/* ============================================================
   AI PhD Daily — Style Sheet
   Aesthetic: Editorial / Academic Journal
   Think: The Economist meets Distill.pub meets Nature Briefing
   ============================================================ */

/* --- CSS Variables --- */
:root {
  /* Colors */
  --color-bg: #fafaf8;
  --color-bg-pure: #ffffff;
  --color-bg-warm: #f5f4f0;
  --color-bg-sidebar: #f0efeb;
  --color-primary: #1a1a2e;
  --color-primary-light: #2d2d44;
  --color-text: #1a1a2e;
  --color-text-secondary: #4a4a5e;
  --color-text-tertiary: #7a7a8e;
  --color-accent: #b8860b;
  --color-accent-light: #d4a843;
  --color-accent-bg: #fdf8ed;
  --color-rule: #d4d2cc;
  --color-rule-light: #e8e6e1;
  --color-link: #1a1a2e;
  --color-link-hover: #b8860b;
  --color-tag-bg: #eceae4;
  --color-tag-text: #4a4a5e;
  --color-success: #2d6a4f;
  --color-success-bg: #f0f7f4;

  /* Typography */
  --font-display: 'Playfair Display', 'Georgia', 'Times New Roman', serif;
  --font-body: 'Source Sans 3', 'Helvetica Neue', 'Arial', sans-serif;
  --font-mono: 'JetBrains Mono', 'Consolas', monospace;

  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2.5rem;
  --space-2xl: 4rem;
  --space-3xl: 6rem;

  /* Layout */
  --max-width: 1200px;
  --content-width: 780px;
  --header-height: 64px;

  /* Transitions */
  --ease: cubic-bezier(0.25, 0.1, 0.25, 1);
  --duration: 0.3s;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  color: var(--color-text);
  background-color: var(--color-bg);
  line-height: 1.7;
  font-weight: 400;
  min-height: 100vh;
}

a {
  color: var(--color-link);
  text-decoration: none;
  transition: color var(--duration) var(--ease);
}

a:hover {
  color: var(--color-link-hover);
}

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

/* --- Animations --- */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

.animate-in {
  animation: fadeInUp 0.5s var(--ease) both;
}

.animate-fade {
  animation: fadeIn 0.4s var(--ease) both;
}

/* Staggered delays for list items */
.stagger-1 { animation-delay: 0.05s; }
.stagger-2 { animation-delay: 0.1s; }
.stagger-3 { animation-delay: 0.15s; }
.stagger-4 { animation-delay: 0.2s; }
.stagger-5 { animation-delay: 0.25s; }
.stagger-6 { animation-delay: 0.3s; }
.stagger-7 { animation-delay: 0.35s; }

/* --- HEADER --- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(250, 250, 248, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-rule-light);
  height: var(--header-height);
  transition: box-shadow var(--duration) var(--ease);
}

.site-header.scrolled {
  box-shadow: 0 1px 8px rgba(26, 26, 46, 0.06);
}

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

/* Logotype */
.logotype {
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--color-primary);
  letter-spacing: -0.01em;
  text-decoration: none;
  display: flex;
  align-items: baseline;
  gap: 0.2em;
}

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

.logo-ai {
  font-weight: 700;
}

.logo-phd {
  font-weight: 500;
  font-style: italic;
}

.logo-daily {
  font-weight: 400;
  color: var(--color-accent);
}

/* Navigation */
.main-nav {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
}

.nav-link {
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text-secondary);
  text-decoration: none;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  padding: 0.25rem 0;
  position: relative;
  transition: color var(--duration) var(--ease);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 1.5px;
  background: var(--color-accent);
  transition: width var(--duration) var(--ease);
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-primary);
}

.nav-link.active::after,
.nav-link:hover::after {
  width: 100%;
}

.nav-link--subscribe {
  color: var(--color-accent);
  font-weight: 600;
}

.nav-link--subscribe:hover {
  color: var(--color-accent-light);
}

/* Mobile menu button */
.mobile-menu-btn {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.mobile-menu-btn span {
  display: block;
  width: 22px;
  height: 1.5px;
  background: var(--color-primary);
  transition: all var(--duration) var(--ease);
}

