/* ===================== RESET & VARIABLES ===================== */
:root {
  --clr-primary-900: #0A192F;
  --clr-primary-700: #1A3A6B;
  --clr-primary-500: #2196F3;
  --clr-primary-300: #64B5F6;
  --clr-accent: #FFD700;
  --clr-accent-light: #FFE082;
  --clr-neutral-100: #F5F7FA;
  --clr-neutral-900: #1A1A2E;
  --clr-success: #4CAF50;
  --clr-warning: #FF9800;

  --ff-primary: Inter, system-ui, -apple-system, sans-serif;
  --fw-heading: 800;
  --fw-body: 400;
  --fs-heading-lg: clamp(2.2rem, 5vw, 3rem);
  --fs-heading-md: clamp(1.5rem, 3vw, 2rem);
  --fs-body: 1rem;
  --lh-body: 1.6;

  --container-max: 1200px;
  --container-pad: 1.5rem;
  --shadow-card: 0 2px 0 rgba(255, 215, 0, 0.3), 0 4px 0 rgba(255, 215, 0, 0.1);
  --shadow-nav: 0 4px 20px rgba(0,0,0,0.6);
  --duration-m: 0.3s;
  --duration-l: 0.5s;
}

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

ul, ol {
  list-style: none;
}

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

img, svg {
  display: block;
  max-width: 100%;
}

button {
  cursor: pointer;
  font: inherit;
  color: inherit;
  background: none;
  border: none;
}

/* ===================== BASE TYPOGRAPHY ===================== */
html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--ff-primary);
  font-weight: var(--fw-body);
  font-size: var(--fs-body);
  line-height: var(--lh-body);
  background-color: var(--clr-primary-900);
  color: var(--clr-neutral-100);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4 {
  font-weight: var(--fw-heading);
  line-height: 1.2;
  color: var(--clr-neutral-100);
  letter-spacing: -0.02em;
}

h1 { font-size: var(--fs-heading-lg); }
h2 { font-size: var(--fs-heading-md); }
h3 { font-size: 1.35rem; }
h4 { font-size: 1.1rem; }

::selection {
  background-color: var(--clr-accent);
  color: var(--clr-primary-900);
}

:focus-visible {
  outline: 2px solid var(--clr-accent);
  outline-offset: 4px;
}

/* ===================== UTILITY ===================== */
.container {
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--container-pad);
  padding-right: var(--container-pad);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
}

.skip-link {
  position: absolute;
  top: -100%;
  left: 1rem;
  padding: 0.5rem 1rem;
  background-color: var(--clr-accent);
  color: var(--clr-primary-900);
  z-index: 1000;
  font-weight: 700;
  transition: top var(--duration-m);
}
.skip-link:focus {
  top: 0.5rem;
}

/* ===================== SCROLL PROGRESS ===================== */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 0%;
  height: 3px;
  background: linear-gradient(90deg, var(--clr-primary-500), var(--clr-accent));
  z-index: 999;
  transition: width 0.1s linear;
}

@media (prefers-reduced-motion: reduce) {
  .scroll-progress {
    display: none;
  }
}

/* ===================== HEADER ===================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--clr-primary-900);
  border-bottom: 2px solid var(--clr-primary-700);
  box-shadow: var(--shadow-nav);
}

.header__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1rem;
  padding-top: 0.8rem;
  padding-bottom: 0.8rem;
}

.header__brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-right: auto;
}

.brand__logo {
  font-size: 1.6rem;
  font-weight: 900;
  letter-spacing: 0.05em;
  color: var(--clr-neutral-100);
  text-transform: uppercase;
  background: linear-gradient(135deg, var(--clr-primary-300), var(--clr-primary-500));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  border-right: 2px solid var(--clr-accent);
  padding-right: 0.75rem;
}

.brand__tagline {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.tag {
  display: inline-block;
  border: 1px solid var(--clr-accent);
  color: var(--clr-accent);
  padding: 0.2rem 0.6rem;
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* Navigation Toggle */
.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 4px;
  padding: 0.5rem;
  background: none;
  border: none;
  cursor: pointer;
}
.nav-toggle__bar {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--clr-neutral-100);
  transition: transform var(--duration-m);
}

/* Navigation */
.header__nav {
  display: flex;
  align-items: center;
}

.nav__list {
  display: flex;
  gap: 0.25rem;
}

.nav__link {
  display: block;
  padding: 0.5rem 1rem;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--clr-primary-300);
  border: 1px solid transparent;
  transition: color var(--duration-m), border-color var(--duration-m), background-color var(--duration-m);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.nav__link:hover,
.nav__link:focus-visible {
  color: var(--clr-accent);
  border-color: var(--clr-accent);
  background-color: rgba(255, 215, 0, 0.05);
}

.nav__link[aria-current="page"] {
  color: var(--clr-neutral-100);
  background-color: var(--clr-primary-700);
  border-color: var(--clr-primary-500);
}

/* User Switcher */
.header__tools {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.user-switcher {
  display: flex;
  border: 1px solid var(--clr-primary-500);
  overflow: hidden;
}

.switcher__btn {
  padding: 0.4rem 1rem;
  font-size: 0.8rem;
  font-weight: 600;
  background-color: transparent;
  color: var(--clr-primary-300);
  transition: background-color var(--duration-m), color var(--duration-m);
  cursor: pointer;
  white-space: nowrap;
}

