/* ============================================================
   HUZIHUB DESIGN SYSTEM & RESET
   ============================================================ */

:root {
  --ink: #15132b;
  --ink-soft: #4d4a6b;
  --ink-faint: #8985a8;
  --bg: #fcfbff;
  --bg-soft: #f4f2ff;
  --line: #e7e4f6;
  --line-soft: #f0eefb;
  --primary: #4f46e5;
  --primary-dark: #3b33c4;
  --primary-light: #eeebff;
  --accent: #7c3aed;
  --white: #ffffff;

  --font-heading: "Lexend", -apple-system, BlinkMacSystemFont, sans-serif;
  --font-body: "Inter", -apple-system, BlinkMacSystemFont, sans-serif;
  --shadow-sm: 0 2px 8px rgba(21, 19, 43, 0.04);
  --shadow-md: 0 8px 24px rgba(21, 19, 43, 0.08);
  --shadow-lg: 0 16px 32px rgba(79, 70, 229, 0.12);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-family: var(--font-body);
  background-color: var(--bg);
  color: var(--ink);
  line-height: 1.5;
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body {
  width: 100%;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
}
main {
  flex: 1;
}

/* Layout Utilities */
.container {
  width: 100%;
  max-width: 1200px;
  margin-inline: auto;
  padding-inline: 1.5rem;
}

/* Typography */
h1,
h2,
h3,
h4 {
  font-family: var(--font-heading);
  color: var(--ink);
  font-weight: 700;
  line-height: 1.2;
}

a {
  color: inherit;
  text-decoration: none;
}

button,
input {
  font: inherit;
}

/* ============================================================
   HEADER & NAVBAR
   ============================================================ */

.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: rgba(252, 251, 255, 0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line-soft);
}

.nav-container {
  max-width: 1280px;
  margin-inline: auto;
  padding: 1rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-family: var(--font-heading);
  font-weight: 800;
  font-size: 1.35rem;
  color: var(--ink);
}

.brand-logo img {
  width: 34px;
  height: 34px;
  object-fit: contain;
}

.desktop-nav {
  display: flex;
}

.nav-list {
  display: flex;
  align-items: center;
  list-style: none;
  gap: 0.5rem;
}

.nav-item {
  position: relative;
}

.dropdown-toggle,
.nav-link {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.5rem 0.85rem;
  background: transparent;
  border: none;
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--ink-soft);
  cursor: pointer;
  border-radius: var(--radius-sm);
  transition: var(--transition);
}

.dropdown-toggle:hover,
.nav-link:hover,
.dropdown-toggle.active-category {
  color: var(--primary);
  background-color: var(--primary-light);
}

.dropdown-toggle .arrow {
  font-size: 0.65rem;
  transition: transform 0.25s ease;
}

.dropdown-item.open .arrow {
  transform: rotate(180deg);
}

.dropdown-menu {
  position: absolute;
  top: calc(100% + 8px);
  left: 0;
  min-width: 220px;
  background-color: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  padding: 0.5rem;
  list-style: none;
  display: none;
  flex-direction: column;
  z-index: 1010;
}

.dropdown-item.open .dropdown-menu {
  display: flex;
}

.dropdown-menu a {
  padding: 0.6rem 0.85rem;
  font-size: 0.9rem;
  color: var(--ink-soft);
  border-radius: var(--radius-sm);
  transition: var(--transition);
  display: block;
}

.dropdown-menu a:hover {
  background-color: var(--bg-soft);
  color: var(--primary);
}

.dropdown-menu a.active-link {
  background-color: var(--primary-light);
  color: var(--primary);
  font-weight: 600;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.search-trigger {
  background: transparent;
  border: none;
  color: var(--ink-soft);
  padding: 0.5rem;
  cursor: pointer;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
}

.search-trigger:hover {
  color: var(--primary);
  background-color: var(--primary-light);
}

.hamburger-btn {
  display: none;
  flex-direction: column;
  justify-content: space-between;
  width: 28px;
  height: 20px;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 0;
}

.hamburger-btn .bar {
  width: 100%;
  height: 2px;
  background-color: var(--ink);
  border-radius: 2px;
  transition: var(--transition);
}

/* Mobile Menu Drawer */
.mobile-menu {
  display: none;
  position: fixed;
  top: 67px;
  left: 0;
  width: 100%;
  background-color: var(--white);
  border-bottom: 1px solid var(--line);
  box-shadow: var(--shadow-md);
  z-index: 999;
  max-height: calc(100vh - 67px);
  overflow-y: auto;
}

