/* ============================================
   Qing Press — Stripe-Inspired Design System
   ============================================ */

:root {
  /* Brand */
  --color-primary: #533afd;
  --color-primary-hover: #4434d4;
  --color-primary-light: #b9b9f9;
  --color-primary-subtle: rgba(83, 58, 253, 0.05);

  /* Dark Brand Sections */
  --color-brand-dark: #1c1e54;
  --color-dark-navy: #0d253d;

  /* Accent (decorative only) */
  --color-ruby: #ea2261;
  --color-magenta: #f96bee;

  /* Surfaces */
  --color-bg: #ffffff;
  --color-bg-alt: #f6f9fc;
  --color-surface: #ffffff;

  /* Text */
  --color-heading: #061b31;
  --color-label: #273951;
  --color-body: #64748d;
  --color-muted: #8793a6;

  /* Borders */
  --color-border: #e5edf5;
  --color-border-light: #f6f9fc;

  /* Semantic */
  --color-success: #15be53;
  --color-success-text: #108c3d;
  --color-danger: #ea2261;

  /* Typography */
  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'SF Pro Display',
    'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Helvetica Neue', sans-serif;
  --font-mono: 'Source Code Pro', 'SFMono-Regular', ui-monospace, monospace;

  /* Shadows — blue-tinted, Stripe signature */
  --shadow-sm: rgba(23, 23, 23, 0.06) 0px 3px 6px;
  --shadow-md: rgba(23, 23, 23, 0.08) 0px 15px 35px;
  --shadow-lg: rgba(50, 50, 93, 0.25) 0px 30px 45px -30px,
    rgba(0, 0, 0, 0.1) 0px 18px 36px -18px;
  --shadow-xl: rgba(3, 3, 39, 0.25) 0px 14px 21px -14px,
    rgba(0, 0, 0, 0.1) 0px 8px 17px -8px;

  /* Radius — conservative, Stripe-style */
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;

  /* Transitions */
  --duration-fast: 150ms;
  --duration-normal: 250ms;
  --ease-default: cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
  font-family: var(--font-primary);
  font-size: 16px;
  line-height: 1.5;
  color: var(--color-body);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  font-feature-settings: 'ss01';
}

a { color: var(--color-primary); text-decoration: none; transition: color var(--duration-fast) var(--ease-default); }
a:hover { color: var(--color-primary-hover); }

/* === Typography === */
.h-display { font-size: 48px; font-weight: 300; line-height: 1.15; letter-spacing: -0.96px; color: var(--color-heading); }
.h-section { font-size: 32px; font-weight: 300; line-height: 1.1; letter-spacing: -0.64px; color: var(--color-heading); }
.h-sub { font-size: 22px; font-weight: 300; line-height: 1.1; letter-spacing: -0.22px; color: var(--color-heading); }
.h-card { font-size: 18px; font-weight: 400; line-height: 1.4; color: var(--color-heading); }

.text-body-lg { font-size: 18px; font-weight: 300; line-height: 1.6; color: var(--color-body); }
.text-body { font-size: 16px; font-weight: 300; line-height: 1.5; color: var(--color-body); }
.text-caption { font-size: 14px; font-weight: 400; line-height: 1.5; color: var(--color-body); }
.text-small { font-size: 13px; font-weight: 400; line-height: 1.5; color: var(--color-muted); }

/* Dark section text */
.dark-section { color: rgba(255, 255, 255, 0.7); }
.dark-section .h-display, .dark-section .h-section, .dark-section .h-sub { color: #ffffff; }

/* === Buttons === */
.btn-primary {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 10px 20px; font-size: 16px; font-weight: 400; font-family: var(--font-primary);
  color: #fff; background: var(--color-primary); border: none; border-radius: var(--radius-sm);
  cursor: pointer; transition: background var(--duration-fast) var(--ease-default);
  font-feature-settings: 'ss01';
}
.btn-primary:hover { background: var(--color-primary-hover); color: #fff; }

.btn-ghost {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 10px 20px; font-size: 16px; font-weight: 400; font-family: var(--font-primary);
  color: var(--color-primary); background: transparent;
  border: 1px solid var(--color-primary-light); border-radius: var(--radius-sm);
  cursor: pointer; transition: background var(--duration-fast) var(--ease-default);
  font-feature-settings: 'ss01';
}
.btn-ghost:hover { background: var(--color-primary-subtle); }

