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

html { scroll-behavior: smooth; }

body.landing {
  font-family: var(--font-ui);
  background: var(--bg-dark);
  color: var(--text);
  min-height: 100vh;
  min-height: 100dvh;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
  display: flex;
  flex-direction: column;
}

/* ── Floating math symbols ── */
.math-field {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  overflow: hidden;
}

.math-sym {
  position: absolute;
  font-family: var(--font-serif);
  color: rgba(124, 144, 255, 0.13);
  user-select: none;
  animation: floatSym linear infinite;
  will-change: transform;
}

@keyframes floatSym {
  0%   { transform: translateY(0px) rotate(var(--rot-start)); opacity: 0; }
  8%   { opacity: 1; }
  92%  { opacity: 1; }
  100% { transform: translateY(calc(-100vh - 80px)) rotate(var(--rot-end)); opacity: 0; }
}

/* ── Background vignette ── */
.landing__bg {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background: radial-gradient(ellipse 70% 40% at 50% -10%, rgba(124, 144, 255, 0.09), transparent 60%);
}

/* ── Shell ── */
.landing__shell {
  position: relative;
  z-index: 1;
  flex: 1;
  display: flex;
  flex-direction: column;
  width: 100%;
  max-width: 1040px;
  margin: 0 auto;
  padding: 0 max(24px, env(safe-area-inset-right)) 0 max(24px, env(safe-area-inset-left));
}

/* ── Nav ── */
.landing__nav {
  position: sticky;
  top: 0;
  z-index: 40;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 18px 0;
  padding-top: max(18px, env(safe-area-inset-top));
  border-bottom: 1px solid transparent;
  transition: background 0.25s, border-color 0.25s;
}

.landing__nav.is-scrolled {
  background: rgba(7, 7, 8, 0.88);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom-color: var(--border-color);
  margin-left: calc(-1 * max(24px, env(safe-area-inset-left)));
  margin-right: calc(-1 * max(24px, env(safe-area-inset-right)));
  padding-left: max(24px, env(safe-area-inset-left));
  padding-right: max(24px, env(safe-area-inset-right));
}

.landing__brand {
  display: inline-flex;
  align-items: center;
  gap: 11px;
  text-decoration: none;
  color: var(--text);
  font-weight: 700;
  font-size: 1rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.landing__brand img {
  width: 34px;
  height: 34px;
  border-radius: 8px;
  object-fit: contain;
  opacity: 0.92;
}

.landing__nav-actions {
  display: flex;
  align-items: center;
  gap: 8px;
}

.landing__link {
  display: inline-flex;
  align-items: center;
  min-height: 38px;
  padding: 0 14px;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--muted);
  text-decoration: none;
  transition: color 0.15s, background 0.15s;
}

.landing__link:hover {
  color: var(--text);
  background: rgba(255, 255, 255, 0.05);
}

.landing__link--ghost {
  border: 1px solid var(--border-strong);
  color: var(--text);
}

.landing__link--ghost:hover {
  background: rgba(255, 255, 255, 0.06);
  border-color: rgba(255, 255, 255, 0.18);
}

/* ── Main ── */
.landing__main {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding-bottom: clamp(48px, 8vw, 88px);
}

/* ── Hero ── */
.landing__hero {
  width: 100%;
  max-width: 680px;
  margin: 0 auto;
  padding: clamp(52px, 8vw, 88px) 0 clamp(48px, 7vw, 72px);
}

.landing__hero-inner { position: relative; }

.landing__eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 0.88rem;
  color: var(--muted);
  letter-spacing: 0.02em;
  margin-bottom: 28px;
}

.landing__eyebrow-dot {
  display: inline-block;
  color: var(--border-strong);
  font-style: normal;
  font-size: 1.2rem;
  line-height: 1;
}

.landing__title {
  font-size: clamp(2.4rem, 6vw, 3.5rem);
  font-weight: 700;
  letter-spacing: -0.04em;
  line-height: 1.08;
  margin-bottom: 22px;
  text-wrap: balance;
}

.landing__title-gradient {
  color: var(--text);
  background: none;
  -webkit-background-clip: unset;
  background-clip: unset;
}

.landing__title-sub {
  display: block;
  color: var(--muted);
  font-size: 0.72em;
  font-weight: 600;
  margin-top: 4px;
}

