/* ── CSS Variables ─────────────────────────────────── */
:root {
  --bg-color: #f4f4f6;
  --text-color: #1a1a1a;
  --header-bg: #ffffff;
  --card-bg: #ffffff;
  --border-color: #e0e0e0;
  --desc-color: #444444;
  --source-color: #888888;
  --btn-bg: #1a1a1a;
  --btn-text: #ffffff;
  --btn-hover-bg: #333333;
  --link-color: #7c3aed;
  --badge-bg: #7c3aed;
  --badge-text: #ffffff;
  --footer-bg: #ffffff;
  --footer-text: #777777;
  --tag-bg: #f0ebff;
  --tag-text: #7c3aed;
  --hero-bg: #7c3aed;
  --hero-text: #ffffff;
  --input-bg: #ffffff;
  --input-border: #d1d1d1;
  --required-color: #e53e3e;
}

body.dark {
  --bg-color: #0f0f13;
  --text-color: #e8e8e8;
  --header-bg: #1a1a22;
  --card-bg: #1e1e2a;
  --border-color: #2e2e40;
  --desc-color: #b0b0b0;
  --source-color: #666666;
  --btn-bg: #e8e8e8;
  --btn-text: #0f0f13;
  --btn-hover-bg: #cccccc;
  --link-color: #a78bfa;
  --badge-bg: #7c3aed;
  --badge-text: #ffffff;
  --footer-bg: #1a1a22;
  --footer-text: #555555;
  --tag-bg: #2e2040;
  --tag-text: #a78bfa;
  --hero-bg: #3b1e8a;
  --hero-text: #ffffff;
  --input-bg: #1e1e2a;
  --input-border: #3a3a50;
  --required-color: #fc8181;
}

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

body {
  background-color: var(--bg-color);
  color: var(--text-color);
  font-family: 'Segoe UI', 'Apple SD Gothic Neo', system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  transition: background-color 0.3s ease, color 0.3s ease;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

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

/* ── Header ────────────────────────────────────────── */
header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.9rem 2rem;
  background-color: var(--header-bg);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 100;
  gap: 1rem;
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

.logo-link {
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.logo-badge {
  background-color: var(--badge-bg);
  color: var(--badge-text);
  font-size: 0.75rem;
  font-weight: 800;
  padding: 0.25rem 0.6rem;
  border-radius: 6px;
  letter-spacing: 0.05em;
}

.site-name {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-color);
}

/* Navigation */
.main-nav {
  display: flex;
  gap: 0.25rem;
}

.nav-link {
  padding: 0.4rem 0.85rem;
  border-radius: 8px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--desc-color);
  transition: background-color 0.2s, color 0.2s;
}

.nav-link:hover,
.nav-link.active {
  background-color: var(--tag-bg);
  color: var(--link-color);
  font-weight: 600;
}

/* Theme Toggle */
#theme-toggle {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.4rem 0.9rem;
  background-color: var(--btn-bg);
  color: var(--btn-text);
  border: none;
  border-radius: 999px;
  cursor: pointer;
  font-size: 0.82rem;
  font-weight: 600;
  white-space: nowrap;
  transition: background-color 0.3s ease, color 0.3s ease, transform 0.1s ease;
}

#theme-toggle:hover { background-color: var(--btn-hover-bg); }
#theme-toggle:active { transform: scale(0.96); }

/* ── Hero ──────────────────────────────────────────── */
.hero {
  background-color: var(--hero-bg);
  color: var(--hero-text);
  text-align: center;
  padding: 3.5rem 2rem;
  transition: background-color 0.3s ease;
}

.hero h1 {
  font-size: 2.2rem;
  font-weight: 800;
  margin-bottom: 0.6rem;
  letter-spacing: -0.02em;
}

.hero p {
  font-size: 1.05rem;
  opacity: 0.88;
  max-width: 560px;
  margin: 0 auto;
}

/* ── Main ──────────────────────────────────────────── */
main {
  max-width: 1100px;
  width: 100%;
  margin: 0 auto;
  padding: 2.5rem 1.5rem;
  flex: 1;
}

.section-header {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  margin-bottom: 1.75rem;
}

.section-title {
  font-size: 1.4rem;
  font-weight: 700;
}

.article-count {
  font-size: 0.85rem;
  color: var(--source-color);
}

/* ── Static Pages ──────────────────────────────────── */
main.static-page {
  max-width: 760px;
}

main.static-page h1 {
  font-size: 2rem;
  font-weight: 800;
  margin-bottom: 0.4rem;
}

.last-updated {
  font-size: 0.85rem;
  color: var(--source-color);
  margin-bottom: 2rem;
}

