/* ============================================
   MATHEMATICAL STUDY POINT — Global Stylesheet
   ============================================ */
:root {
  --navy: #0f0a1e;
  --navy-light: #1a2d5a;
  --blue: #2563eb;
  --blue-light: #3b82f6;
  --blue-pale: #dbeafe;
  --blue-bg: #eff6ff;
  --accent: #00d4ff;
  --accent-light: #e3f7fc;
  --amber-dark: #d97706;
  --amber-light: #fef3c7;
  --success: #16a34a;
  --success-bg: #dcfce7;
  --white: #ffffff;
  --gray-50: #f8fafc;
  --gray-100: #f1f5f9;
  --gray-200: #e2e8f0;
  --gray-300: #cbd5e1;
  --gray-400: #94a3b8;
  --gray-500: #64748b;
  --gray-600: #475569;
  --gray-700: #334155;
  --gray-800: #1e293b;
  --gray-900: #0f172a;
  --text: #1e293b;
  --text-light: #475569;
  --text-muted: #64748b;
  --font-heading: "Outfit", sans-serif;
  --font-body: "Source Sans 3", sans-serif;
  --section-pad: 5rem 0;
  --container: 1140px;
  --gap: 2rem;
  --radius: 8px;
  --radius-lg: 16px;
  --shadow-sm:
    0 1px 3px rgba(15, 27, 61, 0.06), 0 1px 2px rgba(15, 27, 61, 0.04);
  --shadow: 0 4px 12px rgba(15, 27, 61, 0.08);
  --shadow-lg: 0 12px 32px rgba(15, 27, 61, 0.12);
  --shadow-xl: 0 20px 48px rgba(15, 27, 61, 0.16);
  --ease: cubic-bezier(0.4, 0, 0.2, 1);
  --duration: 0.3s;
}
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}
html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  font-size: 16px;
}
body {
  font-family: var(--font-body);
  color: var(--text);
  background: var(--white);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
img,
svg {
  max-width: 100%;
  display: block;
}
a {
  color: inherit;
  text-decoration: none;
}
ul,
ol {
  list-style: none;
}
button,
input,
textarea,
select {
  font: inherit;
  border: none;
  outline: none;
  background: none;
}
h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.2;
  color: var(--navy);
}
h1 {
  font-size: clamp(2rem, 5vw, 3.25rem);
  letter-spacing: -0.02em;
}
h2 {
  font-size: clamp(1.6rem, 4vw, 2.5rem);
  letter-spacing: -0.015em;
}
h3 {
  font-size: clamp(1.2rem, 3vw, 1.5rem);
}
h4 {
  font-size: 1.125rem;
}
p {
  margin-bottom: 1rem;
  color: var(--text-light);
}
p:last-child {
  margin-bottom: 0;
}
strong {
  font-weight: 600;
  color: var(--text);
}
.container {
  width: 100%;
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 1.25rem;
}
section {
  padding: var(--section-pad);
}
.section-label {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.8125rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--blue);
  margin-bottom: 1rem;
}
.section-label svg {
  width: 16px;
  height: 16px;
}
.section-title {
  margin-bottom: 1rem;
}
.section-desc {
  max-width: 640px;
  color: var(--text-muted);
  font-size: 1.0625rem;
}
.section-header {
  margin-bottom: 3rem;
}
.section-header.center {
  text-align: center;
}
.section-header.center .section-desc {
  margin-left: auto;
  margin-right: auto;
}
.text-center {
  text-align: center;
}
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.8125rem 1.75rem;
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 0.9375rem;
  border-radius: var(--radius);
  cursor: pointer;
  transition: all var(--duration) var(--ease);
  white-space: nowrap;
  position: relative;
  overflow: hidden;
}
.btn svg {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
  transition: transform var(--duration) var(--ease);
}
.btn:hover svg {
  transform: translateX(3px);
}
.btn-primary {
  background: var(--blue);
  color: var(--white);
  box-shadow: 0 2px 8px rgba(37, 99, 235, 0.3);
}
.btn-primary:hover {
  background: var(--navy);
  box-shadow: 0 4px 16px rgba(15, 27, 61, 0.25);
  transform: translateY(-1px);
}
.btn-amber {
  background: var(--amber-dark);
  color: var(--white);
