/* ---------------------------------------------------------------------------
   TradeSpark AI Aesthetic — see DESIGN.md
   --------------------------------------------------------------------------- */

:root {
  /* Material-You palette (mirrors DESIGN.md frontmatter) */
  --md-surface: #f6fafd;
  --md-surface-dim: #d6dbdd;
  --md-surface-bright: #f6fafd;
  --md-surface-container-lowest: #ffffff;
  --md-surface-container-low: #f0f4f7;
  --md-surface-container: #eaeef1;
  --md-surface-container-high: #e5e9ec;
  --md-surface-container-highest: #dfe3e6;
  --md-on-surface: #171c1f;
  --md-on-surface-variant: #43474f;
  --md-inverse-surface: #2c3134;
  --md-inverse-on-surface: #edf1f4;
  --md-outline: #737780;
  --md-outline-variant: #c3c6d0;
  --md-primary: #002851;
  --md-on-primary: #ffffff;
  --md-primary-container: #183e6d;
  --md-on-primary-container: #89aae0;
  --md-secondary: #b12e00;
  --md-secondary-container: #fe6436;
  --md-tertiary-container: #5f3200;
  --md-error: #ba1a1a;

  /* Component-level aliases per the narrative spec */
  --color-bg: #f4f8fb;
  --color-card: #ffffff;
  --color-card-border: rgba(24, 62, 109, 0.08);
  --color-primary: #183e6d;
  --color-primary-hover: #234777;
  --color-primary-glow: rgba(24, 62, 109, 0.18);
  --color-action: #e45125;
  --color-action-hover: #c8421a;
  --color-tertiary: #f7983a;
  --color-text: #171c1f;
  --color-text-muted: #43474f;
  --color-text-subtle: #737780;
  --color-error: #ba1a1a;

  /* Shadows */
  --shadow-soft: 0 10px 30px rgba(24, 62, 109, 0.05);
  --shadow-lift: 0 16px 40px rgba(24, 62, 109, 0.10);

  /* Radius */
  --radius-sm: 0.25rem;
  --radius: 0.5rem;
  --radius-md: 0.75rem;
  --radius-lg: 1rem;
  --radius-xl: 1.5rem;
  --radius-full: 9999px;

  /* Spacing */
  --space-base: 8px;
  --space-stack-sm: 12px;
  --space-stack-md: 24px;
  --space-stack-lg: 48px;
  --space-section: 80px;
  --gutter: 24px;
  --container-max: 1200px;

  /* Typography */
  --font-sans: "Plus Jakarta Sans", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-sans);
  font-size: 16px;
  font-weight: 400;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color 0.15s ease;
}
a:hover { color: var(--color-action); }

/* ---------------------------------------------------------------------------
   Typography utility classes (mirror DESIGN.md type scale)
   --------------------------------------------------------------------------- */

.t-display {
  font-size: 48px;
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.02em;
}
.t-headline-lg {
  font-size: 32px;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.01em;
}
.t-headline-md {
  font-size: 24px;
  font-weight: 600;
  line-height: 1.3;
}
.t-body-lg { font-size: 18px; line-height: 1.6; }
.t-body-md { font-size: 16px; line-height: 1.6; }
.t-label-sm {
  font-size: 12px;
  font-weight: 600;
  line-height: 1;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--color-text-muted);
}

h1 { font-size: 32px; font-weight: 700; line-height: 1.2; letter-spacing: -0.01em; margin: 0 0 var(--space-stack-md); }
h2 { font-size: 24px; font-weight: 600; line-height: 1.3; margin: var(--space-stack-lg) 0 var(--space-stack-md); }
h3 { font-size: 18px; font-weight: 600; line-height: 1.4; margin: var(--space-stack-md) 0 var(--space-stack-sm); }
p  { margin: 0 0 var(--space-stack-sm); }

/* ---------------------------------------------------------------------------
   Layout — site shell
   --------------------------------------------------------------------------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px var(--gutter);
  background: rgba(255, 255, 255, 0.72);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-card-border);
}

