/* TrendVault — Stripe/Linear-inspired premium dark theme */

:root {
  --bg: #0a0b0f;
  --bg-elev: #11131a;
  --bg-elev-2: #161922;
  --border: #1f2330;
  --border-strong: #2a3040;
  --text: #e8eaf1;
  --text-muted: #9aa3b8;
  --text-faint: #6b7286;
  --brand: #7c5cff;
  --brand-2: #00d4ff;
  --brand-grad: linear-gradient(135deg, #7c5cff 0%, #00d4ff 100%);
  --success: #1ed98a;
  --warn: #ffb547;
  --danger: #ff5d6c;
  --tiktok: #ff2c55;
  --instagram: #e1306c;
  --youtube: #ff0033;
  --amazon: #ff9900;
  --radius: 14px;
  --radius-sm: 8px;
  --shadow-card: 0 1px 0 rgba(255,255,255,0.04) inset, 0 8px 24px rgba(0,0,0,0.35);
  --shadow-hover: 0 1px 0 rgba(255,255,255,0.06) inset, 0 14px 40px rgba(0,0,0,0.5);
  --container: 1180px;
  --gutter: 24px;
  --t-fast: 160ms cubic-bezier(.2,.7,.2,1);
  --t-med: 280ms cubic-bezier(.2,.7,.2,1);
  --font: 'Inter', system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, sans-serif;
}

[data-theme="light"] {
  --bg: #ffffff;
  --bg-elev: #f7f8fb;
  --bg-elev-2: #eef0f6;
  --border: #e5e8ef;
  --border-strong: #d3d8e4;
  --text: #0e1220;
  --text-muted: #4a5168;
  --text-faint: #717892;
  --shadow-card: 0 1px 0 rgba(255,255,255,0.8) inset, 0 6px 20px rgba(20,25,40,0.06);
  --shadow-hover: 0 1px 0 rgba(255,255,255,0.9) inset, 0 12px 32px rgba(20,25,40,0.1);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: 0.001ms !important; transition-duration: 0.001ms !important; }
}

body {
  margin: 0;
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img, svg { max-width: 100%; display: block; }

a { color: var(--text); text-decoration: none; }
a:hover { color: var(--brand-2); }

h1, h2, h3, h4 { font-weight: 700; letter-spacing: -0.02em; line-height: 1.2; margin: 0 0 .5em; }
h1 { font-size: clamp(2.2rem, 5vw, 3.6rem); letter-spacing: -0.03em; }
h2 { font-size: clamp(1.6rem, 3.2vw, 2.2rem); }
h3 { font-size: 1.15rem; }
p { margin: 0 0 1em; }

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

.visually-hidden { position: absolute !important; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }

.skip-link {
  position: absolute; top: -40px; left: 0; padding: 8px 14px;
  background: var(--brand); color: #fff; z-index: 999; border-radius: 0 0 8px 0;
}
.skip-link:focus { top: 0; }

/* Header */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in oklab, var(--bg) 80%, transparent);
  backdrop-filter: saturate(160%) blur(10px);
  -webkit-backdrop-filter: saturate(160%) blur(10px);
  border-bottom: 1px solid var(--border);
}
.nav-wrap { display: flex; align-items: center; justify-content: space-between; padding: 14px 24px; gap: 16px; }
.logo { display: inline-flex; align-items: center; gap: 10px; font-weight: 800; letter-spacing: -.02em; }
.logo-mark {
  display: inline-grid; place-items: center; width: 32px; height: 32px;
  border-radius: 8px; color: #fff; font-size: .8rem; font-weight: 800;
  background: var(--brand-grad);
  box-shadow: 0 4px 14px rgba(124,92,255,.45);
}
.logo-text { font-size: 1.05rem; }

.primary-nav ul { list-style: none; padding: 0; margin: 0; display: flex; gap: 6px; }
.primary-nav a {
  padding: 8px 12px; border-radius: 8px; font-size: .94rem;
  color: var(--text-muted); transition: color var(--t-fast), background var(--t-fast);
}
.primary-nav a:hover { color: var(--text); background: var(--bg-elev); }

