:root {
  --bg: #0f1226;
  --bg-accent: #15193a;
  --card: rgba(255,255,255,0.08);
  --border: rgba(255,255,255,0.18);
  --text: #e8e9f3;
  --muted: #a6a8c9;
  --accent: #7c5cff;   /* primary accent */
  --accent-2: #19c37d; /* equals */
  --danger: #ff5d5d;   /* clear */
  --warning: #ffb020;  /* delete */
  --shadow: 0 10px 20px rgba(0,0,0,0.35), 0 2px 6px rgba(0,0,0,0.2);
}

* { box-sizing: border-box; }

html, body {
  height: 100%;
}

body {
  margin: 0;
  display: grid;
  place-items: center;
  background: radial-gradient(1200px 600px at 10% 10%, #1a1f4b 0%, #0f1226 40%),
              radial-gradient(800px 400px at 90% 90%, #251a4b 0%, #0f1226 40%),
              linear-gradient(180deg, #0f1226 0%, #0a0c1c 100%);
  color: var(--text);
  font: 500 16px/1.4 Inter, Segoe UI, Roboto, Helvetica, Arial, system-ui, -apple-system, sans-serif;
}

#outside-border {
  width: min(92vw, 420px);
  height: auto;
  display: flex;
  flex-direction: column;
  gap: 14px;
  padding: 18px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 18px;
  box-shadow: var(--shadow);
  backdrop-filter: blur(10px);
}

#screen {
  background: linear-gradient(180deg, #1a1f3f 0%, #121530 100%);
  border: 1px solid #2a2f60;
  border-radius: 12px;
  min-height: 110px;
  padding: 14px 16px;
  text-align: right;
  display: flex;
  flex-direction: column;
  justify-content: center;
  color: var(--text);
  box-shadow: inset 0 2px 8px rgba(0,0,0,0.35);
}

#small-screen-text {
  margin: 0 0 4px 0;
  font-size: clamp(12px, 2.5vw, 14px);
  color: var(--muted);
  letter-spacing: 0.4px;
}

#big-screen-text {
  margin: 0;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  font-size: clamp(26px, 6vw, 42px);
}

.button-row {
  display: flex;
  gap: 10px;
}

.button {
  user-select: none;
  -webkit-tap-highlight-color: transparent;
  flex: 1 1 0;
  height: 56px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 14px;
  background: linear-gradient(180deg, #2a2f60 0%, #1a1f4a 100%);
  border: 1px solid #2e3366;
  color: var(--text);
  letter-spacing: 0.2px;
  cursor: pointer;
  transition: transform .08s ease, filter .15s ease, box-shadow .15s ease;
  box-shadow: 0 3px 10px rgba(0,0,0,0.25);
}

.button.operator {
  background: linear-gradient(180deg, #3b2f8f 0%, #2a2373 100%);
  border-color: #4732a5;
}

#equals {
  background: linear-gradient(180deg, #1fbf6d 0%, #199e5a 100%);
  border-color: #1aa163;
}

#clear { background: linear-gradient(180deg, #ff6b6b 0%, #e85050 100%); border-color: #ff6b6b; }
#delete { background: linear-gradient(180deg, #ffb020 0%, #e59a17 100%); border-color: #ffb020; }

.button:hover { filter: brightness(1.06); transform: translateY(-1px); }
.button:active { filter: brightness(0.96); transform: translateY(0); }

.button:focus-visible {
  outline: 3px solid color-mix(in oklab, var(--accent), white 20%);
  outline-offset: 2px;
}

@media (max-width: 380px) {
  .button { height: 52px; }
}
/* --- Decorative background flairs --- */
body { animation: bg-pan 30s ease-in-out infinite alternate; background-size: 120% 120%; }
@keyframes bg-pan { from { background-position: 0% 0%; } to { background-position: 100% 60%; } }

.decor {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}

/* Glowing orbs */
.blob {
  position: absolute;
  width: 45vmax;
  height: 45vmax;
  filter: blur(60px) saturate(120%);
  opacity: 0.35;
  mix-blend-mode: screen;
  will-change: transform;
}

.blob.b1 {
  top: -15vmax; left: -10vmax;
  background: radial-gradient(35% 35% at 30% 30%, #7c5cff 0%, rgba(124,92,255,0.25) 45%, transparent 60%);
  animation: float-1 28s ease-in-out infinite;
}
.blob.b2 {
  bottom: -18vmax; right: -10vmax;
  background: radial-gradient(35% 35% at 70% 50%, #19c37d 0%, rgba(25,195,125,0.25) 45%, transparent 60%);
  animation: float-2 32s ease-in-out infinite;
}
.blob.b3 {
  top: 10vmax; right: -12vmax;
  background: radial-gradient(35% 35% at 60% 30%, #ff7b7b 0%, rgba(255,123,123,0.22) 45%, transparent 60%);
  animation: float-3 36s ease-in-out infinite;
}

@keyframes float-1 { 0% { transform: translate(0,0) rotate(0deg) scale(1); } 50% { transform: translate(6vmax, 2vmax) rotate(15deg) scale(1.05); } 100% { transform: translate(1vmax, -3vmax) rotate(0deg) scale(1.02); } }
@keyframes float-2 { 0% { transform: translate(0,0) rotate(0deg) scale(1); } 50% { transform: translate(-4vmax, -1vmax) rotate(-10deg) scale(1.04); } 100% { transform: translate(-2vmax, 3vmax) rotate(0deg) scale(1.01); } }
@keyframes float-3 { 0% { transform: translate(0,0) rotate(0deg) scale(1); } 50% { transform: translate(-5vmax, 2vmax) rotate(12deg) scale(1.06); } 100% { transform: translate(2vmax, 0vmax) rotate(0deg) scale(1.02); } }

/* Subtle tech grid overlay */
.grid {
  position: absolute;
  inset: -50%;
  background-image: 
    linear-gradient(to right, rgba(255,255,255,0.05) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255,255,255,0.05) 1px, transparent 1px);
  background-size: 40px 40px, 40px 40px;
  transform: rotate(2deg) scale(1.2);
  opacity: 0.09;
  animation: grid-drift 16s ease-in-out infinite alternate;
}
@keyframes grid-drift { from { transform: rotate(2deg) translateY(0) scale(1.2); } to { transform: rotate(2deg) translateY(-1.5%) scale(1.22); } }

/* Ensure card sits above decorations */
#outside-border { position: relative; z-index: 1; }
/* Prevent overflow in the display area */
#small-screen-text, #big-screen-text { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
/* Dynamic font sizing for long numbers */
#big-screen-text { font-size: clamp(28px, 6vw, 42px); }
#big-screen-text.size-medium { font-size: clamp(24px, 5vw, 34px); }
#big-screen-text.size-small { font-size: clamp(20px, 4.5vw, 28px); }
#big-screen-text.size-xsmall { font-size: clamp(16px, 4vw, 24px); }