:root {
  color-scheme: dark;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: #f3f8ff;
  background: #071321;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

* {
  box-sizing: border-box;
}

body {
  min-width: 320px;
  min-height: 100vh;
  margin: 0;
  overflow-x: hidden;
  background:
    radial-gradient(ellipse at 50% 0%, rgb(51 102 153 / 32%), transparent 48rem),
    linear-gradient(160deg, #0b1c2f 0%, #091523 54%, #101a2b 100%);
}

body::before {
  position: fixed;
  inset: 0;
  z-index: 0;
  background:
    radial-gradient(1px 1px at 15% 23%, rgb(255 255 255 / 54%) 50%, transparent 100%),
    radial-gradient(1px 1px at 75% 38%, rgb(255 255 255 / 48%) 50%, transparent 100%),
    radial-gradient(1px 1px at 42% 76%, rgb(255 255 255 / 36%) 50%, transparent 100%);
  content: "";
  pointer-events: none;
}

.page {
  position: relative;
  z-index: 1;
  display: grid;
  min-height: 100vh;
  place-items: center;
  padding: 32px 20px;
}

.card {
  width: min(100%, 620px);
  padding: clamp(32px, 7vw, 64px);
  border: 1px solid rgb(213 232 255 / 15%);
  border-radius: 28px;
  background: linear-gradient(145deg, rgb(20 39 61 / 88%), rgb(12 27 44 / 88%));
  box-shadow: 0 32px 100px rgb(0 0 0 / 28%), inset 0 1px rgb(255 255 255 / 7%);
  text-align: center;
  backdrop-filter: blur(16px);
}

.eyebrow {
  margin: 0 0 18px;
  color: #a9c7e8;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  text-transform: uppercase;
}

h1 {
  margin: 0;
  font-size: clamp(2.6rem, 9vw, 5rem);
  font-weight: 650;
  letter-spacing: -0.07em;
  line-height: 1;
}

.description {
  max-width: 410px;
  margin: 22px auto 30px;
  color: #c1d0e0;
  font-size: 1.05rem;
  line-height: 1.7;
}

.hint {
  margin: 20px 0 0;
  color: #8fa7bf;
  font-size: 0.85rem;
}


.playground {
  margin-top: 22px;
  text-align: left;
}

.playground summary {
  cursor: pointer;
  color: #a9c7e8;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  text-align: center;
}

.playground summary:focus-visible {
  outline: 3px solid #82caff;
  outline-offset: 3px;
}

.playground-hint {
  margin: 14px 0 10px;
  color: #8fa7bf;
  font-size: 0.8rem;
  line-height: 1.5;
}

.playground-hint code {
  color: #c1d0e0;
}

.pg-textarea {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid rgb(220 238 255 / 18%);
  border-radius: 12px;
  background: rgb(4 12 22 / 60%);
  color: #dceeff;
  font-family: ui-monospace, "Cascadia Code", Consolas, monospace;
  font-size: 0.82rem;
  line-height: 1.5;
  resize: vertical;
}

.pg-textarea:focus-visible {
  outline: 3px solid #82caff;
  outline-offset: 2px;
}

.pg-actions {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-top: 10px;
}

.pg-button {
  min-height: 38px;
  padding: 0 18px;
  border: 1px solid rgb(220 238 255 / 30%);
  border-radius: 999px;
  background: #dceeff;
  color: #10243a;
  cursor: pointer;
  font: inherit;
  font-size: 0.85rem;
  font-weight: 700;
}

.pg-button:hover {
  background: #fff;
}

.pg-fps-toggle {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: #8fa7bf;
  font-size: 0.82rem;
  cursor: pointer;
  accent-color: #82caff;
}

.pg-error {
  margin: 10px 0 0;
  color: #ff9d9d;
  font-size: 0.8rem;
}

.fps-overlay {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 1001;
  padding: 4px 10px;
  border-radius: 8px;
  background: rgb(4 12 22 / 70%);
  color: #82caff;
  font-family: ui-monospace, Consolas, monospace;
  font-size: 0.75rem;
  pointer-events: none;
}