:root {
  --bg-top: #0f1419;
  --bg-bottom: #1a1f2e;
  --card: rgba(26, 31, 46, 0.9);
  --text: #ffffff;
  --muted: #b0b8c1;
  --accent: #00d4ff;
  --accent-strong: #00a8cc;
  --border: #2a3142;
  --success: #00d4ff;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100svh;
  font-family: "Space Grotesk", "Avenir Next", "Segoe UI", sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at 20% 0%, rgba(0, 212, 255, 0.08), transparent 35%),
    radial-gradient(circle at 90% 100%, rgba(0, 212, 255, 0.06), transparent 32%),
    linear-gradient(170deg, var(--bg-top), var(--bg-bottom));
}

.app-shell {
  width: min(680px, 100%);
  margin: 0 auto;
  padding: 18px 14px 28px;
  display: grid;
  gap: 14px;
}

.hero {
  border-radius: 20px;
  padding: 22px;
  background: linear-gradient(125deg, #1a1f2e 0%, #0f1419 100%);
  border: 1px solid rgba(0, 212, 255, 0.15);
  color: #fff;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
  animation: fade-slide 500ms ease-out;
}

.eyebrow {
  margin: 0;
  font-size: 0.8rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: #00d4ff;
}

h1 {
  margin: 10px 0 8px;
  line-height: 1.06;
  font-size: clamp(1.65rem, 4.8vw, 2.3rem);
}

.subtitle {
  margin: 0;
  color: #b0b8c1;
}

.card {
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 18px;
  background: var(--card);
  backdrop-filter: blur(3px);
  box-shadow: 0 8px 18px rgba(0, 0, 0, 0.3);
  animation: fade-slide 650ms ease-out both;
}

.card:nth-of-type(2) {
  animation-delay: 100ms;
}

h2 {
  margin: 0 0 12px;
  font-size: 1.2rem;
}

label {
  display: block;
  margin-top: 10px;
  margin-bottom: 7px;
  font-weight: 500;
}

input,
button {
  width: 100%;
  border-radius: 12px;
  font: inherit;
}

input {
  border: 1px solid rgba(0, 212, 255, 0.2);
  padding: 12px;
  background: rgba(255, 255, 255, 0.08);
  color: #ffffff;
}

input[type="date"] {
  display: block;
  min-width: 0;
  max-width: 100%;
  appearance: none;
  -webkit-appearance: none;
}

input::placeholder {
  color: #b0b8c1;
}

input:focus-visible,
button:focus-visible {
  outline: 3px solid rgba(0, 212, 255, 0.5);
  outline-offset: 1px;
}

button {
  margin-top: 14px;
  border: 0;
  background: linear-gradient(140deg, #00d4ff 0%, #00a8cc 100%);
  color: #1a1f2e;
  font-weight: 700;
  padding: 12px;
  cursor: pointer;
  transition: transform 170ms ease, box-shadow 170ms ease;
}

button:active {
  transform: translateY(1px);
}

button:hover {
  box-shadow: 0 9px 20px rgba(0, 212, 255, 0.4);
  transform: translateY(-1px);
}

.message {
  min-height: 1.4em;
  margin: 10px 0 0;
  color: var(--success);
  font-weight: 500;
}

.attendance-summary {
  min-height: 1.4em;
  margin: 14px 0 0;
  color: var(--muted);
}

.people-list {
  margin: 14px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 8px;
}

.people-list li {
  border: 1px solid rgba(0, 212, 255, 0.1);
  border-radius: 11px;
  background: rgba(255, 255, 255, 0.05);
  padding: 10px 12px;
  color: #ffffff;
}

.people-list li.empty {
  border-style: dashed;
  color: #1a1f2e;
  background: rgba(255, 255, 255, 0.6);
}

@media (min-width: 740px) {
  .app-shell {
    padding: 30px 20px 36px;
    gap: 18px;
  }

  .card {
    padding: 22px;
  }
}

@keyframes fade-slide {
  from {
    opacity: 0;
    transform: translateY(12px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}