/* These color variables keep the party palette consistent across the page. */
:root {
  --bg-deep: #111827;
  --bg-warm: #ff5f6d;
  --bg-gold: #ffd166;
  --panel-light: rgba(255, 248, 240, 0.9);
  --panel-dark: rgba(17, 24, 39, 0.72);
  --text-light: #fff8f0;
  --text-dark: #172033;
  --accent-coral: #ff5f6d;
  --accent-teal: #1fb7a6;
  --accent-yellow: #ffd166;
  --accent-pink: #ff4fa3;
  --border-bright: rgba(255, 255, 255, 0.3);
  --shadow-strong: 0 20px 45px rgba(12, 18, 32, 0.35);
}

/* This makes sizing predictable, which helps layouts stay stable. */
*,
*::before,
*::after {
  box-sizing: border-box;
}

/* The page background mixes a party photo with warm overlays for energy. */
body {
  margin: 0;
  min-height: 100vh;
  font-family: "Trebuchet MS", "Helvetica Neue", Arial, sans-serif;
  color: var(--text-light);
  background-color: var(--bg-deep);
  background-image:
    linear-gradient(rgba(17, 24, 39, 0.55), rgba(17, 24, 39, 0.82)),
    url("https://images.unsplash.com/photo-1493225457124-a3eb161ffa5f?auto=format&fit=crop&w=1400&q=80");
  background-position: center;
  background-repeat: no-repeat;
  background-size: cover;
}

/* This adds a colorful confetti-like layer without getting in the way. */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image:
    repeating-linear-gradient(
      115deg,
      rgba(255, 209, 102, 0.18) 0 12px,
      transparent 12px 42px
    ),
    repeating-linear-gradient(
      55deg,
      rgba(31, 183, 166, 0.14) 0 10px,
      transparent 10px 34px
    );
  mix-blend-mode: screen;
}

/* This swaps in the celebration GIF when the guest says they are attending. */
body.attending-background {
  background-image:
    linear-gradient(rgba(17, 24, 39, 0.45), rgba(17, 24, 39, 0.65)),
    url("https://media.giphy.com/media/l2JHPB58MjfV8W3K0/giphy.gif");
  background-position: center;
  background-repeat: no-repeat;
  background-size: cover;
}

/* This swaps in a different GIF when the guest cannot attend. */
body.not-attending-background {
  background-image:
    linear-gradient(rgba(17, 24, 39, 0.45), rgba(17, 24, 39, 0.65)),
    url("https://media.giphy.com/media/JER2en0ZRiGUE/giphy.gif");
  background-position: center;
  background-repeat: no-repeat;
  background-size: cover;
}

/* This centers the invitation and gives it room to breathe on every screen. */
main {
  position: relative;
  z-index: 1;
  width: min(100%, 1200px);
  margin: 0 auto;
  padding: 24px;
}

/* This is the main content shell that holds the event details and the form. */
.invite {
  display: grid;
  gap: 24px;
  align-items: stretch;
  min-height: calc(100vh - 48px);
}

/* The header area gets a dark glass effect so bright text stays readable. */
.invite-header {
  padding: 28px;
  border: 1px solid var(--border-bright);
  border-radius: 8px;
  background:
    linear-gradient(160deg, rgba(255, 95, 109, 0.28), rgba(17, 24, 39, 0.75)),
    var(--panel-dark);
  box-shadow: var(--shadow-strong);
}

/* This small label acts like a fun event tag above the main headline. */
.eyebrow {
  display: inline-block;
  margin: 0 0 16px;
  padding: 8px 14px;
  border-radius: 999px;
  background-color: rgba(255, 209, 102, 0.95);
  color: var(--text-dark);
  font-size: 0.95rem;
  font-weight: 700;
}

/* The headline is bold and celebratory, but sized to stay readable on phones. */
h1 {
  margin: 0;
  font-size: 2.5rem;
  line-height: 1.05;
}

/* The date stands out as a quick visual anchor. */
.event-date {
  margin: 18px 0 14px;
  color: var(--accent-yellow);
  font-size: 1.15rem;
  font-weight: 700;
}

