* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Noto Sans JP", system-ui, sans-serif;
  color: #f8fafc;
  background:
    radial-gradient(circle at 25% 30%, rgba(56, 189, 248, 0.28), transparent 32%),
    radial-gradient(circle at 75% 25%, rgba(236, 72, 153, 0.22), transparent 30%),
    linear-gradient(135deg, #06101f 0%, #10172f 45%, #280d25 100%);
}

.page {
  width: 100%;
  min-height: 100vh;
  padding: 44px 18px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.tool-card {
  width: min(880px, 100%);
  padding: 42px;
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: 24px;
  background:
    linear-gradient(135deg, rgba(255, 255, 255, 0.14), rgba(255, 255, 255, 0.05)),
    rgba(15, 23, 42, 0.72);
  box-shadow: 0 24px 80px rgba(0, 0, 0, 0.42);
  backdrop-filter: blur(18px);
}

.badge {
  width: fit-content;
  margin: 0 auto 14px;
  padding: 7px 14px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 700;
  color: #cbd5e1;
  border: 1px solid rgba(255, 255, 255, 0.18);
  background: rgba(15, 23, 42, 0.48);
}

h1 {
  margin: 0;
  text-align: center;
  font-size: clamp(30px, 5vw, 46px);
  font-weight: 900;
  letter-spacing: 0.02em;
}

.lead {
  max-width: 620px;
  margin: 14px auto 30px;
  text-align: center;
  line-height: 1.8;
  color: #cbd5e1;
  font-size: 15px;
  font-weight: 700;
}

.tabs {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
  margin-bottom: 24px;
}

.tab-button {
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: 999px;
  padding: 12px 10px;
  color: #cbd5e1;
  font-weight: 900;
  background: rgba(15, 23, 42, 0.72);
  cursor: pointer;
}

.tab-button.active {
  color: #ffffff;
  border-color: transparent;
  background: linear-gradient(135deg, #38bdf8, #8b5cf6, #ec4899);
  box-shadow: 0 12px 28px rgba(56, 189, 248, 0.22);
}

.tab-panel {
  display: none;
}

.tab-panel.active {
  display: block;
}

label {
  display: block;
  margin: 16px 0 8px;
  font-size: 13px;
  font-weight: 900;
  color: #dbeafe;
}

input[type="color"] {
  width: 100%;
  height: 58px;
  padding: 6px;
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: 16px;
  background: rgba(2, 6, 23, 0.62);
  cursor: pointer;
}

.text-input,
.result-grid input {
  width: 100%;
  min-height: 48px;
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 14px;
  padding: 0 14px;
  color: #f8fafc;
  font-size: 15px;
  font-weight: 700;
  outline: none;
  background: rgba(2, 6, 23, 0.7);
}

.text-input:focus {
  border-color: rgba(56, 189, 248, 0.7);
  box-shadow: 0 0 0 4px rgba(56, 189, 248, 0.12);
}

.color-preview {
  height: 88px;
  border-radius: 20px;
  margin-bottom: 18px;
  border: 1px solid rgba(255, 255, 255, 0.16);
  background: #38bdf8;
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.08);
}

.result-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
  margin-top: 18px;
}

.result-grid span {
  display: block;
  margin-bottom: 7px;
  color: #94a3b8;
  font-size: 12px;
  font-weight: 900;
}

.main-button {
  display: block;
  min-width: 170px;
  margin: 24px auto 0;
  border: none;
  border-radius: 999px;
  padding: 13px 24px;
  color: #ffffff;
  font-size: 15px;
  font-weight: 900;
  background: linear-gradient(135deg, #38bdf8, #8b5cf6, #ec4899);
  box-shadow: 0 14px 34px rgba(56, 189, 248, 0.24);
  cursor: pointer;
}

.main-button:hover {
  transform: translateY(-1px);
}

.result-box,
.code-box {
  margin-top: 18px;
  padding: 18px;
  border-radius: 18px;
  line-height: 1.8;
  color: #e2e8f0;
  background: rgba(2, 6, 23, 0.74);
  border: 1px solid rgba(255, 255, 255, 0.12);
  white-space: pre-wrap;
}

.two-columns {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

input[type="range"] {
  width: 100%;
  accent-color: #38bdf8;
}

.small-text {
  margin-top: 8px;
  color: #cbd5e1;
  font-size: 13px;
  font-weight: 700;
}

.css-preview {
  margin-top: 20px;
  padding: 30px;
  border-radius: 20px;
  text-align: center;
  line-height: 1.8;
  font-size: 20px;
  font-weight: 900;
  background: #0f172a;
  color: #ffffff;
  border: 1px solid rgba(255, 255, 255, 0.16);
}

.code-box {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 13px;
}

footer {
  margin-top: 34px;
  text-align: center;
  color: #94a3b8;
  font-size: 12px;
  font-weight: 900;
}

footer a {
  color: #c4b5fd;
  text-decoration: none;
}

@media (max-width: 720px) {
  .page {
    padding: 24px 14px;
    align-items: flex-start;
  }

  .tool-card {
    padding: 26px 18px;
    border-radius: 22px;
  }

  .tabs {
    grid-template-columns: 1fr 1fr;
  }

  .result-grid,
  .two-columns {
    grid-template-columns: 1fr;
  }

  .css-preview {
    font-size: 17px;
    padding: 24px 16px;
  }
}@media (max-width: 420px) {
  h1 {
  font-size: 30px;
  line-height: 1.25;
}

  .lead {
    font-size: 15px;
    line-height: 1.9;
  }

  .tab-button {
    font-size: 14px;
    padding: 13px 8px;
  }

  .color-preview {
    height: 76px;
  }
}


/* 無料バッジ */
.badge-free-pill {
  display: inline-flex;
  align-items: center;
  background: #1D9E75;
  color: #E1F5EE;
  font-size: 10px;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 999px;
  letter-spacing: 0.04em;
}

.badge-free-outline {
  display: inline-flex;
  align-items: center;
  background: transparent;
  color: #1D9E75;
  font-size: 11px;
  font-weight: 500;
  padding: 2px 7px;
  border-radius: 4px;
  border: 1.5px solid #1D9E75;
  letter-spacing: 0.03em;
}