/* ===== Reset & Base ===== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --color-primary: #2563eb;
  --color-primary-hover: #1d4ed8;
  --color-bg: #f8fafc;
  --color-surface: #ffffff;
  --color-text: #1e293b;
  --color-text-light: #64748b;
  --color-border: #e2e8f0;
  --color-accent: #f59e0b;
  --color-error: #ef4444;
  --color-success: #22c55e;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.06);
  --shadow-lg: 0 4px 12px rgba(0,0,0,0.1);
  --max-width: 1080px;
}

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Noto Sans KR', sans-serif;
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

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

a:hover {
  text-decoration: underline;
}

/* ===== Layout ===== */
.site-header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  padding: 0.75rem 1rem;
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.site-logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text);
}

.site-logo:hover {
  text-decoration: none;
  color: var(--color-primary);
}

.site-nav {
  display: flex;
  gap: 1rem;
  font-size: 0.9rem;
}

.site-nav a {
  color: var(--color-text-light);
}

.site-nav a:hover {
  color: var(--color-primary);
  text-decoration: none;
}

.main-content {
  flex: 1;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1.5rem 1rem;
  width: 100%;
}

.site-footer {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  padding: 1.5rem 1rem;
  text-align: center;
  font-size: 0.85rem;
  color: var(--color-text-light);
  margin-top: auto;
}

/* ===== Ad Slots ===== */
.ad-slot {
  background: var(--color-border);
  min-height: 90px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius);
  margin: 1rem 0;
  font-size: 0.8rem;
  color: var(--color-text-light);
  overflow: hidden;
}

.ad-slot--banner {
  min-height: 90px;
}

.ad-slot--rectangle {
  min-height: 250px;
}

/* ===== Calculator Card (Index Page) ===== */
.calc-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1rem;
  margin-top: 1rem;
}

.calc-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.5rem;
  transition: box-shadow 0.2s, transform 0.2s;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.calc-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

.calc-card__icon {
  font-size: 2rem;
  line-height: 1;
}

.calc-card__title {
  font-size: 1.1rem;
  font-weight: 600;
}

.calc-card__desc {
  font-size: 0.875rem;
  color: var(--color-text-light);
}

.calc-card a {
  color: inherit;
}

.calc-card a:hover {
  text-decoration: none;
}

/* ===== Calculator Page Common ===== */
.calc-container {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 2rem;
  box-shadow: var(--shadow);
}

.calc-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.calc-description {
  color: var(--color-text-light);
  margin-bottom: 1.5rem;
  font-size: 0.95rem;
}

.calc-form {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.form-group label {
  font-size: 0.9rem;
  font-weight: 500;
}

.form-group input,
.form-group select {
  padding: 0.65rem 0.85rem;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  font-size: 1rem;
  color: var(--color-text);
  background: var(--color-surface);
  transition: border-color 0.2s;
}

.form-group input:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

.form-row {
  display: flex;
  gap: 1rem;
}

.form-row .form-group {
  flex: 1;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.7rem 1.5rem;
  border: none;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s, transform 0.1s;
}

.btn:active {
  transform: scale(0.98);
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
}

.btn-primary:hover {
  background: var(--color-primary-hover);
}

.btn-secondary {
  background: var(--color-border);
  color: var(--color-text);
}

.btn-secondary:hover {
  background: #cbd5e1;
}

.btn-group {
  display: flex;
  gap: 0.5rem;
  margin-top: 0.5rem;
}

/* ===== Result ===== */
.result-box {
  background: #f0f9ff;
  border: 1px solid #bae6fd;
  border-radius: var(--radius);
  padding: 1.25rem;
  margin-top: 1rem;
  display: none;
}

.result-box.visible {
  display: block;
}

.result-label {
  font-size: 0.85rem;
  color: var(--color-text-light);
  margin-bottom: 0.25rem;
}

.result-value {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--color-primary);
}

.result-detail {
  font-size: 0.9rem;
  color: var(--color-text-light);
  margin-top: 0.5rem;
}

.result-copy-btn {
  margin-top: 0.75rem;
  font-size: 0.85rem;
  padding: 0.4rem 0.8rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 6px;
  cursor: pointer;
  color: var(--color-text-light);
  transition: background 0.2s;
}

.result-copy-btn:hover {
  background: var(--color-bg);
}

/* ===== Error ===== */
.error-msg {
  color: var(--color-error);
  font-size: 0.85rem;
  display: none;
}

.error-msg.visible {
  display: block;
}

/* ===== Breadcrumb ===== */
.breadcrumb {
  font-size: 0.85rem;
  color: var(--color-text-light);
  margin-bottom: 1rem;
}

.breadcrumb a {
  color: var(--color-text-light);
}

.breadcrumb a:hover {
  color: var(--color-primary);
}

/* ===== Info Section ===== */
.info-section {
  margin-top: 2rem;
  padding: 1.5rem;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.info-section h2 {
  font-size: 1.15rem;
  margin-bottom: 0.75rem;
}

