@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;700&display=swap');

:root {
  /* Color System */
  --color-primary: #0064e0;
  --color-primary-deep: #0457cb;
  --color-primary-soft: rgba(0, 100, 224, 0.08);
  --color-fb-blue: #1876f2;
  --color-success: #31a24c;
  --color-success-bg: rgba(49, 162, 76, 0.1);
  --color-warning: #f7b928;
  --color-warning-bg: rgba(247, 185, 40, 0.1);
  --color-critical: #e41e3f;
  --color-critical-strong: #f0284a;
  --color-critical-bg: rgba(228, 30, 63, 0.08);
  --color-canvas: #ffffff;
  --color-surface-soft: #f1f4f7;
  --color-ink-deep: #0a1317;
  --color-ink: #1c1e21;
  --color-charcoal: #444950;
  --color-slate: #4b4c4f;
  --color-steel: #5d6c7b;
  --color-stone: #8595a4;
  --color-hairline: #ced0d4;
  --color-hairline-soft: #dee3e9;
  --color-disabled-text: #bcc0c4;
  --color-ink-button: #000000;
  --color-on-ink-button: #ffffff;

  /* Typography Scale */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;

  /* Border Radius */
  --rounded-xs: 2px;
  --rounded-sm: 4px;
  --rounded-md: 6px;
  --rounded-lg: 8px;
  --rounded-xl: 16px;
  --rounded-xxl: 24px;
  --rounded-xxxl: 32px;
  --rounded-feature: 40px;
  --rounded-full: 100px;
  --rounded-circle: 50%;

  /* Spacing */
  --space-xxs: 4px;
  --space-xs: 8px;
  --space-sm: 10px;
  --space-md: 12px;
  --space-base: 16px;
  --space-lg: 20px;
  --space-xl: 24px;
  --space-xxl: 32px;
  --space-xxxl: 40px;
  --space-section-sm: 48px;
  --space-section: 64px;
  --space-section-lg: 80px;
  --space-hero: 120px;

  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.1, 0.9, 0.2, 1);
  --transition-normal: 250ms cubic-bezier(0.1, 0.9, 0.2, 1);
}

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

body {
  font-family: var(--font-family);
  background-color: var(--color-canvas);
  color: var(--color-ink);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  line-height: 1.5;
  letter-spacing: -0.16px;
}

/* Scrollbar styling */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}
::-webkit-scrollbar-track {
  background: var(--color-surface-soft);
}
::-webkit-scrollbar-thumb {
  background: var(--color-hairline);
  border-radius: var(--rounded-full);
}
::-webkit-scrollbar-thumb:hover {
  background: var(--color-stone);
}

/* Typography Utility Classes */
h1, h2, h3, h4, h5, h6 {
  font-weight: 500;
  color: var(--color-ink-deep);
  letter-spacing: -0.02em;
}

.hero-display {
  font-size: clamp(36px, 5vw, 64px);
  font-weight: 500;
  line-height: 1.16;
}

.display-lg {
  font-size: clamp(28px, 4vw, 48px);
  font-weight: 500;
  line-height: 1.17;
}

.heading-lg {
  font-size: 36px;
  font-weight: 500;
  line-height: 1.28;
}

.heading-md {
  font-size: 28px;
  font-weight: 300;
  line-height: 1.21;
}

.heading-sm {
  font-size: 24px;
  font-weight: 500;
  line-height: 1.25;
}

.subtitle-lg {
  font-size: 18px;
  font-weight: 700;
  line-height: 1.44;
}

.subtitle-md {
  font-size: 18px;
  font-weight: 400;
  line-height: 1.44;
}

.body-md {
  font-size: 16px;
  font-weight: 400;
  line-height: 1.50;
  letter-spacing: -0.16px;
}

.body-md-bold {
  font-size: 16px;
  font-weight: 700;
  line-height: 1.50;
  letter-spacing: -0.16px;
}

