/* ==========================================================================
   Oasis Website - Design System Stylesheet
   ========================================================================== */

/* ==========================================================================
   CSS Custom Properties (Design Tokens)
   ========================================================================== */

:root {
  /* Colors - Primary */
  --color-primary-blue: #0500E1;
  --color-secondary-blue: #007BFF;
  --color-light-cyan: #50D3FF;

  /* Colors - Neutral */
  --color-white: #FFFFFF;
  --color-black: #000000;
  --color-dark-gray: #c0ccda;

  /* Colors - Focus */
  --color-focus-blue: #4d65ff;

  /* Typography - Font Families */
  /* Using system fonts for static hosting - no external dependencies */
  --font-heading: 'SF Mono', 'Monaco', 'Inconsolata', 'Roboto Mono', 'Courier New', monospace;
  --font-body: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue', sans-serif;
  --font-mono: 'SF Mono', 'Monaco', 'Inconsolata', 'Roboto Mono', 'Courier New', monospace;
  --font-ui: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Inter', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue', sans-serif;

  /* Typography - Font Sizes */
  --font-size-h1: clamp(2rem, calc(0.625rem + 4vw), 3rem);
  --font-size-h2: clamp(1.5rem, calc(0.625rem + 2.5vw), 2rem);
  --font-size-h3: clamp(1.25rem, calc(0.625rem + 1.5vw), 1.5rem);
  --font-size-body: 1rem;
  --font-size-small: 0.875rem;

  /* Typography - Font Weights */
  --font-weight-light: 300;
  --font-weight-regular: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;

  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 4rem;

  /* Borders */
  --border-width: 0.125rem;
  --border-radius: 0;

  /* Components - Buttons */
  --button-height: 3.5rem;
  --button-padding: 0 1.5rem;
  --button-font-size: 1rem;

  /* Transitions */
  --transition-fast: 0.2s ease-in-out;
  --transition-normal: 0.3s ease-in-out;

  /* Layout */
  --max-width: 1200px;
  --header-height: 80px;
}

/* ==========================================================================
   CSS Reset & Base Styles
   ========================================================================== */

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  font-size: var(--font-size-body);
  font-weight: var(--font-weight-regular);
  line-height: 1.6;
  color: var(--color-black);
  background-color: var(--color-white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

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

ul, ol {
  list-style: none;
}

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

/* Focus States */
:focus-visible {
  outline: var(--border-width) solid var(--color-focus-blue);
  outline-offset: var(--border-width);
}

/* ==========================================================================
   Typography
   ========================================================================== */

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  line-height: 1.2;
  margin-bottom: var(--spacing-sm);
}

h1 {
  font-size: var(--font-size-h1);
  font-weight: var(--font-weight-bold);
}

h2 {
  font-size: var(--font-size-h2);
  font-weight: var(--font-weight-semibold);
}

h3 {
  font-size: var(--font-size-h3);
  font-weight: var(--font-weight-medium);
}

p {
  margin-bottom: var(--spacing-sm);
}

p:last-child {
  margin-bottom: 0;
}

.text-small {
  font-size: var(--font-size-small);
}

.text-muted {
  color: var(--color-dark-gray);
}

/* ==========================================================================
   Layout Utilities
   ========================================================================== */

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.section {
  padding: var(--spacing-xl) 0;
}

.section--dark {
  background-color: var(--color-black);
  color: var(--color-white);
}

.section--light {
  background-color: var(--color-white);
  color: var(--color-black);
}

/* ==========================================================================
   Header & Navigation
   ========================================================================== */

.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background-color: var(--color-white);
  border-bottom: var(--border-width) solid var(--color-black);
  z-index: 1000;
  transition: transform var(--transition-fast);
}

.header--hidden {
  transform: translateY(-100%);
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

.header__logo {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: var(--font-weight-bold);
  color: var(--color-black);
  text-decoration: none;
}

.header__logo:hover {
  color: var(--color-primary-blue);
}

/* Navigation */
.nav {
  display: none;
}

.nav__list {
  display: flex;
  align-items: center;
  gap: var(--spacing-lg);
}

.nav__item {
  position: relative;
}

.nav__link {
  font-family: var(--font-ui);
  font-size: var(--font-size-small);
  font-weight: var(--font-weight-medium);
  color: var(--color-black);
  text-decoration: none;
  padding: var(--spacing-xs) 0;
  transition: color var(--transition-fast);
}

