline: none; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
    scroll-behavior: auto !important;
  }
}

/* ---------- Header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 40;
  background: var(--bg-elevated);
  background: color-mix(in srgb, var(--bg-elevated) 88%, transparent);
  backdrop-filter: saturate(160%) blur(10px);
  border-bottom: 1px solid var(--border);
}
@supports not (backdrop-filter: blur(2px)) {
  .site-header { background: var(--bg-elevated); }
}

.header-inner {
  display: flex; align-items: center; justify-content: space-between;
  gap: 16px; padding-block: 14px;
}

.brand { display: flex; align-items: center; gap: 12px; min-width: 0; }
.brand-mark {
  display: grid; place-items: center; flex: none;
  width: 42px; height: 42px; border-radius: 13px;
  color: var(--accent); background: var(--accent-soft);
  border: 1px solid var(--border);
  border-color: color-mix(in srgb, var(--accent) 25%, transparent);
}
.brand-text { display: flex; flex-direction: column; min-width: 0; }
.brand-text strong { font-size: 1.02rem; letter-spacing: -0.01em; }
.brand-text small { color: var(--text-muted); font-size: .8rem; line-height: 1.35; }

.theme-toggle { display: inline-flex; align-items: center; gap: 8px; flex: none; }
.theme-icon { display: grid; place-items: center; width: 18px; height: 18px; }
html[data-theme="light"] .icon-moon { display: none; }
html[data-theme="dark"] .icon-sun { display: none; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  font: inherit; font-weight: 600; font-size: .92rem;
  padding: .6rem 1rem; border-radius: var(--radius-md);
  border: 1px solid var(--border-strong);
  background: var(--surface); color: var(--text);
  cursor: pointer; transition: background-color .16s ease, border-color .16s ease,
    transform .08s ease, box-shadow .16s ease, color .16s ease;
}
.btn:hover { border-color: var(--accent); color: var(--accent-strong); }
.btn:active { transform: translateY(1px); }
.btn:disabled { opacity: .5; cursor: not-allowed; transform: none; }
.btn:disabled:hover { border-color: var(--border-strong); color: var(--text); }

.btn-primary { background: var(--accent); border-color: var(--accent); color: var(--on-accent); }
.btn-primary:hover { background: var(--accent-strong); border-color: var(--accent-strong); color: var(--on-accent); }

.btn-ghost { background: transparent; border-color: var(--border); color: var(--text-muted); }
.btn-ghost:hover { background: var(--surface-2); color: var(--text); border-color: var(--border-strong); }

.btn-outline { background: transparent; border-color: var(--border-strong); color: var(--text); }
.btn-outline:hover:not(:disabled) { background: var(--accent-soft); border-color: var(--accent); color: var(--accent-strong); }
.btn-outline.is-copied { background: var(--accent-soft); border-color: var(--accent); color: var(--accent-strong); }

.btn-danger-ghost { background: transparent; border-color: var(--border-strong); color: var(--danger); }
.btn-danger-ghost:hover { background: var(--danger-soft); border-color: var(--danger); color: var(--danger); }

/* ---------- Hero ---------- */
.hero { padding-block: clamp(28px, 5vw, 46px) 8px; text-align: center; max-width: 760px; }
.hero .lead { color: var(--text-muted); font-size: 1.02rem; margin-bottom: 0; }

/* ---------- Ads ---------- */
.ad-slot { margin-block: clamp(16px, 3vw, 24px); }
.ad-label {
  display: block; text-align: center; font-size: .66rem; font-weight: 700;
  letter-spacing: .14em; text-transform: uppercase; color: var(--text-faint);
  margin-bottom: 6px;
}
.ad-box {
  display: grid; place-items: center; width: 100%;
  border: 1px dashed var(--border-strong); border-radius: var(--radius-md);
  background:
    repeating-linear-gradient(45deg, transparent 0 10px, var(--surface-2) 10px 20px);
  min-height: 90px; padding: 12px;
}
.ad-rectangle { min-height: 250px; }
.ad-placeholder { margin: 0; color: var(--text-faint); font-size: .78rem; text-align: center; }

