/* Grasp Website Design System */
@import url('https://fonts.googleapis.com/css2?family=Instrument+Serif:ital@0;1&family=Plus+Jakarta+Sans:wght@300;400;500;600;700&display=swap');

:root {
  --bg-cream: #EDEBE4;
  --bg-cream-dark: #E4E1DA;
  --surface: #FFFFFF;
  --surface-secondary: #F7F5F0;
  --text-dark: #1A1A1A;
  --text-muted: #6E6C64;
  --text-light: #999790;
  --coral: #E8593C;
  --coral-light: #FDE8E4;
  --teal: #1D9E75;
  --teal-light: #E6F6F1;
  --yellow: #FAC775;
  --yellow-light: #FEF7EB;
  --border: #E0DDD7;
  --border-dark: #D8D5CE;

  --font-sans: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-serif: 'Instrument Serif', Georgia, Cambria, "Times New Roman", Times, serif;

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 24px;
  --radius-xl: 32px;

  --transition: all 0.3s cubic-bezier(0.2, 0.8, 0.2, 1);
}

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

body {
  font-family: var(--font-sans);
  background: var(--bg-cream);
  color: var(--text-dark);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* Scrollbar styling */
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-cream);
}

::-webkit-scrollbar-thumb {
  background: var(--border-dark);
  border-radius: var(--radius-sm);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-light);
}

/* Base Styles */
h1,
h2,
h3,
h4 {
  font-family: var(--font-sans);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.serif {
  font-family: var(--font-serif);
  font-weight: 400;
  font-style: italic;
}

p {
  color: var(--text-muted);
}

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* Header & Nav */
header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 20px 0;
  transition: var(--transition);
}

header.scrolled {
  background: rgba(237, 235, 228, 0.8);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.05);
  padding: 12px 0;
}

.nav-wrapper {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 22px;
  font-weight: 700;
  letter-spacing: -0.03em;
}

.logo svg {
  color: var(--text-dark);
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 32px;
  list-style: none;
}

.nav-link {
  font-size: 14px;
  font-weight: 500;
  color: var(--text-muted);
}

.nav-link:hover,
.nav-link.active {
  color: var(--text-dark);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 24px;
  border-radius: 100px;
  font-size: 14px;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: var(--transition);
}

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

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 16px rgba(0, 0, 0, 0.1);
}

.btn-coral {
  background: var(--coral);
  color: var(--surface);
}

.btn-coral:hover {
  transform: translateY(-2px);
  background: #d44d32;
  box-shadow: 0 8px 16px rgba(232, 89, 60, 0.25);
}

.btn-outline {
  background: transparent;
  color: var(--text-dark);
  border: 1px solid var(--border-dark);
}

.btn-outline:hover {
  background: rgba(0, 0, 0, 0.03);
}

.hamburger {
  display: none;
  flex-direction: column;
  gap: 6px;
  border: none;
  background: transparent;
  cursor: pointer;
  z-index: 1001;
}

.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-dark);
  border-radius: 2px;
  transition: var(--transition);
}

/* Mobile Nav Open */
.hamburger.open span:nth-child(1) {
  transform: translateY(8px) rotate(45deg);
}

.hamburger.open span:nth-child(2) {
  opacity: 0;
}

.hamburger.open span:nth-child(3) {
  transform: translateY(-8px) rotate(-45deg);
}

/* Hero Section */
.hero {
  padding: 160px 0 100px;
  position: relative;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 64px;
  align-items: center;
}

.hero-title {
  font-size: 64px;
  line-height: 1.05;
  margin-bottom: 24px;
  color: var(--text-dark);
}

.hero-title span {
  font-size: 80px;
  display: block;
}

.hero-desc {
  font-size: 18px;
  color: var(--text-muted);
  margin-bottom: 40px;
  max-width: 520px;
}

.hero-cta {
  display: flex;
  gap: 16px;
  margin-bottom: 48px;
}

.hero-stats {
  display: flex;
  gap: 36px;
  border-top: 1px dashed var(--border-dark);
  padding-top: 24px;
}