/* This paragraph explains the vibe of the event in a comfortable reading width. */
.invite-description {
  max-width: 34rem;
  margin: 0;
  font-size: 1.05rem;
  line-height: 1.7;
}

/* The RSVP block uses a lighter panel so the form feels easy to use. */
.rsvp-section {
  align-self: center;
  padding: 28px;
  border-radius: 8px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.96), rgba(255, 241, 229, 0.92));
  color: var(--text-dark);
  box-shadow: var(--shadow-strong);
}

/* This keeps the RSVP title simple and easy to spot. */
.rsvp-section h2 {
  margin: 0 0 20px;
  font-size: 1.9rem;
}

/* This stacks form fields with even spacing. */
#rsvp-form {
  display: grid;
  gap: 18px;
}

/* Each form group keeps its label and control together. */
.form-group {
  display: grid;
  gap: 8px;
}

/* Labels are slightly bold so guests can scan the form quickly. */
label {
  font-weight: 700;
}

/* Inputs and dropdowns are large enough for touch screens and desktops. */
input,
select,
button {
  width: 100%;
  font: inherit;
}

/* Form controls use clear contrast, roomy padding, and a stable height. */
input,
select {
  min-height: 52px;
  padding: 14px 16px;
  border: 2px solid rgba(23, 32, 51, 0.12);
  border-radius: 8px;
  background-color: rgba(255, 255, 255, 0.95);
  color: var(--text-dark);
  transition: border-color 180ms ease, box-shadow 180ms ease, transform 180ms ease;
}

/* Focus styles help keyboard users and make the page feel polished. */
input:focus,
select:focus {
  outline: none;
  border-color: var(--accent-teal);
  box-shadow: 0 0 0 4px rgba(31, 183, 166, 0.2);
  transform: translateY(-1px);
}

/* The button uses bright colors to feel festive and clickable. */
button {
  min-height: 56px;
  padding: 14px 18px;
  border: none;
  border-radius: 8px;
  background:
    linear-gradient(135deg, var(--accent-coral), var(--accent-pink));
  color: var(--text-light);
  font-size: 1rem;
  font-weight: 800;
  cursor: pointer;
  box-shadow: 0 14px 24px rgba(255, 79, 163, 0.28);
  transition: transform 180ms ease, box-shadow 180ms ease, filter 180ms ease;
}

/* Hover and focus states give the button a little motion and feedback. */
button:hover,
button:focus-visible {
  transform: translateY(-2px);
  box-shadow: 0 18px 28px rgba(255, 79, 163, 0.34);
  filter: saturate(1.08);
}

/* A gentle pressed state keeps the interaction feeling responsive. */
button:active {
  transform: translateY(0);
}

/* This message area appears only after JavaScript adds text to it. */
.confirmation-message {
  margin-top: 18px;
  padding: 14px 16px;
  border-left: 6px solid var(--accent-teal);
  border-radius: 8px;
  background-color: rgba(31, 183, 166, 0.12);
  font-weight: 700;
  line-height: 1.5;
}

/* When the message box is empty, it stays hidden from view. */
.confirmation-message:empty {
  display: none;
}

/* Tablet and desktop screens get a side-by-side layout for more drama. */
@media (min-width: 820px) {
  .invite {
    grid-template-columns: minmax(0, 1.25fr) minmax(340px, 0.9fr);
    gap: 28px;
  }

  .invite-header,
  .rsvp-section {
    padding: 40px;
  }
}

/* Smaller screens get tighter spacing and a slightly smaller headline. */
@media (max-width: 819px) {
  h1 {
    font-size: 2rem;
  }
}

/* Very small phones need extra padding control so nothing feels cramped. */
@media (max-width: 540px) {
  main {
    padding: 16px;
  }

  .invite {
    min-height: auto;
    gap: 18px;
  }

  .invite-header,
  .rsvp-section {
    padding: 22px;
  }

  h1 {
    font-size: 1.7rem;
  }

  .invite-description {
    font-size: 1rem;
  }
}