/* ============================================
   NATURE-STYLE SCIENTIFIC JOURNAL THEME
   Вдохновлено журналом Nature
   ============================================ */

/* === CSS VARIABLES FOR CONSISTENCY === */
:root {
  /* Light Theme (Nature-inspired) */
  --color-light-bg: #ffffff;
  --color-light-bg-secondary: #f8f9fa;
  --color-light-bg-tertiary: #f1f3f4;
  --color-light-text-primary: #212121;
  --color-light-text-secondary: #5f6368;
  --color-light-text-tertiary: #80868b;
  --color-light-border: #dadce0;
  --color-light-accent: #1a73e8;
  --color-light-accent-hover: #0d62d9;
  --color-light-accent-light: #e8f0fe;
  --color-nature-blue: #2c5aa0;
  --color-nature-red: #d32f2f;
  --color-nature-green: #0d8044;
  
  /* Dark Theme */
  --color-dark-bg: #202124;
  --color-dark-bg-secondary: #292a2d;
  --color-dark-bg-tertiary: #35363a;
  --color-dark-text-primary: #e8eaed;
  --color-dark-text-secondary: #9aa0a6;
  --color-dark-text-tertiary: #80868b;
  --color-dark-border: #3c4043;
  --color-dark-accent: #8ab4f8;
  --color-dark-accent-hover: #a8c7fa;
  --color-dark-accent-light: rgba(138, 180, 248, 0.1);
  --color-nature-blue-dark: #5d8cc9;
  --color-nature-red-dark: #f28b82;
  --color-nature-green-dark: #81c995;
  
  /* Typography (Nature-style) */
  --font-family-primary: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica Neue', Arial, sans-serif;
  --font-family-serif: 'Charter', 'Georgia', 'Times New Roman', Times, serif;
  --font-family-headings: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  --font-weight-normal: 400;
  --font-weight-medium: 500;
  --font-weight-bold: 700;
  --font-weight-black: 900;
  --border-radius: 8px;
  --border-radius-sm: 4px;
  --transition-speed: 0.2s;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 2px 6px rgba(0, 0, 0, 0.07);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.1);
  --nature-header-height: 64px;
}

/* === BASE STYLES === */
* {
  box-sizing: border-box;
}

body {
  font-family: var(--font-family-primary);
  font-size: 16px;
  line-height: 1.6;
  background-color: var(--color-light-bg);
  color: var(--color-light-text-primary);
  transition: background-color var(--transition-speed), color var(--transition-speed);
  margin: 0;
  padding: 0;
}

/* === NATURE-STYLE HEADER === */
.nature-header {
  background-color: var(--color-light-bg);
  border-bottom: 1px solid var(--color-light-border);
  height: var(--nature-header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow-sm);
}

.nature-logo {
  font-family: var(--font-family-headings);
  font-weight: var(--font-weight-black);
  font-size: 1.8rem;
  color: var(--color-nature-blue);
  letter-spacing: -0.5px;
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: 8px;
}

.nature-logo::before {
  content: "●";
  color: var(--color-nature-red);
  font-size: 1.2rem;
}

.nature-nav {
  display: flex;
  gap: 32px;
}

.nature-nav a {
  color: var(--color-light-text-primary);
  text-decoration: none;
  font-weight: var(--font-weight-medium);
  font-size: 0.95rem;
  padding: 8px 0;
  position: relative;
  transition: color var(--transition-speed);
}

.nature-nav a:hover {
  color: var(--color-light-accent);
}

.nature-nav a.active {
  color: var(--color-nature-blue);
  font-weight: var(--font-weight-bold);
}

.nature-nav a.active::after {
  content: '';
  position: absolute;
  bottom: -1px;
  left: 0;
  width: 100%;
  height: 2px;
  background-color: var(--color-nature-blue);
}

/* === CONTENT CONTAINER (Nature-style layout) === */
.nature-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 32px 24px;
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 40px;
}

@media (max-width: 992px) {
  .nature-container {
    grid-template-columns: 1fr;
    gap: 32px;
  }
}