  box-shadow: 0 2px 8px rgba(245, 158, 11, 0.3);
}
.btn-amber:hover {
  background: var(--amber-dark);
  transform: translateY(-1px);
}
.btn-outline {
  border: 2px solid var(--blue);
  color: var(--blue);
}
.btn-outline:hover {
  background: var(--blue);
  color: var(--white);
  transform: translateY(-1px);
}
.btn-white {
  background: var(--white);
  color: var(--navy);
  box-shadow: var(--shadow);
}
.btn-white:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-1px);
}
.btn-sm {
  padding: 0.5rem 1.25rem;
  font-size: 0.8125rem;
}
.btn-lg {
  padding: 1rem 2.25rem;
  font-size: 1rem;
}
.card {
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--gray-200);
  transition: all var(--duration) var(--ease);
}
.card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
  border-color: var(--blue-pale);
}
.site-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--gray-200);
  transition: all var(--duration) var(--ease);
}
.site-nav.scrolled {
  box-shadow: var(--shadow);
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--navy);
}
.nav-logo-icon {
  width: 40px;
  height: 40px;
  background: var(--blue);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--white);
  font-weight: 800;
  font-size: 1.125rem;
  font-family: var(--font-heading);
}
.nav-logo span {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}
.nav-logo .logo-sub {
  font-size: 0.6875rem;
  font-weight: 500;
  color: var(--text-muted);
  letter-spacing: 0.02em;
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
}
.nav-links a {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--text-light);
  transition: color var(--duration) var(--ease);
  position: relative;
}
.nav-links a::after {
  content: "";
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--blue);
  border-radius: 2px;
  transition: width var(--duration) var(--ease);
}
.nav-links a:hover,
.nav-links a.active {
  color: var(--blue);
}
.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}
.nav-cta {
  margin-left: 0.5rem;
}
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 4px;
  z-index: 1001;
}
.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--navy);
  border-radius: 2px;
  transition: all var(--duration) var(--ease);
}
.hamburger.active span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.hamburger.active span:nth-child(2) {
  opacity: 0;
}
.hamburger.active span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}
.mobile-menu {
  position: fixed;
  inset: 0;
  z-index: 999;
  background: var(--white);
  padding: 5.5rem 1.5rem 2rem;
  display: flex;
  flex-direction: column;
  transform: translateX(100%);
  transition: transform 0.4s var(--ease);
  overflow-y: auto;
}
.mobile-menu.open {
  transform: translateX(0);
}
.mobile-menu a {
  display: block;
  padding: 1rem 0;
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--navy);
  border-bottom: 1px solid var(--gray-100);
}
.mobile-menu a:hover {
  color: var(--blue);
}
.mobile-menu .btn {
  margin-top: 1.5rem;
  justify-content: center;
  width: 100%;
  display: inline-flex;
  color: var(--white);
}
.mobile-menu .btn:hover {
  color: var(--white);
}
.site-footer {
  background: var(--navy);
  color: var(--gray-300);
  padding: 4rem 0 0;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: 3rem;
}
.footer-brand {
  max-width: 280px;
}
.footer-brand .nav-logo {
  color: var(--white);
  margin-bottom: 1rem;
}
.footer-brand .nav-logo-icon {
  background: var(--blue);
}
.footer-brand p {
  color: var(--gray-400);
  font-size: 0.9375rem;
  line-height: 1.6;
}
.footer-heading {
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 0.9375rem;
  color: var(--white);
  margin-bottom: 1.25rem;
}
.footer-links a {
  display: block;
  padding: 0.375rem 0;
