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

:root {
  --bg: #2f343c;
  --panel: #3a4048;
  --panel-2: #454c56;
  --field: #505863;

  --text: #f3f4f6;
  --muted: #c6ccd4;

  --border: #606977;

  --accent: #7dd3fc;
  --accent-2: #38bdf8;

  --good: #86efac;
  --warn: #facc15;
  --danger: #f87171;

  --shadow: 0 18px 50px rgba(0, 0, 0, 0.18);
  --radius: 16px;
}

html[data-theme="light"] {
  --bg: #f6f7f9;
  --panel: #ffffff;
  --panel-2: #f1f5f9;
  --field: #ffffff;
  --text: #111827;
  --muted: #5e6b78;
  --border: #dce3eb;
  --accent: #0369a1;
  --accent-2: #0284c7;
  --good: #15803d;
  --warn: #a16207;
  --danger: #b91c1c;
  --shadow: 0 18px 45px rgba(15, 23, 42, 0.08);
}

html {
  scroll-behavior: smooth;
  /* ADDED: Smooth transition for theme changes */
  transition: background-color 0.3s ease, color 0.3s ease;
}

body {
  min-height: 100vh;
  background: var(--bg);
  color: var(--text);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Arial, Helvetica, sans-serif;
  line-height: 1.5;
  padding-top: 74px; /* Prevents content from hiding behind fixed navbar */
  /* ADDED: Smooth transition for body */
  transition: background-color 0.3s ease, color 0.3s ease;
}

button,
input,
select {
  font: inherit;
}

nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 12px 6%;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  /* ADDED: Smooth transition for navbar */
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1rem;
  font-weight: 800;
  letter-spacing: -0.035em;
  color: var(--text);
  min-width: 0;
  text-decoration: none;
  /* ADDED: Smooth transition for logo */
  transition: color 0.3s ease;
}

.logo:hover,
.logo:focus,
.logo:visited {
  color: var(--text);
  text-decoration: none;
}

/* ADDED: Ensures the logo text stays styled properly */
.logo span {
  color: var(--text);
  font-size: 1rem;
  font-weight: 800;
  letter-spacing: -0.035em;
  transition: color 0.3s ease;
}

.logo:hover span {
  color: var(--text);
}

.logo img {
  width: 36px;
  height: 36px;
  object-fit: contain;
  border-radius: 0;
  flex: 0 0 auto;
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  gap: 7px;
  border: 1px solid var(--border);
  background: var(--panel);
  color: var(--text);
  padding: 8px 12px;
  border-radius: 999px;
  cursor: pointer;
  font-size: 0.88rem;
  font-weight: 800;
  transition: border-color 0.18s ease, color 0.18s ease, transform 0.18s ease, background-color 0.3s ease;
  white-space: nowrap;
}

.theme-toggle:hover {
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-1px);
}

.menu-toggle {
  display: none;
  width: 42px;
  height: 42px;
  padding: 10px;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--panel);
  cursor: pointer;
  flex-direction: column;
  align-items: stretch;
  justify-content: center;
  gap: 5px;
  flex: 0 0 auto;
  /* ADDED: Smooth transition */
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

.menu-toggle span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--text);
  border-radius: 999px;
  transition: transform 0.2s ease, opacity 0.2s ease, background-color 0.3s ease;
}

.menu-toggle.active span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.menu-toggle.active span:nth-child(2) {
  opacity: 0;
}

.menu-toggle.active span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.nav-actions {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 8px;
  margin-left: auto;
}

.nav-link,
.dropdown-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  min-height: 38px;
  border: 1px solid var(--border);
  background: var(--panel);
  color: var(--text);
  padding: 8px 12px;
  border-radius: 999px;
  text-decoration: none;
  cursor: pointer;
  font-size: 0.88rem;
  font-weight: 800;
  line-height: 1;
  white-space: nowrap;
  transition: border-color 0.18s ease, color 0.18s ease, transform 0.18s ease, background-color 0.3s ease;
}

.nav-link:hover,
.dropdown-toggle:hover,
.dropdown.open .dropdown-toggle {
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-1px);
}

main {
  padding: 42px 6% 28px;
}

.page-shell {
  width: min(100%, 660px);
}

.hero {
  margin-bottom: 22px;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--accent);
  border: 1px solid var(--border);
  background: var(--panel);
  border-radius: 999px;
  padding: 6px 10px;
  font-size: 0.78rem;
  font-weight: 800;
  margin-bottom: 14px;
  /* ADDED: Smooth transition */
  transition: background-color 0.3s ease, border-color 0.3s ease, color 0.3s ease;
}

h1 {
  max-width: 620px;
  font-size: clamp(2rem, 5vw, 3.65rem);
  line-height: 1.02;
  letter-spacing: -0.065em;
  margin-bottom: 12px;
  /* ADDED: Smooth transition */
  transition: color 0.3s ease;
}

