* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: Arial, sans-serif;
}
:root {
  --bg-main: linear-gradient(135deg, #0f172a, #1e3a8a, #06b6d4);
  --card-bg: rgba(255, 255, 255, 0.12);
  --card-border: rgba(255, 255, 255, 0.18);
  --text-main: #f8fafc;
  --text-soft: #cbd5e1;
  --shadow: 0 20px 60px rgba(0, 0, 0, 0.25);
}
body {
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  background: var(--bg-main);
  color: var(--text-main);
  position: relative;
  overflow: hidden;
  padding: 20px;
}
body::before,
body::after {
  content: "";
  position: absolute;
  border-radius: 50%;
  filter: blur(70px);
  z-index: 0;
}
body::before {
  width: 260px;
  height: 260px;
  background: rgba(34, 197, 94, 0.22);
  top: 40px;
  left: 40px;
}
body::after {
  width: 320px;
  height: 320px;
  background: rgba(59, 130, 246, 0.2);
  bottom: 40px;
  right: 40px;
}
.app {
  width: 100%;
  max-width: 580px;
  position: relative;
  z-index: 1;
}
.clock-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  box-shadow: var(--shadow);
  border-radius: 28px;
  padding: 35px 28px;
  text-align: center;
}
.eyebrow {
  font-size: 0.85em;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--text-soft);
  margin-bottom: 18px;
}
.title {
  font-size: 2em;
  margin-bottom: 10px;
}
.subtitle {
  color: var(--text-soft);
  font-size: 1em;
  line-height: 1.6;
  margin-bottom: 28px;
}

.clock-box {
  background: rgba(255, 255, 255, 0.08);
  border-radius: 22px;
  padding: 28px 20px;
  border: 1px solid rgba(255, 255, 255, 0.08);
}
.clock-time {
  font-size: 3.4em;
  font-size: 800;
  letter-spacing: 4px;
  margin-bottom: 14px;
  text-shadow: 0 4px 18px rgba(0, 0, 0, 0.2);
}
.clock-day {
  font-size: 1.25em;
  font-weight: bold;
  color: var(--text-main);
  margin-bottom: 8px;
}
.clock-date {
  font-size: 1em;
  color: var(--text-soft);
}

.theme-toggle {
  position: absolute;
  top: 20px;
  right: 20px;
  z-index: 2;
  border: none;
  border-radius: 14px;
  padding: 12px 16px;
  cursor: pointer;
  font-size: 1em;
  font-weight: bold;
  background: rgba(255, 255, 255, 0.18);
  backdrop-filter: blur(10px);
  transition:
    transform 0.2s ease,
    opacity 0.2s ease;
}
.theme-toggle:hover {
  transform: translateY(-5px);
  opacity: 0.8;
}

/* DARK MODE */
body.dark {
  --bg-main: linear-gradient(135deg, #020617, #111827, #1e293b);
  --card-bg: rgba(15, 23, 42, 0.78);
  --card-border: rgba(255, 255, 255, 0.08);
  --text-main: #f8fafc;
  --text-soft: #cbd5e1;
}

/* RESPONSIVE */
@media (max-width: 600px) {
  .clock-card {
    padding: 26px 18px;
    border-radius: 22px;
  }
  .title {
    font-size: 1.65rem;
  }

  .clock-time {
    font-size: 2.4rem;
    letter-spacing: 2px;
  }

  .clock-day {
    font-size: 1.1rem;
  }

  .clock-date {
    font-size: 0.95rem;
  }
  .theme-toggle {
    top: 14px;
    right: 14px;
    padding: 10px 14px;
  }
}