/* ==========================================================================
   Keifa Unit Converter - Universal CSS Design System
   Brand: Keifa Tools (keifa.net)
   ========================================================================== */

:root {
  --bg: #071311;
  --bg-2: #0d1d1a;
  --bg-3: #122421;
  --ink: #f7fbf4;
  --ink-secondary: #d1ded7;
  --muted: #95a89f;
  --soft: #e2ece3;
  --panel: rgba(12, 29, 26, 0.82);
  --panel-solid: #10231f;
  --panel-glass: rgba(16, 35, 31, 0.65);
  --panel-border: rgba(255, 255, 255, 0.12);
  --line: rgba(255, 255, 255, 0.12);
  --line-focus: rgba(115, 199, 223, 0.5);

  --amber: #f0bf63;
  --amber-soft: rgba(240, 191, 99, 0.15);
  --amber-ink: #211604;
  --teal: #73c7df;
  --teal-glow: rgba(115, 199, 223, 0.28);
  --coral: #e9755f;
  --green: #4db888;
  --green-glow: rgba(77, 184, 136, 0.24);

  --shadow-sm: 0 4px 14px rgba(0, 0, 0, 0.25);
  --shadow-md: 0 12px 36px rgba(0, 0, 0, 0.35);
  --shadow-lg: 0 24px 70px rgba(0, 0, 0, 0.45);

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-pill: 9999px;
  --trans: 0.22s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  background:
    radial-gradient(circle at 50% 0%, rgba(115, 199, 223, 0.12), transparent 45%),
    linear-gradient(180deg, var(--bg) 0%, #0a1715 45%, #0e1916 100%);
  font-family: Cairo, Inter, system-ui, -apple-system, sans-serif;
  overflow-x: hidden;
  line-height: 1.6;
}

/* Background high-tech engineering grid overlay */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -2;
  pointer-events: none;
  background:
    linear-gradient(rgba(255, 255, 255, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.035) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(ellipse at 50% 30%, #000 35%, transparent 80%);
}

body::after {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(ellipse at 85% 15%, rgba(240, 191, 99, 0.05), transparent 40%),
    radial-gradient(ellipse at 15% 75%, rgba(77, 184, 136, 0.05), transparent 40%);
}

button, input, select {
  font: inherit;
  color: inherit;
}

.shell {
  width: min(1180px, calc(100% - 32px));
  margin-inline: auto;
}

/* ==========================================================================
   Header & Navigation
   ========================================================================== */

.topbar {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 12px 0;
  border-bottom: 1px solid var(--panel-border);
  background: rgba(7, 19, 17, 0.88);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
  color: inherit;
  text-decoration: none;
  min-width: 0;
}

.logo {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  display: grid;
  place-items: center;
  background: linear-gradient(135deg, var(--amber) 0%, #e2a637 100%);
  color: var(--amber-ink);
  font-weight: 900;
  font-size: 1.1rem;
  letter-spacing: 0.5px;
  box-shadow: 0 4px 18px rgba(240, 191, 99, 0.35);
}

.brand-text {
  display: flex;
  flex-direction: column;
}

.brand-text b {
  font-size: 1.05rem;
  font-weight: 700;
  line-height: 1.25;
}

.brand-text small {
  font-size: 0.76rem;
  color: var(--muted);
}

.top-actions {
  display: flex;
  align-items: center;
  gap: 14px;
}

.stat-badge {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  border-radius: var(--radius-pill);
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--panel-border);
  font-size: 0.82rem;
  color: var(--soft);
}

.pulse-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--green);
  box-shadow: 0 0 8px var(--green);
  animation: pulseGlow 2s infinite;
}

@keyframes pulseGlow {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(0.85); }
}

.language-picker select {
  background: rgba(18, 36, 33, 0.8);
  border: 1px solid var(--panel-border);
  border-radius: var(--radius-pill);
  color: var(--ink);
  padding: 6px 14px;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  outline: none;
  transition: var(--trans);
}

.language-picker select:hover,
.language-picker select:focus {
  border-color: var(--teal);
  box-shadow: 0 0 10px var(--teal-glow);
}

/* ==========================================================================
   AdSense Container
   ========================================================================== */

.ad-wrapper {
  margin: 16px auto 8px;
  overflow: hidden;
  border-radius: var(--radius-sm);
}