.mobile-menu-btn.open span:nth-child(1) {
  transform: rotate(45deg) translate(4.5px, 4.5px);
}
.mobile-menu-btn.open span:nth-child(2) {
  opacity: 0;
}
.mobile-menu-btn.open span:nth-child(3) {
  transform: rotate(-45deg) translate(4.5px, -4.5px);
}

/* Mobile nav overlay */
.mobile-nav-overlay {
  display: none;
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(250, 250, 248, 0.98);
  backdrop-filter: blur(20px);
  z-index: 99;
  opacity: 0;
  transition: opacity var(--duration) var(--ease);
}

.mobile-nav-overlay.open {
  opacity: 1;
}

.mobile-nav {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100%;
  gap: var(--space-xl);
}

.mobile-nav-link {
  font-family: var(--font-display);
  font-size: 1.75rem;
  font-weight: 500;
  color: var(--color-primary);
  text-decoration: none;
}

.mobile-nav-link:hover {
  color: var(--color-accent);
}

/* --- HERO --- */
.hero {
  padding: var(--space-3xl) 0 var(--space-2xl);
  text-align: center;
  border-bottom: 1px solid var(--color-rule);
}

.hero-inner {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 var(--space-xl);
}

.hero-edition {
  font-family: var(--font-body);
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-lg);
  animation: fadeIn 0.6s var(--ease) 0.1s both;
}

.hero-title {
  font-family: var(--font-display);
  font-size: 2.25rem;
  font-weight: 500;
  line-height: 1.3;
  color: var(--color-primary);
  margin-bottom: var(--space-lg);
  letter-spacing: -0.01em;
  animation: fadeInUp 0.6s var(--ease) 0.2s both;
}

.hero-rule {
  width: 48px;
  height: 2px;
  background: var(--color-accent);
  margin: 0 auto var(--space-lg);
  animation: fadeIn 0.6s var(--ease) 0.3s both;
}

.hero-subtitle {
  font-family: var(--font-body);
  font-size: 1.0625rem;
  color: var(--color-text-secondary);
  font-weight: 400;
  font-style: italic;
  animation: fadeInUp 0.6s var(--ease) 0.4s both;
}

/* --- EDITION LAYOUT --- */
.edition-layout {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: var(--space-2xl) var(--space-xl);
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: var(--space-3xl);
}

.section-header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  margin-bottom: var(--space-xl);
  padding-bottom: var(--space-md);
  border-bottom: 2px solid var(--color-primary);
}

.section-title {
  font-family: var(--font-display);
  font-size: 1.375rem;
  font-weight: 600;
  color: var(--color-primary);
}

.section-count {
  font-family: var(--font-body);
  font-size: 0.8125rem;
  color: var(--color-text-tertiary);
  font-weight: 500;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

/* --- BRIEFING CARDS --- */
.briefing-item {
  padding: var(--space-xl) 0;
  border-bottom: 1px solid var(--color-rule-light);
  cursor: pointer;
  transition: background var(--duration) var(--ease);
}

.briefing-item:last-child {
  border-bottom: none;
}

.briefing-item:hover {
  background: var(--color-bg-warm);
  margin-left: calc(-1 * var(--space-lg));
  margin-right: calc(-1 * var(--space-lg));
  padding-left: var(--space-lg);
  padding-right: var(--space-lg);
  border-radius: 4px;
}

.briefing-meta {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  margin-bottom: var(--space-sm);
}

.briefing-tag {
  font-family: var(--font-body);
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent);
  background: var(--color-accent-bg);
  padding: 0.2em 0.7em;
  border-radius: 2px;
}

.briefing-number {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-text-tertiary);
}

.briefing-headline {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 600;
  line-height: 1.4;
  color: var(--color-primary);
  margin-bottom: var(--space-sm);
  transition: color var(--duration) var(--ease);
}