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

.mobile-menu-inner {
  padding: 1rem 1.5rem 2rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.mobile-acc-trigger {
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.75rem 0;
  background: transparent;
  border: none;
  border-bottom: 1px solid var(--line-soft);
  font-weight: 600;
  color: var(--ink);
  font-size: 1rem;
}

.mobile-acc-content {
  display: none;
  flex-direction: column;
  padding-left: 1rem;
  padding-block: 0.5rem;
  gap: 0.5rem;
}

.mobile-acc-item.open .mobile-acc-content {
  display: flex;
}

.mobile-acc-item.open .mobile-acc-trigger .arrow {
  transform: rotate(180deg);
}

.mobile-acc-content a,
.mobile-link {
  padding: 0.5rem 0;
  color: var(--ink-soft);
  font-size: 0.95rem;
  border-bottom: 1px solid var(--line-soft);
}

.mobile-link {
  font-weight: 600;
  color: var(--ink);
}

/* ============================================================
   SEARCH OVERLAY
   ============================================================ */

.search-overlay {
  position: fixed;
  inset: 0;
  background-color: rgba(21, 19, 43, 0.6);
  backdrop-filter: blur(4px);
  z-index: 2000;
  display: none;
  align-items: flex-start;
  justify-content: center;
  padding: 4rem 1rem 1rem;
}

.search-overlay.open {
  display: flex;
}

.search-modal {
  background-color: var(--white);
  width: 100%;
  max-width: 600px;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  border: 1px solid var(--line);
}

.search-modal-header {
  display: flex;
  align-items: center;
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--line);
  gap: 0.75rem;
}

.search-input-wrap {
  display: flex;
  align-items: center;
  flex: 1;
  gap: 0.75rem;
  color: var(--ink-faint);
}

.search-input-wrap input {
  width: 100%;
  border: none;
  outline: none;
  font-size: 1.05rem;
  color: var(--ink);
}

.search-close-btn {
  background: transparent;
  border: none;
  font-size: 1.5rem;
  color: var(--ink-faint);
  cursor: pointer;
}

.search-results-container {
  max-height: 380px;
  overflow-y: auto;
  padding: 0.75rem;
}

.search-result-item {
  display: block;
  padding: 0.75rem 1rem;
  border-radius: var(--radius-sm);
  transition: var(--transition);
}

.search-result-item:hover {
  background-color: var(--bg-soft);
}

.search-result-item .s-name {
  font-weight: 600;
  color: var(--ink);
  display: block;
}

.search-result-item .s-cat {
  font-size: 0.75rem;
  text-transform: uppercase;
  color: var(--primary);
  font-weight: 700;
}

.search-result-item .s-desc {
  font-size: 0.85rem;
  color: var(--ink-soft);
}

.no-results {
  padding: 2rem;
  text-align: center;
  color: var(--ink-faint);
}

/* ============================================================
   HERO SECTION & 3D VISUALIZATION
   ============================================================ */

.hero-section {
  padding-block: 4rem 3rem;
  background: radial-gradient(
    circle at 80% 20%,
    var(--primary-light) 0%,
    transparent 40%
  );
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(0, 0.8fr);
  gap: 3rem;
  align-items: center;
}

.eyebrow {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--primary);
  margin-bottom: 0.75rem;
}

.hero-content h1 {
  font-size: clamp(2.2rem, 4vw, 3.2rem);
  margin-bottom: 1rem;
}

.hero-desc {
  font-size: 1.1rem;
  color: var(--ink-soft);
  margin-bottom: 1.75rem;
  max-width: 520px;
}

.hero-ctas {
  display: flex;
  gap: 1rem;
  margin-bottom: 2rem;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.8rem 1.6rem;
  border-radius: var(--radius-sm);
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  border: 1px solid transparent;
}

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

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

.btn-secondary {
  background-color: var(--white);
  color: var(--ink);
  border-color: var(--line);
}

.btn-secondary:hover {
  background-color: var(--bg-soft);
}

.btn-outline {
  background: transparent;
  color: var(--ink-soft);
  border-color: var(--line);
  width: 100%;
}

.btn-outline:hover {
  border-color: var(--ink-faint);
  color: var(--ink);
}

.btn-secondary-light {
  background-color: var(--bg-soft);
  color: var(--ink);
  font-size: 0.875rem;
  flex: 1;
}

.btn-secondary-light:hover {
  background-color: var(--line-soft);
}

.hero-features {
  list-style: none;
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
  font-size: 0.9rem;
  color: var(--ink-soft);
  font-weight: 500;
}

.hero-features li {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.check-icon {
  width: 18px;
  height: 18px;
  stroke: var(--primary);
  stroke-width: 2.5;
  fill: none;
}

/* 3D Visualizer */
.hero-visual {
  width: 100%;
  display: flex;
  justify-content: center;
}

