/*
 * app.css — base element styles, components, and utilities.
 * Neutral, modern, ChatGPT-adjacent aesthetic built on tokens.css.
 */

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

html {
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: var(--leading-normal);
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
  line-height: var(--leading-tight);
  margin: 0 0 var(--space-4);
  font-weight: 650;
}

h1 { font-size: var(--text-2xl); }
h2 { font-size: var(--text-xl); }

p { margin: 0 0 var(--space-4); }

a {
  color: var(--color-accent);
  text-decoration: none;
}
a:hover { text-decoration: underline; }

/* Consistent keyboard focus ring for all interactive elements. Mouse users
   don't see it (:focus-visible); keyboard users always get a token ring. */
a:focus-visible,
button:focus-visible,
summary:focus-visible,
[tabindex]:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* Respect users who ask for less motion: kill decorative animation. */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}

code, pre {
  font-family: var(--font-mono);
  font-size: 0.9em;
}

/* --- Layout shell -------------------------------------------------------- */

.app-shell {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  min-height: 100dvh;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  height: var(--header-height);
  padding: 0 var(--space-5);
  border-bottom: 1px solid var(--color-border);
  background: var(--color-bg);
  position: sticky;
  top: 0;
  z-index: 10;
}

.brand {
  font-weight: 700;
  font-size: var(--text-lg);
  color: var(--color-text);
}
.brand:hover { text-decoration: none; }
.brand-accent { color: var(--color-accent); }

.site-nav {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.inline-form { display: inline; margin: 0; }

.site-main {
  flex: 1;
  width: 100%;
  max-width: var(--measure);
  margin: 0 auto;
  padding: var(--space-6) var(--space-5);
}

.site-footer {
  padding: var(--space-5);
  text-align: center;
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
  border-top: 1px solid var(--color-border);
}

/* --- Buttons ------------------------------------------------------------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  font: inherit;
  font-size: var(--text-sm);
  font-weight: 550;
  line-height: 1;
  border: 1px solid transparent;
  border-radius: var(--radius-md);
  cursor: pointer;
  background: transparent;
  color: var(--color-text);
  transition: background-color 0.15s ease, border-color 0.15s ease,
    color 0.15s ease;
}
.btn:hover { text-decoration: none; }
.btn:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 2px;
}
.btn { white-space: nowrap; }

.btn-primary {
  background: var(--color-accent);
  color: var(--color-accent-contrast);
}
.btn-primary:hover { background: var(--color-accent-hover); }

.btn-ghost {
  border-color: transparent;
  color: var(--color-text);
}
.btn-ghost:hover { background: var(--color-surface); }

.btn-danger {
  background: var(--color-danger);
  color: #fff;
}
.btn-danger:hover { background: var(--color-danger-hover); }

.btn-icon {
  padding: var(--space-2);
  width: 2.25rem;
  height: 2.25rem;
  border-radius: var(--radius-full);
  font-size: var(--text-lg);
}
.btn-icon:hover { background: var(--color-surface); }

.btn-lg {
  padding: var(--space-3) var(--space-5);
  font-size: var(--text-base);
}

.btn-block { width: 100%; }

/* Touch devices: guarantee comfortable ≥44px tap targets for icon buttons
   without inflating the denser mouse/desktop layout. */
@media (pointer: coarse) {
  .btn-icon {
    width: 2.75rem;
    height: 2.75rem;
  }
  .btn { min-height: 2.75rem; }
}

/* --- Forms --------------------------------------------------------------- */

input[type="text"],
input[type="email"],
input[type="password"],
input[type="search"],
input[type="number"],
textarea,
select {
  width: 100%;
  padding: var(--space-3) var(--space-3);
  font: inherit;
  color: var(--color-text);
  background: var(--color-surface-raised);
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-md);
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}
input:focus,
textarea:focus,
select:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--color-accent) 25%, transparent);
}

.field { display: block; }
.field-label {
  display: block;
  margin-bottom: var(--space-1);
  font-size: var(--text-sm);
  font-weight: 550;
  color: var(--color-text-secondary);
}
.field-error {
  display: block;
  margin-top: var(--space-1);
  font-size: var(--text-sm);
  color: var(--color-danger);
}

.stack { display: flex; flex-direction: column; gap: var(--space-4); }

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

.hero {
  padding: var(--space-10) 0;
  text-align: center;
}
.hero-title {
  font-size: var(--text-3xl);
  margin-bottom: var(--space-5);
}
.hero-lede {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  max-width: 40rem;
  margin: 0 auto var(--space-6);
}
.hero-actions {
  display: flex;
  gap: var(--space-3);
  justify-content: center;
  flex-wrap: wrap;
}
.hero-note {
  margin-top: var(--space-5);
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
}

.panel {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
}
.panel-centered { text-align: center; }

.auth-card {
  max-width: 24rem;
  margin: var(--space-8) auto;
  padding: var(--space-6);
  background: var(--color-surface-raised);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
}
.auth-alt {
  margin-top: var(--space-5);
  margin-bottom: 0;
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  text-align: center;
}

.messages {
  list-style: none;
  margin: 0 0 var(--space-5);
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}
.message {
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  font-size: var(--text-sm);
}
.message-error { border-color: var(--color-danger); }

/* --- Utilities ----------------------------------------------------------- */

.text-secondary { color: var(--color-text-secondary); }
.text-sm { font-size: var(--text-sm); }
.text-center { text-align: center; }
.mt-4 { margin-top: var(--space-4); }
.mb-0 { margin-bottom: 0; }
.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
  border: 0;
}