/* ==========================================================================
   Hero Section & Search
   ========================================================================== */

.hero {
  padding: 24px 0 16px;
  text-align: center;
}

.hero-copy {
  max-width: 820px;
  margin: 0 auto 20px;
}

.eyebrow {
  display: inline-block;
  font-size: 0.82rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--amber);
  margin-bottom: 8px;
  background: var(--amber-soft);
  padding: 4px 14px;
  border-radius: var(--radius-pill);
  border: 1px solid rgba(240, 191, 99, 0.25);
}

.hero h1 {
  margin: 0 0 10px;
  font-size: clamp(1.6rem, 4vw, 2.5rem);
  font-weight: 800;
  line-height: 1.25;
  background: linear-gradient(135deg, #ffffff 30%, var(--soft) 70%, var(--teal) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero p {
  margin: 0;
  font-size: 1.05rem;
  color: var(--muted);
}

/* Universal Search Box */
.search-box {
  position: relative;
  max-width: 600px;
  margin: 0 auto 24px;
}

.search-icon {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  inset-inline-start: 16px;
  pointer-events: none;
  font-size: 1rem;
  opacity: 0.7;
}

.search-box input {
  width: 100%;
  padding: 13px 44px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--panel-border);
  background: rgba(18, 36, 33, 0.7);
  color: var(--ink);
  font-size: 0.96rem;
  outline: none;
  backdrop-filter: blur(12px);
  box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.3);
  transition: var(--trans);
}

.search-box input:focus {
  border-color: var(--teal);
  box-shadow: 0 0 16px var(--teal-glow), inset 0 2px 4px rgba(0, 0, 0, 0.3);
}

/* Category Tabs Bar */
.category-tabs-container {
  overflow-x: auto;
  padding: 6px 4px 14px;
  scrollbar-width: thin;
  scrollbar-color: var(--panel-border) transparent;
}

.category-tabs {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  min-width: min-content;
}

.cat-tab {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--panel-border);
  background: rgba(16, 35, 31, 0.65);
  color: var(--soft);
  font-size: 0.88rem;
  font-weight: 600;
  cursor: pointer;
  white-space: nowrap;
  backdrop-filter: blur(10px);
  transition: var(--trans);
  user-select: none;
}

.cat-tab:hover {
  background: rgba(26, 52, 47, 0.85);
  border-color: rgba(255, 255, 255, 0.22);
  transform: translateY(-2px);
  color: #fff;
}

.cat-tab.active {
  background: linear-gradient(135deg, rgba(240, 191, 99, 0.22), rgba(115, 199, 223, 0.18));
  border-color: var(--amber);
  color: #fff;
  box-shadow: 0 4px 18px rgba(240, 191, 99, 0.22);
}

.cat-icon {
  font-size: 1.1rem;
}

.cat-count {
  background: rgba(255, 255, 255, 0.1);
  padding: 1px 6px;
  border-radius: 10px;
  font-size: 0.72rem;
  font-weight: 700;
  color: var(--muted);
}

.cat-tab.active .cat-count {
  background: var(--amber);
  color: var(--amber-ink);
}

.empty-search-msg {
  padding: 18px;
  color: var(--muted);
  font-size: 0.9rem;
}

/* ==========================================================================
   Main Converter Card Core
   ========================================================================== */

.converter-section {
  margin: 10px auto 36px;
}

.converter-card {
  position: relative;
  background: linear-gradient(160deg, rgba(16, 36, 32, 0.92) 0%, rgba(10, 22, 20, 0.95) 100%);
  border: 1px solid var(--panel-border);
  border-radius: var(--radius-lg);
  padding: 28px;
  box-shadow: var(--shadow-lg);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
}

.converter-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 10%;
  right: 10%;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(240, 191, 99, 0.6), transparent);
}

.converter-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 20px;
  padding-bottom: 16px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.category-heading {
  display: flex;
  align-items: center;
  gap: 10px;
}

.cat-pill-indicator {
  color: var(--amber);
  font-size: 0.75rem;
}

.category-heading h2 {
  margin: 0;
  font-size: 1.35rem;
  font-weight: 700;
  color: #fff;
}

.converter-controls {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
}

.control-group {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.84rem;
  color: var(--muted);
}