.briefing-item:hover .briefing-headline {
  color: var(--color-accent);
}

.briefing-summary {
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-md);
}

.briefing-read-more {
  font-family: var(--font-body);
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--color-accent);
  letter-spacing: 0.03em;
  display: inline-flex;
  align-items: center;
  gap: 0.4em;
  transition: gap var(--duration) var(--ease);
}

.briefing-item:hover .briefing-read-more {
  gap: 0.7em;
}

/* --- SIDEBAR --- */
.edition-sidebar {
  padding-top: var(--space-xl);
}

.sidebar-block {
  margin-bottom: var(--space-2xl);
}

.sidebar-title {
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-primary);
  padding-bottom: var(--space-sm);
  border-bottom: 2px solid var(--color-primary);
  margin-bottom: var(--space-lg);
}

/* Editor's Pick */
.editors-pick {
  background: var(--color-bg-warm);
  border-left: 3px solid var(--color-accent);
  padding: var(--space-lg);
}

.editors-pick .pick-tag {
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-sm);
}

.editors-pick .pick-headline {
  font-family: var(--font-display);
  font-size: 1.0625rem;
  font-weight: 600;
  line-height: 1.4;
  color: var(--color-primary);
  margin-bottom: var(--space-sm);
}

.editors-pick .pick-summary {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
  margin-bottom: var(--space-md);
}

.editors-pick .pick-link {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--color-accent);
  cursor: pointer;
}

/* Trending Papers */
.trending-list {
  list-style: none;
  counter-reset: trending;
}

.trending-list li {
  counter-increment: trending;
  padding: var(--space-sm) 0;
  border-bottom: 1px solid var(--color-rule-light);
  font-size: 0.875rem;
  line-height: 1.5;
  display: flex;
  gap: var(--space-md);
}

.trending-list li:last-child {
  border-bottom: none;
}

.trending-list li::before {
  content: counter(trending);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.125rem;
  color: var(--color-accent);
  flex-shrink: 0;
  width: 1.5em;
}

.trending-list .trending-title {
  font-weight: 500;
  color: var(--color-primary);
}

.trending-list .trending-authors {
  font-size: 0.8125rem;
  color: var(--color-text-tertiary);
  margin-top: 2px;
}

/* Deadlines */
.deadline-list {
  list-style: none;
}

.deadline-list li {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: var(--space-sm) 0;
  border-bottom: 1px solid var(--color-rule-light);
  font-size: 0.875rem;
}

.deadline-list li:last-child {
  border-bottom: none;
}

.deadline-name {
  font-weight: 600;
  color: var(--color-primary);
}

.deadline-date {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-text-tertiary);
  flex-shrink: 0;
}

/* --- BRIEFING DETAIL --- */
.detail-container {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: var(--space-2xl) var(--space-xl);
}

.detail-back {
  display: inline-flex;
  align-items: center;
  gap: 0.4em;
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--color-text-tertiary);
  letter-spacing: 0.03em;
  text-transform: uppercase;
  margin-bottom: var(--space-2xl);
  cursor: pointer;
  transition: color var(--duration) var(--ease);
  background: none;
  border: none;
  font-family: var(--font-body);
}

.detail-back:hover {
  color: var(--color-accent);
}

.detail-tag {
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent);
  background: var(--color-accent-bg);
  padding: 0.2em 0.7em;
  border-radius: 2px;
  display: inline-block;
  margin-bottom: var(--space-md);
}

.detail-headline {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 600;
  line-height: 1.3;
  color: var(--color-primary);
  margin-bottom: var(--space-md);
}

.detail-date {
  font-size: 0.875rem;
  color: var(--color-text-tertiary);
  margin-bottom: var(--space-2xl);
  padding-bottom: var(--space-lg);
  border-bottom: 1px solid var(--color-rule);
}

.detail-body {
  font-size: 1.0625rem;
  line-height: 1.85;
  color: var(--color-text-secondary);
}