.landing__sub {
  font-size: clamp(0.95rem, 2.2vw, 1.08rem);
  line-height: 1.72;
  color: var(--muted);
  max-width: 40em;
  margin: 0 auto 34px;
}

.landing__sub strong {
  color: var(--muted-bright);
  font-weight: 600;
}

.landing__cta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
}

.landing__btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 46px;
  padding: 0 22px;
  border-radius: var(--radius-sm);
  font-family: inherit;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  text-decoration: none;
  transition: opacity 0.15s, transform 0.15s;
}

.landing__btn--primary {
  background: var(--text);
  color: var(--bg-dark);
}

.landing__btn--primary:hover { opacity: 0.88; transform: translateY(-1px); }

.landing__btn--secondary {
  background: transparent;
  color: var(--muted-bright);
  border: 1px solid var(--border-strong);
}

.landing__btn--secondary:hover {
  color: var(--text);
  background: rgba(255, 255, 255, 0.04);
  transform: translateY(-1px);
}

.landing__btn:active { transform: translateY(0); }

/* ── Feature grid — 2×2 ── */
.landing__features {
  display: grid;
  width: 100%;
  max-width: 820px;
  grid-template-columns: repeat(2, 1fr);
  gap: 1px;
  margin: 0 auto 64px;
  text-align: left;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--border-color);
}

.landing__feature {
  padding: 30px 26px;
  background: var(--bg-dark);
  transition: background 0.2s;
}

.landing__feature:hover {
  background: var(--bg-elevated);
}

/* reveal animation */
html.js .landing__feature[data-reveal] {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.45s ease, transform 0.45s ease;
}
html.js .landing__feature[data-reveal].is-revealed {
  opacity: 1;
  transform: none;
}
@media (prefers-reduced-motion: no-preference) {
  html.js .landing__feature[data-reveal]:nth-child(2).is-revealed { transition-delay: 70ms; }
  html.js .landing__feature[data-reveal]:nth-child(3).is-revealed { transition-delay: 140ms; }
  html.js .landing__feature[data-reveal]:nth-child(4).is-revealed { transition-delay: 210ms; }
}
@media (prefers-reduced-motion: reduce) {
  html.js .landing__feature[data-reveal] { opacity: 1; transform: none; }
}

/* numbered label — accent tinted */
.landing__feature::before {
  content: attr(data-num);
  display: block;
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 1.1rem;
  color: var(--accent);
  opacity: 0.5;
  margin-bottom: 14px;
  line-height: 1;
}

.landing__feature h3 {
  font-size: 0.97rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin-bottom: 8px;
  color: var(--text);
}

.landing__feature p {
  font-size: 0.84rem;
  line-height: 1.65;
  color: var(--muted);
}

/* ── Signup section ── */
.landing__signup-wrap {
  width: 100%;
  max-width: 440px;
  margin: 0 auto;
  position: relative;
}

/* Floating math symbols around the form */
.form-math-canvas {
  position: absolute;
  inset: 0;
  pointer-events: none;
  overflow: hidden;
  border-radius: var(--radius-lg);
  z-index: 0;
}

.form-math-sym {
  position: absolute;
  font-family: var(--font-serif);
  font-style: italic;
  color: rgba(124, 144, 255, 0.11);
  user-select: none;
  animation: formFloat ease-in-out infinite alternate;
  will-change: transform;
}

@keyframes formFloat {
  0%   { transform: translateY(0px) rotate(var(--fr)); }
  100% { transform: translateY(var(--fy)) rotate(var(--fr2)); }
}

.landing__signup-label {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 0.82rem;
  color: var(--muted);
  margin-bottom: 14px;
  letter-spacing: 0.02em;
}

/* ── Card / Form ── */
.card,
.signup-card {
  background: var(--bg-elevated);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 30px 26px;
  text-align: left;
  position: relative;
  z-index: 1;
}

.form-header {
  margin-bottom: 22px;
  text-align: center;
}

.form-header h2 {
  font-size: 1.2rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text);
  margin-bottom: 5px;
}

.form-header p {
  color: var(--muted);
  font-size: 0.85rem;
}

/* ── Progress stepper ── */
.form-stepper {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  margin-bottom: 22px;
}