.body-sm {
  font-size: 14px;
  font-weight: 400;
  line-height: 1.43;
  letter-spacing: -0.14px;
  color: var(--color-steel);
}

.body-sm-bold {
  font-size: 14px;
  font-weight: 700;
  line-height: 1.43;
  letter-spacing: -0.14px;
}

.caption {
  font-size: 12px;
  font-weight: 400;
  line-height: 1.33;
  color: var(--color-stone);
}

.caption-bold {
  font-size: 12px;
  font-weight: 700;
  line-height: 1.33;
}

/* Layout Elements */
.header-promo {
  background-color: var(--color-ink-deep);
  color: var(--color-canvas);
  font-size: 14px;
  font-weight: 700;
  text-align: center;
  padding: var(--space-md) var(--space-xl);
  letter-spacing: -0.14px;
}

.header-promo a {
  color: var(--color-warning);
  text-decoration: none;
  margin-left: var(--space-xs);
  border-bottom: 1px solid currentColor;
  transition: opacity var(--transition-fast);
}

.header-promo a:hover {
  opacity: 0.8;
}

.header-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  height: 64px;
  border-bottom: 1px solid var(--color-hairline-soft);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-xxl);
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  text-decoration: none;
  font-size: 20px;
  font-weight: 700;
  color: var(--color-ink-deep);
}

.nav-logo-icon {
  width: 28px;
  height: 28px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-fb-blue));
  border-radius: var(--rounded-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 700;
  font-size: 16px;
}

.nav-menu {
  display: flex;
  gap: var(--space-sm);
  align-items: center;
}

.nav-menu-title {
  font-size: 12px;
  font-weight: 700;
  color: var(--color-steel);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-right: var(--space-xs);
}

.nav-item {
  background-color: var(--color-canvas);
  color: var(--color-ink);
  font-size: 14px;
  font-weight: 700;
  text-decoration: none;
  padding: 8px 16px;
  border-radius: var(--rounded-full);
  border: 1px solid var(--color-hairline);
  transition: all var(--transition-fast);
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.nav-item:hover {
  background-color: var(--color-surface-soft);
  border-color: var(--color-steel);
}

.nav-item.active {
  background-color: var(--color-ink-deep);
  color: var(--color-canvas);
  border-color: var(--color-ink-deep);
}

.nav-item img {
  width: 16px;
  height: 16px;
  border-radius: var(--rounded-circle);
}

/* Page Container */
.container {
  max-width: 1280px;
  margin: 0 auto;
  padding: var(--space-section) var(--space-xxl);
}

/* Hero Section */
.hero-section {
  text-align: center;
  margin-bottom: var(--space-section-lg);
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
}

.hero-subtitle {
  color: var(--color-steel);
  margin-top: var(--space-md);
  margin-bottom: var(--space-xl);
}

/* Main Grid Layout */
.main-grid {
  display: grid;
  grid-template-columns: 3fr 2fr;
  gap: var(--space-xxl);
  align-items: start;
}

@media (max-width: 1024px) {
  .main-grid {
    grid-template-columns: 1fr;
  }
}

/* Card Styles */
.card {
  background-color: var(--color-canvas);
  border-radius: var(--rounded-xxxl);
  border: 1px solid var(--color-hairline-soft);
  padding: var(--space-xxl);
  box-shadow: none;
  position: relative;
  overflow: hidden;
}

.card-title {
  margin-bottom: var(--space-xs);
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

.card-subtitle {
  color: var(--color-steel);
  margin-bottom: var(--space-xl);
}

/* Form Styles */
.form-group {
  margin-bottom: var(--space-xl);
}

.form-label {
  display: block;
  font-size: 14px;
  font-weight: 700;
  color: var(--color-ink-deep);
  margin-bottom: var(--space-xs);
}

.input-container {
  position: relative;
  display: flex;
  align-items: center;
}

.text-input {
  width: 100%;
  height: 48px;
  padding: 0 var(--space-base);
  font-family: var(--font-family);
  font-size: 16px;
  color: var(--color-ink);
  background-color: var(--color-canvas);
  border: 1px solid var(--color-hairline);
  border-radius: var(--rounded-lg);
  outline: none;
  transition: all var(--transition-fast);
}