.nav__link:hover {
  color: var(--color-secondary-blue);
}

/* Dropdown */
.nav__dropdown {
  position: relative;
}

.nav__dropdown-toggle {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  cursor: pointer;
}

.nav__dropdown-toggle::after {
  content: '';
  width: 0;
  height: 0;
  border-left: 5px solid transparent;
  border-right: 5px solid transparent;
  border-top: 5px solid currentColor;
  transition: transform var(--transition-fast);
}

.nav__dropdown:hover .nav__dropdown-toggle::after {
  transform: rotate(180deg);
}

.nav__dropdown-menu {
  position: absolute;
  top: 100%;
  left: 0;
  min-width: 280px;
  background-color: var(--color-white);
  border: var(--border-width) solid var(--color-black);
  padding: var(--spacing-sm);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: all var(--transition-fast);
  z-index: 100;
}

.nav__dropdown:hover .nav__dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.nav__dropdown-item {
  display: block;
  padding: var(--spacing-xs) var(--spacing-sm);
  font-family: var(--font-ui);
  font-size: var(--font-size-small);
  color: var(--color-black);
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.nav__dropdown-item:hover {
  background-color: var(--color-black);
  color: var(--color-white);
}

/* Mobile Menu Toggle */
.nav-toggle {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: var(--spacing-xs);
  cursor: pointer;
}

.nav-toggle__bar {
  width: 24px;
  height: 2px;
  background-color: var(--color-black);
  transition: all var(--transition-fast);
}

.nav-toggle--active .nav-toggle__bar:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.nav-toggle--active .nav-toggle__bar:nth-child(2) {
  opacity: 0;
}

.nav-toggle--active .nav-toggle__bar:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* Mobile Navigation */
.mobile-nav {
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  bottom: 0;
  background-color: var(--color-white);
  padding: var(--spacing-lg);
  transform: translateX(100%);
  transition: transform var(--transition-fast);
  overflow-y: auto;
  z-index: 999;
}

.mobile-nav--open {
  transform: translateX(0);
}

.mobile-nav__list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.mobile-nav__link {
  display: block;
  font-family: var(--font-ui);
  font-size: 1rem;
  font-weight: var(--font-weight-medium);
  padding: var(--spacing-sm);
  border-bottom: 1px solid var(--color-dark-gray);
  transition: color var(--transition-fast);
}

.mobile-nav__link:hover {
  color: var(--color-secondary-blue);
}

.mobile-nav__section-title {
  font-family: var(--font-heading);
  font-size: var(--font-size-small);
  font-weight: var(--font-weight-bold);
  color: var(--color-dark-gray);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-top: var(--spacing-lg);
  margin-bottom: var(--spacing-sm);
}

/* ==========================================================================
   Buttons
   ========================================================================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: var(--button-height);
  padding: var(--button-padding);
  font-family: var(--font-heading);
  font-size: var(--button-font-size);
  font-weight: var(--font-weight-medium);
  text-decoration: none;
  border: var(--border-width) solid var(--color-black);
  cursor: pointer;
  transition: all var(--transition-fast);
  position: relative;
}

.btn::before {
  content: '';
  position: absolute;
  top: 0.5rem;
  left: 0.5rem;
  right: -0.5rem;
  bottom: -0.5rem;
  background-color: var(--color-black);
  z-index: -1;
  opacity: 0;
  transition: opacity var(--transition-fast);
}

.btn:hover {
  transform: translate(-0.5rem, -0.5rem);
}

.btn:hover::before {
  opacity: 1;
}

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

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

.btn--secondary {
  background-color: transparent;
  color: var(--color-black);
}

.btn--secondary:hover {
  background-color: var(--color-black);
  color: var(--color-white);
}

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

.btn--white::before {
  background-color: var(--color-white);
  opacity: 0.3;
}

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

.btn-group {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-md);
}

/* ==========================================================================
   Hero Section
   ========================================================================== */