  color: var(--gray-400);
  font-size: 0.9375rem;
  transition: color var(--duration) var(--ease);
}
.footer-links a:hover {
  color: var(--accent);
}
.footer-contact-item {
  display: flex;
  gap: 0.75rem;
  margin-bottom: 1rem;
  font-size: 0.9375rem;
  color: var(--gray-400);
}
.footer-contact-item svg {
  width: 18px;
  height: 18px;
  color: var(--blue-light);
  flex-shrink: 0;
  margin-top: 3px;
}
.footer-bottom {
  margin-top: 3rem;
  padding: 1.5rem 0;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  text-align: center;
  font-size: 0.8125rem;
  color: var(--gray-500);
}
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}
.highlight {
  color: var(--blue);
}
.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  padding: 0.25rem 0.75rem;
  border-radius: 50px;
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.badge-blue {
  background: var(--blue-pale);
  color: var(--blue);
}
.badge-amber {
  background: var(--amber-light);
  color: var(--amber-dark);
}
.badge-green {
  background: var(--success-bg);
  color: var(--success);
}
.divider {
  width: 60px;
  height: 4px;
  border-radius: 4px;
  background: linear-gradient(90deg, var(--blue), var(--accent));
  margin: 1rem 0;
}
.divider.center {
  margin-left: auto;
  margin-right: auto;
}
.fade-up {
  opacity: 0;
  transform: translateY(30px);
  transition:
    opacity 0.6s var(--ease),
    transform 0.6s var(--ease);
}
.fade-up.visible {
  opacity: 1;
  transform: translateY(0);
}
.fade-up.d1 {
  transition-delay: 0.1s;
}
.fade-up.d2 {
  transition-delay: 0.2s;
}
.fade-up.d3 {
  transition-delay: 0.3s;
}
.fade-up.d4 {
  transition-delay: 0.4s;
}
.stat-number {
  font-family: var(--font-heading);
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 800;
  color: var(--navy);
  line-height: 1;
}
.stat-label {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-top: 0.375rem;
}
.icon-box {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.icon-box svg {
  width: 28px;
  height: 28px;
}
.icon-box.blue {
  background: var(--blue-pale);
  color: var(--blue);
}
.icon-box.amber {
  background: var(--amber-light);
  color: var(--amber-dark);
}
.icon-box.navy {
  background: var(--navy);
  color: var(--white);
}
.icon-box.accent {
  background: var(--accent-light);
  color: var(--accent);
}
.icon-box.green {
  background: var(--success-bg);
  color: var(--success);
}
.faq-list {
  max-width: 780px;
  margin: 0 auto;
}
.faq-item {
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  margin-bottom: 1rem;
  overflow: hidden;
  transition: border-color var(--duration) var(--ease);
}
.faq-item:hover {
  border-color: var(--blue-pale);
}
.faq-item.open {
  border-color: var(--blue);
}
.faq-q {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.25rem 1.5rem;
  font-family: var(--font-heading);
  font-size: 1rem;
  font-weight: 600;
  color: var(--navy);
  cursor: pointer;
  background: none;
  text-align: left;
  gap: 1rem;
}
.faq-q svg {
  width: 20px;
  height: 20px;
  flex-shrink: 0;
  color: var(--blue);
  transition: transform var(--duration) var(--ease);
}
.faq-item.open .faq-q svg {
  transform: rotate(180deg);
}
.faq-a {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s var(--ease);
}
.faq-item.open .faq-a {
  max-height: 500px;
}
.faq-a-inner {
  padding: 0 1.5rem 1.25rem;
  font-size: 0.9375rem;
  color: var(--text-light);
  line-height: 1.7;
}
@media (max-width: 1024px) {
  .nav-links,
  .nav-cta {
    display: none;
  }
  .hamburger {
    display: flex;
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}
@media (max-width: 640px) {
  section {
    padding: 3.5rem 0;
  }
  .footer-grid {
    grid-template-columns: 1fr;
  }
  .nav-inner {
    height: 64px;
  }
}