/* ============================================================
   HiTechBits — Modern Dark Theme Stylesheet
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=Inter:ital,wght@0,400;0,500;0,600;0,700;1,400&family=Syne:wght@600;700;800&family=JetBrains+Mono:wght@400;500&display=swap');

/* ── CSS Variables ─────────────────────────────────────────── */
:root {
  --bg-base:        #0f1117;
  --bg-surface:     #161b27;
  --bg-card:        #1c2333;
  --bg-card-hover:  #212840;
  --bg-deep:        #161b27;
  --bg-void:        #0f1117;

  --border:         #2a3550;
  --border-hi:      #3d5080;

  --accent:         #4f9eff;
  --accent-dim:     #2d6fd4;
  --accent-glow:    rgba(79,158,255,0.15);
  --cyan:           #4f9eff;
  --cyan-dim:       #2d6fd4;
  --green:          #34d399;
  --amber:          #fbbf24;
  --red:            #f87171;
  --purple:         #a78bfa;

  --text-primary:   #f0f4ff;
  --text-secondary: #a8b8d8;
  --text-dim:       #5a6e92;

  --font-display: 'Syne', sans-serif;
  --font-ui:      'Inter', sans-serif;
  --font-mono:    'JetBrains Mono', monospace;

  --shadow-card:  0 2px 12px rgba(0,0,0,0.4), 0 1px 3px rgba(0,0,0,0.3);
  --shadow-hover: 0 8px 32px rgba(0,0,0,0.5), 0 2px 8px rgba(0,0,0,0.3);
  --glow-cyan:    0 0 16px rgba(79,158,255,0.3);
  --glow-green:   0 0 12px rgba(52,211,153,0.3);
  --glow-card:    var(--shadow-hover);
}

/* ── Reset & Base ───────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }

body {
  background: var(--bg-base);
  color: var(--text-primary);
  font-family: var(--font-ui);
  font-size: 16px;
  line-height: 1.6;
  overflow-x: hidden;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body::before {
  content: '';
  position: fixed;
  top: -200px; left: 50%; transform: translateX(-50%);
  width: 900px; height: 600px;
  background: radial-gradient(ellipse at center, rgba(79,158,255,0.06) 0%, transparent 70%);
  pointer-events: none;
  z-index: 0;
}

/* ── Scrollbar ──────────────────────────────────────────────── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg-base); }
::-webkit-scrollbar-thumb { background: var(--border-hi); border-radius: 3px; }

/* ── Header ─────────────────────────────────────────────────── */
header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(15,17,23,0.92);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  max-width: 1400px; margin: 0 auto; padding: 0 2rem;
  height: 64px; display: flex; align-items: center; gap: 1.25rem;
}

.logo {
  display: flex; align-items: center; gap: 10px;
  text-decoration: none; flex-shrink: 0;
}

.logo-icon {
  width: 34px; height: 34px;
  background: linear-gradient(135deg, var(--accent-dim), var(--accent));
  border-radius: 8px;
  display: flex; align-items: center; justify-content: center;
  box-shadow: 0 2px 12px rgba(79,158,255,0.3);
  flex-shrink: 0;
}

.logo-text {
  font-family: var(--font-display);
  font-size: 1.15rem; font-weight: 700;
  color: var(--text-primary); letter-spacing: -0.01em;
}

.logo-text span { color: var(--accent); }

.ticker-wrap {
  flex: 1; min-width: 0; overflow: hidden;
  height: 24px; position: relative; max-width: 480px;
}

.ticker-wrap::before, .ticker-wrap::after {
  content: ''; position: absolute; top: 0; bottom: 0; width: 48px; z-index: 2;
}
.ticker-wrap::before { left: 0;  background: linear-gradient(to right, rgba(15,17,23,0.95), transparent); }
.ticker-wrap::after  { right: 0; background: linear-gradient(to left,  rgba(15,17,23,0.95), transparent); }