.text-input:focus {
  border: 2px solid var(--color-fb-blue);
  padding: 0 calc(var(--space-base) - 1px);
}

.text-input.error {
  border: 1px solid var(--color-critical-strong);
  background-color: rgba(240, 40, 74, 0.02);
}

.input-prefix {
  position: absolute;
  left: var(--space-base);
  color: var(--color-stone);
  font-weight: 500;
  pointer-events: none;
  user-select: none;
}

.text-input.has-prefix {
  padding-left: 90px; /* Adjust according to "jbinx.kr/" size */
}

.input-helper {
  font-size: 12px;
  color: var(--color-stone);
  margin-top: var(--space-xs);
}

.input-error-msg {
  font-size: 13px;
  color: var(--color-critical-strong);
  margin-top: var(--space-xs);
  display: none;
}

/* Preview Area */
.preview-box {
  background-color: var(--color-surface-soft);
  border-radius: var(--rounded-xl);
  padding: var(--space-lg);
  margin-bottom: var(--space-xl);
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.preview-label {
  font-size: 12px;
  font-weight: 700;
  color: var(--color-steel);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.preview-value {
  font-size: 18px;
  font-weight: 700;
  color: var(--color-primary);
  word-break: break-all;
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

.preview-placeholder {
  color: var(--color-stone);
  font-weight: 400;
}

/* Button Styles */
.button-primary {
  background-color: var(--color-ink-button);
  color: var(--color-on-ink-button);
  font-family: var(--font-family);
  font-size: 14px;
  font-weight: 700;
  padding: 14px 30px;
  border-radius: var(--rounded-full);
  border: none;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-xs);
  width: 100%;
  transition: background-color var(--transition-fast);
}

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

.button-primary:active {
  background-color: #333333;
}

.button-primary:disabled {
  background-color: var(--color-disabled-text);
  color: var(--color-canvas);
  cursor: not-allowed;
}

.button-buy-cta {
  background-color: var(--color-primary);
  color: white;
  font-family: var(--font-family);
  font-size: 14px;
  font-weight: 700;
  padding: 14px 30px;
  border-radius: var(--rounded-full);
  border: none;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-xs);
  width: 100%;
  transition: background-color var(--transition-fast);
}

.button-buy-cta:hover {
  background-color: var(--color-primary-deep);
}

.button-buy-cta:active {
  background-color: #0246a4;
}

.button-buy-cta:disabled {
  background-color: var(--color-disabled-text);
  color: var(--color-canvas);
  cursor: not-allowed;
}

.button-secondary {
  background-color: transparent;
  color: var(--color-ink-deep);
  font-family: var(--font-family);
  font-size: 14px;
  font-weight: 700;
  padding: 12px 28px;
  border-radius: var(--rounded-full);
  border: 2px solid var(--color-ink-deep);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-xs);
  transition: all var(--transition-fast);
}

.button-secondary:hover {
  background-color: var(--color-surface-soft);
}

.button-secondary:active {
  background-color: var(--color-hairline-soft);
}

/* Badges */
.badge {
  display: inline-flex;
  align-items: center;
  font-size: 12px;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: var(--rounded-full);
  letter-spacing: -0.01em;
}

.badge-yellow {
  background-color: var(--color-warning-bg);
  color: #c98a00;
  border: 1px solid rgba(247, 185, 40, 0.3);
}

.badge-success {
  background-color: var(--color-success-bg);
  color: var(--color-success);
  border: 1px solid rgba(49, 162, 76, 0.3);
}

.badge-critical {
  background-color: var(--color-critical-bg);
  color: var(--color-critical-strong);
  border: 1px solid rgba(240, 40, 74, 0.2);
}

/* Recent Links List */
.links-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-base);
}

