:root {
  --yellow: #F1C40F;
  --yellow-soft: rgba(241, 196, 15, 0.34);
  --yellow-strong: #FFD84A;
  --charcoal: #2C3E50;
  --white-border: rgba(255, 255, 255, 0.64);
  --paper: rgba(255, 255, 255, 0.72);
  --danger: #9B2C2C;
  --success: #1F6F4A;
  --shadow: 0 22px 70px rgba(44, 62, 80, 0.18);
  --radius-xl: 28px;
  --radius-lg: 22px;
  --bottom-space: 104px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  min-height: 100vh;
  color: var(--charcoal);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background:
    radial-gradient(circle at top left, rgba(255, 255, 255, 0.92), transparent 32rem),
    radial-gradient(circle at 82% 18%, rgba(241, 196, 15, 0.72), transparent 24rem),
    radial-gradient(circle at 14% 85%, rgba(255, 216, 74, 0.75), transparent 22rem),
    linear-gradient(135deg, #FBE27A 0%, #F1C40F 46%, #F8EAA8 100%);
  background-attachment: fixed;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(44, 62, 80, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(44, 62, 80, 0.05) 1px, transparent 1px);
  background-size: 42px 42px;
  mask-image: linear-gradient(to bottom, rgba(0,0,0,.7), rgba(0,0,0,.08));
}

button, input, select { font: inherit; color: var(--charcoal); }

button {
  border: 0;
  cursor: pointer;
  transition: transform .18s ease, box-shadow .18s ease, background .18s ease;
}

button:active { transform: scale(.97); }
button:focus-visible, input:focus-visible, select:focus-visible { outline: 3px solid rgba(44, 62, 80, .44); outline-offset: 3px; }

.app-shell {
  width: min(1180px, 100%);
  margin: 0 auto;
  padding: 18px 14px var(--bottom-space);
}

.glass-panel, .glass-card {
  background: linear-gradient(145deg, rgba(255,255,255,.58), rgba(241,196,15,.32));
  border: 1px solid var(--white-border);
  box-shadow: var(--shadow);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
}

.topbar {
  position: sticky;
  top: 10px;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 14px 16px;
  border-radius: 24px;
}

.eyebrow {
  margin: 0 0 5px;
  text-transform: uppercase;
  letter-spacing: .13em;
  font-size: .72rem;
  font-weight: 900;
  color: rgba(44, 62, 80, .78);
}

h1, h2, h3, p { margin-top: 0; }
h1 { margin-bottom: 0; font-size: clamp(1.35rem, 5vw, 2.1rem); line-height: 1; }
h2 { font-size: clamp(1.6rem, 6vw, 3rem); line-height: 1.02; letter-spacing: -0.045em; margin-bottom: 10px; }
h3 { font-size: 1.1rem; margin-bottom: 12px; }
p { line-height: 1.55; }

.score-chip {
  min-width: 76px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 12px;
  border-radius: 999px;
  background: rgba(255, 255, 255, .64);
  border: 1px solid rgba(255,255,255,.7);
}

.content { padding-top: 18px; }
.view { display: none; animation: rise .28s ease both; }
.view.active { display: block; }

@keyframes rise {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.hero-card {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 18px;
  align-items: center;
  padding: clamp(18px, 5vw, 34px);
  border-radius: var(--radius-xl);
  overflow: hidden;
  position: relative;
}

.hero-card::after {
  content: "VAT • BODMAS • SCALE • DATA";
  position: absolute;
  right: -74px;
  bottom: 18px;
  font-weight: 900;
  color: rgba(44, 62, 80, .08);
  font-size: clamp(1.8rem, 7vw, 5rem);
  letter-spacing: .06em;
  white-space: nowrap;
}

.hero-copy { position: relative; z-index: 2; }
.hero-copy p:last-child { max-width: 56ch; margin-bottom: 0; font-weight: 600; }
.hero-badge {
  position: relative;
  z-index: 2;
  width: clamp(86px, 20vw, 160px);
  aspect-ratio: 1;
  display: grid;
  place-items: center;
  border-radius: 36px;
  background: linear-gradient(145deg, #fff6bb, #f1c40f);
  border: 1px solid rgba(255,255,255,.8);
  box-shadow: inset 0 -18px 48px rgba(44,62,80,.14), 0 20px 60px rgba(44,62,80,.18);
  transform: rotate(-6deg);
}
.hero-badge span { font-size: clamp(2.8rem, 13vw, 6.5rem); font-weight: 950; }

.bento-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 14px;
  margin-top: 16px;
}

.feature-card {
  min-height: 158px;
  text-align: left;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  justify-content: flex-end;
  padding: 18px;
  border-radius: var(--radius-lg);
}
.feature-card:hover { transform: translateY(-3px); box-shadow: 0 28px 80px rgba(44, 62, 80, .21); }
.feature-card.wide { grid-column: span 2; }
.feature-card strong { font-size: 1.05rem; margin: 8px 0 5px; }
.feature-card small { font-weight: 700; opacity: .75; }
.feature-icon { font-size: 2rem; }