.hero {
  padding-top: calc(var(--header-height) + var(--spacing-xl));
  padding-bottom: var(--spacing-xl);
  min-height: 80vh;
  display: flex;
  align-items: center;
}

.hero--dark {
  background-color: var(--color-black);
  color: var(--color-white);
}

.hero__content {
  max-width: 800px;
}

.hero__headline {
  font-size: var(--font-size-h1);
  margin-bottom: var(--spacing-md);
}

.hero__subheadline {
  font-size: 1.125rem;
  line-height: 1.7;
  color: var(--color-dark-gray);
  margin-bottom: var(--spacing-lg);
}

.hero--dark .hero__subheadline {
  color: var(--color-dark-gray);
}

/* ==========================================================================
   Cards
   ========================================================================== */

.card {
  background-color: var(--color-white);
  border: var(--border-width) solid var(--color-black);
  padding: var(--spacing-lg);
  transition: all var(--transition-fast);
}

.card:hover {
  transform: translate(-0.25rem, -0.25rem);
  box-shadow: 0.25rem 0.25rem 0 var(--color-black);
}

.card__title {
  font-family: var(--font-heading);
  font-size: var(--font-size-h3);
  margin-bottom: var(--spacing-sm);
  transition: color var(--transition-fast);
}

.card:hover .card__title {
  color: var(--color-secondary-blue);
}

.card__text {
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.card__outcome {
  margin-top: var(--spacing-md);
  padding-top: var(--spacing-md);
  border-top: 1px solid var(--color-dark-gray);
  font-weight: var(--font-weight-medium);
}

/* Card Grid */
.card-grid {
  display: grid;
  gap: var(--spacing-lg);
  grid-template-columns: 1fr;
}

/* ==========================================================================
   Value Propositions
   ========================================================================== */

.value-props {
  padding: var(--spacing-xl) 0;
}

.value-prop {
  padding: var(--spacing-xl) 0;
  border-bottom: 1px solid var(--color-dark-gray);
}

.value-prop:last-child {
  border-bottom: none;
}

.value-prop__number {
  font-family: var(--font-heading);
  font-size: var(--font-size-h1);
  font-weight: var(--font-weight-bold);
  color: var(--color-light-cyan);
  margin-bottom: var(--spacing-sm);
}

.value-prop__title {
  font-size: var(--font-size-h2);
  margin-bottom: var(--spacing-md);
}

.value-prop__text {
  font-size: 1.125rem;
  line-height: 1.7;
  color: var(--color-dark-gray);
  margin-bottom: var(--spacing-md);
  max-width: 700px;
}

.value-prop__outcome {
  font-family: var(--font-heading);
  font-size: 1rem;
  font-weight: var(--font-weight-medium);
  color: var(--color-primary-blue);
}

/* ==========================================================================
   CTA Section
   ========================================================================== */

.cta-section {
  padding: var(--spacing-xl) 0;
  text-align: center;
}

.cta-section__title {
  font-size: var(--font-size-h2);
  margin-bottom: var(--spacing-md);
}

.cta-section__text {
  font-size: 1.125rem;
  color: var(--color-dark-gray);
  max-width: 600px;
  margin: 0 auto var(--spacing-lg);
}

.cta-section--dark {
  background-color: var(--color-black);
  color: var(--color-white);
}

.cta-section--dark .cta-section__text {
  color: var(--color-dark-gray);
}

/* ==========================================================================
   Product Page Sections
   ========================================================================== */

.product-section {
  padding: var(--spacing-xl) 0;
}

.product-section--alt {
  background-color: #f8f9fa;
}

.product-section__title {
  font-size: var(--font-size-h2);
  margin-bottom: var(--spacing-md);
  color: var(--color-primary-blue);
}

.product-section__text {
  font-size: 1.125rem;
  line-height: 1.8;
  max-width: 800px;
}

/* Benefits List */
.benefits-list {
  display: grid;
  gap: var(--spacing-lg);
}

.benefit-item {
  padding: var(--spacing-md);
  border-left: 4px solid var(--color-primary-blue);
  background-color: var(--color-white);
}