.detail-body p {
  font-size: inherit;
  line-height: inherit;
  color: inherit;
  margin-bottom: var(--space-lg);
  text-align: justify;
  -webkit-hyphens: auto;
  hyphens: auto;
}

.detail-body p:first-child {
  font-size: 1.1875rem;
  color: var(--color-text);
  line-height: 1.8;
}

.detail-body p:first-child::first-letter {
  font-family: var(--font-display);
  font-size: 3.5em;
  float: left;
  line-height: 0.8;
  padding-right: 0.08em;
  padding-top: 0.06em;
  color: var(--color-primary);
  font-weight: 700;
}

/* Reading progress indicator */
.detail-reading-info {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  font-size: 0.8125rem;
  color: var(--color-text-tertiary);
  margin-bottom: var(--space-xl);
  padding-bottom: var(--space-lg);
  border-bottom: 1px solid var(--color-rule-light);
}

.detail-reading-info .reading-time {
  font-weight: 500;
}

.detail-reading-info .reading-depth {
  font-style: italic;
}

/* Section breaks between analytical sections */
.detail-body .section-break {
  text-align: center;
  margin: var(--space-2xl) 0;
  color: var(--color-accent);
  font-size: 1.25rem;
  letter-spacing: 0.5em;
}

/* Pull quotes */
.detail-body blockquote {
  margin: var(--space-xl) 0;
  padding: var(--space-lg) var(--space-xl);
  border-left: 3px solid var(--color-accent);
  background: var(--color-accent-bg);
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-style: italic;
  line-height: 1.6;
  color: var(--color-primary);
}

.detail-links {
  display: flex;
  gap: var(--space-lg);
  margin-top: var(--space-2xl);
  padding-top: var(--space-lg);
  border-top: 1px solid var(--color-rule);
}

.detail-link {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-accent);
  display: inline-flex;
  align-items: center;
  gap: 0.4em;
}

.detail-link:hover {
  color: var(--color-accent-light);
}

/* --- ARCHIVE PAGE --- */
.archive-container {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: var(--space-2xl) var(--space-xl) var(--space-3xl);
}

.archive-header {
  margin-bottom: var(--space-2xl);
  padding-bottom: var(--space-xl);
  border-bottom: 2px solid var(--color-primary);
}

.archive-title {
  font-family: var(--font-display);
  font-size: 2rem;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: var(--space-sm);
}

.archive-subtitle {
  font-size: 1rem;
  color: var(--color-text-secondary);
  font-style: italic;
}

.archive-edition {
  border-bottom: 1px solid var(--color-rule-light);
}

.archive-edition-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-lg) 0;
  cursor: pointer;
  transition: color var(--duration) var(--ease);
}

.archive-edition-header:hover {
  color: var(--color-accent);
}

.archive-edition-date {
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-weight: 600;
}

.archive-edition-count {
  font-size: 0.8125rem;
  color: var(--color-text-tertiary);
}

.archive-edition-toggle {
  font-size: 0.75rem;
  color: var(--color-text-tertiary);
  transition: transform var(--duration) var(--ease);
}

.archive-edition.open .archive-edition-toggle {
  transform: rotate(180deg);
}

.archive-edition-body {
  display: none;
  padding: 0 0 var(--space-lg);
}

.archive-edition.open .archive-edition-body {
  display: block;
}

.archive-briefing-item {
  padding: var(--space-sm) 0;
  display: flex;
  align-items: baseline;
  gap: var(--space-md);
  font-size: 0.9375rem;
  cursor: pointer;
  transition: color var(--duration) var(--ease);
}

.archive-briefing-item:hover {
  color: var(--color-accent);
}

.archive-briefing-tag {
  font-size: 0.625rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent);
  background: var(--color-accent-bg);
  padding: 0.15em 0.5em;
  border-radius: 2px;
  flex-shrink: 0;
}

/* --- ABOUT PAGE --- */
.about-container {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: var(--space-2xl) var(--space-xl) var(--space-3xl);
}