.nav-actions { display: flex; align-items: center; gap: 8px; }

.theme-toggle, .hamburger {
  background: var(--bg-elev); color: var(--text);
  border: 1px solid var(--border);
  border-radius: 10px; padding: 8px; cursor: pointer;
  display: inline-grid; place-items: center;
  transition: background var(--t-fast), border-color var(--t-fast), transform var(--t-fast);
}
.theme-toggle:hover, .hamburger:hover { border-color: var(--border-strong); }
.theme-toggle .icon-moon { display: none; }
[data-theme="light"] .theme-toggle .icon-sun { display: none; }
[data-theme="light"] .theme-toggle .icon-moon { display: block; }

.hamburger { display: none; flex-direction: column; gap: 4px; width: 38px; height: 38px; }
.hamburger span { display: block; width: 18px; height: 2px; background: var(--text); border-radius: 2px; transition: transform var(--t-fast), opacity var(--t-fast); }
.hamburger[aria-expanded="true"] span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.hamburger[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.hamburger[aria-expanded="true"] span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

.mobile-nav { border-top: 1px solid var(--border); background: var(--bg-elev); }
.mobile-nav ul { list-style: none; padding: 8px 16px; margin: 0; display: grid; gap: 4px; }
.mobile-nav a { display: block; padding: 10px 12px; border-radius: 8px; color: var(--text-muted); }
.mobile-nav a:hover { color: var(--text); background: var(--bg-elev-2); }

@media (max-width: 820px) {
  .primary-nav { display: none; }
  .hamburger { display: inline-flex; }
}

/* Hero */
.hero {
  padding: 88px 0 64px;
  position: relative; overflow: hidden;
  background:
    radial-gradient(1000px 500px at 80% -10%, rgba(124,92,255,.22), transparent 60%),
    radial-gradient(800px 400px at 10% 10%, rgba(0,212,255,.14), transparent 60%);
}
.eyebrow {
  display: inline-block; font-size: .82rem; font-weight: 600;
  color: var(--brand-2); letter-spacing: .04em; text-transform: uppercase;
  padding: 6px 12px; border-radius: 999px;
  background: color-mix(in oklab, var(--brand-2) 14%, transparent);
  border: 1px solid color-mix(in oklab, var(--brand-2) 30%, transparent);
  margin-bottom: 18px;
}
.hero h1 {
  background: linear-gradient(180deg, var(--text) 60%, color-mix(in oklab, var(--text) 70%, transparent));
  -webkit-background-clip: text; background-clip: text; color: transparent;
  max-width: 900px;
}
.lede { font-size: clamp(1.05rem, 1.4vw, 1.2rem); color: var(--text-muted); max-width: 680px; }

.hero-form, .newsletter-form {
  display: flex; gap: 8px; flex-wrap: wrap;
  background: var(--bg-elev); border: 1px solid var(--border);
  padding: 8px; border-radius: 14px; max-width: 540px;
  box-shadow: var(--shadow-card);
}
.hero-form input, .newsletter-form input {
  flex: 1 1 220px; min-width: 0;
  background: transparent; border: 0; outline: none;
  color: var(--text); font-family: inherit; font-size: 1rem; padding: 12px 14px;
}
.hero-form input::placeholder, .newsletter-form input::placeholder { color: var(--text-faint); }

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  font-family: inherit; font-weight: 600; font-size: .95rem;
  padding: 12px 18px; border-radius: 10px; border: 0; cursor: pointer;
  transition: transform var(--t-fast), box-shadow var(--t-fast), opacity var(--t-fast);
}
.btn-primary { color: #fff; background: var(--brand-grad); box-shadow: 0 8px 22px rgba(124,92,255,.35); }
.btn-primary:hover { transform: translateY(-1px); box-shadow: 0 12px 28px rgba(124,92,255,.5); }
.btn-primary:active { transform: translateY(0); }

.hero-meta { color: var(--text-faint); font-size: .88rem; margin-top: 14px; }

/* Section heads */
.section-head { margin-bottom: 28px; }
.section-head p { color: var(--text-muted); margin: 0; }

/* Trending */
.trending { padding: 72px 0; }
.filters {
  display: flex; flex-wrap: wrap; gap: 8px;
  background: var(--bg-elev); border: 1px solid var(--border);
  padding: 6px; border-radius: 12px; margin-bottom: 24px; width: max-content; max-width: 100%;
}
.filter {
  padding: 8px 14px; border-radius: 8px; border: 0; cursor: pointer;
  color: var(--text-muted); background: transparent;
  font-family: inherit; font-weight: 500; font-size: .9rem;
  transition: color var(--t-fast), background var(--t-fast);
}
.filter:hover { color: var(--text); }
.filter.is-active { color: var(--text); background: var(--bg-elev-2); box-shadow: 0 1px 0 rgba(255,255,255,.05) inset; }