.page-intro {
  font-size: 1.05rem;
  color: var(--desc-color);
  margin-bottom: 2rem;
  line-height: 1.75;
}

main.static-page section {
  margin-bottom: 2rem;
}

main.static-page h2 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  color: var(--text-color);
}

main.static-page p {
  color: var(--desc-color);
  line-height: 1.8;
  margin-bottom: 0.75rem;
}

main.static-page ul {
  padding-left: 1.5rem;
  color: var(--desc-color);
  line-height: 1.8;
}

main.static-page ul li {
  margin-bottom: 0.5rem;
}

main.static-page a {
  color: var(--link-color);
  text-decoration: underline;
}

/* ── News Grid ─────────────────────────────────────── */
.news-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(310px, 1fr));
  gap: 1.5rem;
}

/* ── News Card ─────────────────────────────────────── */
.news-card {
  background-color: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: 14px;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
  transition: background-color 0.3s ease, border-color 0.3s ease,
              transform 0.2s ease, box-shadow 0.2s ease;
}

.news-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 10px 28px rgba(0,0,0,0.09);
}

.card-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.tag {
  background-color: var(--tag-bg);
  color: var(--tag-text);
  font-size: 0.73rem;
  font-weight: 700;
  padding: 0.2rem 0.65rem;
  border-radius: 999px;
  letter-spacing: 0.02em;
}

.date {
  font-size: 0.78rem;
  color: var(--source-color);
}

.card-title {
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.45;
  color: var(--text-color);
}

.card-desc {
  font-size: 0.875rem;
  color: var(--desc-color);
  line-height: 1.75;
  flex: 1;
}

.card-link {
  display: inline-block;
  color: var(--link-color);
  font-size: 0.85rem;
  font-weight: 600;
  margin-top: 0.2rem;
  transition: opacity 0.2s;
}

.card-link:hover { opacity: 0.7; text-decoration: underline; }

.source {
  font-size: 0.74rem;
  color: var(--source-color);
}

/* ── AdSense ───────────────────────────────────────── */
.ad-banner {
  width: 100%;
  background-color: var(--header-bg);
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
  padding: 0.5rem 1rem;
  text-align: center;
  transition: background-color 0.3s ease, border-color 0.3s ease;
}


/* ── Contact Form ──────────────────────────────────── */
.contact-form {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  margin-bottom: 3rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.form-group label {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-color);
}

.required {
  color: var(--required-color);
}

.form-group input,
.form-group select,
.form-group textarea {
  padding: 0.65rem 0.9rem;
  background-color: var(--input-bg);
  color: var(--text-color);
  border: 1px solid var(--input-border);
  border-radius: 8px;
  font-size: 0.95rem;
  font-family: inherit;
  transition: border-color 0.2s, background-color 0.3s;
  outline: none;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  border-color: var(--link-color);
}

.form-group textarea {
  resize: vertical;
  min-height: 140px;
}

.submit-btn {
  align-self: flex-start;
  padding: 0.7rem 2rem;
  background-color: var(--btn-bg);
  color: var(--btn-text);
  border: none;
  border-radius: 999px;
  cursor: pointer;
  font-size: 0.95rem;
  font-weight: 700;
  transition: background-color 0.2s, transform 0.1s;
}

.submit-btn:hover { background-color: var(--btn-hover-bg); }
.submit-btn:active { transform: scale(0.97); }

.form-feedback {
  font-size: 0.9rem;
  color: #16a34a;
  min-height: 1.2rem;
}

.contact-alt {
  border-top: 1px solid var(--border-color);
  padding-top: 2rem;
}

.contact-alt h2 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.contact-alt p {
  color: var(--desc-color);
  line-height: 1.75;
}

/* ── Footer ────────────────────────────────────────── */
footer {
  background-color: var(--footer-bg);
  border-top: 1px solid var(--border-color);
  transition: background-color 0.3s ease, border-color 0.3s ease;
}

.footer-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 2rem 1.5rem;
  text-align: center;
}

.footer-links {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0.25rem 1.5rem;
  margin-bottom: 1rem;
}

.footer-links a {
  font-size: 0.88rem;
  color: var(--link-color);
  font-weight: 500;
  transition: opacity 0.2s;
}

.footer-links a:hover { opacity: 0.7; text-decoration: underline; }

.footer-note {
  font-size: 0.78rem;
  color: var(--footer-text);
  line-height: 1.6;
  max-width: 640px;
  margin: 0 auto 0.5rem;
}

.footer-copy {
  font-size: 0.78rem;
  color: var(--footer-text);
}

/* ── Responsive ────────────────────────────────────── */
@media (max-width: 640px) {
  header { padding: 0.75rem 1rem; gap: 0.5rem; }
  .main-nav { display: none; }
  .hero { padding: 2.5rem 1.25rem; }
  .hero h1 { font-size: 1.6rem; }
  main { padding: 1.5rem 1rem; }
  .news-grid { grid-template-columns: 1fr; }
}