.benefit-item__title {
  font-family: var(--font-heading);
  font-size: 1.125rem;
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--spacing-xs);
}

.benefit-item__text {
  color: var(--color-dark-gray);
}

/* Use Cases */
.use-cases {
  display: grid;
  gap: var(--spacing-lg);
}

.use-case {
  padding: var(--spacing-lg);
  background-color: var(--color-white);
  border: var(--border-width) solid var(--color-black);
}

.use-case__title {
  font-family: var(--font-heading);
  font-size: var(--font-size-h3);
  margin-bottom: var(--spacing-sm);
  color: var(--color-primary-blue);
}

.use-case__text {
  line-height: 1.7;
}

/* ==========================================================================
   Footer
   ========================================================================== */

.footer {
  background-color: var(--color-black);
  color: var(--color-white);
  padding: var(--spacing-xl) 0;
  border-top: var(--border-width) solid var(--color-dark-gray);
}

.footer__inner {
  display: grid;
  gap: var(--spacing-xl);
}

.footer__brand {
  max-width: 300px;
}

.footer__logo {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: var(--font-weight-bold);
  margin-bottom: var(--spacing-sm);
}

.footer__tagline {
  font-size: var(--font-size-small);
  color: var(--color-dark-gray);
}

.footer__nav {
  display: grid;
  gap: var(--spacing-lg);
  grid-template-columns: repeat(2, 1fr);
}

.footer__nav-section {
  margin-bottom: var(--spacing-md);
}

.footer__nav-title {
  font-family: var(--font-heading);
  font-size: var(--font-size-small);
  font-weight: var(--font-weight-bold);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--spacing-sm);
  color: var(--color-white);
}

.footer__nav-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.footer__nav-link {
  font-size: var(--font-size-small);
  color: var(--color-dark-gray);
  transition: color var(--transition-fast);
}

.footer__nav-link:hover {
  color: var(--color-light-cyan);
}

.footer__bottom {
  padding-top: var(--spacing-lg);
  border-top: 1px solid var(--color-dark-gray);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  font-size: var(--font-size-small);
  color: var(--color-dark-gray);
}

.footer__copyright {
  color: var(--color-dark-gray);
}

.footer__links {
  display: flex;
  gap: var(--spacing-md);
}

.footer__links a {
  color: var(--color-dark-gray);
  transition: color var(--transition-fast);
}

.footer__links a:hover {
  color: var(--color-white);
}

/* ==========================================================================
   Utility Classes
   ========================================================================== */

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

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

.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }

.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }

/* ==========================================================================
   Responsive Styles
   ========================================================================== */

/* Tablet (768px) */
@media (min-width: 768px) {
  .card-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer__nav {
    grid-template-columns: repeat(3, 1fr);
  }

  .footer__bottom {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }

  .benefits-list {
    grid-template-columns: repeat(2, 1fr);
  }

  .use-cases {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* Desktop (991px) */
@media (min-width: 991px) {
  .nav {
    display: flex;
  }

  .nav-toggle {
    display: none;
  }

  .mobile-nav {
    display: none;
  }

  .card-grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .footer__inner {
    grid-template-columns: 1fr 2fr;
  }

  .footer__nav {
    grid-template-columns: repeat(4, 1fr);
  }

  .hero__content {
    max-width: 700px;
  }

  .value-prop {
    display: grid;
    grid-template-columns: 100px 1fr;
    gap: var(--spacing-lg);
  }

  .value-prop__number {
    text-align: right;
  }

  .use-cases {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* Large (1440px) */
@media (min-width: 1440px) {
  :root {
    --font-size-h1: 3.5rem;
    --font-size-h2: 2.5rem;
  }

  .container {
    max-width: 1400px;
  }
}

/* Mobile-first: Small devices */
@media (max-width: 479px) {
  :root {
    --spacing-xl: 3rem;
    --button-height: 3rem;
  }

  .btn-group {
    flex-direction: column;
  }

  .btn-group .btn {
    width: 100%;
  }

  .hero {
    min-height: auto;
    padding-top: calc(var(--header-height) + var(--spacing-lg));
    padding-bottom: var(--spacing-lg);
  }
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  html {
    scroll-behavior: auto;
  }
}