/* ---------- Calculator layout ---------- */
.calculator-wrap {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 300px;
  gap: clamp(16px, 2.4vw, 26px);
  align-items: start;
  padding-block: 4px clamp(24px, 4vw, 40px);
}
.ad-side { margin-block: 0; }

@media (max-width: 900px) {
  .calculator-wrap { grid-template-columns: minmax(0, 1fr); }
  .ad-side { margin-block: 4px 0; }
  .ad-side .ad-box { min-height: 120px; }
}

/* ---------- Card ---------- */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  padding: clamp(18px, 2.6vw, 28px);
}

/* ---------- Tabs ---------- */
.tabs {
  position: relative;
  display: grid; grid-template-columns: 1fr 1fr;
  gap: 4px; padding: 4px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 999px;
  margin-bottom: clamp(18px, 2.6vw, 24px);
}
.tab {
  position: relative; z-index: 1;
  font: inherit; font-weight: 650; font-size: .95rem;
  padding: .62rem 1rem; border: 0; border-radius: 999px;
  background: transparent; color: var(--text-muted); cursor: pointer;
  transition: color .18s ease;
}
.tab:hover { color: var(--text); }
.tab[aria-selected="true"] { color: var(--accent-strong); }
.tab-indicator {
  position: absolute; z-index: 0; top: 4px; bottom: 4px; left: 4px;
  width: calc(50% - 6px);
  background: var(--surface);
  border: 1px solid var(--border-strong);
  border-radius: 999px;
  box-shadow: var(--shadow-sm);
  transition: transform .22s cubic-bezier(.4, 0, .2, 1);
}
.tabs[data-mode="remove"] .tab-indicator { transform: translateX(calc(100% + 4px)); }
@media (prefers-reduced-motion: reduce) { .tab-indicator { transition: none; } }

/* ---------- Fields ---------- */
.field { margin-bottom: 18px; min-width: 0; }
fieldset.field { border: 0; padding: 0; margin-inline: 0; }
legend {
  font-weight: 650; font-size: .95rem; padding: 0; margin-bottom: 10px;
  color: var(--text);
}
label {
  display: block; font-weight: 600; font-size: .9rem;
  margin-bottom: 7px; color: var(--text);
}
.hint-inline { font-weight: 500; color: var(--text-faint); font-size: .85em; }

.input-group {
  display: flex; align-items: stretch;
  background: var(--surface-2);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: border-color .16s ease, box-shadow .16s ease, background-color .16s ease;
}
.input-group:focus-within {
  border-color: var(--accent);
  background: var(--surface);
  box-shadow: var(--focus);
}
.input-group.has-error { border-color: var(--danger); }
.input-group.has-error:focus-within { box-shadow: 0 0 0 3px var(--danger-soft); }

.input-prefix, .input-suffix {
  display: grid; place-items: center;
  padding: 0 .85rem; font-weight: 600; color: var(--text-muted);
  background: var(--surface-2);
  border-right: 1px solid var(--border);
  font-size: .95rem; flex: none;
}
.input-suffix { border-right: 0; border-left: 1px solid var(--border); }

input[type="text"], select, textarea {
  font: inherit; color: var(--text);
  width: 100%; padding: .78rem .85rem;
  background: transparent; border: 0; outline: none;
}
select {
  appearance: none;
  background-image: url("data:image/svg+xml;charset=utf-8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%235b6577' stroke-width='2.2' stroke-linecap='round'%3E%3Cpath d='M6 9.5l6 6 6-6'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right .7rem center;
  background-size: 16px;
  padding-right: 2.1rem;
  cursor: pointer;
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-md);
  background-color: var(--surface-2);
}
select:focus-visible { border-color: var(--accent); box-shadow: var(--focus); }
select option { background: var(--surface); color: var(--text); }

input::placeholder, textarea::placeholder { color: var(--text-faint); }
input[type="text"] { font-variant-numeric: tabular-nums; letter-spacing: .01em; }

.field-error {
  min-height: 1.15em; margin: 6px 0 0;
  color: var(--danger); font-size: .82rem; font-weight: 600;
}
.field-error:empty { display: none; }
.micro-help { color: var(--text-faint); font-size: .8rem; margin: -6px 0 18px; }