.ticker {
  display: flex; align-items: center; height: 100%;
  white-space: nowrap; animation: ticker-scroll 14s linear infinite;
}

.ticker-item {
  font-family: var(--font-mono); font-size: 0.68rem; font-weight: 400;
  color: var(--text-dim); padding: 0 2rem; letter-spacing: 0.02em;
}

.ticker-item::before { content: '· '; color: var(--accent); }

@keyframes ticker-scroll {
  from { transform: translateX(0); }
  to   { transform: translateX(-50%); }
}

.header-right { display: flex; align-items: center; gap: 1rem; flex-shrink: 0; }

.status-dot {
  display: flex; align-items: center; gap: 7px;
  font-family: var(--font-mono); font-size: 0.65rem;
  color: var(--text-dim); letter-spacing: 0.06em;
}

.dot {
  width: 7px; height: 7px; border-radius: 50%;
  background: var(--green); box-shadow: var(--glow-green);
  animation: pulse-dot 2s ease-in-out infinite;
}

@keyframes pulse-dot {
  0%, 100% { opacity: 1; transform: scale(1); }
  50%       { opacity: 0.5; transform: scale(0.82); }
}

.btn-refresh {
  font-family: var(--font-ui); font-size: 0.78rem; font-weight: 600;
  color: var(--accent); background: transparent;
  border: 1px solid var(--border-hi);
  padding: 0.38rem 0.9rem; border-radius: 6px;
  cursor: pointer; transition: all 0.2s; letter-spacing: 0.01em;
}

.btn-refresh:hover { background: var(--accent-glow); border-color: var(--accent-dim); }

/* ── Filter Bar ─────────────────────────────────────────────── */
.filter-bar {
  background: var(--bg-surface); border-bottom: 1px solid var(--border);
  position: sticky; top: 64px; z-index: 99;
}

.filter-inner {
  max-width: 1400px; margin: 0 auto; padding: 0 2rem;
  display: flex; align-items: center; gap: 0.35rem; height: 46px;
  overflow-x: auto; scrollbar-width: none;
}

.filter-inner::-webkit-scrollbar { display: none; }

.filter-label {
  font-family: var(--font-mono); font-size: 0.62rem; color: var(--text-dim);
  letter-spacing: 0.08em; text-transform: uppercase;
  white-space: nowrap; margin-right: 0.4rem; flex-shrink: 0;
}

.filter-btn {
  font-family: var(--font-ui); font-size: 0.78rem; font-weight: 500;
  color: var(--text-dim); background: transparent;
  border: 1px solid transparent;
  padding: 0.25rem 0.85rem; border-radius: 20px;
  cursor: pointer; transition: all 0.15s;
  white-space: nowrap; letter-spacing: 0.01em;
}

.filter-btn:hover { color: var(--text-secondary); background: rgba(255,255,255,0.05); }

.filter-btn.active {
  color: var(--accent); background: rgba(79,158,255,0.1);
  border-color: rgba(79,158,255,0.3); font-weight: 600;
}

/* ── Hero Section ───────────────────────────────────────────── */
.hero {
  max-width: 1400px; margin: 0 auto; padding: 2rem 2rem 1.5rem;
  position: relative; z-index: 1;
}

.hero-grid {
  display: grid; grid-template-columns: 1fr 320px; gap: 1.25rem;
}

/* ── Featured Card ──────────────────────────────────────────── */
.card-featured {
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: 12px; overflow: hidden; cursor: pointer;
  transition: transform 0.25s, box-shadow 0.25s, border-color 0.25s;
  box-shadow: var(--shadow-card);
}

.card-featured:hover {
  transform: translateY(-3px); box-shadow: var(--shadow-hover); border-color: var(--border-hi);
}

.card-featured .card-image-wrap {
  overflow: hidden; position: relative; height: 340px; background: var(--bg-surface);
}

