/* Reset and Box Model */
*,
*::before,
*::after {
  box-sizing: border-box;
}

:root {
  --ff-primary: 'Lora', serif;
  --ff-secondary: 'Roboto Slab', serif;

  --fw-reg: 400;
  --fw-bold: 700;

  --clr-light: #fff;
  --clr-dark: #303030;
  --clr-accent: #16e0bd;
  --clr-gray: #B0BEC5;

  --fs-h1: 3rem;
  --fs-h2: 2.25rem;
  --fs-h3: 1.25rem;
  --fs-body: 1rem;

  --bs: 0.25em 0.25em 0.75em rgba(0,0,0,.25),
        0.125em 0.125em 0.25em rgba(0,0,0,.15);
}

@media (min-width: 800px) {
  :root {
    --fs-h1: 4.5rem;
    --fs-h2: 3.75rem;
    --fs-h3: 1.5rem;
    --fs-body: 1.125rem;
  }
}

body {
  margin: 0;
  font-family: var(--ff-primary);
  font-size: var(--fs-body);
  background: var(--clr-light);
  color: var(--clr-dark);
  line-height: 1.6;
  padding: 2em;
}

h1 {
  font-size: var(--fs-h1);
  margin: 0 0 0.5em;
  text-align: center;
  font-weight: var(--fw-bold);
}

form,
.tab-content {
  max-width: 600px;
  margin: 0 auto;
  background: var(--clr-light);
  padding: 2em;
  box-shadow: var(--bs);
  border-radius: 8px;
}

label {
  display: block;
  margin-bottom: 0.25em;
  font-weight: var(--fw-bold);
}

input {
  width: 100%;
  padding: 0.5em;
  margin-bottom: 1.5em;
  font-size: 1rem;
  border: 1px solid var(--clr-gray);
  border-radius: 4px;
}

input:focus {
  outline: 3px solid var(--clr-accent);
  outline-offset: 2px;
}

.output {
  text-align: center;
  font-size: 2rem;
  margin-bottom: 1em;
  color: var(--clr-accent);
  font-weight: var(--fw-bold);
  border-bottom: 2px solid var(--clr-accent);
  padding-bottom: 0.5em;
}

/* Header layout */
header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--clr-light);
  flex-wrap: wrap;
  padding: 1em;
}

.header-center-text {
  font-size: 1.25rem;
  font-weight: var(--fw-bold);
  color: var(--clr-dark);
  text-align: center;
  width: 100%;
  order: 3;
  margin-top: 0.5em;
}

/* Mobile-specific overrides */
@media (max-width: 600px) {
  body {
    padding: 1em;
  }

  form {
    padding: 1.5em;
  }

  h1 {
    font-size: 2rem;
  }

  header {
    flex-direction: row;
    justify-content: space-between;
  }

  .logo {
    order: 1;
  }

  .nav-toggle {
    order: 2;
  }

  .header-center-text {
    order: 3;
    margin-top: 0.75em;
    font-size: 1rem;
  }
}

/* Tabs */
.tabs {
  display: flex;
  justify-content: center;
  gap: 1em;
  margin-bottom: 2em;
  flex-wrap: wrap;
}

.tab-button {
  background-color: var(--clr-light);
  border: 2px solid var(--clr-accent);
  color: var(--clr-dark);
  padding: 0.5em 1.5em;
  font-size: 1rem;
  font-family: var(--ff-secondary);
  font-weight: var(--fw-bold);
  cursor: pointer;
  transition: all 0.2s ease-in-out;
  border-radius: 5px;
}

.tab-button:hover {
  background-color: var(--clr-accent);
  color: var(--clr-light);
}

.tab-button.active {
  background-color: var(--clr-accent);
  color: var(--clr-light);
}

.tab-content {
  display: none;
}

.tab-content.active {
  display: block;
}