/* ==========================================================================
   Exam Insights — Base components
   Buttons · Inputs · Cards · Nav shell · Hero scaffold.
   Depends on tokens.css + base.css.
   ========================================================================== */

/* ==========================================================================
   BUTTONS
   .btn + variant (--primary / --secondary / --ghost) + size (--sm / --lg)
   ========================================================================== */
.btn {
  --btn-bg: transparent;
  --btn-fg: var(--color-text);
  --btn-border: transparent;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  min-height: 44px;              /* touch target */
  padding: 0 var(--space-5);
  font-family: var(--font-sans);
  font-size: var(--text-base);
  font-weight: var(--weight-semibold);
  letter-spacing: var(--tracking-snug);
  line-height: 1;
  color: var(--btn-fg);
  background: var(--btn-bg);
  border: 1px solid var(--btn-border);
  border-radius: var(--radius-full);
  cursor: pointer;
  white-space: nowrap;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
  transition: background-color var(--dur) var(--ease-out),
              border-color var(--dur) var(--ease-out),
              color var(--dur) var(--ease-out),
              transform var(--dur-fast) var(--ease-out),
              box-shadow var(--dur) var(--ease-out);
}
.btn:active { transform: scale(0.97); }           /* tactile press, no layout shift */
.btn:focus-visible { box-shadow: var(--shadow-focus); outline: none; }

.btn .btn__icon { width: 18px; height: 18px; flex: none; }

/* Primary — blue fill, white text */
.btn--primary {
  --btn-bg: var(--color-accent);
  --btn-fg: var(--color-text-on-accent);
  box-shadow: var(--shadow-sm);
}
.btn--primary:hover { --btn-bg: var(--color-accent-hover); box-shadow: var(--shadow-md); }
.btn--primary:active { --btn-bg: var(--color-accent-active); }

/* Secondary — surface chip with hairline */
.btn--secondary {
  --btn-bg: var(--color-surface);
  --btn-fg: var(--color-text);
  --btn-border: var(--color-border-strong);
  box-shadow: var(--shadow-xs);
}
.btn--secondary:hover { --btn-bg: var(--color-surface-sunken); }

/* Ghost — text-only until hover */
.btn--ghost {
  --btn-fg: var(--color-text-soft);
}
.btn--ghost:hover { --btn-bg: var(--color-surface-sunken); --btn-fg: var(--color-text); }

/* Sizes */
.btn--sm { min-height: 36px; padding: 0 var(--space-4); font-size: var(--text-sm); }
.btn--lg { min-height: 52px; padding: 0 var(--space-8); font-size: var(--text-md); }
.btn--block { width: 100%; }
.btn--icon { padding: 0; width: 44px; min-height: 44px; border-radius: var(--radius-full); }

/* Disabled + loading */
.btn:disabled,
.btn[aria-disabled="true"] {
  opacity: 0.45;
  cursor: not-allowed;
  pointer-events: none;
}
.btn[data-loading="true"] { color: transparent; pointer-events: none; position: relative; }
.btn[data-loading="true"]::after {
  content: "";
  position: absolute;
  width: 18px; height: 18px;
  border: 2px solid currentColor;
  border-top-color: transparent;
  border-radius: var(--radius-full);
  color: var(--btn-fg);
  animation: spin 0.7s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* ==========================================================================
   FORM FIELDS
   .field wraps label + control + helper/error
   ========================================================================== */
.field { display: flex; flex-direction: column; gap: var(--space-2); }
.field__label {
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  color: var(--color-text-soft);
}
.field__label .req { color: var(--color-danger); margin-left: 2px; }

.input, .textarea, .select {
  width: 100%;
  min-height: 48px;             /* comfortable mobile touch input */
  padding: var(--space-3) var(--space-4);
  font-size: var(--text-base);
  color: var(--color-text);
  background: var(--color-surface);
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-md);
  transition: border-color var(--dur) var(--ease-out),
              box-shadow var(--dur) var(--ease-out),
              background-color var(--dur) var(--ease-out);
  appearance: none;
}
.input::placeholder, .textarea::placeholder { color: var(--color-text-faint); }
.textarea { min-height: 120px; resize: vertical; line-height: var(--leading-normal); }

.input:hover, .textarea:hover, .select:hover { border-color: var(--color-text-faint); }
.input:focus, .textarea:focus, .select:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: var(--shadow-focus);
}