.card-featured .card-image-wrap::after {
  content: ''; position: absolute; inset: 0;
  background: linear-gradient(to top, rgba(28,35,51,0.97) 0%, rgba(28,35,51,0.4) 50%, transparent 100%);
}

.card-featured .card-image {
  width: 100%; height: 100%; object-fit: cover; display: block; transition: transform 0.5s;
}

.card-featured:hover .card-image { transform: scale(1.03); }

.card-featured .no-image {
  height: 340px; display: flex; align-items: center; justify-content: center;
  font-family: var(--font-display); font-size: 4rem; font-weight: 800; color: var(--border-hi);
  background: linear-gradient(135deg, var(--bg-surface), var(--bg-card));
}

.card-featured .card-body { padding: 1.5rem; }

/* ── Shared Card Elements ───────────────────────────────────── */
.card-source-tag {
  display: inline-flex; align-items: center; gap: 6px;
  font-family: var(--font-mono); font-size: 0.65rem; font-weight: 500;
  letter-spacing: 0.04em; text-transform: uppercase;
  padding: 0.18rem 0.55rem; border-radius: 4px; margin-bottom: 0.65rem;
  background: rgba(255,255,255,0.06); color: currentColor;
}

.card-title {
  font-family: var(--font-display); font-size: 1.3rem; font-weight: 700;
  line-height: 1.35; letter-spacing: -0.01em;
  color: var(--text-primary); margin-bottom: 0.6rem; transition: color 0.2s;
}

.card-featured:hover .card-title { color: var(--accent); }

.card-desc {
  font-family: var(--font-ui); font-size: 0.92rem; font-weight: 400;
  color: var(--text-secondary); line-height: 1.7; margin-bottom: 1rem;
}

.card-meta {
  display: flex; align-items: center; gap: 0.65rem;
  font-family: var(--font-mono); font-size: 0.67rem;
  color: var(--text-dim); letter-spacing: 0.02em;
}

.card-meta-dot { color: var(--border-hi); }

/* ── Sidebar / Compact Cards ────────────────────────────────── */
.sidebar-stack { display: flex; flex-direction: column; gap: 0.85rem; }

.card-compact {
  background: var(--bg-card); border: 1px solid var(--border); border-radius: 10px;
  padding: 1rem; cursor: pointer; transition: all 0.2s;
  position: relative; overflow: hidden; box-shadow: var(--shadow-card);
}

.card-compact::before {
  content: ''; position: absolute; left: 0; top: 0; bottom: 0; width: 3px;
  background: var(--source-color, var(--accent)); border-radius: 0 2px 2px 0;
  transform: scaleY(0); transition: transform 0.2s; transform-origin: bottom;
}

.card-compact:hover { background: var(--bg-card-hover); border-color: var(--border-hi); }
.card-compact:hover::before { transform: scaleY(1); }

.card-compact .card-title { font-size: 0.9rem; font-weight: 600; line-height: 1.4; margin-bottom: 0.3rem; }
.card-compact:hover .card-title { color: var(--accent); }
.card-compact .card-desc { display: none; }

/* ── Main Grid ──────────────────────────────────────────────── */
.main-content {
  max-width: 1400px; margin: 0 auto; padding: 0 2rem 4rem;
  position: relative; z-index: 1;
}

.section-header {
  display: flex; align-items: center; gap: 1rem;
  margin: 2rem 0 1.25rem; padding-bottom: 0.75rem; border-bottom: 1px solid var(--border);
}

.section-title {
  font-family: var(--font-mono); font-size: 0.72rem; font-weight: 500;
  letter-spacing: 0.1em; text-transform: uppercase; color: var(--accent);
}

.section-line { flex: 1; height: 1px; background: linear-gradient(to right, var(--border), transparent); }

.section-count { font-family: var(--font-mono); font-size: 0.65rem; color: var(--text-dim); letter-spacing: 0.05em; }

.articles-grid {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); gap: 1.25rem;
}