/* === MAIN CONTENT (Nature-style typography) === */
.nature-main-content {
  background-color: var(--color-light-bg);
  padding: 0;
}

.nature-article-title {
  font-family: var(--font-family-headings);
  font-size: 2.5rem;
  font-weight: var(--font-weight-bold);
  line-height: 1.2;
  margin: 0 0 16px 0;
  color: var(--color-light-text-primary);
  letter-spacing: -0.5px;
}

.nature-article-meta {
  color: var(--color-light-text-tertiary);
  font-size: 0.9rem;
  margin-bottom: 32px;
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--color-light-border);
}

.nature-article-meta a {
  color: var(--color-nature-blue);
  text-decoration: none;
  font-weight: var(--font-weight-medium);
}

.nature-article-meta a:hover {
  text-decoration: underline;
}

.nature-article-abstract {
  background-color: var(--color-light-bg-secondary);
  border-left: 4px solid var(--color-nature-blue);
  padding: 24px;
  margin: 32px 0;
  border-radius: var(--border-radius-sm);
}

.nature-article-abstract h3 {
  font-family: var(--font-family-headings);
  font-size: 1.1rem;
  font-weight: var(--font-weight-bold);
  color: var(--color-nature-blue);
  margin: 0 0 12px 0;
}

.nature-article-abstract p {
  margin: 0;
  line-height: 1.7;
}

.nature-article-body {
  font-family: var(--font-family-serif);
  line-height: 1.8;
  font-size: 1.05rem;
}

.nature-article-body h2 {
  font-family: var(--font-family-headings);
  font-size: 1.5rem;
  font-weight: var(--font-weight-bold);
  margin: 48px 0 16px 0;
  color: var(--color-light-text-primary);
}

.nature-article-body h3 {
  font-family: var(--font-family-headings);
  font-size: 1.2rem;
  font-weight: var(--font-weight-bold);
  margin: 32px 0 12px 0;
  color: var(--color-light-text-primary);
}

.nature-article-body p {
  margin: 0 0 24px 0;
  text-align: justify;
}

.nature-article-body figure {
  margin: 32px 0;
  text-align: center;
}

.nature-article-body figcaption {
  font-size: 0.9rem;
  color: var(--color-light-text-tertiary);
  margin-top: 8px;
  line-height: 1.5;
}

.nature-citation {
  background-color: var(--color-light-bg-secondary);
  padding: 4px 8px;
  border-radius: var(--border-radius-sm);
  font-family: var(--font-family-primary);
  font-size: 0.9rem;
  color: var(--color-nature-blue);
}

.nature-reference-list {
  margin-top: 48px;
  padding-top: 24px;
  border-top: 1px solid var(--color-light-border);
}

.nature-reference-list h2 {
  font-family: var(--font-family-headings);
  font-size: 1.5rem;
  font-weight: var(--font-weight-bold);
  margin: 0 0 24px 0;
  color: var(--color-light-text-primary);
}

.nature-reference-item {
  margin-bottom: 16px;
  padding-left: 20px;
  text-indent: -20px;
  font-size: 0.95rem;
  line-height: 1.6;
}

.nature-reference-item a {
  color: var(--color-nature-blue);
  text-decoration: none;
}

.nature-reference-item a:hover {
  text-decoration: underline;
}

/* === SIDEBAR (Nature-style) === */
.nature-sidebar {
  background-color: var(--color-light-bg);
  padding: 0;
}

.nature-sidebar-section {
  background-color: var(--color-light-bg);
  border: 1px solid var(--color-light-border);
  border-radius: var(--border-radius);
  padding: 24px;
  margin-bottom: 24px;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-speed);
}

.nature-sidebar-section:hover {
  box-shadow: var(--shadow-md);
}

.nature-sidebar-section h3 {
  font-family: var(--font-family-headings);
  font-size: 1.1rem;
  font-weight: var(--font-weight-bold);
  margin: 0 0 16px 0;
  color: var(--color-light-text-primary);
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-light-border);
}

.nature-sidebar-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.nature-sidebar-list li {
  margin-bottom: 12px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--color-light-border);
}