@media (max-width: 640px) {
  .site-main { padding: var(--space-5) var(--space-4); }
  .hero-title { font-size: var(--text-2xl); }
  .site-header { padding: 0 var(--space-3); gap: var(--space-2); }
  .site-nav { gap: var(--space-1); }
  .site-header .btn { padding: var(--space-2) var(--space-3); }
}

/* --- Skeleton loaders ---------------------------------------------------- */

.skeleton {
  position: relative;
  overflow: hidden;
  background: var(--skeleton-base);
  border-radius: var(--radius-sm);
}
.skeleton::after {
  content: "";
  position: absolute;
  inset: 0;
  transform: translateX(-100%);
  background: linear-gradient(
    90deg,
    transparent,
    var(--skeleton-shine),
    transparent
  );
  animation: skeleton-shimmer 1.4s ease-in-out infinite;
}
@keyframes skeleton-shimmer {
  100% { transform: translateX(100%); }
}

/* --- Empty states (tables / lists) --------------------------------------- */

.empty-block {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: var(--space-2);
  padding: var(--space-8) var(--space-4);
  color: var(--color-text-secondary);
}
.empty-block-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.75rem;
  height: 2.75rem;
  border-radius: var(--radius-full);
  background: var(--color-surface-raised);
  border: 1px solid var(--color-border);
  font-size: var(--text-xl);
  color: var(--color-text-secondary);
}
.empty-block-title {
  font-weight: 600;
  color: var(--color-text);
  font-size: var(--text-sm);
}
.empty-block-text {
  font-size: var(--text-sm);
  max-width: 26rem;
  margin: 0;
}

/* --- Landing page -------------------------------------------------------- */

.landing-hero {
  position: relative;
  text-align: center;
  padding: var(--space-10) 0 var(--space-8);
}
.landing-hero::before {
  content: "";
  position: absolute;
  inset: -6rem 0 0;
  background: var(--gradient-hero);
  pointer-events: none;
  z-index: -1;
}
.landing-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-1) var(--space-3);
  margin-bottom: var(--space-5);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  background: var(--color-surface-raised);
  font-size: var(--text-xs);
  color: var(--color-text-secondary);
  font-weight: 550;
}
.landing-dot {
  width: 0.5rem;
  height: 0.5rem;
  border-radius: var(--radius-full);
  background: var(--color-accent);
}
.landing-title {
  font-size: var(--text-3xl);
  line-height: 1.1;
  letter-spacing: -0.01em;
  margin-bottom: var(--space-4);
  max-width: 20ch;
  margin-inline: auto;
}
.landing-title .brand-accent { color: var(--color-accent); }
.landing-lede {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  max-width: 40rem;
  margin: 0 auto var(--space-6);
}
.landing-actions {
  display: flex;
  gap: var(--space-3);
  justify-content: center;
  flex-wrap: wrap;
}
.landing-note {
  margin-top: var(--space-4);
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
}

/* Pure-CSS app mock */
.landing-mock {
  margin: var(--space-8) auto 0;
  max-width: 44rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  background: var(--color-surface-raised);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
}
.mock-bar {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid var(--color-border);
  background: var(--color-surface);
}
.mock-dot {
  width: 0.7rem;
  height: 0.7rem;
  border-radius: var(--radius-full);
  background: var(--color-border-strong);
}
.mock-bar-title {
  margin-left: var(--space-2);
  font-size: var(--text-xs);
  color: var(--color-text-secondary);
}
.mock-body {
  display: grid;
  grid-template-columns: 12rem 1fr;
  min-height: 15rem;
}
.mock-side {
  border-right: 1px solid var(--color-border);
  padding: var(--space-3);
  background: var(--color-surface);
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}
.mock-side-new {
  height: 1.9rem;
  border-radius: var(--radius-md);
  background: var(--color-accent);
  opacity: 0.9;
}
.mock-side-item {
  height: 0.85rem;
  border-radius: var(--radius-sm);
  background: var(--color-border);
}
.mock-side-item:nth-child(2) { width: 90%; }
.mock-side-item:nth-child(3) { width: 70%; }
.mock-side-item:nth-child(4) { width: 82%; }
.mock-side-item:nth-child(5) { width: 60%; }
.mock-chat {
  padding: var(--space-4);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  text-align: left;
}
.mock-msg { max-width: 78%; }
.mock-msg-user {
  align-self: flex-end;
  background: var(--color-surface);
  border-radius: var(--radius-xl);
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-sm);
  color: var(--color-text);
}
.mock-msg-ai {
  align-self: flex-start;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}
.mock-line {
  height: 0.7rem;
  border-radius: var(--radius-sm);
  background: var(--color-border);
}
.mock-line.w-90 { width: 90%; }
.mock-line.w-70 { width: 70%; }
.mock-line.w-50 { width: 50%; }
.mock-pill {
  align-self: flex-start;
  font-size: var(--text-xs);
  color: var(--color-accent);
  border: 1px solid color-mix(in srgb, var(--color-accent) 40%, transparent);
  border-radius: var(--radius-full);
  padding: 2px var(--space-2);
}

/* Feature grid */
.landing-features {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--space-4);
  margin-top: var(--space-10);
}
.feature-card {
  padding: var(--space-5);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background: var(--color-surface);
}
.feature-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: var(--radius-md);
  background: color-mix(in srgb, var(--color-accent) 14%, transparent);
  color: var(--color-accent);
  font-size: var(--text-lg);
  margin-bottom: var(--space-3);
}
.feature-card h3 {
  font-size: var(--text-base);
  margin: 0 0 var(--space-2);
}
.feature-card p {
  margin: 0;
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
}

@media (max-width: 720px) {
  .landing-features { grid-template-columns: 1fr; }
  .mock-body { grid-template-columns: 1fr; }
  .mock-side { display: none; }
}