/* ── Article Cards ──────────────────────────────────────────── */
.card-article {
  background: var(--bg-card); border: 1px solid var(--border); border-radius: 12px;
  overflow: hidden; cursor: pointer; display: flex; flex-direction: column;
  transition: transform 0.25s, box-shadow 0.25s, border-color 0.25s;
  box-shadow: var(--shadow-card);
}

.card-article:hover { transform: translateY(-3px); box-shadow: var(--shadow-hover); border-color: var(--border-hi); }

.card-article .card-image-wrap {
  height: 185px; overflow: hidden; position: relative;
  background: var(--bg-surface); flex-shrink: 0;
}

.card-article .card-image-wrap::after {
  content: ''; position: absolute; inset: 0;
  background: linear-gradient(to top, rgba(28,35,51,0.85) 0%, transparent 60%);
}

.card-article .card-image { width: 100%; height: 100%; object-fit: cover; display: block; transition: transform 0.4s; }
.card-article:hover .card-image { transform: scale(1.04); }

/* Pattern placeholders — don't zoom or darken, they're already designed */
.card-image--pattern {
  image-rendering: crisp-edges;
  transition: none !important;
}
.card-featured:hover .card-image--pattern,
.card-article:hover  .card-image--pattern { transform: none; }

.card-article .no-image {
  width: 100%; height: 100%; display: flex; align-items: center; justify-content: center;
  font-family: var(--font-display); font-size: 2.5rem; font-weight: 800; color: var(--border-hi);
}

.card-article .card-body { padding: 1.1rem; flex: 1; display: flex; flex-direction: column; }
.card-article .card-title { font-size: 1rem; margin-bottom: 0.5rem; }
.card-article:hover .card-title { color: var(--accent); }
.card-article .card-desc { font-size: 0.84rem; flex: 1; margin-bottom: 0.75rem; }

/* ── Loader ─────────────────────────────────────────────────── */
.loader { display: flex; flex-direction: column; align-items: center; justify-content: center; padding: 5rem 2rem; gap: 1.25rem; }

.loader-ring {
  width: 40px; height: 40px; border: 2px solid var(--border);
  border-top-color: var(--accent); border-radius: 50%; animation: spin 0.8s linear infinite;
}

@keyframes spin { to { transform: rotate(360deg); } }

.loader-text { font-family: var(--font-mono); font-size: 0.72rem; color: var(--text-dim); letter-spacing: 0.1em; text-transform: uppercase; }

/* ── Error State ────────────────────────────────────────────── */
.error-state { display: flex; flex-direction: column; align-items: center; padding: 5rem 2rem; gap: 1rem; text-align: center; }
.error-code  { font-family: var(--font-display); font-size: 2.5rem; font-weight: 800; color: var(--red); letter-spacing: 0.05em; }
.error-msg   { font-size: 0.9rem; color: var(--text-secondary); }

/* ── Footer ─────────────────────────────────────────────────── */
footer { background: var(--bg-surface); border-top: 1px solid var(--border); position: relative; z-index: 1; }

.footer-inner {
  max-width: 1400px; margin: 0 auto; padding: 1.75rem 2rem;
  display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 1rem;
}

.footer-brand { font-family: var(--font-display); font-size: 0.9rem; font-weight: 700; color: var(--text-dim); letter-spacing: -0.01em; }
.footer-brand span { color: var(--accent); }

.footer-links { display: flex; gap: 1.5rem; }
.footer-links a { font-size: 0.82rem; font-weight: 500; color: var(--text-dim); text-decoration: none; transition: color 0.2s; }
.footer-links a:hover { color: var(--text-secondary); }

.footer-copy { font-family: var(--font-mono); font-size: 0.65rem; color: var(--text-dim); }

/* ── Animations ─────────────────────────────────────────────── */
.fade-in { animation: fadeInUp 0.45s ease forwards; opacity: 0; }

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(14px); }
  to   { opacity: 1; transform: translateY(0); }
}