.trend-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 20px; }

.trend-card {
  background: var(--bg-elev); border: 1px solid var(--border);
  border-radius: var(--radius); overflow: hidden;
  box-shadow: var(--shadow-card);
  transition: transform var(--t-med), box-shadow var(--t-med), border-color var(--t-med);
  display: flex; flex-direction: column;
}
.trend-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-hover); border-color: var(--border-strong); }

.trend-media { position: relative; aspect-ratio: 4/3; overflow: hidden; }
.placeholder { width: 100%; height: 100%; background: var(--bg-elev-2); }
.placeholder-1 { background: linear-gradient(135deg, #2d1b69 0%, #11998e 100%); }
.placeholder-2 { background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%); }
.placeholder-3 { background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%); }
.placeholder-4 { background: linear-gradient(135deg, #fa709a 0%, #fee140 100%); }
.placeholder-5 { background: linear-gradient(135deg, #30cfd0 0%, #330867 100%); }
.placeholder-6 { background: linear-gradient(135deg, #a8edea 0%, #fed6e3 100%); }

.platform-badge {
  position: absolute; top: 12px; left: 12px;
  font-size: .72rem; font-weight: 700; letter-spacing: .04em; text-transform: uppercase;
  color: #fff; padding: 5px 10px; border-radius: 999px;
  backdrop-filter: blur(8px);
}
.platform-tiktok { background: color-mix(in oklab, var(--tiktok) 75%, transparent); }
.platform-instagram { background: color-mix(in oklab, var(--instagram) 75%, transparent); }
.platform-youtube { background: color-mix(in oklab, var(--youtube) 75%, transparent); }
.platform-amazon { background: color-mix(in oklab, var(--amazon) 80%, transparent); }

.trend-body { padding: 18px; display: flex; flex-direction: column; gap: 10px; flex: 1; }
.trend-body h3 { margin: 0; }
.trend-meta { color: var(--text-muted); font-size: .92rem; margin: 0; }
.trend-stats { list-style: none; padding: 0; margin: 4px 0 0; display: flex; gap: 14px; flex-wrap: wrap; font-size: .82rem; color: var(--text-faint); }
.trend-stats strong { color: var(--text); font-weight: 600; }
.trend-stats li { display: inline-flex; align-items: center; gap: 4px; }

.affiliate-link {
  margin-top: auto;
  display: inline-flex; align-items: center; gap: 8px;
  padding: 9px 12px; border-radius: 8px;
  background: var(--bg-elev-2); color: var(--text);
  font-weight: 500; font-size: .9rem;
  border: 1px solid var(--border);
  transition: background var(--t-fast), border-color var(--t-fast);
  align-self: flex-start;
}
.affiliate-link:hover { background: var(--bg); border-color: var(--border-strong); color: var(--brand-2); }
.aff-badge {
  display: inline-block; font-size: .65rem; font-weight: 700; letter-spacing: .06em;
  background: var(--warn); color: #1a1100; padding: 2px 6px; border-radius: 4px;
}

/* Newsletter */
.newsletter {
  padding: 72px 0;
  background:
    radial-gradient(700px 320px at 90% 50%, rgba(124,92,255,.18), transparent 60%),
    radial-gradient(700px 320px at 0% 50%, rgba(0,212,255,.12), transparent 60%),
    var(--bg);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}
.newsletter-inner { display: grid; grid-template-columns: 1.1fr 1fr; gap: 48px; align-items: center; }
.benefits { list-style: none; padding: 0; margin: 14px 0 0; display: grid; gap: 8px; }
.benefits li { color: var(--text-muted); padding-left: 24px; position: relative; }
.benefits li::before { content: ""; position: absolute; left: 0; top: .55em; width: 14px; height: 14px; border-radius: 4px; background: var(--brand-grad); }
.form-note { width: 100%; font-size: .8rem; color: var(--text-faint); margin: 4px 0 0; }
.form-note a { color: var(--brand-2); text-decoration: underline; }

