:root {
  /* Colors */
  --color-primary-red: hsl(0, 100%, 74%);
  --color-primary-green: hsl(154, 59%, 51%);
  --color-primary-green-hover: hsl(154, 59%, 61%);
  --color-accent-purple: hsl(248, 32%, 49%);
  --color-neutral-dark: hsl(249, 10%, 26%);
  --color-neutral-light: hsl(246, 25%, 77%);
  --color-white: hsl(0, 0%, 100%);

  /* Typography */
  --font-family: 'Poppins', sans-serif;
  --font-size-body: 1rem; /* 16px */
  
  /* Layout Spacing */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.25rem;
  --space-lg: 2.5rem;
  
  /* Component Defaults */
  --border-radius-global: 8px;
  --box-shadow-global: 0 8px 0px rgba(0, 0, 0, 0.15);
}

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

body {
  font-family: var(--font-family);
  font-size: var(--font-size-body);
  color: var(--color-white);
  background-color: var(--color-primary-red);
  background-image: url('./images/bg-intro-mobile.png');
  background-repeat: repeat;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: clamp(var(--space-lg), 5vw, 5rem) var(--space-md);
}

@media (min-width: 48rem) {
  body {
    background-image: url('./images/bg-intro-desktop.png');
  }
}

/* Screen Reader Only Helper (WCAG Best Practice) */
.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;
}

.intro-container {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-lg);
  max-width: 32rem;
  width: 100%;
  margin-block-end: var(--space-lg);
}

@media (min-width: 64rem) {
  .intro-container {
    grid-template-columns: 1fr 1fr;
    max-width: 70rem;
    align-items: center;
    gap: 3rem;
  }
}

.intro-container__hero {
  text-align: center;
}

@media (min-width: 64rem) {
  .intro-container__hero {
    text-align: start;
  }
}

.intro-container__heading {
  font-size: clamp(1.75rem, 5vw, 3.125rem);
  line-height: 1.15;
  font-weight: 700;
  margin-block-end: var(--space-md);
}

.intro-container__description {
  font-size: clamp(0.95rem, 2vw, 1rem);
  font-weight: 500;
  line-height: 1.6;
}

.intro-container__form-wrapper {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

/* Promo Banner Component */
.promo-banner {
  background-color: var(--color-accent-purple);
  padding: var(--space-md) var(--space-lg);
  border-radius: var(--border-radius-global);
  box-shadow: var(--box-shadow-global);
  text-align: center;
}

.promo-banner__text {
  font-weight: 400;
  font-size: 0.9375rem;
  letter-spacing: 0.27px;
  line-height: 1.5;
}

.promo-banner__text strong {
  font-weight: 700;
}

/* SignUp Form  */
.signup-form {
  background-color: var(--color-white);
  padding: clamp(1.25rem, 4vw, 2.5rem);
  border-radius: var(--border-radius-global);
  box-shadow: var(--box-shadow-global);
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.signup-form__field {
  position: relative;
  display: flex;
  flex-direction: column;
}

.signup-form__input {
  width: 100%;
  padding: var(--space-md) var(--space-lg);
  font-family: var(--font-family);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-neutral-dark);
  border: 1px solid var(--color-neutral-light);
  border-radius: 5px;
  outline: none;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.signup-form__input::placeholder {
  color: var(--color-neutral-dark);
  opacity: 0.6;
}

/* Active and Interactive Focus States */
.signup-form__input:focus {
  border-color: var(--color-accent-purple);
  box-shadow: 0 0 0 2px var(--color-neutral-light);
}

/* Error States */
.signup-form__field--error .signup-form__input {
  border-color: var(--color-primary-red);
  color: var(--color-primary-red);
  border-width: 2px;
}

.signup-form__field--error .signup-form__input::placeholder {
  color: transparent; /* Hides original placeholder text during an error state */
}

.signup-form__error-icon {
  display: none;
  position: absolute;
  inline-size: 24px;
  block-size: 24px;
  inset-inline-end: var(--space-md);
  inset-block-start: 17px;
  background-image: url('./images/icon-error.svg');
  background-repeat: no-repeat;
  background-size: contain;
}

.signup-form__field--error .signup-form__error-icon {
  display: block;
}

.signup-form__error-message {
  font-size: 0.6875rem;
  font-weight: 500;
  font-style: italic;
  color: var(--color-primary-red);
  text-align: end;
  margin-block-start: var(--space-xs);
  display: none;
}

.signup-form__field--error .signup-form__error-message {
  display: block;
}

/* Submit Button */
.signup-form__button {
  width: 100%;
  padding: var(--space-md);
  background-color: var(--color-primary-green);
  color: var(--color-white);
  border: none;
  border-bottom: 3px solid hsl(154, 59%, 41%);
  border-radius: 5px;
  font-family: var(--font-family);
  font-size: 0.9375rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 1px;
  cursor: pointer;
  transition: background-color 0.2s ease;
}

.signup-form__button:hover,
.signup-form__button:focus-visible {
  background-color: var(--color-primary-green-hover);
  outline: 2px solid var(--color-accent-purple);
  outline-offset: 2px;
}

/* Footer / Terms Section */
.signup-form__terms {
  font-size: 0.6875rem;
  line-height: 1.6;
  color: var(--color-neutral-light);
  text-align: center;
  font-weight: 500;
}

.signup-form__link {
  color: var(--color-primary-red);
  text-decoration: none;
  font-weight: 700;
}

.signup-form__link:hover {
  text-decoration: underline;
}

/* Atrribution  */
.attribution {
  font-size: 0.6875rem;
  text-align: center;
  color: var(--color-white);
}

.attribution a {
  color: var(--color-neutral-dark);
  font-weight: 700;
}