/* ==========================================================================
   Solar Fire Project - Main Stylesheet
   Palette: P6 Copper | Typography: T1 Modern (Inter)
   ========================================================================== */

/* Variables
   ========================================================================== */
:root {
  /* Palette P6 - Copper */
  --color-primary: #b45309;
  --color-primary-light: #d97706;
  --color-primary-dark: #92400e;
  --color-secondary: #292524;
  --color-accent: #0d9488;
  --color-background: #fafaf9;
  --color-surface: #ffffff;
  --color-text: #1c1917;
  --color-text-muted: #78716c;
  --color-border: #e7e5e4;
  
  /* Typography T1 - Modern */
  --font-heading: 'Inter', -apple-system, sans-serif;
  --font-body: 'Inter', -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
  
  /* Scale */
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;
  --text-4xl: 2.25rem;
  --text-5xl: 3rem;
  
  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  
  /* Layout */
  --container-max: 1200px;
  --container-narrow: 800px;
  --header-height: 80px;
  
  /* Effects */
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.07);
  --shadow-lg: 0 10px 15px rgba(0,0,0,0.1);
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --transition: 0.2s ease;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-background);
  -webkit-font-smoothing: antialiased;
}

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

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

ul, ol {
  list-style: none;
}

/* Header
   ========================================================================== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--header-height);
  transition: background var(--transition), box-shadow var(--transition);
}

.header--transparent {
  background: transparent;
}

.header--scrolled {
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow-sm);
}

.header__container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-6);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.header__logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-weight: 600;
  font-size: var(--text-lg);
}

.header__logo-icon {
  font-size: var(--text-2xl);
}

.header__menu {
  display: flex;
  gap: var(--space-8);
}

.header__link {
  font-weight: 500;
  font-size: var(--text-sm);
  color: var(--color-text);
  position: relative;
  padding: var(--space-2) 0;
}

.header__link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-primary);
  transition: width var(--transition);
}

.header__link:hover::after {
  width: 100%;
}

.header__toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-2);
}

.header__toggle-bar {
  width: 24px;
  height: 2px;
  background: var(--color-text);
  transition: var(--transition);
}

.header__mobile-nav {
  display: none;
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  background: var(--color-surface);
  padding: var(--space-6);
  box-shadow: var(--shadow-lg);
}

.header__mobile-nav.active {
  display: block;
}

.header__mobile-menu {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.header__mobile-link {
  font-size: var(--text-lg);
  font-weight: 500;
  padding: var(--space-2) 0;
}

@media (max-width: 768px) {
  .header__nav {
    display: none;
  }
  .header__toggle {
    display: flex;
  }
}

/* Hero Magazine
   ========================================================================== */
.hero--magazine {
  padding: calc(var(--header-height) + var(--space-12)) 0 var(--space-16);
  background: var(--color-surface);
}

.hero__container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.hero__header {
  margin-bottom: var(--space-8);
}

.hero__date {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.hero__title {
  font-size: var(--text-4xl);
  font-weight: 700;
  margin-top: var(--space-2);
  color: var(--color-secondary);
}

.hero__grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr;
  gap: var(--space-6);
}

.hero__featured {
  position: relative;
}

.hero__featured-link {
  display: block;
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
}

.hero__featured-image {
  position: relative;
  aspect-ratio: 16/10;
}

.hero__featured-image .hero__img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero__featured-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to top, rgba(0,0,0,0.7) 0%, transparent 50%);
}

.hero__featured-content {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: var(--space-8);
  color: white;
}

.hero__category {
  display: inline-block;
  font-size: var(--text-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  background: var(--color-primary);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-sm);
  margin-bottom: var(--space-3);
}

.hero__category--small {
  font-size: 0.65rem;
  padding: 2px var(--space-2);
}

.hero__featured-title {
  font-size: var(--text-3xl);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--space-3);
}

.hero__featured-excerpt {
  font-size: var(--text-base);
  opacity: 0.9;
  line-height: 1.5;
}

.hero__secondary {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-4);
}

.hero__secondary-item {
  background: var(--color-background);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: transform var(--transition), box-shadow var(--transition);
}

.hero__secondary-item:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.hero__secondary-link {
  display: block;
}

.hero__secondary-image {
  aspect-ratio: 16/10;
  overflow: hidden;
}

.hero__secondary-image .hero__img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition);
}

