/* ==========================================================================
   BioOnSun — shared stylesheet
   ========================================================================== */

:root {
  --color-bg: #f7faf9;
  --color-surface: #ffffff;
  --color-border: #e1e8e6;
  --color-text: #1c2b28;
  --color-text-muted: #5b6b67;
  --color-primary: #0f7a5c;
  --color-primary-dark: #0b5c45;
  --color-primary-light: #e6f4ef;
  --color-accent: #2f9e6f;
  --color-code-bg: #0f1f1b;
  --color-code-text: #d9f2e7;
  --radius: 10px;
  --radius-sm: 6px;
  --shadow: 0 2px 10px rgba(15, 43, 34, 0.06);
  --shadow-md: 0 6px 24px rgba(15, 43, 34, 0.10);
  --max-width: 1080px;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "Pretendard", "Noto Sans KR", Roboto, Helvetica, Arial, sans-serif;
  --font-mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--color-primary); text-decoration: none; }
a:hover { text-decoration: underline; }

img { max-width: 100%; display: block; }

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 20px;
}

/* ---------- Header ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(247, 250, 249, 0.92);
  backdrop-filter: saturate(180%) blur(8px);
  border-bottom: 1px solid var(--color-border);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 800;
  font-size: 1.25rem;
  color: var(--color-text);
  letter-spacing: -0.02em;
}
.brand:hover { text-decoration: none; }
.brand .brand-dot { color: var(--color-primary); }
.brand-logo {
  width: 30px;
  height: 30px;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 15px;
  font-weight: 800;
}

.main-nav {
  display: flex;
  align-items: center;
  gap: 22px;
}

.main-nav a {
  color: var(--color-text-muted);
  font-weight: 600;
  font-size: 0.95rem;
}
.main-nav a:hover,
.main-nav a.active {
  color: var(--color-primary-dark);
  text-decoration: none;
}

.lang-switch {
  display: flex;
  gap: 4px;
  border: 1px solid var(--color-border);
  border-radius: 999px;
  padding: 3px;
  background: var(--color-surface);
}
.lang-switch a {
  padding: 4px 12px;
  border-radius: 999px;
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--color-text-muted);
}
.lang-switch a.active {
  background: var(--color-primary);
  color: #fff;
}
.lang-switch a:hover { text-decoration: none; }

.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  width: 40px;
  height: 40px;
  cursor: pointer;
  font-size: 1.1rem;
}

@media (max-width: 760px) {
  .main-nav {
    position: fixed;
    top: 64px;
    left: 0;
    right: 0;
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    align-items: flex-start;
    padding: 16px 20px;
    gap: 14px;
    display: none;
    box-shadow: var(--shadow-md);
  }
  .main-nav.open { display: flex; }
  .nav-toggle { display: inline-flex; align-items: center; justify-content: center; }
}

/* ---------- Hero ---------- */

.hero {
  padding: 56px 0 40px;
  text-align: center;
}
.hero h1 {
  font-size: clamp(1.7rem, 3.2vw, 2.5rem);
  margin: 0 0 14px;
  letter-spacing: -0.02em;
}
.hero p.lead {
  color: var(--color-text-muted);
  font-size: 1.08rem;
  max-width: 640px;
  margin: 0 auto;
}

.pill {
  display: inline-block;
  background: var(--color-primary-light);
  color: var(--color-primary-dark);
  font-size: 0.78rem;
  font-weight: 700;
  padding: 5px 12px;
  border-radius: 999px;
  margin-bottom: 16px;
  letter-spacing: 0.02em;
}

/* ---------- Tool cards / grid ---------- */

.tool-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 16px;
  margin: 32px 0;
}

.tool-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 22px;
  box-shadow: var(--shadow);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.tool-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}
.tool-card h3 {
  margin: 0;
  font-size: 1.05rem;
  display: flex;
  align-items: center;
  gap: 8px;
}
.tool-card p {
  margin: 0;
  color: var(--color-text-muted);
  font-size: 0.92rem;
}
.tool-card .icon {
  width: 34px; height: 34px;
  border-radius: 8px;
  background: var(--color-primary-light);
  color: var(--color-primary-dark);
  display: inline-flex; align-items: center; justify-content: center;
  font-size: 1rem;
}
.tool-card.disabled {
  opacity: 0.6;
}
.tool-card .badge-soon {
  font-size: 0.7rem;
  font-weight: 700;
  color: var(--color-text-muted);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  padding: 2px 8px;
  border-radius: 999px;
  align-self: flex-start;
}

/* ---------- Sections / prose ---------- */

section { padding: 36px 0; }
section + section { border-top: 1px solid var(--color-border); }