/* ---------- Rate presets ---------- */
.preset-row { display: flex; flex-wrap: wrap; gap: 8px; margin-bottom: 14px; }
.chip {
  font: inherit; font-size: .86rem; font-weight: 600;
  padding: .42rem .82rem; border-radius: 999px;
  border: 1px solid var(--border-strong);
  background: var(--surface-2); color: var(--text-muted); cursor: pointer;
  transition: all .15s ease;
  font-variant-numeric: tabular-nums;
}
.chip:hover { border-color: var(--accent); color: var(--accent-strong); }
.chip.is-active {
  background: var(--accent); border-color: var(--accent); color: var(--on-accent);
  box-shadow: 0 4px 12px -4px var(--accent-ring);
}
.rate-input-row {
  display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: 14px;
}
@media (max-width: 560px) { .rate-input-row { grid-template-columns: minmax(0, 1fr); gap: 0; } }

/* ---------- Results ---------- */
.results {
  margin-top: clamp(18px, 2.6vw, 26px);
  padding: clamp(16px, 2.2vw, 22px);
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
}
.results-title {
  font-size: .72rem; text-transform: uppercase; letter-spacing: .13em;
  color: var(--text-faint); margin-bottom: 14px; font-weight: 700;
}
.result-grid { margin: 0; display: grid; gap: 2px; }
.result-row {
  display: flex; align-items: baseline; justify-content: space-between;
  gap: 16px; padding: .58rem 0; border-bottom: 1px dashed var(--border);
}
.result-row:last-of-type { border-bottom: 0; }
.result-row dt { font-weight: 600; font-size: .92rem; color: var(--text-muted); }
.result-row dd {
  margin: 0; font-weight: 650; font-size: 1rem; color: var(--text);
  font-variant-numeric: tabular-nums; text-align: right;
  overflow-wrap: anywhere;
}
.result-total {
  margin-top: 6px; padding-top: .9rem;
  border-top: 2px solid var(--border-strong); border-bottom: 0;
}
.result-total dt { color: var(--text); font-size: 1rem; }
.result-total dd {
  font-size: clamp(1.3rem, 1rem + 1.1vw, 1.6rem);
  color: var(--accent-strong); font-weight: 750; letter-spacing: -0.02em;
}
.result-note { margin: 12px 0 0; font-size: .8rem; color: var(--text-faint); }
.result-note.is-error { color: var(--danger); font-weight: 600; }

.actions {
  display: flex; flex-wrap: wrap; gap: 10px;
  margin-top: 16px; padding-top: 16px; border-top: 1px solid var(--border);
}
.actions .btn { flex: 1 1 150px; }

/* ---------- Privacy note ---------- */
.privacy-note {
  display: flex; align-items: flex-start; gap: 10px;
  margin-top: 18px; padding: 12px 14px;
  background: var(--surface-2);
  border: 1px solid var(--border-strong);
  background: color-mix(in srgb, var(--success) 8%, transparent);
  border-color: color-mix(in srgb, var(--success) 28%, transparent);
  border-radius: var(--radius-md);
  color: var(--text-muted);
}
.privacy-note svg { flex: none; margin-top: 2px; color: var(--success); }
.privacy-note p { margin: 0; font-size: .82rem; line-height: 1.5; }

/* ---------- FAQ ---------- */
.faq { margin-bottom: clamp(28px, 5vw, 48px); }
.faq h2 { margin-bottom: 14px; }
.faq details {
  border: 1px solid var(--border); border-radius: var(--radius-md);
  padding: 0; margin-bottom: 10px; background: var(--surface-2);
  transition: background-color .16s ease, border-color .16s ease;
}
.faq details[open] { background: var(--surface); border-color: var(--border-strong); }
.faq summary {
  cursor: pointer; list-style: none; padding: .95rem 1.1rem;
  font-weight: 620; font-size: .96rem; display: flex;
  align-items: center; justify-content: space-between; gap: 12px;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: ""; flex: none; width: 10px; height: 10px;
  border-right: 2px solid var(--text-muted); border-bottom: 2px solid var(--text-muted);
  transform: rotate(45deg) translate(-2px, -2px);
  transition: transform .2s ease;
}
.faq details[open] summary::after { transform: rotate(225deg) translate(-2px, -2px); }
.faq summary:hover { color: var(--accent-strong); }
.faq details p { margin: 0; padding: 0 1.1rem 1.1rem; color: var(--text-muted); font-size: .93rem; }