.hero__secondary-item:hover .hero__img {
  transform: scale(1.05);
}

.hero__secondary-content {
  padding: var(--space-4);
}

.hero__secondary-title {
  font-size: var(--text-sm);
  font-weight: 600;
  line-height: 1.4;
  color: var(--color-text);
}

@media (max-width: 968px) {
  .hero__grid {
    grid-template-columns: 1fr;
  }
  .hero__secondary {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .hero__title {
    font-size: var(--text-3xl);
  }
  .hero__secondary {
    grid-template-columns: 1fr;
  }
  .hero__featured-title {
    font-size: var(--text-2xl);
  }
}

/* Sections
   ========================================================================== */
.section {
  padding: var(--space-16) 0;
}

.section__container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.section__header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--space-8);
}

.section__header--center {
  flex-direction: column;
  text-align: center;
}

.section__title {
  font-size: var(--text-2xl);
  font-weight: 700;
  color: var(--color-secondary);
}

.section__title--light {
  color: white;
}

.section__subtitle {
  color: rgba(255,255,255,0.8);
  margin-top: var(--space-2);
}

.section__link {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-primary);
}

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

.section__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-6);
}

@media (max-width: 968px) {
  .section__grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .section__grid {
    grid-template-columns: 1fr;
  }
}

/* Section Stats
   ========================================================================== */
.section--stats {
  background: var(--color-secondary);
  color: white;
}

.stats__grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-8);
  margin-top: var(--space-12);
}

.stats__item {
  text-align: center;
}

.stats__value {
  display: block;
  font-size: var(--text-5xl);
  font-weight: 700;
  color: var(--color-primary-light);
  line-height: 1;
}

.stats__label {
  display: block;
  font-size: var(--text-sm);
  color: rgba(255,255,255,0.7);
  margin-top: var(--space-2);
}

@media (max-width: 768px) {
  .stats__grid {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-6);
  }
  .stats__value {
    font-size: var(--text-4xl);
  }
}

/* Section CTA
   ========================================================================== */
.section--cta {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  color: white;
}

.cta__content {
  max-width: 700px;
  margin: 0 auto;
  text-align: center;
}

.cta__title {
  font-size: var(--text-3xl);
  font-weight: 700;
  margin-bottom: var(--space-4);
}

.cta__text {
  font-size: var(--text-lg);
  opacity: 0.9;
  margin-bottom: var(--space-8);
}

.cta__buttons {
  display: flex;
  gap: var(--space-4);
  justify-content: center;
  flex-wrap: wrap;
}

.cta__button {
  display: inline-flex;
  align-items: center;
  padding: var(--space-4) var(--space-8);
  font-weight: 600;
  font-size: var(--text-base);
  border-radius: var(--radius-md);
  transition: transform var(--transition), box-shadow var(--transition);
}

.cta__button:hover {
  transform: translateY(-2px);
}

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

.cta__button--secondary {
  background: transparent;
  color: white;
  border: 2px solid rgba(255,255,255,0.5);
}

.cta__button--secondary:hover {
  border-color: white;
}

.cta__trust {
  display: flex;
  gap: var(--space-6);
  justify-content: center;
  margin-top: var(--space-8);
  flex-wrap: wrap;
}

.cta__trust-item {
  font-size: var(--text-sm);
  opacity: 0.9;
  display: flex;
  align-items: center;
}

/* Cards
   ========================================================================== */
.card--vertical {
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition), box-shadow var(--transition);
}

.card--vertical:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.card__link {
  display: block;
}

.card__image {
  position: relative;
  aspect-ratio: 16/10;
  overflow: hidden;
}

.card__img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition);
}

.card--vertical:hover .card__img {
  transform: scale(1.05);
}

.card__category {
  position: absolute;
  top: var(--space-4);
  left: var(--space-4);
  font-size: var(--text-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  background: var(--color-primary);
  color: white;
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-sm);
}

.card__content {
  padding: var(--space-6);
}

.card__title {
  font-size: var(--text-lg);
  font-weight: 600;
  line-height: 1.3;
  margin-bottom: var(--space-3);
  color: var(--color-text);
}

.card__excerpt {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
  margin-bottom: var(--space-4);
}

.card__meta {
  display: flex;
  gap: var(--space-4);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}