.hero-stat h3 {
  font-size: 28px;
  color: var(--coral);
}

.hero-stat p {
  font-size: 12px;
  color: var(--text-light);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-top: 2px;
}

/* Floating App Mockup UI */
.mockup-container {
  position: relative;
  width: 100%;
}

.app-card {
  background: var(--surface);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  box-shadow: 0 30px 60px rgba(0, 0, 0, 0.06);
  padding: 24px;
  position: relative;
  width: 100%;
  max-width: 380px;
  margin: 0 auto;
}

.app-card-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 24px;
}

.card-title {
  font-size: 18px;
  font-family: var(--font-sans);
  font-weight: 700;
}

.badge-streak {
  background: var(--coral-light);
  color: var(--coral);
  padding: 4px 12px;
  border-radius: 100px;
  font-size: 12px;
  font-weight: 600;
}

.mock-stat-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-bottom: 20px;
}

.mock-stat-card {
  background: var(--surface-secondary);
  border-radius: var(--radius-md);
  padding: 16px;
  border: 1px solid var(--border);
}

.mock-stat-card .val {
  font-size: 32px;
  font-weight: 700;
  display: block;
}

.mock-stat-card .lbl {
  font-size: 11px;
  color: var(--text-light);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.concept-list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.concept-item {
  background: var(--surface-secondary);
  border-radius: var(--radius-md);
  padding: 12px 16px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border: 1px solid var(--border);
}

.concept-info .name {
  font-size: 14px;
  font-family: var(--font-sans);
  font-weight: 600;
  display: block;
}

.concept-info .sub {
  font-size: 11px;
  color: var(--text-light);
}

.concept-progress {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  border: 3px solid var(--border-dark);
  border-top-color: var(--teal);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 9px;
  font-weight: 700;
  color: var(--teal);
}

/* Floating elements */
.float-card {
  position: absolute;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 8px 14px;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.08);
  display: flex;
  align-items: center;
  gap: 10px;
  z-index: 10;
}

.float-card-1 {
  top: 55px;
  left: -50px;
  animation: float 6s ease-in-out infinite;
}

.float-card-2 {
  bottom: 60px;
  right: -30px;
  animation: float 6s ease-in-out infinite 3s;
}

.float-card .icon-wrap {
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: var(--coral-light);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--coral);
}

.float-card .text {
  font-size: 11px;
  font-weight: 600;
}

@keyframes float {

  0%,
  100% {
    transform: translateY(0);
  }

  50% {
    transform: translateY(-10px);
  }
}

/* Features Section */
.features {
  background: var(--surface-secondary);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: 100px 0;
}

.section-hdr {
  text-align: center;
  max-width: 600px;
  margin: 0 auto 64px;
}

.section-label {
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--coral);
  margin-bottom: 12px;
  display: block;
}

.section-title {
  font-size: 40px;
  line-height: 1.15;
  color: var(--text-dark);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 40px 32px;
  transition: var(--transition);
}

.feature-card.grad-1 {
  background: linear-gradient(180deg, #FFEDD5 0%, #FFFFFF 100%);
}

.feature-card.grad-2 {
  background: linear-gradient(180deg, #D1FAE5 0%, #FFFFFF 100%);
}

.feature-card.grad-3 {
  background: linear-gradient(180deg, #E0E7FF 0%, #FFFFFF 100%);
}

.feature-card.grad-4 {
  background: linear-gradient(180deg, #d5fcff 0%, #FFFFFF 100%);
}

.feature-card.grad-5 {
  background: linear-gradient(180deg, #FEF9C3 0%, #FFFFFF 100%);
}

.feature-card.grad-6 {
  background: linear-gradient(180deg, #CFFAFE 0%, #FFFFFF 100%);
}

.feature-card:hover {
  transform: translateY(-8px);
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.04);
}

.feature-icon-wrap {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--bg-cream);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-dark);
  margin-bottom: 24px;
}

.feature-card h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 12px;
}

.feature-card p {
  font-size: 14px;
  color: var(--text-muted);
}

/* Content Ecosystem Section */
.ecosystem {
  padding: 100px 0;
}

.ecosystem-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  align-items: center;
}