.scene-3d {
  width: 100%;
  max-width: 320px;
  perspective: 1000px;
}

.card-3d {
  background: linear-gradient(
    135deg,
    rgba(255, 255, 255, 0.9),
    rgba(244, 242, 255, 0.7)
  );
  backdrop-filter: blur(10px);
  border: 1px solid var(--white);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  box-shadow: 0 20px 40px rgba(79, 70, 229, 0.15);
  transform: rotateX(8deg) rotateY(-12deg);
  transition: transform 0.5s ease;
  transform-style: preserve-3d;
  position: relative;
}

.card-3d:hover {
  transform: rotateX(0deg) rotateY(0deg);
}

.demo-badge {
  position: absolute;
  top: 1rem;
  right: 1rem;
  background-color: var(--primary-light);
  color: var(--primary);
  font-size: 0.65rem;
  font-weight: 800;
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
  letter-spacing: 0.05em;
}

.d3-row {
  display: flex;
  justify-content: space-between;
  margin-bottom: 0.75rem;
  font-size: 0.9rem;
  color: var(--ink-soft);
}

.d3-row strong {
  color: var(--ink);
}

.d3-row .highlight {
  color: var(--primary);
}

.d3-divider {
  border: none;
  border-top: 1px dashed var(--line);
  margin-block: 0.75rem;
}

.total-row {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 0;
  color: var(--ink);
}

/* ============================================================
   CALCULATOR CARD
   ============================================================ */

.calc-section {
  padding-block: 2rem 4rem;
}

.calc-card {
  background-color: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
  overflow: hidden;
}

.calc-inputs {
  padding: 2.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.75rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.form-group label {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--ink-soft);
}

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

.input-with-symbol input {
  width: 100%;
  padding: 0.8rem 1rem 0.8rem 2.2rem;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--ink);
  outline: none;
  transition: var(--transition);
}

.input-with-symbol input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px var(--primary-light);
}

.input-with-symbol .symbol {
  position: absolute;
  left: 0.85rem;
  font-weight: 600;
  color: var(--ink-faint);
}

.tip-preset-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.5rem;
}

.tip-btn {
  padding: 0.65rem 0.5rem;
  background-color: var(--bg-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  font-weight: 600;
  color: var(--ink);
  cursor: pointer;
  transition: var(--transition);
}

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

.tip-btn.active {
  background-color: var(--primary);
  color: var(--white);
  border-color: var(--primary);
}

.custom-tip-container {
  margin-top: 0.5rem;
}

.custom-tip-container.hidden {
  display: none;
}

.custom-tip-container input {
  padding-left: 1rem;
  padding-right: 2.2rem;
}

.custom-tip-container .symbol {
  left: auto;
  right: 0.85rem;
}

.people-stepper {
  display: flex;
  align-items: center;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.people-stepper button {
  width: 48px;
  height: 48px;
  background-color: var(--bg-soft);
  border: none;
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--ink);
  cursor: pointer;
  transition: var(--transition);
}

.people-stepper button:hover {
  background-color: var(--line-soft);
}

.people-stepper input {
  flex: 1;
  border: none;
  text-align: center;
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--ink);
  outline: none;

  /* Hides default native stepper buttons */
  -moz-appearance: textfield;
}

.people-stepper input::-webkit-outer-spin-button,
.people-stepper input::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

.error-msg {
  font-size: 0.75rem;
  color: #dc2626;
  min-height: 1rem;
}

/* Results Panel */
.calc-results-panel {
  background-color: var(--bg-soft);
  padding: 2.5rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  border-left: 1px solid var(--line);
  gap: 1.5rem;
}

.results-header h2 {
  font-size: 1.25rem;
}

.primary-result-box {
  background-color: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  text-align: center;
  box-shadow: var(--shadow-sm);
}

.res-label {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--ink-faint);
  display: block;
  margin-bottom: 0.25rem;
}

.res-value {
  font-size: 2.5rem;
  font-family: var(--font-heading);
  font-weight: 800;
  color: var(--primary);
  line-height: 1.1;
  margin-bottom: 0.25rem;
}

.sub-text {
  font-size: 0.85rem;
  color: var(--ink-soft);
}

.secondary-results {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.res-item {
  display: flex;
  justify-content: space-between;
  font-size: 0.95rem;
  color: var(--ink-soft);
}

.res-item strong {
  color: var(--ink);
}

/* Visual Breakdown */
.visual-breakdown {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.breakdown-label {
  display: flex;
  justify-content: space-between;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--ink-faint);
}

.breakdown-bar {
  height: 10px;
  width: 100%;
  background-color: var(--line);
  border-radius: 5px;
  display: flex;
  overflow: hidden;
}