/* ---------- Footer ---------- */
.site-footer {
  border-top: 1px solid var(--border);
  background: var(--bg-elevated);
  padding-block: 22px 26px;
  margin-top: clamp(20px, 4vw, 40px);
}
.footer-inner { display: grid; gap: 10px; text-align: center; }
.footer-nav { display: flex; flex-wrap: wrap; gap: 8px 18px; justify-content: center; }
.footer-nav a {
  color: var(--text-muted); text-decoration: none; font-size: .88rem; font-weight: 600;
}
.footer-nav a:hover { color: var(--accent-strong); text-decoration: underline; }
.footer-copy { margin: 0; color: var(--text-faint); font-size: .8rem; }

/* ---------- Cookie bar ---------- */
.cookie-bar {
  position: fixed; left: 0; right: 0; bottom: 0; z-index: 60;
  background: var(--bg-elevated);
  border-top: 1px solid var(--border-strong);
  box-shadow: 0 -12px 32px -18px rgba(0, 0, 0, .4);
  padding-block: 14px 16px;
}
.cookie-inner { display: flex; align-items: center; gap: 18px; flex-wrap: wrap; }
.cookie-inner p { margin: 0; flex: 1 1 320px; font-size: .85rem; color: var(--text-muted); }
.cookie-actions { display: flex; gap: 10px; flex-wrap: wrap; }
@media (max-width: 560px) {
  .cookie-actions { width: 100%; }
  .cookie-actions .btn { flex: 1 1 45%; }
}

/* ---------- Toast ---------- */
.toast {
  position: fixed; left: 50%; bottom: 24px; transform: translate(-50%, 10px);
  z-index: 70; background: var(--text); color: var(--bg);
  padding: .6rem 1rem; border-radius: 999px; font-size: .85rem; font-weight: 600;
  box-shadow: var(--shadow-md); opacity: 0; transition: opacity .2s ease, transform .2s ease;
  pointer-events: none;
}
.toast.is-visible { opacity: 1; transform: translate(-50%, 0); }

/* ---------- Info pages ---------- */
.page-hero {
  padding-block: clamp(28px, 5vw, 44px) clamp(16px, 3vw, 24px);
  border-bottom: 1px solid var(--border);
  background: var(--bg-elevated);
  text-align: center; /* match the homepage hero */
}
.page-hero p { color: var(--text-muted); margin: 0; max-width: 62ch; margin-inline: auto; }
.breadcrumb { font-size: .82rem; color: var(--text-faint); margin-bottom: 10px; }
.breadcrumb a { color: var(--text-muted); }

.prose { max-width: 74ch; margin-block: clamp(22px, 4vw, 34px); margin-inline: auto; } /* centre the reading column */
.prose h2 { margin-top: 1.8em; font-size: 1.15rem; }
.prose h3 { margin-top: 1.4em; font-size: 1rem; }
.prose ul { padding-left: 1.2rem; color: var(--text-muted); }
.prose li { margin-bottom: .45rem; }
.prose p, .prose li { color: var(--text-muted); }
.prose strong { color: var(--text); }

.contact-grid { display: grid; gap: 14px; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); }
.contact-card {
  border: 1px solid var(--border); border-radius: var(--radius-md);
  padding: 16px 18px; background: var(--surface-2);
}
.contact-card h3 { margin-bottom: 4px; font-size: .98rem; }
.contact-card p { margin: 0; font-size: .88rem; }

.notice {
  border-left: 3px solid var(--accent);
  background: var(--accent-soft);
  padding: 14px 16px; border-radius: 0 var(--radius-md) var(--radius-md) 0;
  margin-block: 18px;
}
.notice p { margin: 0; font-size: .9rem; color: var(--text-muted); }

@media print {
  .site-header, .ad-slot, .cookie-bar, .actions, .theme-toggle { display: none !important; }
  body { background: #fff; color: #000; }
  .card { box-shadow: none; border-color: #ccc; }
}