.nature-sidebar-list li:last-child {
  margin-bottom: 0;
  padding-bottom: 0;
  border-bottom: none;
}

.nature-sidebar-list a {
  color: var(--color-light-text-primary);
  text-decoration: none;
  font-size: 0.95rem;
  display: flex;
  align-items: flex-start;
  gap: 8px;
  transition: color var(--transition-speed);
}

.nature-sidebar-list a:hover {
  color: var(--color-light-accent);
}

.nature-sidebar-list a::before {
  content: "›";
  color: var(--color-nature-blue);
  font-weight: var(--font-weight-bold);
  margin-top: 2px;
}

.nature-metrics {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-top: 16px;
}

.nature-metric {
  text-align: center;
  flex: 1;
  min-width: 80px;
}

.nature-metric-value {
  font-family: var(--font-family-headings);
  font-size: 1.8rem;
  font-weight: var(--font-weight-bold);
  color: var(--color-nature-blue);
  display: block;
  line-height: 1;
}

.nature-metric-label {
  font-size: 0.8rem;
  color: var(--color-light-text-tertiary);
  display: block;
  margin-top: 4px;
}

/* === CATEGORY TAGS (Nature-style) === */
.nature-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 24px 0;
}

.nature-tag {
  background-color: var(--color-light-bg-secondary);
  color: var(--color-light-text-secondary);
  padding: 6px 12px;
  border-radius: 16px;
  font-size: 0.85rem;
  font-weight: var(--font-weight-medium);
  border: 1px solid var(--color-light-border);
  transition: all var(--transition-speed);
  text-decoration: none;
}

.nature-tag:hover {
  background-color: var(--color-light-accent-light);
  color: var(--color-light-accent);
  border-color: var(--color-light-accent);
  transform: translateY(-1px);
}

.nature-tag-primary {
  background-color: var(--color-nature-blue);
  color: white;
  border-color: var(--color-nature-blue);
}

.nature-tag-primary:hover {
  background-color: var(--color-light-accent-hover);
  color: white;
}

/* === BUTTONS (Nature-style) === */
.nature-button {
  background-color: var(--color-nature-blue);
  color: white;
  border: none;
  border-radius: var(--border-radius-sm);
  padding: 12px 24px;
  font-family: var(--font-family-headings);
  font-weight: var(--font-weight-medium);
  font-size: 0.95rem;
  cursor: pointer;
  transition: all var(--transition-speed);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  text-decoration: none;
}

.nature-button:hover {
  background-color: var(--color-light-accent-hover);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  color: white;
}

.nature-button-secondary {
  background-color: transparent;
  color: var(--color-nature-blue);
  border: 1px solid var(--color-nature-blue);
}

.nature-button-secondary:hover {
  background-color: var(--color-light-accent-light);
  color: var(--color-light-accent-hover);
}

/* === ALERTS & NOTICES (Nature-style) === */
.nature-alert {
  padding: 16px 20px;
  border-radius: var(--border-radius-sm);
  margin: 24px 0;
  font-size: 0.95rem;
  display: flex;
  align-items: flex-start;
  gap: 12px;
}

.nature-alert::before {
  font-weight: var(--font-weight-bold);
  font-size: 1.1rem;
}

.nature-alert-info {
  background-color: var(--color-light-accent-light);
  color: var(--color-nature-blue);
  border-left: 4px solid var(--color-nature-blue);
}

.nature-alert-info::before {
  content: "ℹ";
}

.nature-alert-warning {
  background-color: #fff8e1;
  color: #ff8f00;
  border-left: 4px solid #ff8f00;
}

.nature-alert-warning::before {
  content: "⚠";
}

.nature-alert-success {
  background-color: #e8f5e9;
  color: var(--color-nature-green);
  border-left: 4px solid var(--color-nature-green);
}

.nature-alert-success::before {
  content: "✓";
}

/* === FOOTER (Nature-style) === */
.nature-footer {
  background-color: var(--color-light-bg-secondary);
  border-top: 1px solid var(--color-light-border);
  padding: 40px 24px;
  margin-top: 64px;
}