.ecosystem-left h2 {
  font-size: 48px;
  line-height: 1.1;
  margin-bottom: 24px;
}

.ecosystem-left p {
  font-size: 16px;
  margin-bottom: 32px;
}

.eco-features {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.eco-item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
}

.eco-check {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--teal-light);
  color: var(--teal);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  margin-top: 2px;
}

.eco-text h4 {
  font-size: 15px;
  font-weight: 700;
}

.eco-text p {
  font-size: 13px;
  margin-top: 2px;
}

/* Content Showcase visual graph mockup */
.showcase-graph {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px;
  height: 320px;
  position: relative;
  overflow: hidden;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.03);
}

.showcase-node {
  position: absolute;
  padding: 8px 16px;
  border-radius: 100px;
  font-size: 12px;
  font-weight: 600;
  border: 1px solid var(--border);
  background: var(--surface);
}

.showcase-node.accent {
  background: var(--coral);
  color: var(--surface);
  border-color: var(--coral);
}

.showcase-node.mathematics {
  background: #EFF6FF;
  color: #2563EB;
  border-color: #DBEAFE;
}

.showcase-node.computer-science {
  background: #ECFEFF;
  color: #0891B2;
  border-color: #CFFAFE;
}

.showcase-node.physics {
  background: #FEF2F2;
  color: #DC2626;
  border-color: #FEE2E2;
}

.showcase-node.chemistry {
  background: #EEF2FF;
  color: #4F46E5;
  border-color: #E0E7FF;
}

.showcase-node.biology {
  background: #EBF8F2;
  color: #059669;
  border-color: #D1FAE5;
}

.showcase-node.economics {
  background: #FEFDF0;
  color: #CA8A04;
  border-color: #FEF9C3;
}

/* Footer */
footer {
  background: var(--surface);
  border-top: 1px solid var(--border);
  padding: 64px 0 32px;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 48px;
}

.footer-brand p {
  font-size: 14px;
  margin-top: 12px;
  max-width: 280px;
}

.footer-links h4 {
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-light);
  margin-bottom: 16px;
}

.footer-links ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.footer-links a {
  font-size: 14px;
  color: var(--text-muted);
}

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

.footer-bottom {
  border-top: 1px solid var(--border-dark);
  padding-top: 32px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.footer-bottom p {
  font-size: 12px;
  color: var(--text-light);
}

.brand-sig {
  display: flex;
  align-items: center;
  gap: 3px;
  font-size: 12px;
  color: var(--text-light);
  flex-wrap: wrap;
}

.footer-gs-link {
  font-size: 11px;
  color: var(--coral);
  font-weight: 600;
  margin-left: 4px;
  opacity: 0.85;
  transition: opacity 0.2s;
}

.footer-gs-link:hover {
  opacity: 1;
}

/* Responsive Overrides */
@media (max-width: 992px) {

  .hero-grid,
  .ecosystem-grid {
    grid-template-columns: 1fr;
    gap: 48px;
  }

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

  .mockup-container {
    max-width: 420px;
    margin: 0 auto;
  }

  .nav-menu {
    position: fixed;
    top: 0;
    right: -100%;
    bottom: 0;
    width: 280px;
    background: var(--surface);
    flex-direction: column;
    padding: 100px 24px;
    box-shadow: -10px 0 30px rgba(0, 0, 0, 0.05);
    transition: var(--transition);
  }

  .nav-menu.open {
    right: 0;
  }

  .hamburger {
    display: flex;
  }

  .hero-title {
    font-size: 48px;
  }

  .hero-title span {
    font-size: 56px;
  }
}

@media (max-width: 576px) {
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .footer-bottom {
    flex-direction: column;
    gap: 16px;
    align-items: flex-start;
  }

  .hero-cta {
    flex-direction: column;
  }
}

/* Inner Page styling (Terms, Privacy, Open Source) */
.inner-hero {
  padding: 160px 0 64px;
  border-bottom: 1px solid var(--border);
}