.info-section p {
  font-size: 0.9rem;
  color: var(--color-text-light);
  line-height: 1.7;
  margin-bottom: 0.5rem;
}

/* ===== Content Pages (About, Contact) ===== */
.content-section {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.5rem 2rem;
  margin-bottom: 1rem;
}

.content-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
}

.content-subtitle {
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: 1rem;
}

.content-text {
  font-size: 0.95rem;
  color: var(--color-text-light);
  line-height: 1.8;
  margin-bottom: 0.5rem;
}

.content-card {
  background: var(--color-bg);
  border-radius: 8px;
  padding: 1.25rem;
  margin-bottom: 0.75rem;
}

.content-card:last-child {
  margin-bottom: 0;
}

.content-card__title {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.content-list {
  list-style: none;
  padding: 0;
}

.content-list li {
  position: relative;
  padding-left: 1.25rem;
  font-size: 0.95rem;
  color: var(--color-text);
  line-height: 2;
}

.content-list li::before {
  content: "\2022";
  position: absolute;
  left: 0;
  color: var(--color-primary);
  font-weight: 700;
}

/* Feature Grid */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 1rem;
}

.feature-item {
  background: var(--color-bg);
  border-radius: 8px;
  padding: 1.25rem;
  text-align: center;
}

.feature-item__icon {
  font-size: 2rem;
  margin-bottom: 0.5rem;
}

.feature-item__title {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.feature-item__desc {
  font-size: 0.875rem;
  color: var(--color-text-light);
}

/* Notice Box */
.notice-box {
  background: #fffbeb;
  border: 1px solid #fde68a;
  border-radius: 8px;
  padding: 1.25rem;
}

.notice-box p {
  font-size: 0.95rem;
  color: var(--color-text);
  line-height: 1.8;
  margin: 0;
}

.notice-box p + p {
  margin-top: 0.25rem;
}

/* Contact */
.contact-box {
  background: var(--color-bg);
  border-radius: 8px;
  padding: 1.5rem;
}

.contact-email {
  display: flex;
  align-items: center;
  gap: 1rem;
  margin-bottom: 1rem;
}

.contact-label {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--color-text-light);
  min-width: 60px;
}

.contact-value {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--color-primary);
}

.contact-response {
  font-size: 0.9rem;
  color: var(--color-text-light);
}

/* FAQ */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.faq-item {
  background: var(--color-bg);
  border-radius: 8px;
  padding: 1.25rem;
}

.faq-question {
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 0.5rem;
}

.faq-answer {
  font-size: 0.925rem;
  color: var(--color-text-light);
  line-height: 1.7;
}

@media (max-width: 768px) {
  .content-section {
    padding: 1.25rem;
  }

  .feature-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .form-row {
    flex-direction: column;
  }

  .calc-container {
    padding: 1.25rem;
  }

  .result-value {
    font-size: 1.4rem;
  }

  .site-nav {
    display: none;
  }

  .mobile-menu-btn {
    display: block;
  }

  .mobile-nav.open {
    display: flex;
  }
}

@media (min-width: 1024px) {
  .page-layout {
    display: grid;
    grid-template-columns: 1fr 300px;
    gap: 1.5rem;
    align-items: start;
  }

  .page-sidebar .ad-slot {
    position: sticky;
    top: 80px;
  }
}

/* ===== Mobile Menu ===== */
.mobile-menu-btn {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--color-text);
  padding: 0.25rem;
  line-height: 1;
}

.mobile-nav {
  display: none;
  flex-direction: column;
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  padding: 0.5rem 1rem 1rem;
}

.mobile-nav a {
  padding: 0.5rem 0;
  color: var(--color-text-light);
  font-size: 0.9rem;
  border-bottom: 1px solid var(--color-border);
}

.mobile-nav a:last-child {
  border-bottom: none;
}

.mobile-nav a:hover {
  color: var(--color-primary);
  text-decoration: none;
}

/* ===== Footer Links ===== */
.footer-links {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  margin-bottom: 0.75rem;
  flex-wrap: wrap;
}

.footer-links a {
  color: var(--color-text-light);
  font-size: 0.85rem;
}

.footer-links a:hover {
  color: var(--color-primary);
}

/* ===== Cookie Banner ===== */
.cookie-banner {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  background: var(--color-text);
  color: #fff;
  padding: 1rem 1.5rem;
  z-index: 9999;
  display: none;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  font-size: 0.875rem;
  flex-wrap: wrap;
}

.cookie-banner.visible {
  display: flex;
}

.cookie-banner p {
  margin: 0;
  flex: 1;
  min-width: 200px;
}

.cookie-banner a {
  color: #93c5fd;
}

.cookie-btn {
  background: var(--color-primary);
  color: #fff;
  border: none;
  padding: 0.5rem 1.25rem;
  border-radius: 6px;
  cursor: pointer;
  font-size: 0.875rem;
  font-weight: 600;
  white-space: nowrap;
}

.cookie-btn:hover {
  background: var(--color-primary-hover);
}