.nature-footer-container {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
}

@media (max-width: 768px) {
  .nature-footer-container {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 480px) {
  .nature-footer-container {
    grid-template-columns: 1fr;
  }
}

.nature-footer-section h4 {
  font-family: var(--font-family-headings);
  font-size: 1rem;
  font-weight: var(--font-weight-bold);
  margin: 0 0 16px 0;
  color: var(--color-light-text-primary);
}

.nature-footer-links {
  list-style: none;
  padding: 0;
  margin: 0;
}

.nature-footer-links li {
  margin-bottom: 8px;
}

.nature-footer-links a {
  color: var(--color-light-text-secondary);
  text-decoration: none;
  font-size: 0.9rem;
  transition: color var(--transition-speed);
}

.nature-footer-links a:hover {
  color: var(--color-light-accent);
}

.nature-footer-bottom {
  max-width: 1200px;
  margin: 40px auto 0;
  padding-top: 24px;
  border-top: 1px solid var(--color-light-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 0.9rem;
  color: var(--color-light-text-tertiary);
}

/* === DARK THEME === */
body.dark-theme {
  background-color: var(--color-dark-bg);
  color: var(--color-dark-text-primary);
}

body.dark-theme .nature-header {
  background-color: var(--color-dark-bg);
  border-bottom-color: var(--color-dark-border);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

body.dark-theme .nature-logo {
  color: var(--color-nature-blue-dark);
}

body.dark-theme .nature-nav a {
  color: var(--color-dark-text-primary);
}

body.dark-theme .nature-nav a:hover {
  color: var(--color-dark-accent);
}

body.dark-theme .nature-nav a.active {
  color: var(--color-nature-blue-dark);
}

body.dark-theme .nature-nav a.active::after {
  background-color: var(--color-nature-blue-dark);
}

body.dark-theme .nature-article-title {
  color: var(--color-dark-text-primary);
}

body.dark-theme .nature-article-meta {
  color: var(--color-dark-text-tertiary);
  border-bottom-color: var(--color-dark-border);
}

body.dark-theme .nature-article-meta a {
  color: var(--color-nature-blue-dark);
}

body.dark-theme .nature-article-abstract {
  background-color: var(--color-dark-bg-secondary);
  border-left-color: var(--color-nature-blue-dark);
}

body.dark-theme .nature-article-abstract h3 {
  color: var(--color-nature-blue-dark);
}

body.dark-theme .nature-article-body h2,
body.dark-theme .nature-article-body h3 {
  color: var(--color-dark-text-primary);
}

body.dark-theme .nature-article-body figcaption {
  color: var(--color-dark-text-tertiary);
}

body.dark-theme .nature-citation {
  background-color: var(--color-dark-bg-secondary);
  color: var(--color-nature-blue-dark);
}

body.dark-theme .nature-reference-list {
  border-top-color: var(--color-dark-border);
}

body.dark-theme .nature-reference-list h2 {
  color: var(--color-dark-text-primary);
}

body.dark-theme .nature-reference-item a {
  color: var(--color-nature-blue-dark);
}

body.dark-theme .nature-sidebar-section {
  background-color: var(--color-dark-bg-secondary);
  border-color: var(--color-dark-border);
}

body.dark-theme .nature-sidebar-section h3 {
  color: var(--color-dark-text-primary);
  border-bottom-color: var(--color-dark-border);
}

body.dark-theme .nature-sidebar-list li {
  border-bottom-color: var(--color-dark-border);
}

body.dark-theme .nature-sidebar-list a {
  color: var(--color-dark-text-primary);
}

body.dark-theme .nature-sidebar-list a:hover {
  color: var(--color-dark-accent);
}

body.dark-theme .nature-sidebar-list a::before {
  color: var(--color-nature-blue-dark);
}

body.dark-theme .nature-metric-value {
  color: var(--color-nature-blue-dark);
}

body.dark-theme .nature-metric-label {
  color: var(--color-dark-text-tertiary);
}

