:root {
  --bg-1: #091220;
  --bg-2: #15253d;
  --surface: #14253f;
  --surface-2: #1b3152;
  --surface-3: #213d66;
  --text: #e9f1ff;
  --muted: #adc0dd;
  --border: #355885;
  --accent: #6ed6ff;
  --accent-2: #73ffbe;
  --danger: #ff9fb0;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Trebuchet MS", "Gill Sans", "Segoe UI", sans-serif;
  background:
    radial-gradient(1000px 360px at 20% -10%, rgba(110, 214, 255, 0.2), transparent 70%),
    radial-gradient(820px 320px at 90% 0%, rgba(115, 255, 190, 0.16), transparent 70%),
    linear-gradient(180deg, var(--bg-2), var(--bg-1));
  color: var(--text);
  line-height: 1.45;
}

.hidden {
  display: none !important;
}

.page-shell {
  width: min(840px, calc(100% - 28px));
  margin: 26px auto;
  display: grid;
  gap: 14px;
}

.back-link {
  width: fit-content;
  text-decoration: none;
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 8px 14px;
  background: linear-gradient(180deg, var(--surface-2), var(--surface));
  font-weight: 600;
  letter-spacing: 0.01em;
  position: relative;
  z-index: 5;
}

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

.feedback-card {
  position: relative;
  border: 1px solid var(--border);
  border-radius: 18px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.02), transparent 28%),
    var(--surface);
  padding: 18px;
  box-shadow: 0 18px 42px rgba(0, 0, 0, 0.34);
  overflow: hidden;
}

h1 {
  margin: 0;
  font-size: 1.5rem;
  letter-spacing: 0.01em;
}

.intro {
  margin: 8px 0 14px;
  color: var(--muted);
  max-width: 66ch;
  font-size: 0.97rem;
}

fieldset {
  border: 0;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 7px;
}

label {
  font-weight: 700;
  font-size: 0.94rem;
  margin-top: 6px;
}

input,
textarea,
button {
  font: inherit;
}

input,
textarea {
  width: 100%;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--surface-2);
  color: var(--text);
  padding: 11px 12px;
}

input::placeholder,
textarea::placeholder {
  color: #86a4cd;
}

textarea {
  min-height: 164px;
  resize: vertical;
}

.field-help {
  margin: 0;
  color: var(--muted);
  font-size: 0.84rem;
}

input:focus,
textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(110, 214, 255, 0.24);
}

button {
  width: fit-content;
  margin-top: 8px;
  border: 1px solid transparent;
  border-radius: 12px;
  padding: 10px 16px;
  color: #042335;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  cursor: pointer;
  font-weight: 700;
  letter-spacing: 0.01em;
  transition: transform 120ms ease, filter 120ms ease;
}

button:hover {
  transform: translateY(-1px);
  filter: brightness(1.04);
}

button:disabled {
  opacity: 0.45;
  filter: grayscale(0.6);
  cursor: not-allowed;
}

.feedback-status {
  min-height: 1.3em;
  margin: 8px 0 0;
  padding: 8px 10px;
  border-radius: 10px;
  color: #d9e8ff;
  font-size: 0.9rem;
  background: rgba(24, 42, 69, 0.72);
  border: 1px solid rgba(70, 105, 149, 0.7);
}

.feedback-status.error {
  background: rgba(95, 28, 46, 0.34);
  border-color: rgba(255, 159, 176, 0.55);
  color: var(--danger);
}

.cooldown-overlay {
  position: absolute;
  inset: 0;
  display: grid;
  place-content: center;
  text-align: center;
  gap: 8px;
  padding: 20px;
  background: rgba(13, 23, 38, 0.82);
  backdrop-filter: blur(3px);
}

.cooldown-overlay .thanks,
.cooldown-overlay .timer {
  margin: 0;
}

.cooldown-overlay .thanks {
  font-size: 1.24rem;
  font-weight: 700;
}

.cooldown-overlay .timer {
  color: var(--muted);
  font-weight: 700;
}

@media (max-width: 640px) {
  .page-shell {
    width: min(100%, calc(100% - 18px));
    margin: 14px auto;
  }

  .feedback-card {
    border-radius: 14px;
    padding: 14px;
  }

  h1 {
    font-size: 1.32rem;
  }

  textarea {
    min-height: 144px;
  }
}