.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 24px;
}

h2 { font-size: 1.4rem; letter-spacing: -0.01em; margin-top: 0; }
h3 { font-size: 1.12rem; }

.prose p { margin: 0 0 14px; color: var(--color-text); }
.prose h2, .prose h3 { margin-top: 28px; }
.prose ul, .prose ol { color: var(--color-text); padding-left: 22px; }
.prose li { margin-bottom: 6px; }

table.iupac {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.92rem;
  margin: 12px 0 20px;
}
table.iupac th, table.iupac td {
  border: 1px solid var(--color-border);
  padding: 8px 10px;
  text-align: center;
}
table.iupac th {
  background: var(--color-primary-light);
  color: var(--color-primary-dark);
}

/* ---------- Tool UI ---------- */

.tool-app {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-md);
  padding: 24px;
}

.mode-tabs {
  display: flex;
  gap: 8px;
  margin-bottom: 16px;
  flex-wrap: wrap;
}
.mode-tab {
  border: 1px solid var(--color-border);
  background: var(--color-bg);
  color: var(--color-text-muted);
  font-weight: 700;
  font-size: 0.88rem;
  padding: 8px 14px;
  border-radius: 999px;
  cursor: pointer;
}
.mode-tab.active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: #fff;
}

label.field-label {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-weight: 700;
  font-size: 0.9rem;
  margin-bottom: 6px;
  color: var(--color-text);
}

textarea.seq-box {
  width: 100%;
  min-height: 160px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
  font-family: var(--font-mono);
  font-size: 0.92rem;
  resize: vertical;
  background: #fbfdfc;
  color: var(--color-text);
}
textarea.seq-box:focus {
  outline: 2px solid var(--color-primary);
  outline-offset: 1px;
}
textarea[readonly] {
  background: var(--color-code-bg);
  color: var(--color-code-text);
}

.btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 14px 0;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-text);
  font-weight: 700;
  font-size: 0.88rem;
  padding: 9px 16px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background 0.12s ease, transform 0.05s ease;
}
.btn:active { transform: translateY(1px); }
.btn:hover { background: var(--color-bg); text-decoration: none; }
.btn-primary {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: #fff;
}
.btn-primary:hover { background: var(--color-primary-dark); }
.btn-ghost { background: transparent; }

.stats-row {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  margin-top: 14px;
  font-size: 0.86rem;
  color: var(--color-text-muted);
}
.stats-row strong { color: var(--color-text); }

.privacy-note {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  background: var(--color-primary-light);
  color: var(--color-primary-dark);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
  font-size: 0.86rem;
  margin-top: 18px;
}

.toast {
  position: fixed;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: var(--color-text);
  color: #fff;
  padding: 10px 18px;
  border-radius: 999px;
  font-size: 0.88rem;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease, transform 0.2s ease;
  z-index: 200;
}
.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ---------- FAQ ---------- */

.faq-item {
  border-bottom: 1px solid var(--color-border);
  padding: 14px 0;
}
.faq-item summary {
  cursor: pointer;
  font-weight: 700;
  list-style: none;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::before {
  content: "+";
  display: inline-block;
  width: 18px;
  color: var(--color-primary);
  font-weight: 800;
}
.faq-item[open] summary::before { content: "\2212"; }
.faq-item p { margin: 10px 0 0 18px; color: var(--color-text-muted); }

/* ---------- Ad slots ---------- */

.ad-slot {
  margin: 28px 0;
  padding: 10px;
  text-align: center;
  border: 1px dashed var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-text-muted);
  font-size: 0.78rem;
  min-height: 90px;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* ---------- Footer ---------- */

.site-footer {
  border-top: 1px solid var(--color-border);
  margin-top: 48px;
  padding: 32px 0 40px;
  color: var(--color-text-muted);
  font-size: 0.88rem;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 24px;
}
.footer-grid h4 {
  color: var(--color-text);
  font-size: 0.85rem;
  margin: 0 0 10px;
}
.footer-grid ul { list-style: none; padding: 0; margin: 0; }
.footer-grid li { margin-bottom: 8px; }
.footer-bottom {
  margin-top: 24px;
  padding-top: 18px;
  border-top: 1px solid var(--color-border);
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
}

.footer-portal-link {
  margin-top: 20px;
  font-size: 0.85rem;
}
.footer-portal-link a { color: var(--color-text-muted); font-weight: 600; }

@media (max-width: 700px) {
  .footer-grid { grid-template-columns: 1fr; }
}

/* ---------- Utility ---------- */

.text-center { text-align: center; }
.mt-0 { margin-top: 0; }
.small { font-size: 0.85rem; color: var(--color-text-muted); }
.updated-note { font-size: 0.82rem; color: var(--color-text-muted); }