* {
  box-sizing: border-box;
}

:root {
  color-scheme: light;
}

body {
  --bg: #f3f5f9;
  --card-bg: #ffffff;
  --text: #141b2d;
  --muted-text: #4a556f;
  --line: #dde3ef;
  --input-bg: #ffffff;
  --input-border: #c8d1e3;
  --button-bg: #1a56db;
  --button-hover-bg: #1848b8;
  --button-text: #ffffff;
  --shadow: 0 12px 28px rgba(20, 27, 45, 0.1);

  margin: 0;
  font-family: "Noto Sans KR", "Apple SD Gothic Neo", "Malgun Gothic", sans-serif;
  background: linear-gradient(180deg, #f8f9fc 0%, var(--bg) 30%, var(--bg) 100%);
  color: var(--text);
  line-height: 1.65;
  transition: background-color 0.2s ease, color 0.2s ease;
}

body[data-theme='dark'] {
  --bg: #0f1728;
  --card-bg: #1b2437;
  --text: #f3f6ff;
  --muted-text: #c0cae0;
  --line: #32415e;
  --input-bg: #101a2c;
  --input-border: #3d4f72;
  --button-bg: #3f7dff;
  --button-hover-bg: #3568d4;
  --button-text: #ffffff;
  --shadow: 0 14px 28px rgba(0, 0, 0, 0.35);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: color-mix(in srgb, var(--card-bg) 88%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}

.site-header-inner {
  max-width: 980px;
  margin: 0 auto;
  padding: 12px 20px;
  display: flex;
  align-items: center;
  gap: 16px;
}

.brand {
  text-decoration: none;
  font-weight: 800;
  color: var(--text);
  font-size: 1.05rem;
}

.site-nav {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  margin-left: auto;
}

.site-nav a {
  text-decoration: none;
  color: var(--muted-text);
  font-weight: 600;
}

.site-nav a[aria-current='page'] {
  color: var(--text);
}

.theme-toggle {
  margin-left: 4px;
}

.page {
  max-width: 980px;
  margin: 28px auto;
  padding: 0 20px 24px;
  display: grid;
  gap: 22px;
}

.card {
  background: var(--card-bg);
  border: 1px solid var(--line);
  border-radius: 14px;
  box-shadow: var(--shadow);
  padding: 22px;
}

.hero h1 {
  margin: 0 0 10px;
  line-height: 1.25;
}

.updated {
  margin-top: 12px;
  color: var(--muted-text);
  font-size: 0.95rem;
}

.tool-row {
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
}

.primary-button,
.theme-toggle {
  padding: 11px 16px;
  border: 0;
  border-radius: 10px;
  background: var(--button-bg);
  color: var(--button-text);
  font-weight: 700;
  cursor: pointer;
}

.primary-button:hover,
.theme-toggle:hover {
  background: var(--button-hover-bg);
}

.result {
  min-height: 30px;
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: 1px;
}

.note {
  margin-top: 10px;
  color: var(--muted-text);
  font-size: 0.95rem;
}

h1,
h2,
h3 {
  margin-top: 0;
}

h2 {
  margin-bottom: 10px;
}

article + article {
  margin-top: 14px;
}

.checklist {
  margin: 0;
  padding-left: 20px;
}

.checklist li + li {
  margin-top: 8px;
}

.inquiry-form {
  display: grid;
  gap: 9px;
}

.inquiry-form label {
  font-weight: 700;
  font-size: 0.95rem;
}

.inquiry-form input,
.inquiry-form textarea {
  width: 100%;
  border: 1px solid var(--input-border);
  border-radius: 10px;
  padding: 10px 12px;
  background: var(--input-bg);
  color: var(--text);
  font: inherit;
}

.inquiry-form input:focus,
.inquiry-form textarea:focus {
  outline: 2px solid var(--button-bg);
  outline-offset: 1px;
}

.comments-section {
  overflow: hidden;
}

.legal-content p,
.legal-content li {
  color: var(--text);
}

.site-footer {
  border-top: 1px solid var(--line);
  margin-top: 30px;
  padding: 20px;
}

.site-footer-inner {
  max-width: 980px;
  margin: 0 auto;
  color: var(--muted-text);
}

.site-footer p {
  margin: 0;
}

.site-footer p + p {
  margin-top: 6px;
}

@media (max-width: 720px) {
  .site-header-inner {
    align-items: flex-start;
    flex-direction: column;
  }

  .site-nav {
    margin-left: 0;
  }

  .theme-toggle {
    margin-left: 0;
  }

  .card {
    padding: 18px;
  }
}