/* Native select chevron */
.select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='20' height='20' viewBox='0 0 24 24' fill='none' stroke='%235c5c63' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right var(--space-4) center;
  padding-right: var(--space-10);
}

.field__helper { font-size: var(--text-sm); color: var(--color-text-muted); }
.field__error  { font-size: var(--text-sm); color: var(--color-danger); display: none; }

/* Error state */
.field--error .input,
.field--error .textarea,
.field--error .select { border-color: var(--color-danger); }
.field--error .field__error { display: block; }
.field--error .field__helper { display: none; }

/* ==========================================================================
   CARDS
   ========================================================================== */
.card {
  background:
    radial-gradient(130% 90% at 0% 0%, var(--glass-sheen), transparent 55%),
    var(--glass-bg);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(180%);
  backdrop-filter: blur(var(--glass-blur)) saturate(180%);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  box-shadow: var(--glass-shadow), var(--glass-inset);
}
.card__title { font-size: var(--text-xl); margin-bottom: var(--space-2); }
.card__body  { color: var(--color-text-soft); }
.card__footer { margin-top: var(--space-5); display: flex; gap: var(--space-3); }

/* Interactive card — subtle lift on hover (transform only) */
.card--interactive {
  cursor: pointer;
  transition: transform var(--dur) var(--ease-out),
              box-shadow var(--dur) var(--ease-out),
              border-color var(--dur) var(--ease-out);
  will-change: transform;
}
.card--interactive:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-border-strong);
}
.card--interactive:focus-visible { box-shadow: var(--shadow-focus); outline: none; }

.card--feature { padding: var(--space-8); border-radius: var(--radius-xl); }
.card--flush { padding: 0; overflow: hidden; }

/* Badge / pill */
.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-1) var(--space-3);
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  color: var(--color-accent-text);
  background: var(--color-accent-soft);
  border-radius: var(--radius-full);
}

/* ==========================================================================
   NAV SHELL — sticky, glassy off-white, editorial (brand left, links, actions)
   ========================================================================== */
.nav {
  position: sticky;
  top: 0;
  z-index: var(--z-nav);
  height: var(--nav-height);
  display: flex;
  align-items: center;
  gap: var(--space-6);
  padding-inline:
    max(var(--gutter), env(safe-area-inset-left))
    max(var(--gutter), env(safe-area-inset-right));
  background: var(--color-surface-alpha);
  backdrop-filter: saturate(180%) blur(16px);
  -webkit-backdrop-filter: saturate(180%) blur(16px);
  border-bottom: 1px solid var(--color-border);
}

.nav__brand {
  display: inline-flex;
  align-items: baseline;
  font-family: var(--font-display);
  font-weight: var(--weight-bold);
  font-size: clamp(1.375rem, 1.1rem + 1vw, 1.7rem); /* noticeably larger, crafted */
  letter-spacing: -0.022em;
  line-height: 1;
  color: var(--color-text);
  margin-right: var(--space-4);
}
.nav__brand-text { font-optical-sizing: auto; }
.nav__brand-dot {
  color: var(--color-accent);
  font-size: 1.15em;
  line-height: 0;
  margin-left: 1px;
}
.nav__brand:hover .nav__brand-dot { color: var(--color-accent-hover); }
.nav__brand .dot { color: var(--color-accent); }

.nav__links {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  margin-right: auto;            /* push actions to the right */
}
.nav__link {
  position: relative;
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  color: var(--color-text-muted);
  border-radius: var(--radius-sm);
  transition: color var(--dur) var(--ease-out), background-color var(--dur) var(--ease-out);
}
.nav__link:hover { color: var(--color-text); background: var(--color-surface-sunken); }
.nav__link[aria-current="page"] { color: var(--color-text); }
.nav__link[aria-current="page"]::after {
  content: "";
  position: absolute;
  left: var(--space-3);
  right: var(--space-3);
  bottom: -2px;
  height: 2px;
  background: var(--color-accent);
  border-radius: var(--radius-full);
}

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

.nav__icon-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px; height: 44px;
  border-radius: var(--radius-full);
  color: var(--color-text-soft);
  transition: background-color var(--dur) var(--ease-out), color var(--dur) var(--ease-out);
}
.nav__icon-btn:hover { background: var(--color-surface-sunken); color: var(--color-text); }