.inner-hero h1 {
  font-size: 48px;
  line-height: 1.1;
  color: var(--text-dark);
  margin-bottom: 16px;
}

.inner-content {
  padding: 64px 0 100px;
}

.policy-block {
  max-width: 800px;
  margin-bottom: 40px;
}

.policy-block h2 {
  font-size: 24px;
  margin-bottom: 16px;
  color: var(--text-dark);
  font-family: var(--font-sans);
}

.policy-block p {
  font-size: 15px;
  color: var(--text-muted);
  margin-bottom: 16px;
}

.policy-block ul {
  padding-left: 20px;
  margin-bottom: 16px;
  color: var(--text-muted);
}

.policy-block li {
  font-size: 14px;
  margin-bottom: 8px;
}

/* Logo Image */
.logo-img {
  width: 32px;
  height: 32px;
  object-fit: contain;
}

/* OSS Grid */
.oss-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  margin-top: 32px;
}

.oss-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  transition: var(--transition);
}

.oss-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 16px 32px rgba(0, 0, 0, 0.04);
}

.oss-card-icon {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
}

.oss-card h3 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--text-dark);
}

.oss-card p {
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.6;
}

/* Architecture Diagram */
.arch-diagram {
  margin-top: 24px;
  max-width: 800px;
}

.arch-layer {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 24px 28px;
}

.arch-label {
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-light);
  margin-bottom: 16px;
}

.arch-boxes {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.arch-box {
  background: var(--surface-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 16px 20px;
}

.arch-box strong {
  font-size: 14px;
  display: block;
  margin-bottom: 4px;
}

.arch-box span {
  font-size: 12px;
  color: var(--text-light);
}

.arch-box.accent {
  background: var(--coral-light);
  border-color: rgba(232, 89, 60, 0.2);
}

.arch-box.accent strong {
  color: var(--coral);
}

.arch-arrow {
  text-align: center;
  font-size: 24px;
  color: var(--text-light);
  padding: 12px 0;
  letter-spacing: 2px;
}

/* About Builder - Gain and Shine */
.about-builder {
  text-align: center;
  padding-bottom: 32px;
}

.about-divider {
  width: 60px;
  height: 3px;
  border-radius: 2px;
  background: var(--border-dark);
  margin: 0 auto 32px;
}

.about-tagline {
  font-size: 14px;
  color: var(--text-light);
  font-weight: 500;
  letter-spacing: 0.03em;
  margin-bottom: 12px;
}

.gainandshine-brand {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  margin-bottom: 24px;
}

.gas-gain {
  font-size: 42px;
  font-weight: 800;
  background: linear-gradient(135deg, #155dfc, #3080ff);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -0.02em;
}

.gas-and {
  font-size: 42px;
  font-weight: 800;
  background: linear-gradient(135deg, #fb2c36, #ff667f);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -0.02em;
}

.gas-shine {
  font-size: 42px;
  font-weight: 800;
  background: linear-gradient(135deg, #3080ff, #155dfc);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -0.02em;
}

/* Smaller footer version */
.gas-gain-sm {
  font-size: 14px;
  font-weight: 700;
  background: linear-gradient(135deg, #155dfc, #3080ff);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.gas-and-sm {
  font-size: 14px;
  font-weight: 700;
  background: linear-gradient(135deg, #fb2c36, #ff667f);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin: 0 2px;
}

.gas-shine-sm {
  font-size: 14px;
  font-weight: 700;
  background: linear-gradient(135deg, #3080ff, #155dfc);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.about-desc {
  font-size: 15px;
  color: var(--text-muted);
  max-width: 560px;
  margin: 0 auto 28px;
  line-height: 1.7;
}

.about-links {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

/* Responsive: OSS grid + Arch diagram */
@media (max-width: 768px) {
  .oss-grid {
    grid-template-columns: 1fr;
  }

  .arch-boxes {
    grid-template-columns: 1fr;
  }

  .gas-gain,
  .gas-and,
  .gas-shine {
    font-size: 32px;
  }
}