/* Platform shell — aligns with docs/PLATFORM_UX_VISION.md; tokens match frontend/style.css */

:root {
  --bg: #0f1419;
  --surface: #1a1f26;
  --surface-elevated: #222831;
  --border: #2d3748;
  --text: #e7e9ea;
  --text-muted: #71767b;
  --accent: #1d9bf0;
  --accent-hover: #1a8cd8;
  --success: #00ba7c;
  --radius: 0.5rem;
  --nav-gap: clamp(0.35rem, 2vw, 0.75rem);
  --content-max: min(72rem, 100%);
  --reading-max: 65ch;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

body.platform-body {
  margin: 0;
  min-height: 100vh;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
  display: flex;
  flex-direction: column;
}

body.platform-body--interim {
  padding: clamp(1rem, 4vw, 2rem);
}

.platform-skip {
  position: absolute;
  left: -9999px;
  z-index: 999;
}
.platform-skip:focus {
  left: 0.5rem;
  top: 0.5rem;
  padding: 0.5rem 1rem;
  background: var(--accent);
  color: #fff;
}

/* Header */
.platform-header {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: clamp(0.75rem, 2vw, 1rem) clamp(1rem, 4vw, 1.5rem);
  border-bottom: 1px solid var(--border);
  background: var(--surface);
}

.platform-brand {
  font-size: clamp(1.1rem, 2.5vw, 1.35rem);
  font-weight: 700;
  color: var(--text);
  text-decoration: none;
}
.platform-brand:hover {
  color: var(--accent);
}

.platform-header-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem;
}

.platform-user-label {
  font-size: 0.875rem;
  color: var(--text-muted);
  max-width: min(40ch, 100%);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* Primary nav */
.platform-nav-wrap {
  border-bottom: 1px solid var(--border);
  background: var(--bg);
}

.platform-nav {
  display: flex;
  flex-wrap: wrap;
  gap: var(--nav-gap);
  padding: clamp(0.5rem, 2vw, 0.75rem) clamp(1rem, 4vw, 1.5rem);
  max-width: var(--content-max);
  margin: 0 auto;
}

.platform-nav a {
  padding: 0.5rem clamp(0.65rem, 2vw, 1rem);
  font-size: 0.9rem;
  color: var(--text-muted);
  text-decoration: none;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  min-width: 0;
}
.platform-nav a:hover {
  background: var(--surface);
  color: var(--text);
}
.platform-nav a[aria-current="page"] {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

/* Main */
.platform-main {
  flex: 1;
  width: 100%;
  max-width: var(--content-max);
  margin: 0 auto;
  padding: clamp(1rem, 3vw, 1.75rem);
  min-width: 0;
}

.platform-main h1 {
  font-size: clamp(1.35rem, 3vw, 1.65rem);
  margin: 0 0 0.5rem;
  font-weight: 700;
}

.platform-lede {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin: 0 0 1.5rem;
  max-width: var(--reading-max);
}

/* Cards & grids */
.platform-grid {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fill, minmax(min(100%, 17rem), 1fr));
}

.platform-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.1rem;
  min-width: 0;
}

.platform-card h2 {
  font-size: 1.05rem;
  margin: 0 0 0.5rem;
}

.platform-card p {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin: 0 0 1rem;
}

.platform-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.platform-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.55rem 1rem;
  font-size: 0.9rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--surface-elevated);
  color: var(--text);
  text-decoration: none;
  cursor: pointer;
  font-family: inherit;
}
.platform-btn:hover {
  background: var(--border);
}
.platform-btn--primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}
.platform-btn--primary:hover {
  background: var(--accent-hover);
  border-color: var(--accent-hover);
  color: #fff;
}

.platform-todo-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.platform-todo-list li {
  padding: 0.85rem 1rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 0.9rem;
}

.platform-todo-list li strong {
  display: block;
  margin-bottom: 0.25rem;
}

.platform-todo-meta {
  display: block;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.text-muted {
  color: var(--text-muted);
}

.platform-banner {
  padding: 0.75rem 1rem;
  background: var(--surface);
  border: 1px dashed var(--border);
  border-radius: var(--radius);
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 1rem;
}

.platform-banner label {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
}

.platform-footer-note {
  margin-top: 2rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
  font-size: 0.8rem;
  color: var(--text-muted);
}
.platform-footer-note a {
  color: var(--accent);
}

/* Interim landing */
.platform-hero {
  max-width: min(40rem, 100%);
  margin: 0 auto;
  text-align: center;
  padding: clamp(2rem, 8vw, 4rem) 0;
}

.platform-hero h1 {
  font-size: clamp(1.75rem, 5vw, 2.25rem);
  margin: 0 0 0.75rem;
}

.platform-hero .platform-lede {
  margin-left: auto;
  margin-right: auto;
}

.platform-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  justify-content: center;
  margin-top: 1.5rem;
}

/* Sign-in */
.platform-signin {
  max-width: 22rem;
  margin: 0 auto;
  padding: clamp(2rem, 6vw, 3rem) 1rem;
}

.platform-signin h1 {
  text-align: center;
  font-size: 1.5rem;
}

.platform-signin .platform-lede {
  text-align: center;
  margin-left: auto;
  margin-right: auto;
}

.platform-oauth {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin: 1.5rem 0;
}

.platform-divider {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--text-muted);
  font-size: 0.8rem;
  margin: 1rem 0;
}
.platform-divider::before,
.platform-divider::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--border);
}

@media (max-width: 520px) {
  .platform-nav {
    flex-direction: column;
    align-items: stretch;
  }
  .platform-nav a {
    text-align: center;
  }
}