.btn-sm {
  padding: 6px 14px; font-size: 14px;
}

/* === Cards === */
.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: box-shadow var(--duration-normal) var(--ease-default);
}
.card:hover { box-shadow: var(--shadow-lg); }

.card-elevated {
  box-shadow: var(--shadow-md);
}

/* === Forms === */
.form-input {
  width: 100%; padding: 10px 14px; font-size: 14px; font-family: var(--font-primary);
  color: var(--color-heading); background: var(--color-bg);
  border: 1px solid var(--color-border); border-radius: var(--radius-sm);
  outline: none; transition: border-color var(--duration-fast);
  font-feature-settings: 'ss01';
}
.form-input:focus { border-color: var(--color-primary); }
.form-input::placeholder { color: var(--color-muted); }

.form-label {
  display: block; font-size: 14px; font-weight: 400; color: var(--color-label);
  margin-bottom: 6px;
}

.form-error { font-size: 12px; color: var(--color-danger); margin-top: 4px; }

/* === Badge === */
.badge {
  display: inline-flex; align-items: center;
  padding: 2px 8px; font-size: 12px; font-weight: 400;
  border-radius: var(--radius-sm); border: 1px solid var(--color-border-light);
}

.badge-primary {
  color: var(--color-primary); border-color: var(--color-primary-light);
  background: var(--color-primary-subtle);
}

.badge-success {
  color: var(--color-success-text); border-color: rgba(21, 190, 83, 0.4);
  background: rgba(21, 190, 83, 0.1);
}

/* === Pills (category filters) === */
.pill {
  display: inline-flex; align-items: center;
  padding: 6px 14px; font-size: 14px; font-weight: 400;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
  background: var(--color-bg);
  color: var(--color-body);
  cursor: pointer; transition: all var(--duration-fast) var(--ease-default);
}
.pill:hover { border-color: var(--color-primary-light); color: var(--color-primary); }
.pill-active {
  background: var(--color-primary); color: #fff;
  border-color: var(--color-primary);
}

/* === Section rhythm === */
.section { padding: 80px 0; }
.section-dark { background: var(--color-brand-dark); color: rgba(255, 255, 255, 0.7); }
.section-alt { background: var(--color-bg-alt); }

.wrap { max-width: 1080px; margin: 0 auto; padding: 0 24px; }

/* === Prose (article content) === */
.prose { font-size: 17px; line-height: 1.75; color: var(--color-label); }
.prose h1, .prose h2, .prose h3 { color: var(--color-heading); font-weight: 300; margin: 1.5em 0 0.5em; }
.prose h2 { font-size: 24px; letter-spacing: -0.26px; }
.prose h3 { font-size: 20px; }
.prose p { margin-bottom: 1.2em; }
.prose a { color: var(--color-primary); }
.prose img { border-radius: var(--radius-md); margin: 1.5em 0; }
.prose code { font-family: var(--font-mono); font-size: 14px; background: var(--color-bg-alt); padding: 2px 6px; border-radius: 3px; }
.prose pre { background: var(--color-heading); color: #e2e8f0; padding: 20px; border-radius: var(--radius-md); overflow-x: auto; margin: 1.5em 0; }
.prose pre code { background: none; padding: 0; }
.prose ul, .prose ol { margin: 1em 0; padding-left: 1.5em; }
.prose li { margin-bottom: 0.4em; }
.prose blockquote { border-left: 3px solid var(--color-primary); padding-left: 16px; color: var(--color-body); margin: 1.5em 0; }

/* === Pagination === */
.pagination { display: flex; gap: 4px; justify-content: center; margin-top: 48px; }
.pagination a, .pagination span {
  display: inline-flex; align-items: center; justify-content: center;
  min-width: 36px; height: 36px; padding: 0 8px;
  font-size: 14px; border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
  color: var(--color-body); transition: all var(--duration-fast);
}
.pagination a:hover { border-color: var(--color-primary-light); color: var(--color-primary); }
.pagination .active { background: var(--color-primary); color: #fff; border-color: var(--color-primary); }

/* === Responsive === */
@media (max-width: 768px) {
  .h-display { font-size: 32px; letter-spacing: -0.64px; }
  .h-section { font-size: 24px; letter-spacing: -0.26px; }
  .h-sub { font-size: 20px; letter-spacing: -0.22px; }
  .section { padding: 48px 0; }
  .container { padding: 0 16px; }
}