.hero p {
  max-width: 610px;
  color: var(--muted);
  font-size: 0.80rem;
  transition: color 0.3s ease;
}

.calculator {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  margin-bottom: 14px;
  box-shadow: var(--shadow);
  /* ADDED: Smooth transition */
  transition: background-color 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.calc-head {
  display: flex;
  align-items: start;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 12px;
}

.calc-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 27px;
  height: 27px;
  border-radius: 9px;
  background: var(--panel-2);
  border: 1px solid var(--border);
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 900;
  flex: 0 0 auto;
  /* ADDED: Smooth transition */
  transition: background-color 0.3s ease, border-color 0.3s ease, color 0.3s ease;
}

.calc-title-wrap {
  display: flex;
  gap: 10px;
  min-width: 0;
}

.calculator h2 {
  font-size: 1.03rem;
  line-height: 1.18;
  letter-spacing: -0.035em;
  margin-bottom: 4px;
  /* ADDED: Smooth transition */
  transition: color 0.3s ease;
}

.calculator .description {
  color: var(--muted);
  font-size: 0.82rem;
  line-height: 1.4;
  /* ADDED: Smooth transition */
  transition: color 0.3s ease;
}

.grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 9px;
}

.grid.three {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.full {
  grid-column: 1 / -1;
}

label {
  display: block;
  margin-bottom: 4px;
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  /* ADDED: Smooth transition */
  transition: color 0.3s ease;
}

input,
select {
  width: 100%;
  min-height: 38px;
  background: var(--field);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 9px 10px;
  outline: none;
  font-size: 0.9rem;
  transition: border-color 0.15s ease, box-shadow 0.15s ease, background-color 0.3s ease, color 0.3s ease;
}

input:focus,
select:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 18%, transparent);
}

input::placeholder {
  color: color-mix(in srgb, var(--muted) 70%, transparent);
}

.dynamic-list {
  display: grid;
  gap: 8px;
  margin-top: 10px;
}

.row {
  display: grid;
  grid-template-columns: 1.2fr 0.75fr 0.75fr 34px;
  gap: 8px;
  align-items: end;
  padding: 9px;
  background: color-mix(in srgb, var(--panel-2) 64%, transparent);
  border: 1px solid var(--border);
  border-radius: 12px;
  /* ADDED: Smooth transition */
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

.row.two {
  grid-template-columns: 1.2fr 0.85fr 34px;
}

.btns {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 12px;
}

button {
  border: 0;
  cursor: pointer;
  border-radius: 10px;
  padding: 9px 12px;
  font-size: 0.86rem;
  font-weight: 900;
  transition: transform 0.16s ease, background 0.16s ease, border-color 0.16s ease, color 0.16s ease;
}

button:hover {
  transform: translateY(-1px);
}

.primary {
  background: var(--accent);
  color: #061018;
}

.primary:hover {
  background: var(--accent-2);
}

.secondary {
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--border);
}

.secondary:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.remove {
  width: 34px;
  height: 38px;
  padding: 0;
  background: transparent;
  color: var(--muted);
  border: 1px solid var(--border);
  font-size: 1rem;
}

.remove:hover {
  color: var(--danger);
  border-color: color-mix(in srgb, var(--danger) 60%, var(--border));
}

.result {
  margin-top: 12px;
  padding: 12px;
  background: var(--panel-2);
  border: 1px solid var(--border);
  border-radius: 12px;
  color: var(--text);
  white-space: pre-line;
  font-size: 0.86rem;
  line-height: 1.42;
  font-weight: 650;
  min-height: 48px;
  /* ADDED: Smooth transition */
  transition: background-color 0.3s ease, border-color 0.3s ease, color 0.3s ease;
}

.result:empty::before {
  content: "Result will appear here.";
  color: var(--muted);
  font-weight: 600;
}

.content-section {
  width: min(100%, 660px);
  margin-top: 36px;
}

.content-card {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  margin-bottom: 14px;
  box-shadow: var(--shadow);
  /* ADDED: Smooth transition */
  transition: background-color 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

.content-card h2 {
  font-size: 1.18rem;
  letter-spacing: -0.045em;
  margin-bottom: 8px;
  /* ADDED: Smooth transition */
  transition: color 0.3s ease;
}