/* Footer
   ========================================================================== */
.footer {
  background: var(--color-secondary);
  color: white;
  padding: var(--space-16) 0 var(--space-8);
}

.footer__container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-12);
}

.footer__logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-weight: 600;
  font-size: var(--text-lg);
  color: white;
  margin-bottom: var(--space-4);
}

.footer__logo-icon {
  font-size: var(--text-2xl);
}

.footer__description {
  font-size: var(--text-sm);
  color: rgba(255,255,255,0.7);
  line-height: 1.6;
}

.footer__heading {
  font-size: var(--text-sm);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-4);
  color: rgba(255,255,255,0.5);
}

.footer__list {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.footer__link {
  font-size: var(--text-sm);
  color: rgba(255,255,255,0.8);
  transition: color var(--transition);
}

.footer__link:hover {
  color: white;
}

.footer__social {
  display: flex;
  gap: var(--space-3);
}

.footer__social-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: rgba(255,255,255,0.1);
  border-radius: var(--radius-md);
  color: white;
  transition: background var(--transition);
}

.footer__social-link:hover {
  background: var(--color-primary);
}

.footer__bottom {
  margin-top: var(--space-12);
  padding-top: var(--space-8);
  border-top: 1px solid rgba(255,255,255,0.1);
  text-align: center;
}

.footer__copyright {
  font-size: var(--text-sm);
  color: rgba(255,255,255,0.5);
}

@media (max-width: 968px) {
  .footer__grid {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-8);
  }
}

@media (max-width: 640px) {
  .footer__grid {
    grid-template-columns: 1fr;
  }
}

/* Article
   ========================================================================== */
.article__header {
  padding: calc(var(--header-height) + var(--space-12)) 0 var(--space-8);
  background: var(--color-surface);
}

.article__container {
  max-width: var(--container-narrow);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.article__meta {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  font-size: var(--text-sm);
  margin-bottom: var(--space-4);
}

.article__category {
  background: var(--color-primary);
  color: white;
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: var(--text-xs);
  text-transform: uppercase;
}

.article__date,
.article__read {
  color: var(--color-text-muted);
}

.article__title {
  font-size: var(--text-4xl);
  font-weight: 700;
  line-height: 1.2;
  color: var(--color-secondary);
}

.article__lead {
  font-size: var(--text-xl);
  color: var(--color-text-muted);
  margin-top: var(--space-4);
  line-height: 1.6;
}

.article__image {
  margin: var(--space-8) 0;
}

.article__img {
  width: 100%;
  max-height: 500px;
  object-fit: cover;
  border-radius: var(--radius-lg);
}

.article__content {
  padding: var(--space-8) 0;
}

/* Prose */
.prose {
  font-size: var(--text-lg);
  line-height: 1.8;
  color: var(--color-text);
}

.prose h2 {
  font-size: var(--text-2xl);
  font-weight: 700;
  margin-top: var(--space-12);
  margin-bottom: var(--space-4);
  color: var(--color-secondary);
}

.prose h3 {
  font-size: var(--text-xl);
  font-weight: 600;
  margin-top: var(--space-8);
  margin-bottom: var(--space-3);
  color: var(--color-secondary);
}

.prose p {
  margin-bottom: var(--space-6);
}

.prose ul,
.prose ol {
  margin-bottom: var(--space-6);
  padding-left: var(--space-6);
}

.prose ul {
  list-style: disc;
}

.prose ol {
  list-style: decimal;
}

.prose li {
  margin-bottom: var(--space-2);
}

.prose a {
  color: var(--color-primary);
  text-decoration: underline;
}

.prose a:hover {
  color: var(--color-primary-dark);
}

.prose blockquote {
  border-left: 4px solid var(--color-primary);
  padding-left: var(--space-6);
  margin: var(--space-8) 0;
  font-style: italic;
  color: var(--color-text-muted);
}

.prose code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  background: var(--color-background);
  padding: 2px 6px;
  border-radius: var(--radius-sm);
}

.prose pre {
  background: var(--color-secondary);
  color: white;
  padding: var(--space-6);
  border-radius: var(--radius-md);
  overflow-x: auto;
  margin: var(--space-6) 0;
}

.prose pre code {
  background: none;
  padding: 0;
}

.article__tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  padding: var(--space-6) 0;
  border-top: 1px solid var(--color-border);
}