.section-heading {
  padding: 10px 4px 14px;
  max-width: 760px;
}
.section-heading p:last-child { margin-bottom: 0; font-weight: 650; }

.tool-grid, .tariff-layout, .converter-grid {
  display: grid;
  grid-template-columns: minmax(0, .85fr) minmax(0, 1.15fr);
  gap: 16px;
}

.glass-card {
  border-radius: var(--radius-lg);
  padding: 18px;
}

.tool-card label, .tariff-form label, .converter-card label, .quiz-topline label {
  display: grid;
  gap: 7px;
  font-weight: 850;
}

input, select {
  width: 100%;
  border: 1px solid rgba(255,255,255,.75);
  background: rgba(255,255,255,.75);
  min-height: 46px;
  border-radius: 16px;
  padding: 10px 12px;
  font-weight: 850;
}

.money-input {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: center;
  margin: 8px 0 12px;
  border-radius: 18px;
  background: rgba(255,255,255,.76);
  border: 1px solid rgba(255,255,255,.8);
  overflow: hidden;
}
.money-input span { padding-left: 14px; font-weight: 950; font-size: 1.25rem; }
.money-input input { border: 0; background: transparent; font-size: 1.45rem; min-height: 58px; }

.quick-row {
  display: flex;
  flex-wrap: wrap;
  gap: 9px;
  margin: 12px 0;
}
.quick-row button, .converter-card button {
  padding: 10px 12px;
  border-radius: 999px;
  background: rgba(255,255,255,.68);
  border: 1px solid rgba(255,255,255,.74);
  font-weight: 900;
}

.toggle-line {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 12px;
  font-weight: 800;
}
.toggle-line input { width: 20px; min-height: 20px; accent-color: var(--charcoal); }

.result-card { background: linear-gradient(145deg, rgba(255,255,255,.7), rgba(241,196,15,.28)); }
.receipt-header, .receipt-list div, .grand-total {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  align-items: center;
}
.receipt-header {
  padding-bottom: 10px;
  border-bottom: 1px solid rgba(44,62,80,.16);
}
.receipt-list { margin: 0; }
.receipt-list div { padding: 13px 0; border-bottom: 1px solid rgba(44,62,80,.12); }
.receipt-list dt { font-weight: 800; }
.receipt-list dd { margin: 0; font-weight: 950; font-size: 1.2rem; color: var(--charcoal); }
.grand-total dd { font-size: clamp(1.65rem, 5vw, 2.4rem); }
.rounding-row dd.negative { color: var(--success); }
.rounding-row dd.positive { color: var(--danger); }

.hint-box {
  margin: 14px 0 0;
  padding: 12px 14px;
  border-radius: 18px;
  background: rgba(255,255,255,.62);
  border: 1px solid rgba(255,255,255,.72);
  font-weight: 760;
}

.tariff-layout { grid-template-columns: minmax(280px, .76fr) minmax(0, 1.24fr); }
.tariff-form { display: grid; gap: 14px; }
.plan-block {
  display: grid;
  gap: 10px;
  padding: 13px;
  border-radius: 20px;
  background: rgba(255,255,255,.38);
  border: 1px solid rgba(255,255,255,.56);
}
.plan-block h3 { margin-bottom: 0; }
.expected-box { margin-top: 2px; }
.expected-box span { text-align: center; font-size: 1.1rem; }
input[type="range"] { padding: 0; accent-color: var(--charcoal); background: transparent; border: 0; }
.chart-card canvas {
  width: 100%;
  height: auto;
  display: block;
  border-radius: 20px;
  background: rgba(255,255,255,.66);
  border: 1px solid rgba(255,255,255,.78);
}

.converter-grid { grid-template-columns: repeat(3, 1fr); }
.converter-card { display: grid; gap: 10px; }
.converter-icon {
  width: 58px;
  aspect-ratio: 1;
  display: grid;
  place-items: center;
  border-radius: 18px;
  font-size: 2rem;
  background: rgba(255,255,255,.68);
  border: 1px solid rgba(255,255,255,.76);
}
.converter-card p { margin-bottom: 2px; font-weight: 800; }
.converter-card output {
  display: block;
  padding: 14px;
  border-radius: 18px;
  background: rgba(255,255,255,.72);
  color: var(--charcoal);
  border: 1px solid rgba(255,255,255,.82);
  font-weight: 950;
  font-size: 1.45rem;
  text-align: center;
}
.kitchen-mode { outline: 2px solid rgba(255,255,255,.42); }