.switcher__btn[aria-pressed="true"] {
  background-color: var(--clr-accent);
  color: var(--clr-primary-900);
}

.switcher__btn:not([aria-pressed="true"]):hover {
  background-color: var(--clr-primary-700);
  color: var(--clr-neutral-100);
}

/* ===================== FOOTER ===================== */
.site-footer {
  background-color: var(--clr-neutral-900);
  border-top: 2px solid var(--clr-primary-700);
  padding-top: 3rem;
  padding-bottom: 1.5rem;
  margin-top: 4rem;
}

.footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 2rem;
  margin-bottom: 2rem;
}

.footer__heading {
  font-size: 0.9rem;
  color: var(--clr-accent);
  margin-bottom: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.footer__trust {
  margin-top: 1rem;
  font-size: 0.9rem;
  color: var(--clr-primary-300);
  max-width: 30ch;
}

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

.footer__links a {
  color: var(--clr-primary-300);
  font-size: 0.9rem;
  transition: color var(--duration-m);
}

.footer__links a:hover,
.footer__links a:focus-visible {
  color: var(--clr-accent);
}

.footer__contact .btn {
  margin-bottom: 1rem;
}

.footer__contact p {
  font-size: 0.85rem;
  color: var(--clr-primary-300);
  margin-top: 0.3rem;
}

.footer__bottom {
  border-top: 1px solid var(--clr-primary-700);
  padding-top: 1.5rem;
  text-align: center;
  font-size: 0.8rem;
  color: var(--clr-primary-300);
}

/* ===================== COMPONENTS ===================== */
.btn {
  display: inline-block;
  padding: 0.65rem 1.5rem;
  font-size: 0.9rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  transition: background-color var(--duration-m), color var(--duration-m), box-shadow var(--duration-m);
  border: 2px solid transparent;
}

.btn--primary {
  background-color: var(--clr-primary-500);
  color: var(--clr-neutral-100);
  border-color: var(--clr-primary-500);
}
.btn--primary:hover {
  background-color: var(--clr-primary-700);
  border-color: var(--clr-primary-300);
}

.btn--accent {
  background-color: var(--clr-accent);
  color: var(--clr-primary-900);
  border-color: var(--clr-accent);
}
.btn--accent:hover {
  background-color: var(--clr-accent-light);
  box-shadow: 0 0 15px var(--clr-accent);
}

.btn--outline {
  background-color: transparent;
  color: var(--clr-accent);
  border-color: var(--clr-accent);
}
.btn--outline:hover {
  background-color: var(--clr-accent);
  color: var(--clr-primary-900);
}

.card {
  background-color: var(--clr-primary-700);
  padding: 1.5rem;
  border-top: 3px solid var(--clr-accent);
  box-shadow: var(--shadow-card);
  transition: transform var(--duration-m), box-shadow var(--duration-m);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 6px 0 rgba(255, 215, 0, 0.3), 0 10px 20px rgba(0,0,0,0.4);
}

.card__title {
  font-size: 1.2rem;
  margin-bottom: 0.5rem;
  color: var(--clr-neutral-100);
}

.card__body {
  font-size: 0.9rem;
  color: var(--clr-primary-300);
  line-height: 1.6;
}

/* SVG Placeholder for page visuals */
.svg-placeholder {
  background: var(--clr-primary-700);
  background-image:
    linear-gradient(45deg, var(--clr-primary-500) 10%, transparent 10%),
    linear-gradient(-45deg, var(--clr-primary-500) 10%, transparent 10%);
  background-size: 20px 20px;
  min-height: 200px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--clr-primary-500);
  position: relative;
  overflow: hidden;
}

.svg-placeholder::after {
  content: '';
  position: absolute;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--clr-accent), transparent);
  animation: dataFlow 3s linear infinite;
}

@keyframes dataFlow {
  0% { transform: translateX(-100%); }
  100% { transform: translateX(100%); }
}

@media (prefers-reduced-motion: reduce) {
  .svg-placeholder::after {
    animation: none;
    opacity: 0.3;
  }
  .card:hover {
    transform: none;
  }
}

/* ===================== SECTION DEFAULT ===================== */
.section {
  padding: 4rem 0;
}

/* ===================== RESPONSIVE ===================== */
@media (max-width: 1024px) {
  .footer__grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }

  .header__nav {
    display: none;
    width: 100%;
    order: 3;
  }

  .header__nav[data-open] {
    display: block;
  }

  .nav__list {
    flex-direction: column;
    gap: 0;
    padding-top: 1rem;
  }

  .nav__link {
    padding: 0.8rem 1rem;
    border-bottom: 1px solid var(--clr-primary-700);
  }

  .header__tools {
    margin-left: auto;
  }

  .user-switcher {
    flex-direction: column;
  }

  .switcher__btn {
    font-size: 0.7rem;
    padding: 0.3rem 0.6rem;
  }

  .footer__grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .brand__tagline {
    display: none;
  }
}

@media (max-width: 480px) {
  .header__inner {
    gap: 0.5rem;
  }
  .brand__logo {
    font-size: 1.2rem;
  }
}