@media (max-width: 820px) { .newsletter-inner { grid-template-columns: 1fr; gap: 24px; } }

/* Articles */
.articles { padding: 72px 0; }
.article-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 22px; }
.article-card {
  background: var(--bg-elev); border: 1px solid var(--border);
  border-radius: var(--radius); overflow: hidden;
  box-shadow: var(--shadow-card);
  transition: transform var(--t-med), box-shadow var(--t-med), border-color var(--t-med);
}
.article-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-hover); border-color: var(--border-strong); }
.article-media { aspect-ratio: 16/9; }
.article-body { padding: 20px; }
.article-meta { display: flex; flex-wrap: wrap; gap: 10px; font-size: .82rem; color: var(--text-faint); margin-bottom: 10px; align-items: center; }
.tag { color: var(--brand-2); border: 1px solid color-mix(in oklab, var(--brand-2) 35%, transparent); padding: 2px 8px; border-radius: 999px; font-weight: 600; font-size: .72rem; letter-spacing: .04em; text-transform: uppercase; }
.article-card h3 a { background: linear-gradient(currentColor, currentColor) bottom left / 0 1px no-repeat; transition: background-size var(--t-med); }
.article-card h3 a:hover { background-size: 100% 1px; }

/* Footer */
.site-footer { background: var(--bg-elev); border-top: 1px solid var(--border); padding: 56px 0 24px; margin-top: 32px; }
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1fr; gap: 32px; }
.footer-brand p { color: var(--text-muted); font-size: .88rem; margin-top: 14px; max-width: 38ch; }
.footer-nav h2, .footer-social h2 { font-size: .8rem; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--text-faint); margin: 0 0 12px; }
.footer-nav ul, .social-list { list-style: none; padding: 0; margin: 0; display: grid; gap: 8px; }
.footer-nav a, .social-list a { color: var(--text-muted); font-size: .92rem; }
.footer-nav a:hover, .social-list a:hover { color: var(--text); }
.footer-bottom { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 10px; margin-top: 36px; padding-top: 20px; border-top: 1px solid var(--border); color: var(--text-faint); font-size: .85rem; }

@media (max-width: 820px) { .footer-grid { grid-template-columns: 1fr 1fr; } }
@media (max-width: 520px) { .footer-grid { grid-template-columns: 1fr; } }

/* Back to top */
.back-to-top {
  position: fixed; right: 22px; bottom: 22px; z-index: 60;
  width: 44px; height: 44px; border-radius: 12px;
  background: var(--brand-grad); color: #fff; border: 0; cursor: pointer;
  display: inline-grid; place-items: center;
  box-shadow: 0 10px 28px rgba(124,92,255,.45);
  opacity: 0; transform: translateY(8px); transition: opacity var(--t-med), transform var(--t-med);
}
.back-to-top.is-visible { opacity: 1; transform: translateY(0); }

/* Reveal animations (Intersection Observer) */
.reveal { opacity: 0; transform: translateY(14px); transition: opacity 600ms ease, transform 600ms ease; will-change: opacity, transform; }
.reveal.is-visible { opacity: 1; transform: none; }

/* Legal / generic page */
.page {
  padding: 64px 0 80px;
}
.page .container { max-width: 820px; }
.page h1 { margin-bottom: 8px; }
.page .updated { color: var(--text-faint); font-size: .9rem; margin-bottom: 28px; }
.page h2 { margin-top: 36px; }
.page h3 { margin-top: 24px; }
.page ul, .page ol { padding-left: 1.3em; }
.page li { margin: 6px 0; color: var(--text-muted); }
.page p { color: var(--text-muted); }
.page strong { color: var(--text); }
.page a { color: var(--brand-2); text-decoration: underline; }

.callout {
  background: var(--bg-elev); border: 1px solid var(--border);
  border-left: 3px solid var(--brand);
  padding: 16px 18px; border-radius: 10px; margin: 18px 0;
}

/* Focus */
:focus-visible { outline: 2px solid var(--brand-2); outline-offset: 2px; border-radius: 4px; }

/* Forms invalid feedback */
.field-error { color: var(--danger); font-size: .85rem; margin: 6px 0 0; width: 100%; }
.field-success { color: var(--success); font-size: .9rem; margin: 6px 0 0; width: 100%; }