.wide-input { font-size: 1.05rem; font-family: ui-monospace, SFMono-Regular, Menlo, monospace; }
.formula-buttons button { border-radius: 16px; }
.steps-list {
  padding-left: 22px;
  margin: 0;
  display: grid;
  gap: 10px;
}
.steps-list li {
  padding: 10px 12px;
  border-radius: 16px;
  background: rgba(255,255,255,.56);
  font-weight: 820;
}
.final-answer {
  margin-top: 14px;
  padding: 15px;
  border-radius: 18px;
  background: rgba(255,255,255,.72);
  color: var(--charcoal);
  border: 1px solid rgba(255,255,255,.82);
  font-weight: 950;
  font-size: 1.25rem;
}

.quiz-topline {
  display: grid;
  grid-template-columns: 1fr repeat(2, auto);
  gap: 12px;
  align-items: center;
  margin-bottom: 16px;
}
.quiz-topline > div {
  min-width: 112px;
  display: grid;
  gap: 2px;
  padding: 11px 13px;
  border-radius: 18px;
  background: rgba(255,255,255,.58);
  text-align: center;
  font-weight: 850;
}
.quiz-topline span { font-size: .78rem; text-transform: uppercase; letter-spacing: .08em; opacity: .72; }
.quiz-container { display: grid; gap: 14px; }
.question-card {
  border-radius: var(--radius-lg);
  padding: 17px;
  background: linear-gradient(145deg, rgba(255,255,255,.64), rgba(241,196,15,.32));
  border: 1px solid var(--white-border);
  box-shadow: var(--shadow);
}
.question-card header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  margin-bottom: 10px;
}
.question-card header strong { font-size: .92rem; }
.difficulty {
  padding: 6px 10px;
  border-radius: 999px;
  background: rgba(255,255,255,.66);
  font-size: .78rem;
  font-weight: 950;
  text-transform: uppercase;
}
.question-card p { margin-bottom: 12px; font-weight: 760; }
.options { display: grid; gap: 8px; }
.option-line {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px;
  border-radius: 15px;
  background: rgba(255,255,255,.52);
  border: 1px solid rgba(255,255,255,.68);
  font-weight: 760;
}
.option-line input { width: 18px; min-height: 18px; accent-color: var(--charcoal); }
.quiz-feedback {
  display: none;
  margin-top: 12px;
  padding: 11px 12px;
  border-radius: 16px;
  font-weight: 850;
}
.quiz-feedback.show { display: block; }
.quiz-feedback.correct { background: rgba(31,111,74,.14); color: var(--success); }
.quiz-feedback.wrong { background: rgba(155,44,44,.12); color: var(--danger); }
.quiz-actions {
  display: flex;
  gap: 10px;
  position: sticky;
  bottom: 86px;
  margin-top: 16px;
  z-index: 10;
}
.primary-btn, .secondary-btn {
  flex: 1;
  min-height: 52px;
  border-radius: 18px;
  font-weight: 950;
  box-shadow: 0 18px 50px rgba(44,62,80,.18);
}
.primary-btn { background: var(--charcoal); color: white; }
.secondary-btn { background: rgba(255,255,255,.78); color: var(--charcoal); border: 1px solid rgba(255,255,255,.8); }

.bottom-nav {
  position: fixed;
  left: 50%;
  bottom: max(12px, env(safe-area-inset-bottom));
  transform: translateX(-50%);
  width: min(720px, calc(100% - 24px));
  z-index: 30;
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 6px;
  padding: 8px;
  border-radius: 26px;
}
.nav-btn {
  display: grid;
  place-items: center;
  gap: 2px;
  min-height: 58px;
  border-radius: 19px;
  background: transparent;
  font-weight: 900;
}
.nav-btn span { font-size: 1.15rem; }
.nav-btn small { font-size: .68rem; }
.nav-btn.active {
  background: rgba(44, 62, 80, .96);
  color: white;
  box-shadow: 0 14px 42px rgba(44, 62, 80, .24);
}

@media (max-width: 900px) {
  .bento-grid { grid-template-columns: repeat(2, 1fr); }
  .tool-grid, .tariff-layout { grid-template-columns: 1fr; }
  .converter-grid { grid-template-columns: 1fr; }
}

@media (max-width: 560px) {
  .app-shell { padding-inline: 10px; }
  .topbar { border-radius: 22px; }
  .hero-card { grid-template-columns: 1fr; }
  .hero-badge { width: 94px; border-radius: 25px; }
  .bento-grid { grid-template-columns: 1fr; }
  .feature-card, .feature-card.wide { grid-column: span 1; min-height: 128px; }
  .quiz-topline { grid-template-columns: 1fr; }
  .bottom-nav { grid-template-columns: repeat(6, 1fr); padding: 7px; gap: 3px; width: calc(100% - 14px); }
  .nav-btn { min-height: 54px; border-radius: 17px; }
  .nav-btn small { font-size: .58rem; }
  .receipt-list dd { font-size: 1.05rem; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .01ms !important; transition-duration: .01ms !important; scroll-behavior: auto !important; }
}