.about-header {
  margin-bottom: var(--space-2xl);
}

.about-title {
  font-family: var(--font-display);
  font-size: 2.25rem;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: var(--space-lg);
}

.about-rule {
  width: 48px;
  height: 2px;
  background: var(--color-accent);
}

.about-body p {
  font-size: 1.0625rem;
  line-height: 1.8;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-lg);
}

.about-lead {
  font-size: 1.125rem !important;
  color: var(--color-text) !important;
  font-weight: 400;
}

.about-section-title {
  font-family: var(--font-display);
  font-size: 1.375rem;
  font-weight: 600;
  color: var(--color-primary);
  margin-top: var(--space-2xl);
  margin-bottom: var(--space-lg);
  padding-top: var(--space-lg);
  border-top: 1px solid var(--color-rule-light);
}

.sources-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-md);
  margin-top: var(--space-lg);
}

.source-item {
  background: var(--color-bg-warm);
  padding: var(--space-lg);
  border-left: 2px solid var(--color-accent);
}

.source-name {
  display: block;
  font-weight: 600;
  font-size: 0.9375rem;
  color: var(--color-primary);
  margin-bottom: 0.25em;
}

.source-desc {
  font-size: 0.8125rem;
  color: var(--color-text-tertiary);
}

/* --- SUBSCRIBE PAGE --- */
.subscribe-container {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: var(--space-3xl) var(--space-xl);
  text-align: center;
}

.subscribe-header {
  margin-bottom: var(--space-2xl);
}

.subscribe-title {
  font-family: var(--font-display);
  font-size: 2.5rem;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: var(--space-lg);
}

.subscribe-rule {
  width: 48px;
  height: 2px;
  background: var(--color-accent);
  margin: 0 auto var(--space-lg);
}

.subscribe-lead {
  font-size: 1.125rem;
  color: var(--color-text-secondary);
  font-style: italic;
}

.subscribe-form {
  max-width: 480px;
  margin: 0 auto var(--space-xl);
}

.form-row {
  display: flex;
  gap: 0;
  border: 1.5px solid var(--color-rule);
  border-radius: 3px;
  overflow: hidden;
  transition: border-color var(--duration) var(--ease);
}

.form-row:focus-within {
  border-color: var(--color-accent);
}

.subscribe-input {
  flex: 1;
  padding: 0.875rem 1.25rem;
  font-family: var(--font-body);
  font-size: 1rem;
  border: none;
  outline: none;
  background: var(--color-bg-pure);
  color: var(--color-text);
}

.subscribe-input::placeholder {
  color: var(--color-text-tertiary);
}

.subscribe-btn {
  padding: 0.875rem 2rem;
  font-family: var(--font-body);
  font-size: 0.875rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--color-bg-pure);
  background: var(--color-primary);
  border: none;
  cursor: pointer;
  transition: background var(--duration) var(--ease);
}

.subscribe-btn:hover {
  background: var(--color-accent);
}

.subscribe-fine {
  font-size: 0.8125rem;
  color: var(--color-text-tertiary);
  margin-top: var(--space-md);
  letter-spacing: 0.03em;
}

/* Success message */
.subscribe-success {
  max-width: 480px;
  margin: 0 auto var(--space-xl);
  background: var(--color-success-bg);
  border-left: 3px solid var(--color-success);
  padding: var(--space-lg);
  text-align: left;
}

.success-title {
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--color-success);
  margin-bottom: var(--space-sm);
}

.success-text {
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
}

/* Tiers */
.tiers-preview {
  margin-top: var(--space-3xl);
  padding-top: var(--space-2xl);
  border-top: 1px solid var(--color-rule);
}

.tiers-title {
  font-family: var(--font-display);
  font-size: 1.375rem;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: var(--space-xl);
}

.tiers-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-xl);
  max-width: 600px;
  margin: 0 auto;
  text-align: left;
}

