/* AiderEx Design System — Platform + PIDS Alpha 1.0 */

:root {
  /* Color */
  --ink: #15202b;
  --ink-soft: #4a5a6a;
  --ink-muted: #6b7c8c;
  --paper: #f3f1ec;
  --paper-deep: #e6e2d8;
  --paper-elevated: #fffcf7;
  --accent: #0c6b6b;
  --accent-hover: #095555;
  --accent-soft: rgba(12, 107, 107, 0.12);
  --line: rgba(21, 32, 43, 0.12);
  --line-strong: rgba(21, 32, 43, 0.22);
  --sky: #c8d6d0;
  --building: #2a3848;
  --success: #1f6b4a;
  --success-soft: rgba(31, 107, 74, 0.12);
  --warn: #8a5a12;
  --warn-soft: rgba(138, 90, 18, 0.14);
  --danger: #8b2e2e;
  --danger-soft: rgba(139, 46, 46, 0.12);
  --info: #2a4f7a;
  --info-soft: rgba(42, 79, 122, 0.12);

  /* Typography */
  --font-display: "Instrument Serif", Georgia, "Times New Roman", serif;
  --font-body: "DM Sans", "Segoe UI", sans-serif;
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-md: 1rem;
  --text-lg: 1.125rem;
  --text-xl: clamp(1.5rem, 3vw, 2rem);
  --text-display: clamp(2.5rem, 7vw, 4.25rem);

  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.5rem;
  --space-6: 2rem;
  --space-7: 3rem;
  --space-8: 4rem;
  --radius: 2px;
  --max-content: 72rem;
  --max-form: 44rem;
}

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

html {
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  font-family: var(--font-body);
  font-size: var(--text-md);
  color: var(--ink);
  background:
    radial-gradient(ellipse 90% 55% at 8% -10%, rgba(12, 107, 107, 0.1), transparent 55%),
    radial-gradient(ellipse 70% 45% at 100% 100%, rgba(42, 56, 72, 0.07), transparent 50%),
    linear-gradient(168deg, var(--paper) 0%, var(--paper-deep) 100%);
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--accent);
}

a:hover {
  color: var(--accent-hover);
}

.page {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  padding: var(--space-4) clamp(1rem, 4vw, 3rem) var(--space-7);
}

/* —— Site navigation —— */
.site-nav {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-3) var(--space-5);
  margin-bottom: clamp(1.5rem, 4vh, 2.5rem);
  padding-bottom: var(--space-4);
  border-bottom: 1px solid var(--line);
  opacity: 0;
  animation: fade-up 0.55s ease 0.05s forwards;
}

.site-nav__brand {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  text-decoration: none;
  color: var(--ink);
}

.site-nav__mark {
  width: 0.55rem;
  height: 0.55rem;
  background: var(--accent);
}

.site-nav__name {
  font-family: var(--font-display);
  font-size: 1.35rem;
  letter-spacing: -0.02em;
  line-height: 1;
}

.site-nav__links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.15rem 1.1rem;
  margin-left: auto;
}

.site-nav__link {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--ink-soft);
  text-decoration: none;
  padding: 0.2rem 0;
  border-bottom: 2px solid transparent;
}

.site-nav__link:hover,
.site-nav__link.is-active {
  color: var(--ink);
  border-bottom-color: var(--accent);
}

.site-nav__meta {
  width: 100%;
}

@media (min-width: 720px) {
  .site-nav__meta {
    width: auto;
    margin-left: 0;
  }
}

.site-nav__stage {
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-muted);
}

/* —— Buttons —— */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.7rem 1.35rem;
  font-family: var(--font-body);
  font-size: 0.9rem;
  font-weight: 600;
  text-decoration: none;
  border: 1.5px solid transparent;
  border-radius: var(--radius);
  cursor: pointer;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
}

.btn--primary {
  background: var(--accent);
  color: #f5faf9;
}

.btn--primary:hover {
  background: var(--accent-hover);
  color: #f5faf9;
  transform: translateY(-1px);
}

.btn--ghost {
  background: transparent;
  color: var(--ink);
  border-color: var(--line-strong);
}

.btn--ghost:hover {
  border-color: var(--ink);
  transform: translateY(-1px);
}

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

.btn--disabled,
.btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
  transform: none;
}

.btn-group {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
}

/* —— Status badges —— */
.badge {
  display: inline-flex;
  align-items: center;
  padding: 0.2rem 0.55rem;
  font-size: var(--text-xs);
  font-weight: 650;
  letter-spacing: 0.02em;
  border-radius: var(--radius);
  border: 1px solid transparent;
}