.clean-select {
  background: rgba(8, 20, 18, 0.85);
  border: 1px solid var(--panel-border);
  border-radius: var(--radius-sm);
  color: var(--ink);
  padding: 4px 10px;
  font-size: 0.84rem;
  outline: none;
  cursor: pointer;
  transition: var(--trans);
}

.clean-select:hover,
.clean-select:focus {
  border-color: var(--teal);
}

/* Switch Toggle */
.toggle-control {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.84rem;
  color: var(--muted);
  cursor: pointer;
  user-select: none;
}

.toggle-control input {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.toggle-track {
  width: 34px;
  height: 18px;
  border-radius: var(--radius-pill);
  background: rgba(255, 255, 255, 0.15);
  position: relative;
  transition: var(--trans);
}

.toggle-track::after {
  content: "";
  position: absolute;
  top: 2px;
  inset-inline-start: 2px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: #fff;
  transition: var(--trans);
}

.toggle-control input:checked + .toggle-track {
  background: var(--teal);
}

.toggle-control input:checked + .toggle-track::after {
  transform: translateX(16px);
}

[dir="rtl"] .toggle-control input:checked + .toggle-track::after {
  transform: translateX(-16px);
}

/* Quick Value Chips */
.quick-values-row {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 22px;
}

.quick-label {
  font-size: 0.82rem;
  color: var(--muted);
  font-weight: 600;
}

.quick-btns {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.quick-chip {
  padding: 4px 12px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--panel-border);
  background: rgba(255, 255, 255, 0.04);
  color: var(--soft);
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--trans);
}

.quick-chip:hover {
  background: rgba(255, 255, 255, 0.12);
  border-color: rgba(255, 255, 255, 0.25);
  color: #fff;
  transform: translateY(-1px);
}

/* Conversion Grid (Dual boxes + Swap button) */
.conversion-grid {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 20px;
  margin-bottom: 24px;
}

.unit-box {
  background: rgba(8, 20, 18, 0.7);
  border: 1px solid var(--panel-border);
  border-radius: var(--radius-md);
  padding: 16px 20px;
  transition: var(--trans);
  box-shadow: inset 0 2px 6px rgba(0, 0, 0, 0.35);
}

.unit-box:focus-within {
  border-color: var(--teal);
  box-shadow: 0 0 18px var(--teal-glow), inset 0 2px 6px rgba(0, 0, 0, 0.35);
}

.unit-box-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 12px;
}

.box-label {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--amber);
  text-transform: uppercase;
}

.unit-select {
  background: rgba(18, 38, 34, 0.85);
  border: 1px solid var(--panel-border);
  border-radius: var(--radius-sm);
  color: #fff;
  padding: 6px 12px;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  outline: none;
  max-width: 220px;
  transition: var(--trans);
}

.unit-select:hover,
.unit-select:focus {
  border-color: var(--amber);
}

.input-wrapper input {
  width: 100%;
  background: transparent;
  border: none;
  color: #fff;
  font-family: 'JetBrains Mono', Inter, monospace;
  font-size: clamp(1.5rem, 3.2vw, 2.3rem);
  font-weight: 700;
  outline: none;
  padding: 4px 0;
  letter-spacing: -0.5px;
}

.input-wrapper input::placeholder {
  color: rgba(255, 255, 255, 0.2);
}

/* Hide native number spin buttons */
input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
  -webkit-appearance: none;
  margin: 0;
}
input[type="number"] {
  -moz-appearance: textfield;
}

/* Swap Button */
.swap-wrapper {
  display: flex;
  justify-content: center;
  align-items: center;
}

.swap-btn {
  width: 52px;
  height: 52px;
  border-radius: 50%;
  border: 1px solid var(--panel-border);
  background: linear-gradient(135deg, rgba(240, 191, 99, 0.15), rgba(115, 199, 223, 0.15));
  color: var(--amber);
  display: grid;
  place-items: center;
  cursor: pointer;
  transition: var(--trans);
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.3);
}

.swap-btn:hover {
  background: linear-gradient(135deg, var(--amber), #f7cf82);
  color: var(--amber-ink);
  transform: scale(1.08);
  box-shadow: 0 6px 20px rgba(240, 191, 99, 0.4);
}

.swap-btn.spinning {
  transform: rotate(180deg) scale(1.1);
}

/* Action Buttons Row */
.converter-actions-row {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 22px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: var(--radius-sm);
  font-size: 0.92rem;
  font-weight: 700;
  cursor: pointer;
  transition: var(--trans);
  border: 1px solid transparent;
}