.tier-card {
  background: var(--color-bg-pure);
  border: 1.5px solid var(--color-rule);
  padding: var(--space-xl);
  position: relative;
}

.tier-card--premium {
  border-color: var(--color-accent);
}

.tier-name {
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: var(--space-xs);
}

.tier-price {
  font-family: var(--font-display);
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: var(--space-lg);
}

.tier-features {
  list-style: none;
  font-size: 0.875rem;
  color: var(--color-text-secondary);
}

.tier-features li {
  padding: 0.35em 0;
  padding-left: 1.2em;
  position: relative;
}

.tier-features li::before {
  content: '\2013';
  position: absolute;
  left: 0;
  color: var(--color-accent);
}

.tier-badge {
  display: inline-block;
  margin-top: var(--space-lg);
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-text-tertiary);
  background: var(--color-bg-warm);
  padding: 0.3em 0.8em;
  border-radius: 2px;
}

.tier-badge--soon {
  color: var(--color-accent);
  background: var(--color-accent-bg);
}

/* --- FOOTER --- */
.site-footer {
  background: var(--color-primary);
  color: rgba(255, 255, 255, 0.7);
  padding: var(--space-2xl) 0 var(--space-xl);
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-xl);
}

.footer-top {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  padding-bottom: var(--space-xl);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  margin-bottom: var(--space-xl);
}

.footer-logotype {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  color: #fff;
  display: flex;
  gap: 0.2em;
}

.footer-logotype .logo-daily {
  color: var(--color-accent);
}

.footer-tagline {
  font-size: 0.8125rem;
  font-style: italic;
  margin-top: var(--space-sm);
  color: rgba(255, 255, 255, 0.5);
}

.footer-links {
  display: flex;
  gap: var(--space-3xl);
}

.footer-col {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.footer-col-title {
  font-family: var(--font-body);
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.4);
  margin-bottom: var(--space-sm);
}

.footer-col a {
  font-size: 0.875rem;
  color: rgba(255, 255, 255, 0.7);
  transition: color var(--duration) var(--ease);
}

.footer-col a:hover {
  color: var(--color-accent);
}

.footer-bottom {
  font-size: 0.8125rem;
  color: rgba(255, 255, 255, 0.35);
}

/* --- RESPONSIVE --- */
@media (max-width: 1024px) {
  .edition-layout {
    grid-template-columns: 1fr;
    gap: var(--space-2xl);
  }

  .edition-sidebar {
    border-top: 2px solid var(--color-primary);
    padding-top: var(--space-2xl);
  }
}

@media (max-width: 768px) {
  :root {
    --space-xl: 1.5rem;
    --space-2xl: 2.5rem;
    --space-3xl: 3.5rem;
  }

  .main-nav {
    display: none;
  }

  .mobile-menu-btn {
    display: flex;
  }

  .hero-title {
    font-size: 1.625rem;
  }

  .header-inner {
    padding: 0 var(--space-lg);
  }

  .hero-inner {
    padding: 0 var(--space-lg);
  }

  .edition-layout {
    padding: var(--space-xl) var(--space-lg);
  }

  .sources-grid {
    grid-template-columns: 1fr;
  }

  .tiers-grid {
    grid-template-columns: 1fr;
  }

  .footer-top {
    flex-direction: column;
    gap: var(--space-xl);
  }

  .footer-links {
    gap: var(--space-2xl);
  }

  .detail-headline {
    font-size: 1.5rem;
  }

  .subscribe-title {
    font-size: 1.75rem;
  }

  .about-title,
  .archive-title {
    font-size: 1.75rem;
  }

  .form-row {
    flex-direction: column;
  }

  .subscribe-btn {
    padding: 1rem;
  }
}

@media (max-width: 480px) {
  .logotype {
    font-size: 1.15rem;
  }

  .hero {
    padding: var(--space-2xl) 0 var(--space-xl);
  }

  .hero-title {
    font-size: 1.375rem;
  }

  .briefing-headline {
    font-size: 1.0625rem;
  }
}