.site-logo {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--color-primary);
}
.site-logo:hover { color: var(--color-primary-hover); }

.site-nav {
  display: flex;
  align-items: center;
  gap: var(--space-stack-md);
}
.site-nav > a {
  color: var(--color-text-muted);
  font-weight: 600;
  font-size: 14px;
}
.site-nav > a:hover { color: var(--color-primary); }

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

.site-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: var(--space-stack-md) var(--gutter);
  color: var(--color-text-subtle);
  border-top: 1px solid var(--color-card-border);
}

/* ---------------------------------------------------------------------------
   Components
   --------------------------------------------------------------------------- */

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 20px;
  border-radius: var(--radius);
  border: 1px solid transparent;
  font-family: inherit;
  font-size: 14px;
  font-weight: 600;
  line-height: 1;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease, color 0.15s ease;
  text-decoration: none;
}
.btn:disabled { opacity: 0.5; cursor: not-allowed; }

.btn-primary {
  background: var(--color-primary);
  color: #ffffff;
}
.btn-primary:hover:not(:disabled) {
  background: var(--color-primary-hover);
  color: #ffffff;
  transform: translateY(-1px);
  box-shadow: var(--shadow-soft);
}

.btn-action {
  background: var(--color-action);
  color: #ffffff;
}
.btn-action:hover:not(:disabled) {
  background: var(--color-action-hover);
  color: #ffffff;
  transform: translateY(-1px);
  box-shadow: var(--shadow-soft);
}

.btn-ghost {
  background: transparent;
  color: var(--color-primary);
  border-color: var(--color-primary);
}
.btn-ghost:hover:not(:disabled) {
  background: var(--color-primary);
  color: #ffffff;
}

.btn-sm { padding: 6px 12px; font-size: 12px; }

/* Cards */
.card {
  background: var(--color-card);
  border: 1px solid var(--color-card-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-soft);
  padding: var(--space-stack-md);
}

.card-link {
  display: block;
  color: inherit;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}
.card-link:hover {
  color: inherit;
  transform: translateY(-2px);
  box-shadow: var(--shadow-lift);
}

/* Chips & tags */
.chip {
  display: inline-flex;
  align-items: center;
  padding: 4px 10px;
  border-radius: var(--radius-full);
  background: rgba(24, 62, 109, 0.08);
  color: var(--color-primary);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  line-height: 1;
}
.chip-action {
  background: rgba(228, 81, 37, 0.10);
  color: var(--color-action);
}
.chip-tertiary {
  background: rgba(247, 152, 58, 0.14);
  color: #8a4f00;
}

/* Inputs (login form, future demos) */
input[type="text"],
input[type="email"],
input[type="password"],
input[type="search"],
textarea,
select {
  width: 100%;
  padding: 12px 14px;
  background: var(--color-bg);
  color: var(--color-text);
  border: 1px solid var(--color-card-border);
  border-radius: var(--radius);
  font-family: inherit;
  font-size: 15px;
  line-height: 1.4;
  outline: none;
  transition: border-color 0.15s ease, box-shadow 0.15s ease, background 0.15s ease;
}
input:focus,
textarea:focus,
select:focus {
  border-color: var(--color-primary);
  background: #ffffff;
  box-shadow: 0 0 0 3px var(--color-primary-glow);
}

/* ---------------------------------------------------------------------------
   Auth widget (header)
   --------------------------------------------------------------------------- */

.auth-widget {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-size: 13px;
}
.auth-widget .auth-email {
  color: var(--color-text);
  font-weight: 600;
}
.auth-widget a { color: var(--color-primary); font-weight: 600; }
.auth-widget a:hover { color: var(--color-action); }

/* ---------------------------------------------------------------------------
   Footer chip
   --------------------------------------------------------------------------- */

.env-badge {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 4px 10px;
  border-radius: var(--radius-full);
  background: rgba(24, 62, 109, 0.06);
  color: var(--color-primary);
}
.env-badge:empty { display: none; }