.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; }

/* ── Responsive ─────────────────────────────────────────────── */

@media (max-width: 1024px) {
  .hero-grid { grid-template-columns: 1fr; }
  .sidebar-stack { flex-direction: row; flex-wrap: wrap; }
  .card-compact { flex: 1; min-width: 260px; }
  .articles-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 768px) {
  .header-inner { padding: 0 1rem; height: 56px; gap: 0.75rem; }
  .logo-text    { font-size: 1rem; }
  .logo-icon    { width: 28px; height: 28px; border-radius: 6px; }
  .ticker-wrap  { display: none; }
  .search-wrap  { display: none; }
  .status-dot span { display: none; }
  .btn-refresh  { font-size: 0.72rem; padding: 0.3rem 0.65rem; }

  .mobile-search {
    display: block; background: var(--bg-surface); border-bottom: 1px solid var(--border); padding: 0.6rem 1rem;
  }
  .mobile-search .search-box { width: 100%; clip-path: none; border-radius: 8px; height: 40px; }

  .filter-bar { position: relative; top: auto; }
  .filter-inner { padding: 0 1rem; height: 42px; gap: 0.3rem; }
  .filter-btn { font-size: 0.72rem; padding: 0.22rem 0.65rem; }

  .topic-bar { top: auto; }
  .topic-inner { padding: 0 1rem; height: 40px; gap: 0.3rem; }

  .hero { padding: 1rem 1rem 0.5rem; }
  .card-featured { border-radius: 10px; }
  .card-featured .card-image-wrap { height: 210px; }
  .card-featured .no-image        { height: 210px; font-size: 2.5rem; }
  .card-featured .card-body       { padding: 1rem; }
  .card-featured .card-title      { font-size: 1.1rem; }

  .sidebar-stack { flex-direction: column; gap: 0.65rem; }
  .card-compact  { min-width: unset; flex: none; border-radius: 10px; }

  .main-content  { padding: 0 1rem 3rem; }
  .articles-grid { grid-template-columns: 1fr; gap: 0.85rem; }
  .card-article  { border-radius: 10px; }
  .card-article .card-image-wrap { height: 165px; }
  .card-article .card-title      { font-size: 0.95rem; }

  .section-header { margin: 1.5rem 0 1rem; }

  .footer-inner  { flex-direction: column; align-items: flex-start; gap: 0.75rem; padding: 1.5rem 1rem; }
  .footer-links  { gap: 1rem; }
  .footer-copy   { font-size: 0.62rem; }

  .error-code      { font-size: 2rem; }
  .no-results-code { font-size: 1.8rem; }
}

@media (max-width: 480px) {
  .header-inner { height: 52px; }
  .logo-text    { font-size: 0.9rem; }
  .filter-btn   { font-size: 0.68rem; padding: 0.18rem 0.5rem; }
  .filter-label { display: none; }
  .topic-label  { display: none; }
  .topic-btn    { font-size: 0.65rem; padding: 0.18rem 0.6rem; }
  .card-featured .card-image-wrap { height: 175px; }
  .card-featured .card-title      { font-size: 1rem; }
  .card-featured .card-desc       { font-size: 0.85rem; }
  .articles-grid { gap: 0.7rem; }
  .card-article .card-image-wrap  { height: 145px; }
}

/* ── Search ─────────────────────────────────────────────────── */
.search-wrap { flex: 0 0 260px; display: flex; flex-direction: column; gap: 4px; }

.search-box {
  display: flex; align-items: center; background: var(--bg-surface);
  border: 1px solid var(--border); border-radius: 8px;
  padding: 0 0.75rem; height: 36px; gap: 0.5rem;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.search-box:focus-within { border-color: var(--accent-dim); box-shadow: 0 0 0 3px rgba(79,158,255,0.12); }

.search-icon { width: 14px; height: 14px; color: var(--text-dim); flex-shrink: 0; transition: color 0.2s; }
.search-box:focus-within .search-icon { color: var(--accent); }