.article__tag {
  font-size: var(--text-sm);
  color: var(--color-primary);
  background: rgba(180, 83, 9, 0.1);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-sm);
}

/* Related Articles */
.related {
  background: var(--color-background);
  padding: var(--space-16) 0;
}

.related__container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.related__title {
  font-size: var(--text-2xl);
  font-weight: 700;
  margin-bottom: var(--space-8);
  color: var(--color-secondary);
}

.related__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-6);
}

@media (max-width: 968px) {
  .related__grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .article__title {
    font-size: var(--text-3xl);
  }
  .related__grid {
    grid-template-columns: 1fr;
  }
}

/* Archive
   ========================================================================== */
.archive__header {
  padding: calc(var(--header-height) + var(--space-12)) 0 var(--space-12);
  background: var(--color-surface);
  text-align: center;
}

.archive__container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.archive__title {
  font-size: var(--text-4xl);
  font-weight: 700;
  color: var(--color-secondary);
}

.archive__description {
  font-size: var(--text-lg);
  color: var(--color-text-muted);
  margin-top: var(--space-4);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.archive__count {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-top: var(--space-4);
}

.archive__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-6);
  padding: var(--space-12) 0;
}

@media (max-width: 968px) {
  .archive__grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 640px) {
  .archive__title {
    font-size: var(--text-3xl);
  }
  .archive__grid {
    grid-template-columns: 1fr;
  }
}

/* Utilities
   ========================================================================== */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

/* Logo SVG
   ========================================================================== */
.header__logo-icon,
.footer__logo-icon {
  flex-shrink: 0;
}

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

.header--scrolled .header__logo-icon {
  color: var(--color-primary);
}

/* CTA Checkmarks
   ========================================================================== */
.cta__check {
  display: inline-block;
  width: 18px;
  height: 18px;
  margin-right: 6px;
  background: rgba(255,255,255,0.2);
  border-radius: 50%;
  position: relative;
  vertical-align: middle;
}

.cta__check::after {
  content: '';
  position: absolute;
  left: 6px;
  top: 3px;
  width: 5px;
  height: 9px;
  border: solid white;
  border-width: 0 2px 2px 0;
  transform: rotate(45deg);
}

/* Enhanced Animations
   ========================================================================== */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.hero__featured,
.hero__secondary-item,
.card--vertical {
  animation: fadeInUp 0.6s ease-out forwards;
}

.hero__secondary-item:nth-child(1) { animation-delay: 0.1s; }
.hero__secondary-item:nth-child(2) { animation-delay: 0.2s; }
.hero__secondary-item:nth-child(3) { animation-delay: 0.3s; }
.hero__secondary-item:nth-child(4) { animation-delay: 0.4s; }

.section__grid .card--vertical:nth-child(1) { animation-delay: 0.1s; }
.section__grid .card--vertical:nth-child(2) { animation-delay: 0.15s; }
.section__grid .card--vertical:nth-child(3) { animation-delay: 0.2s; }
.section__grid .card--vertical:nth-child(4) { animation-delay: 0.25s; }
.section__grid .card--vertical:nth-child(5) { animation-delay: 0.3s; }
.section__grid .card--vertical:nth-child(6) { animation-delay: 0.35s; }

/* Stats Animation
   ========================================================================== */
.stats__value {
  opacity: 0;
  transform: translateY(10px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.stats__value.animated {
  opacity: 1;
  transform: translateY(0);
}

.stats__item:nth-child(1) .stats__value { transition-delay: 0s; }
.stats__item:nth-child(2) .stats__value { transition-delay: 0.1s; }
.stats__item:nth-child(3) .stats__value { transition-delay: 0.2s; }
.stats__item:nth-child(4) .stats__value { transition-delay: 0.3s; }

/* Focus States (Accessibility)
   ========================================================================== */
a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.header__link:focus-visible,
.footer__link:focus-visible {
  outline-offset: 4px;
}

/* Selection
   ========================================================================== */
::selection {
  background: var(--color-primary);
  color: white;
}

/* Print Styles
   ========================================================================== */
@media print {
  .header,
  .footer,
  .section--cta,
  .related {
    display: none;
  }
  
  .article__content {
    font-size: 12pt;
  }
}