.badge--primary,
.badge--eligible {
  background: var(--success-soft);
  color: var(--success);
  border-color: rgba(31, 107, 74, 0.25);
}

.badge--alternative,
.badge--partial {
  background: var(--warn-soft);
  color: var(--warn);
  border-color: rgba(138, 90, 18, 0.28);
}

.badge--none,
.badge--muted {
  background: rgba(21, 32, 43, 0.06);
  color: var(--ink-soft);
  border-color: var(--line);
}

.badge--excluded,
.badge--danger {
  background: var(--danger-soft);
  color: var(--danger);
  border-color: rgba(139, 46, 46, 0.28);
}

.badge--info {
  background: var(--info-soft);
  color: var(--info);
  border-color: rgba(42, 79, 122, 0.25);
}

/* —— Landing hero —— */
.topbar {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin-bottom: clamp(1.5rem, 5vh, 3rem);
  opacity: 0;
  animation: fade-up 0.7s ease 0.1s forwards;
}

.topbar__mark {
  width: 0.55rem;
  height: 0.55rem;
  background: var(--accent);
}

.topbar__label {
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-soft);
}

.hero {
  flex: 1;
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(2rem, 5vw, 4rem);
  align-items: end;
  max-width: var(--max-content);
  margin: 0 auto;
  width: 100%;
}

@media (min-width: 840px) {
  .hero {
    grid-template-columns: 1.05fr 0.95fr;
    align-items: center;
    min-height: min(72vh, 38rem);
  }
}

.hero__brand {
  font-family: var(--font-display);
  font-size: var(--text-display);
  font-weight: 400;
  line-height: 0.95;
  letter-spacing: -0.02em;
  color: var(--ink);
  margin-bottom: 0.85rem;
  opacity: 0;
  animation: fade-up 0.8s ease 0.2s forwards;
}

.hero__title {
  font-family: var(--font-body);
  font-size: clamp(1.05rem, 2.2vw, 1.35rem);
  font-weight: 600;
  letter-spacing: 0.01em;
  color: var(--accent);
  margin-bottom: 1rem;
  max-width: 26ch;
  opacity: 0;
  animation: fade-up 0.8s ease 0.35s forwards;
}

.hero__lede {
  font-size: clamp(0.95rem, 1.6vw, 1.05rem);
  color: var(--ink-soft);
  max-width: 38ch;
  margin-bottom: 1.75rem;
  opacity: 0;
  animation: fade-up 0.8s ease 0.5s forwards;
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  opacity: 0;
  animation: fade-up 0.8s ease 0.65s forwards;
}

.hero__visual {
  position: relative;
  min-height: 14rem;
  opacity: 0;
  animation: fade-in 1s ease 0.4s forwards;
}

@media (min-width: 840px) {
  .hero__visual {
    min-height: 22rem;
  }
}

.skyline {
  position: relative;
  height: 100%;
  min-height: inherit;
  display: flex;
  align-items: flex-end;
  justify-content: flex-end;
  gap: 0.55rem;
  padding: 1.5rem 0 0;
  background: linear-gradient(180deg, transparent 0%, rgba(197, 212, 206, 0.35) 100%);
  border-bottom: 1px solid var(--line);
  overflow: hidden;
}

.skyline__grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(26, 35, 50, 0.04) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(26, 35, 50, 0.04) 1px, transparent 1px);
  background-size: 28px 28px;
  mask-image: linear-gradient(180deg, transparent, black 40%);
  pointer-events: none;
}

.skyline__block {
  position: relative;
  z-index: 1;
  background: var(--building);
  transform-origin: bottom center;
  animation: rise 0.9s cubic-bezier(0.22, 1, 0.36, 1) both;
}

.skyline__block--a { width: 12%; height: 38%; animation-delay: 0.55s; background: #3d4f62; }
.skyline__block--b { width: 16%; height: 62%; animation-delay: 0.65s; }
.skyline__block--c { width: 14%; height: 48%; animation-delay: 0.75s; background: #1e2a38; }
.skyline__block--d { width: 20%; height: 78%; animation-delay: 0.85s; background: var(--accent); opacity: 0.85; }
.skyline__block--e { width: 11%; height: 42%; animation-delay: 0.95s; background: #556879; }

.panel {
  max-width: 40rem;
  margin: 2.5rem auto 0;
  padding-top: 1.75rem;
  border-top: 1px solid var(--line);
  opacity: 0;
  transform: translateY(0.5rem);
  transition: opacity 0.35s ease, transform 0.35s ease;
}

.panel.is-visible {
  opacity: 1;
  transform: translateY(0);
}

.panel[hidden] {
  display: none;
}

.panel h2 {
  font-family: var(--font-display);
  font-size: 1.65rem;
  font-weight: 400;
  margin-bottom: 0.5rem;
}