.primary-action-btn {
  background: linear-gradient(135deg, var(--amber) 0%, #e0ab44 100%);
  color: var(--amber-ink);
  box-shadow: 0 4px 16px rgba(240, 191, 99, 0.3);
}

.primary-action-btn:hover {
  background: linear-gradient(135deg, #f7cb78 0%, #ebb650 100%);
  transform: translateY(-2px);
  box-shadow: 0 6px 22px rgba(240, 191, 99, 0.45);
}

.secondary-action-btn {
  background: rgba(255, 255, 255, 0.05);
  border-color: var(--panel-border);
  color: var(--soft);
}

.secondary-action-btn:hover {
  background: rgba(255, 255, 255, 0.12);
  border-color: rgba(255, 255, 255, 0.25);
  color: #fff;
  transform: translateY(-2px);
}

/* Mathematical Formula Card */
.formula-card {
  background: rgba(8, 18, 16, 0.65);
  border: 1px dashed rgba(240, 191, 99, 0.3);
  border-radius: var(--radius-md);
  padding: 14px 18px;
}

.formula-header {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 6px;
}

.formula-icon {
  font-size: 0.95rem;
}

.formula-title {
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--amber);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.formula-display {
  font-family: 'JetBrains Mono', Inter, monospace;
  font-size: 1.02rem;
  font-weight: 600;
  color: var(--soft);
  word-break: break-all;
}

/* ==========================================================================
   All Units Comparison Live Grid
   ========================================================================== */

.all-units-section {
  margin: 36px auto;
}

.section-heading {
  margin-bottom: 20px;
}

.section-heading h2 {
  margin: 0;
  font-size: 1.35rem;
  font-weight: 700;
  color: #fff;
}

.all-units-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 16px;
}

.unit-card {
  position: relative;
  background: rgba(14, 32, 28, 0.65);
  border: 1px solid var(--panel-border);
  border-radius: var(--radius-md);
  padding: 16px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  cursor: pointer;
  transition: var(--trans);
  backdrop-filter: blur(12px);
}

.unit-card:hover {
  background: rgba(20, 44, 39, 0.85);
  border-color: rgba(255, 255, 255, 0.25);
  transform: translateY(-3px);
  box-shadow: var(--shadow-sm);
}

.unit-card.target-unit {
  background: linear-gradient(145deg, rgba(240, 191, 99, 0.16), rgba(16, 35, 31, 0.8));
  border-color: var(--amber);
  box-shadow: 0 4px 20px rgba(240, 191, 99, 0.2);
}

.unit-card.source-unit {
  border-color: var(--teal);
  background: linear-gradient(145deg, rgba(115, 199, 223, 0.12), rgba(16, 35, 31, 0.8));
}

.card-top {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 8px;
  flex-wrap: wrap;
}

.card-symbol {
  font-family: 'JetBrains Mono', Inter, monospace;
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--amber);
  background: rgba(240, 191, 99, 0.12);
  padding: 2px 8px;
  border-radius: 4px;
}

.card-name {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--soft);
}

.badge {
  font-size: 0.7rem;
  font-weight: 700;
  padding: 1px 7px;
  border-radius: var(--radius-pill);
  margin-inline-start: auto;
}

.target-badge {
  background: var(--amber);
  color: var(--amber-ink);
}

.source-badge {
  background: var(--teal);
  color: #071311;
}

.card-body {
  margin: 8px 0 12px;
}

.card-val {
  font-family: 'JetBrains Mono', Inter, monospace;
  font-size: 1.25rem;
  font-weight: 700;
  color: #fff;
  word-break: break-all;
  line-height: 1.3;
}

.card-actions {
  display: flex;
  justify-content: flex-end;
}

.mini-copy-btn {
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--panel-border);
  border-radius: var(--radius-sm);
  color: var(--muted);
  font-size: 0.76rem;
  font-weight: 600;
  padding: 4px 10px;
  cursor: pointer;
  transition: var(--trans);
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.mini-copy-btn:hover {
  background: rgba(255, 255, 255, 0.15);
  color: #fff;
  border-color: rgba(255, 255, 255, 0.3);
}