.bar-bill {
  background-color: var(--ink);
  height: 100%;
  transition: width 0.3s ease;
}

.bar-tip {
  background-color: var(--primary);
  height: 100%;
  transition: width 0.3s ease;
}

.breakdown-legend {
  display: flex;
  gap: 1rem;
  font-size: 0.75rem;
  color: var(--ink-soft);
}

.leg-bill::before {
  content: "•";
  color: var(--ink);
  margin-right: 4px;
  font-size: 1rem;
}

.leg-tip::before {
  content: "•";
  color: var(--primary);
  margin-right: 4px;
  font-size: 1rem;
}

.results-actions {
  display: flex;
  gap: 0.75rem;
}

/* Toast */
.toast-container {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  z-index: 3000;
}

.toast {
  background-color: var(--ink);
  color: var(--white);
  padding: 0.75rem 1.25rem;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  box-shadow: var(--shadow-md);
  animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ============================================================
   SEO ARTICLE & FAQ
   ============================================================ */

.seo-content-section,
.faq-section {
  padding-block: 2rem 3rem;
}

.content-card {
  background-color: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  padding: 3rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.content-card h2 {
  font-size: 1.5rem;
  margin-top: 1rem;
}

.content-card p,
.content-card ul {
  color: var(--ink-soft);
  font-size: 1rem;
  line-height: 1.6;
}

.content-card ul {
  padding-left: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.table-responsive {
  width: 100%;
  overflow-x: auto;
}

.seo-table {
  width: 100%;
  border-collapse: collapse;
  margin-block: 1rem;
  text-align: left;
}

.seo-table th,
.seo-table td {
  padding: 0.85rem 1rem;
  border: 1px solid var(--line);
}

.seo-table th {
  background-color: var(--bg-soft);
  font-weight: 600;
  color: var(--ink);
}

.seo-table td {
  color: var(--ink-soft);
  font-size: 0.95rem;
}

.formula-box {
  background-color: var(--bg-soft);
  border-left: 4px solid var(--primary);
  padding: 1.25rem;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.formula-box p {
  color: var(--ink);
  font-size: 0.95rem;
}

.section-title {
  font-size: 1.75rem;
  margin-bottom: 2rem;
  text-align: center;
}

.faq-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.5rem;
}

.faq-card {
  background-color: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  padding: 1.5rem;
}

.faq-card h3 {
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
}

.faq-card p {
  color: var(--ink-soft);
  font-size: 0.95rem;
}

/* ============================================================
   LOCKED FOOTER REQUIREMENT (#000000 & #FFFFFF)
   ============================================================ */

.site-footer {
  background-color: #000000 !important;
  color: #ffffff !important;
  padding-block: 4rem 2rem;
  margin-top: 3rem;
}

.footer-inner {
  display: flex;
  flex-direction: column;
  gap: 3rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 2rem;
}

.footer-heading {
  font-family: var(--font-heading);
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: #ffffff !important;
  display: block;
  margin-bottom: 1.25rem;
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.footer-links a {
  color: #ffffff !important;
  font-size: 0.9rem;
  opacity: 0.85;
  transition: opacity 0.2s ease;
}

.footer-links a:hover {
  opacity: 1;
  text-decoration: underline;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.15);
  padding-top: 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1.5rem;
}

.footer-policies {
  display: flex;
  gap: 1.25rem;
  flex-wrap: wrap;
}

.footer-policies a {
  color: #ffffff !important;
  font-size: 0.85rem;
  opacity: 0.85;
}

.footer-policies a:hover {
  opacity: 1;
}

.footer-right {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.copyright {
  color: #ffffff !important;
  font-size: 0.85rem;
  opacity: 0.75;
}

.footer-socials {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.footer-socials a {
  color: #ffffff !important;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0.85;
  transition: opacity 0.2s ease;
}

.footer-socials a:hover {
  opacity: 1;
}

/* ============================================================
   RESPONSIVE DESIGN (ZERO OVERFLOW ASSURED)
   ============================================================ */

@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-desc {
    margin-inline: auto;
  }

  .hero-ctas,
  .hero-features {
    justify-content: center;
  }

  .calc-card {
    grid-template-columns: 1fr;
  }

  .calc-results-panel {
    border-left: none;
    border-top: 1px solid var(--line);
  }
}

@media (max-width: 840px) {
  .desktop-nav {
    display: none;
  }

  .hamburger-btn {
    display: flex;
  }

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

  .footer-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 600px) {
  .tip-preset-grid {
    grid-template-columns: repeat(3, 1fr);
  }

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

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }

  .footer-right {
    flex-direction: column;
    align-items: flex-start;
    gap: 1rem;
  }
}