.panel p {
  color: var(--ink-soft);
  font-size: 0.95rem;
}

.panel__dev-link {
  margin-top: 1rem;
}

.panel__dev-link a {
  font-size: 0.85rem;
  color: var(--ink-soft);
  text-decoration: underline;
  text-underline-offset: 0.15em;
}

.panel__dev-link a:hover {
  color: var(--accent);
}

/* —— Motion —— */
@keyframes fade-up {
  from { opacity: 0; transform: translateY(0.75rem); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes fade-in {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes rise {
  from { opacity: 0; transform: scaleY(0.15); }
  to { opacity: 1; transform: scaleY(1); }
}

@keyframes reveal {
  from { opacity: 0; transform: translateY(0.4rem); }
  to { opacity: 1; transform: translateY(0); }
}

/* —— Accessibility —— */
.skip-link {
  position: absolute;
  left: -9999px;
  top: 0.5rem;
  z-index: 100;
  padding: 0.55rem 0.9rem;
  background: var(--ink);
  color: var(--paper);
  font-weight: 600;
  text-decoration: none;
}

.skip-link:focus {
  left: 0.5rem;
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

button:focus:not(:focus-visible),
a:focus:not(:focus-visible),
input:focus:not(:focus-visible),
select:focus:not(:focus-visible),
textarea:focus:not(:focus-visible) {
  outline: none;
}

/* —— Breadcrumbs —— */
.breadcrumbs {
  margin: 0 0 var(--space-4);
}

.breadcrumbs__list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 0.5rem;
  list-style: none;
  font-size: var(--text-sm);
  color: var(--ink-muted);
}

.breadcrumbs__item:not(:last-child)::after {
  content: "/";
  margin-left: 0.5rem;
  color: var(--line-strong);
}

.breadcrumbs__link {
  color: var(--ink-soft);
  text-decoration: none;
}

.breadcrumbs__link:hover {
  color: var(--accent);
  text-decoration: underline;
}

.breadcrumbs__current {
  color: var(--ink);
  font-weight: 600;
}

/* —— Auth shell —— */
.page--auth {
  max-width: 28rem;
  margin: 0 auto;
  width: 100%;
}

.auth-card {
  padding: var(--space-6) var(--space-5);
  background: var(--paper-elevated);
  border: 1px solid var(--line);
}

.auth-card__brand {
  font-family: var(--font-display);
  font-size: 2rem;
  line-height: 1;
  margin-bottom: 0.5rem;
}

.auth-card__lede {
  color: var(--ink-soft);
  font-size: var(--text-sm);
  margin-bottom: var(--space-5);
}

.auth-flash {
  margin-bottom: var(--space-4);
  padding: 0.75rem 0.9rem;
  font-size: var(--text-sm);
  border-left: 3px solid var(--danger);
  background: var(--danger-soft);
  color: var(--danger);
}

.auth-flash--info {
  border-left-color: var(--info);
  background: var(--info-soft);
  color: var(--info);
}

.auth-flash--success {
  border-left-color: var(--success);
  background: var(--success-soft);
  color: var(--success);
}

.auth-field {
  margin-bottom: var(--space-4);
}

.auth-field label {
  display: block;
  font-size: var(--text-sm);
  font-weight: 600;
  margin-bottom: 0.35rem;
}

.auth-field input,
.auth-field select {
  width: 100%;
  padding: 0.65rem 0.75rem;
  font: inherit;
  color: var(--ink);
  background: #fff;
  border: 1.5px solid var(--line-strong);
  border-radius: var(--radius);
}

.auth-field input:focus-visible,
.auth-field select:focus-visible {
  border-color: var(--accent);
}

.auth-actions {
  margin-top: var(--space-5);
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  align-items: center;
}

.auth-meta {
  margin-top: var(--space-5);
  font-size: var(--text-sm);
  color: var(--ink-soft);
}

.auth-radio {
  display: flex;
  gap: 0.65rem;
  align-items: flex-start;
  margin: 0.65rem 0;
  font-size: var(--text-sm);
}

/* —— Error pages —— */
.page--error {
  max-width: 36rem;
  margin: 0 auto;
}

.error-panel {
  padding: var(--space-6) var(--space-5);
  background: var(--paper-elevated);
  border: 1px solid var(--line);
  border-left: 3px solid var(--danger);
}

.error-panel__code {
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--danger);
  margin-bottom: 0.5rem;
}

.error-panel__title {
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  margin-bottom: 0.65rem;
}

.error-panel__body {
  color: var(--ink-soft);
  margin-bottom: var(--space-5);
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}