.link-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-base);
  background-color: var(--color-canvas);
  border: 1px solid var(--color-hairline-soft);
  border-radius: var(--rounded-xl);
  transition: border-color var(--transition-fast);
}

.link-item:hover {
  border-color: var(--color-hairline);
}

.link-info {
  display: flex;
  flex-direction: column;
  gap: 2px;
  overflow: hidden;
  padding-right: var(--space-base);
}

.link-short {
  font-size: 16px;
  font-weight: 700;
  color: var(--color-ink-deep);
  text-decoration: none;
  word-break: break-all;
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
}

.link-short:hover {
  color: var(--color-primary);
}

.link-dest {
  font-size: 13px;
  color: var(--color-steel);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.link-actions {
  display: flex;
  gap: var(--space-xs);
  flex-shrink: 0;
}

.icon-btn {
  width: 40px;
  height: 40px;
  border-radius: var(--rounded-circle);
  border: 1px solid var(--color-hairline-soft);
  background-color: var(--color-canvas);
  color: var(--color-ink);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
}

.icon-btn:hover {
  background-color: var(--color-surface-soft);
  border-color: var(--color-hairline);
}

.icon-btn:active {
  background-color: var(--color-hairline-soft);
}

.icon-btn svg {
  width: 18px;
  height: 18px;
}

/* Toast Notification */
.toast-container {
  position: fixed;
  bottom: var(--space-xxl);
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  z-index: 1000;
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
  transition: transform 300ms cubic-bezier(0.1, 0.9, 0.2, 1);
  pointer-events: none;
}

.toast {
  background-color: var(--color-ink-deep);
  color: var(--color-canvas);
  padding: 12px var(--space-xl);
  border-radius: var(--rounded-full);
  font-size: 14px;
  font-weight: 700;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  display: flex;
  align-items: center;
  gap: var(--space-xs);
  pointer-events: auto;
}

.toast.toast-error {
  background-color: var(--color-critical-strong);
}

.toast-container.show {
  transform: translateX(-50%) translateY(0);
}

/* Help Box (KV info) */
.help-box {
  background-color: var(--color-surface-soft);
  border-radius: var(--rounded-xl);
  padding: var(--space-xl);
  margin-top: var(--space-xxl);
}

.help-box h3 {
  font-size: 16px;
  font-weight: 700;
  margin-bottom: var(--space-xs);
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

.help-box p {
  font-size: 14px;
  color: var(--color-steel);
  margin-bottom: var(--space-base);
}

.help-box ol {
  padding-left: var(--space-xl);
  font-size: 14px;
  color: var(--color-steel);
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.help-box code {
  background-color: rgba(0, 0, 0, 0.05);
  padding: 2px 6px;
  border-radius: var(--rounded-sm);
  font-family: monospace;
  font-size: 13px;
  color: var(--color-ink-deep);
}

/* Feature grid in landing page */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-xl);
  margin-top: var(--space-section);
}

@media (max-width: 768px) {
  .feature-grid {
    grid-template-columns: 1fr;
  }
}

.feature-card {
  background-color: var(--color-canvas);
  border: 1px solid var(--color-hairline-soft);
  border-radius: var(--rounded-xl);
  padding: var(--space-xl);
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.feature-icon {
  width: 48px;
  height: 48px;
  background-color: var(--color-primary-soft);
  color: var(--color-primary);
  border-radius: var(--rounded-circle);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-xs);
}

.feature-icon svg {
  width: 24px;
  height: 24px;
}

/* Footer Section */
footer {
  border-top: 1px solid var(--color-hairline-soft);
  padding: var(--space-section) 0;
  margin-top: var(--space-section-lg);
  text-align: center;
}

.footer-logo {
  font-size: 18px;
  font-weight: 700;
  color: var(--color-ink-deep);
  margin-bottom: var(--space-xs);
}

.footer-copy {
  font-size: 13px;
  color: var(--color-steel);
}

/* Utility classes */
.flex-between {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.d-none {
  display: none !important;
}

.text-center {
  text-align: center;
}