.content-card p {
  color: var(--muted);
  font-size: 0.92rem;
  /* ADDED: Smooth transition */
  transition: color 0.3s ease;
}

.faq-list {
  display: grid;
  gap: 8px;
}

details {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 13px;
  /* ADDED: Smooth transition */
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

details[open] {
  background: var(--panel-2);
}

summary {
  cursor: pointer;
  font-size: 0.92rem;
  font-weight: 850;
  letter-spacing: -0.02em;
  padding: 13px 14px;
  /* ADDED: Smooth transition */
  transition: color 0.3s ease;
}

details p {
  color: var(--muted);
  font-size: 0.88rem;
  margin-top: 9px;
  padding: 0 14px 13px 14px;
  /* ADDED: Smooth transition */
  transition: color 0.3s ease;
}

footer {
  padding: 24px 6%;
  color: var(--text);
  border-top: 1px solid var(--border);
  font-size: 0.9rem;
  /* ADDED: Smooth transition */
  transition: color 0.3s ease, border-color 0.3s ease, background-color 0.3s ease;
}


footer a {
  color: var(--accent); !important;
  text-decoration: underline; !important;
  transition: color 0.15s;
}

footer a:hover {
  color: var(--accent-2); !important;
  text-decoration: underline; !important;
}


.toast {
  position: fixed;
  left: 50%;
  bottom: 20px;
  transform: translateX(-50%) translateY(20px);
  opacity: 0;
  pointer-events: none;
  background: var(--panel);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 10px 14px;
  font-size: 0.86rem;
  font-weight: 800;
  box-shadow: var(--shadow);
  transition: opacity 0.18s ease, transform 0.18s ease, background-color 0.3s ease, border-color 0.3s ease, color 0.3s ease;
  z-index: 40;
}

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

.mobile-menu-backdrop {
  display: none;
}

@media (max-width: 780px) {
  .mobile-menu-backdrop {
    position: fixed;
    inset: 0;
    z-index: 15;
    display: block;
    background: rgba(0, 0, 0, 0.45);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity 0.2s ease, visibility 0.2s ease;
  }

  .mobile-menu-backdrop.show {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
  }
}

@media (min-width: 1024px) {
  main {
    padding-right: 40%;
  }
}

@media (max-width: 780px) {
  nav {
    padding: 11px 18px;
    gap: 10px;
    flex-wrap: wrap;
    transition: background-color 0.3s ease, border-color 0.3s ease;
  }

  .menu-toggle {
    display: flex;
    margin-left: auto;
  }

  .nav-actions {
    display: none;
    width: 100%;
    margin-left: 0;
    padding: 10px 0;
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
  }

  .nav-actions.open {
    display: flex;
  }

  .nav-actions > .nav-link:not(.all-splitters-link) {
    order: 1;
  }

  .nav-actions > .theme-toggle {
    order: 2;
  }

  .nav-actions > .all-splitters-link {
    order: 3;
  }

  .nav-link,
  .dropdown-toggle,
  .theme-toggle {
    width: 100%;
    min-height: 46px;
    justify-content: space-between;
    border: 0;
    border-radius: 8px;
    padding: 11px 12px;
    background: transparent;
    color: var(--text);
    font-size: 0.9rem;
    text-align: left;
    box-shadow: none;
    transition: background-color 0.3s ease, color 0.3s ease;
  }

  .nav-link:hover,
  .dropdown-toggle:hover,
  .theme-toggle:hover {
    background: var(--panel-2);
    color: var(--accent);
    transform: none;
  }

  .theme-toggle {
    justify-content: flex-start;
  }

  .all-splitters-link::after {
    content: "›";
    margin-left: auto;
    font-size: 1.35rem;
    line-height: 1;
    color: var(--muted);
  }

  main {
    padding: 34px 18px 24px;
  }

  .page-shell,
  .content-section {
    width: 100%;
  }

  h1 {
    font-size: clamp(2rem, 10vw, 3rem);
  }

  .calculator,
  .content-card {
    padding: 15px;
  }

  .grid,
  .grid.three,
  .row,
  .row.two {
    grid-template-columns: 1fr;
  }

  .row {
    padding: 10px;
  }

  .remove {
    width: 100%;
  }

  .btns button {
    flex: 1 1 145px;
  }
}

@media (max-width: 420px) {
  .logo span {
    display: none;
  }

  .logo img {
    width: 34px;
    height: 34px;
  }

  .nav-link,
  .dropdown-toggle,
  .theme-toggle {
    padding: 10px 11px;
    font-size: 0.82rem;
  }

  .theme-toggle {
    gap: 4px;
  }

  .btns button {
    flex: 1 1 100%;
  }
}