.search-input {
  flex: 1; background: transparent; border: none; outline: none;
  font-family: var(--font-ui); font-size: 0.85rem; font-weight: 400;
  color: var(--text-primary); min-width: 0;
}

.search-input::placeholder { color: var(--text-dim); }
.search-input::-webkit-search-cancel-button { display: none; }

.search-clear { background: transparent; border: none; color: var(--text-dim); cursor: pointer; font-size: 0.7rem; padding: 0 2px; line-height: 1; transition: color 0.2s; flex-shrink: 0; }
.search-clear:hover { color: var(--accent); }

body.searching .ticker-wrap { opacity: 0.3; pointer-events: none; }

.highlight { background: rgba(79,158,255,0.2); color: var(--accent); border-radius: 3px; padding: 0 2px; font-weight: 600; }

.no-results { grid-column: 1 / -1; display: flex; flex-direction: column; align-items: center; padding: 5rem 2rem; gap: 1rem; text-align: center; }
.no-results-code { font-family: var(--font-display); font-size: 2.5rem; font-weight: 800; color: var(--text-dim); letter-spacing: 0.05em; }
.no-results-msg  { font-size: 0.92rem; color: var(--text-secondary); }
.no-results-query { font-family: var(--font-mono); color: var(--accent); }

.search-badge { font-family: var(--font-mono); font-size: 0.62rem; color: var(--accent); background: rgba(79,158,255,0.1); border: 1px solid rgba(79,158,255,0.25); padding: 0.15rem 0.5rem; border-radius: 20px; letter-spacing: 0.06em; display: none; }
.search-badge.visible { display: inline-block; }

@media (max-width: 768px) { .search-wrap { max-width: 100%; } }

/* ── Topic Bar ──────────────────────────────────────────────── */
.topic-bar { background: var(--bg-base); border-bottom: 1px solid var(--border); position: sticky; top: 110px; z-index: 98; }

.topic-inner { max-width: 1400px; margin: 0 auto; padding: 0 2rem; display: flex; align-items: center; gap: 0.4rem; height: 42px; overflow-x: auto; scrollbar-width: none; }
.topic-inner::-webkit-scrollbar { display: none; }

.topic-label { font-family: var(--font-mono); font-size: 0.62rem; color: var(--text-dim); letter-spacing: 0.08em; text-transform: uppercase; white-space: nowrap; margin-right: 0.4rem; flex-shrink: 0; }

.topic-btn {
  font-family: var(--font-ui); font-size: 0.76rem; font-weight: 500; letter-spacing: 0.01em;
  color: var(--text-dim); background: transparent; border: 1px solid var(--border);
  padding: 0.22rem 0.75rem; cursor: pointer;
  transition: color 0.15s, background 0.15s, border-color 0.15s;
  white-space: nowrap; border-radius: 20px;
  display: inline-flex; align-items: center; gap: 5px; flex-shrink: 0; line-height: 1.8;
}

.topic-icon { font-size: 0.75rem; line-height: 1; }

.topic-btn:hover { color: var(--text-secondary); border-color: var(--border-hi); background: rgba(255,255,255,0.04); }

.topic-btn.active { color: #0f1117; border-color: transparent; font-weight: 600; }

.topic-btn[data-topic="hardware"].active      { background: #fbbf24; }
.topic-btn[data-topic="software"].active      { background: #34d399; }
.topic-btn[data-topic="ai"].active            { background: #a78bfa; }
.topic-btn[data-topic="cybersecurity"].active { background: #f87171; }
.topic-btn[data-topic="3dprinting"].active    { background: #22d3ee; }
.topic-btn[data-topic="mobile"].active        { background: #34d399; }
.topic-btn[data-topic="wellness"].active      { background: #f472b6; }

@media (max-width: 768px) { .topic-inner { padding: 0 1rem; } }