/* ---------------------------------------------------------------------------
   Hero (landing)
   --------------------------------------------------------------------------- */

.hero {
  margin-bottom: var(--space-stack-lg);
}
.hero h1 {
  font-size: 48px;
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.02em;
  margin: 0 0 var(--space-stack-sm);
  color: var(--color-primary);
}
.hero p {
  font-size: 18px;
  color: var(--color-text-muted);
  margin: 0;
}

/* ---------------------------------------------------------------------------
   Card grid (demo list, post list)
   --------------------------------------------------------------------------- */

.card-grid {
  margin-top: var(--space-stack-lg);
}
.card-grid h2 {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin: 0 0 var(--space-stack-md);
}

.demo-list,
.post-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: var(--gutter);
}
.demo-list li,
.post-list li {
  background: var(--color-card);
  border: 1px solid var(--color-card-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-soft);
  padding: var(--space-stack-md);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}
.demo-list li:hover,
.post-list li:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lift);
}
.demo-list a,
.post-list a {
  color: var(--color-primary);
  font-size: 16px;
  font-weight: 600;
}
.post-list li time {
  display: block;
  margin-top: 6px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--color-text-subtle);
}

/* ---------------------------------------------------------------------------
   Posts index + single post
   --------------------------------------------------------------------------- */

.posts-index h1 { color: var(--color-primary); }

.post {
  background: var(--color-card);
  border: 1px solid var(--color-card-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-soft);
  padding: var(--space-stack-lg);
  max-width: 760px;
  margin: 0 auto;
}
.post-header {
  margin-bottom: var(--space-stack-md);
  padding-bottom: var(--space-stack-md);
  border-bottom: 1px solid var(--color-card-border);
}
.post-title {
  margin: 0 0 8px;
  font-size: 36px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--color-primary);
}
.post-date {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--color-text-subtle);
}
.post-body { font-size: 16px; }
.post-body h2 { color: var(--color-primary); }
.post-body code {
  font-family: var(--font-mono);
  background: var(--md-surface-container-low);
  padding: 0.1em 0.4em;
  border-radius: var(--radius-sm);
  font-size: 0.92em;
  color: var(--color-text);
}
.post-body pre {
  background: var(--md-surface-container-low);
  border: 1px solid var(--color-card-border);
  padding: var(--space-stack-sm) var(--space-stack-md);
  border-radius: var(--radius);
  overflow-x: auto;
  font-size: 14px;
}
.post-body pre code { background: transparent; padding: 0; }
.post-body blockquote {
  margin: var(--space-stack-md) 0;
  padding: 8px 16px;
  border-left: 3px solid var(--color-primary);
  background: var(--md-surface-container-low);
  border-radius: 0 var(--radius) var(--radius) 0;
  color: var(--color-text-muted);
}
.post-body a { color: var(--color-action); }

/* ---------------------------------------------------------------------------
   Login card
   --------------------------------------------------------------------------- */

.login-card {
  max-width: 420px;
  margin: var(--space-stack-lg) auto;
  padding: var(--space-stack-lg);
  background: var(--color-card);
  border: 1px solid var(--color-card-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-soft);
}
.login-card h1 {
  margin: 0 0 var(--space-stack-md);
  font-size: 24px;
  font-weight: 600;
  color: var(--color-primary);
}
.login-card label {
  display: block;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin: var(--space-stack-sm) 0 6px;
}
.login-card .btn-primary {
  width: 100%;
  margin-top: var(--space-stack-md);
  padding: 12px;
  font-size: 15px;
}
.login-card .form-error {
  margin: var(--space-stack-sm) 0 0;
  font-size: 13px;
  min-height: 1.4em;
  color: var(--color-error);
}

/* ---------------------------------------------------------------------------
   Responsive tweaks
   --------------------------------------------------------------------------- */

@media (max-width: 720px) {
  .site-main { padding: var(--space-stack-lg) var(--gutter); }
  .hero h1 { font-size: 36px; }
  .post { padding: var(--space-stack-md); }
  .post-title { font-size: 28px; }
}