body.dark-theme .nature-tag {
  background-color: var(--color-dark-bg-tertiary);
  color: var(--color-dark-text-secondary);
  border-color: var(--color-dark-border);
}

body.dark-theme .nature-tag:hover {
  background-color: var(--color-dark-accent-light);
  color: var(--color-dark-accent);
  border-color: var(--color-dark-accent);
}

body.dark-theme .nature-tag-primary {
  background-color: var(--color-nature-blue-dark);
  color: var(--color-dark-bg);
  border-color: var(--color-nature-blue-dark);
}

body.dark-theme .nature-tag-primary:hover {
  background-color: var(--color-dark-accent);
  color: var(--color-dark-bg);
}

body.dark-theme .nature-button {
  background-color: var(--color-nature-blue-dark);
  color: var(--color-dark-bg);
}

body.dark-theme .nature-button:hover {
  background-color: var(--color-dark-accent-hover);
  color: var(--color-dark-bg);
}

body.dark-theme .nature-button-secondary {
  background-color: transparent;
  color: var(--color-nature-blue-dark);
  border-color: var(--color-nature-blue-dark);
}

body.dark-theme .nature-button-secondary:hover {
  background-color: var(--color-dark-accent-light);
  color: var(--color-dark-accent-hover);
}

body.dark-theme .nature-alert-info {
  background-color: rgba(138, 180, 248, 0.1);
  color: var(--color-nature-blue-dark);
  border-left-color: var(--color-nature-blue-dark);
}

body.dark-theme .nature-alert-warning {
  background-color: rgba(255, 215, 0, 0.1);
  color: #ffcc00;
  border-left-color: #ffcc00;
}

body.dark-theme .nature-alert-success {
  background-color: rgba(129, 201, 149, 0.1);
  color: var(--color-nature-green-dark);
  border-left-color: var(--color-nature-green-dark);
}

body.dark-theme .nature-footer {
  background-color: var(--color-dark-bg-secondary);
  border-top-color: var(--color-dark-border);
}

body.dark-theme .nature-footer-section h4 {
  color: var(--color-dark-text-primary);
}

body.dark-theme .nature-footer-links a {
  color: var(--color-dark-text-secondary);
}

body.dark-theme .nature-footer-links a:hover {
  color: var(--color-dark-accent);
}

body.dark-theme .nature-footer-bottom {
  border-top-color: var(--color-dark-border);
  color: var(--color-dark-text-tertiary);
}

/* === THEME TOGGLE === */
.theme-toggle {
  background: none;
  border: none;
  color: var(--color-light-text-primary);
  cursor: pointer;
  font-size: 1.2rem;
  padding: 8px;
  border-radius: 50%;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background-color var(--transition-speed);
}

.theme-toggle:hover {
  background-color: var(--color-light-bg-tertiary);
}

body.dark-theme .theme-toggle {
  color: var(--color-dark-text-primary);
}

body.dark-theme .theme-toggle:hover {
  background-color: var(--color-dark-bg-tertiary);
}

/* === RESPONSIVE ADJUSTMENTS === */
@media (max-width: 768px) {
  .nature-header {
    padding: 0 16px;
    height: 56px;
  }
  
  .nature-logo {
    font-size: 1.5rem;
  }
  
  .nature-nav {
    gap: 16px;
  }
  
  .nature-nav a {
    font-size: 0.9rem;
  }
  
  .nature-container {
    padding: 24px 16px;
    gap: 24px;
  }
  
  .nature-article-title {
    font-size: 2rem;
  }
  
  .nature-article-body {
    font-size: 1rem;
  }
}

@media (max-width: 480px) {
  .nature-header {
    flex-direction: column;
    height: auto;
    padding: 12px 16px;
    gap: 12px;
  }
  
  .nature-nav {
    width: 100%;
    justify-content: space-between;
    gap: 8px;
  }
  
  .nature-nav a {
    font-size: 0.85rem;
  }
  
  .nature-article-title {
    font-size: 1.7rem;
  }
  
  .nature-article-meta {
    flex-direction: column;
    gap: 8px;
  }
}