/* ==========================================================================
   History Section
   ========================================================================== */

.history-section {
  margin: 36px auto 48px;
}

.history-card {
  background: rgba(14, 32, 28, 0.7);
  border: 1px solid var(--panel-border);
  border-radius: var(--radius-lg);
  padding: 24px;
  backdrop-filter: blur(16px);
}

.history-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.history-title-block {
  display: flex;
  align-items: center;
  gap: 10px;
}

.history-badge-icon {
  font-size: 1.1rem;
}

.history-title-block h3 {
  margin: 0;
  font-size: 1.1rem;
  font-weight: 700;
  color: #fff;
}

.text-btn {
  background: transparent;
  border: none;
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 600;
  cursor: pointer;
  transition: var(--trans);
}

.text-btn:hover {
  color: var(--coral);
}

.history-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.history-empty {
  text-align: center;
  padding: 20px;
  color: var(--muted);
  font-size: 0.9rem;
}

.history-item {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid rgba(255, 255, 255, 0.06);
  cursor: pointer;
  transition: var(--trans);
}

.history-item:hover {
  background: rgba(255, 255, 255, 0.07);
  border-color: rgba(255, 255, 255, 0.16);
  transform: translateX(-3px);
}

[dir="ltr"] .history-item:hover {
  transform: translateX(3px);
}

.history-icon {
  font-size: 1.25rem;
}

.history-content {
  flex: 1;
  min-width: 0;
}

.history-equation {
  display: block;
  font-size: 0.94rem;
  color: #fff;
  font-family: 'JetBrains Mono', Inter, monospace;
}

.history-meta {
  display: block;
  font-size: 0.76rem;
  color: var(--muted);
}

.history-copy-btn {
  background: transparent;
  border: 1px solid var(--panel-border);
  border-radius: 4px;
  color: var(--muted);
  font-size: 0.85rem;
  padding: 4px 8px;
  cursor: pointer;
  transition: var(--trans);
}

.history-copy-btn:hover {
  background: rgba(255, 255, 255, 0.12);
  color: #fff;
}

/* ==========================================================================
   Footer
   ========================================================================== */

.footer {
  border-top: 1px solid var(--panel-border);
  padding: 32px 0;
  margin-top: 50px;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 20px;
}

.footer-brand b {
  font-size: 1.05rem;
  color: #fff;
}

.footer-brand p {
  margin: 4px 0 0;
  font-size: 0.84rem;
  color: var(--muted);
  max-width: 480px;
}

.footer-links {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 6px;
}

[dir="ltr"] .footer-links {
  align-items: flex-start;
}

.footer-links a {
  color: var(--amber);
  text-decoration: none;
  font-weight: 700;
  font-size: 0.92rem;
  transition: var(--trans);
}

.footer-links a:hover {
  text-decoration: underline;
  color: #fff;
}

.footer-copy {
  font-size: 0.78rem;
  color: var(--muted);
}

/* ==========================================================================
   Toast Notification
   ========================================================================== */

.toast {
  position: fixed;
  bottom: 28px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: rgba(14, 34, 30, 0.95);
  border: 1px solid var(--amber);
  color: #fff;
  padding: 10px 22px;
  border-radius: var(--radius-pill);
  font-size: 0.9rem;
  font-weight: 600;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
  z-index: 100;
  opacity: 0;
  pointer-events: none;
  transition: var(--trans);
  backdrop-filter: blur(14px);
}

.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

.hidden {
  display: none !important;
}

/* ==========================================================================
   Responsive Breakpoints
   ========================================================================== */

@media (max-width: 860px) {
  .conversion-grid {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .swap-btn {
    transform: rotate(90deg);
  }

  .swap-btn:hover {
    transform: rotate(90deg) scale(1.08);
  }

  .swap-btn.spinning {
    transform: rotate(270deg) scale(1.1);
  }

  .unit-select {
    max-width: 170px;
  }

  .hidden-mobile {
    display: none;
  }
}

@media (max-width: 600px) {
  .converter-card {
    padding: 20px 16px;
  }

  .all-units-grid {
    grid-template-columns: 1fr;
  }

  .converter-header {
    flex-direction: column;
    align-items: flex-start;
  }

  .footer-inner {
    flex-direction: column;
    align-items: flex-start;
  }

  .footer-links {
    align-items: flex-start;
  }
}