/* Mobile menu toggle (hidden on desktop) */
.nav__toggle { display: none; }

/* Off-canvas drawer (mobile) */
.nav__drawer {
  position: fixed;
  inset: 0 0 0 auto;
  width: min(320px, 84vw);
  z-index: var(--z-modal);
  background: var(--color-surface);
  border-left: 1px solid var(--color-border);
  box-shadow: var(--shadow-xl);
  padding: calc(var(--nav-height) + var(--space-4))
           max(var(--space-6), env(safe-area-inset-right))
           max(var(--space-6), env(safe-area-inset-bottom))
           var(--space-6);
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  transform: translateX(100%);
  transition: transform var(--dur-slow) var(--ease-out);
}
.nav__drawer[data-open="true"] { transform: translateX(0); }
.nav__drawer .nav__link { font-size: var(--text-md); padding: var(--space-3); }
.nav__drawer .nav__link[aria-current="page"]::after { display: none; }
.nav__drawer .nav__link[aria-current="page"] {
  background: var(--color-accent-soft);
  color: var(--color-accent-text);
}

.nav__scrim {
  position: fixed;
  inset: 0;
  z-index: var(--z-overlay);
  background: rgba(11, 11, 12, 0.5);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--dur) var(--ease-out), visibility var(--dur) var(--ease-out);
}
.nav__scrim[data-open="true"] { opacity: 1; visibility: visible; }

@media (max-width: 860px) {
  .nav__links:not(.nav__drawer .nav__links) { display: none; }
  .nav__toggle { display: inline-flex; }
}

/* ==========================================================================
   HERO — line-led, centred editorial. Signature = drifting line field (SVG,
   transform-only) + a one-shot drawn underline. GPU-light; motion stops under
   prefers-reduced-motion (handled by the global guard in base.css).
   ========================================================================== */
.hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  min-height: clamp(560px, 82vh, 800px);
  display: flex;
  align-items: center;
  padding-block: var(--section-y);
}

/* Aurora keyframe for the auth split-panel */
@keyframes aurora-drift-a {
  0%, 100% { transform: translate3d(0, 0, 0) scale(1); }
  33%      { transform: translate3d(8%, 10%, 0) scale(1.15); }
  66%      { transform: translate3d(-6%, 4%, 0) scale(0.92); }
}

.hero__inner {
  position: relative;
  z-index: 1;
  max-width: 900px;
  margin-inline: auto;
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
}
.hero__title {
  margin-top: var(--space-5);
  font-size: var(--text-display);
  line-height: 0.98;
  letter-spacing: var(--tracking-tight);
}
.hero__em { font-style: italic; color: var(--color-accent-text); }

/* Hand-drawn underline beneath the accent phrase */
.hero__stroke {
  width: clamp(220px, 32vw, 360px);
  height: 22px;
  margin-top: calc(var(--space-2) * -1);
  color: var(--color-accent);
  overflow: visible;
}
.hero__stroke path {
  stroke-dasharray: 1;
  stroke-dashoffset: 1;
  animation: hero-stroke 1s var(--ease-out) 0.4s forwards;
}
@keyframes hero-stroke { to { stroke-dashoffset: 0; } }

.hero__sub {
  margin-top: var(--space-6);
  font-size: var(--text-md);
  line-height: var(--leading-relaxed);
  color: var(--color-text-soft);
  max-width: 54ch;
}
.hero__actions { margin-top: var(--space-8); display: flex; flex-wrap: wrap; justify-content: center; gap: var(--space-3); }

/* ==========================================================================
   ROUTE VIEWS — router toggles [hidden]; entrance via transform/opacity
   ========================================================================== */
.route { display: none; }
.route[data-active="true"] { display: block; animation: route-in var(--dur-slow) var(--ease-out); }
@keyframes route-in {
  from { opacity: 0; transform: translate3d(0, 8px, 0); }
  to   { opacity: 1; transform: translate3d(0, 0, 0); }
}

/* Empty-route placeholder used by the skeleton (next step replaces these) */
.route-placeholder {
  min-height: 50vh;
  display: grid;
  place-items: center;
  text-align: center;
  padding: var(--section-y) var(--gutter);
}
.route-placeholder .eyebrow { margin-bottom: var(--space-3); }
.route-placeholder h1 { margin-bottom: var(--space-3); }
.route-placeholder p { color: var(--color-text-muted); margin-inline: auto; }