.step-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--border-strong);
  transition: background 0.3s, transform 0.3s;
}

.step-dot.active {
  background: var(--accent);
  transform: scale(1.4);
}

.step-dot.done {
  background: var(--success);
  transform: scale(1);
}

.step-line {
  width: 28px;
  height: 1px;
  background: var(--border-color);
}

/* ── Form layout ── */
.form-group {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.form-row-two {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

/* Field wrapper — holds input + inline tick */
.field-wrap { position: relative; }

label {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--muted);
  margin-bottom: 6px;
  display: block;
}

input[type="email"],
input[type="text"],
input[type="password"] {
  width: 100%;
  min-height: 44px;
  padding: 0 12px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-strong);
  background: var(--input-bg);
  color: var(--text);
  font-size: 16px;
  font-family: inherit;
  transition: border-color 0.2s, box-shadow 0.2s;
}

@media (min-width: 768px) {
  input[type="email"],
  input[type="text"],
  input[type="password"] { font-size: 0.9rem; }
}

input:hover { border-color: rgba(255, 255, 255, 0.16); }

input[type="email"]:focus,
input[type="text"]:focus,
input[type="password"]:focus {
  outline: none;
  border-color: rgba(124, 144, 255, 0.5);
  box-shadow: 0 0 0 3px rgba(124, 144, 255, 0.1);
}

input::placeholder { color: rgba(255, 255, 255, 0.28); }

/* Inline validation checkmark */
.field-tick {
  position: absolute;
  right: 10px;
  top: 50%;
  transform: translateY(-50%) scale(0);
  width: 18px;
  height: 18px;
  background: rgba(74, 222, 128, 0.12);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.2s;
  pointer-events: none;
}

.field-tick svg {
  width: 10px;
  height: 10px;
  stroke: var(--success);
  stroke-width: 2.5;
  stroke-linecap: round;
  stroke-linejoin: round;
  fill: none;
}

.field-wrap.valid .field-tick {
  transform: translateY(-50%) scale(1);
}

.field-wrap.valid input {
  padding-right: 36px;
}

/* ── Buttons ── */
.btn {
  width: 100%;
  min-height: 46px;
  padding: 0 1.2rem;
  border-radius: var(--radius-sm);
  font-weight: 700;
  font-size: 0.9rem;
  cursor: pointer;
  font-family: inherit;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: none;
  transition: opacity 0.15s, transform 0.15s;
}

.btn--primary {
  background: var(--text);
  color: var(--bg-dark);
}

.btn--primary:hover:not(:disabled) { opacity: 0.88; transform: translateY(-1px); }
.btn--primary:disabled { opacity: 0.45; cursor: not-allowed; }
.btn--primary:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }
.btn--ghost { display: none; }

/* ── Auth switch ── */
.auth-switch {
  text-align: center;
  margin-top: 16px;
  font-size: 0.85rem;
  color: var(--muted);
}

.auth-switch a {
  color: var(--text);
  font-weight: 600;
  text-decoration: none;
  border-bottom: 1px solid var(--border-strong);
  padding-bottom: 1px;
  transition: border-color 0.15s;
}

.auth-switch a:hover { border-bottom-color: var(--text); }

.success { color: var(--success); font-weight: 600; font-size: 0.95rem; }
.error   { color: var(--danger);  font-weight: 500; font-size: 0.85rem; }

/* ── Notifications checkbox ── */
.checkbox-group {
  display: none;
  align-items: flex-start;
  gap: 10px;
  padding: 12px 14px;
  background: rgba(255, 255, 255, 0.02);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
}

.checkbox-group.visible { display: flex; }

.checkbox-group input[type="checkbox"] {
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
}

.custom-checkbox {
  width: 18px;
  height: 18px;
  border: 1.5px solid rgba(255, 255, 255, 0.22);
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  flex-shrink: 0;
  margin-top: 2px;
  transition: border-color 0.15s, background 0.15s;
}

.checkbox-group input[type="checkbox"]:checked + .custom-checkbox {
  border-color: var(--accent);
  background: rgba(124, 144, 255, 0.12);
}

.checkbox-group input[type="checkbox"]:checked + .custom-checkbox svg { display: block; }

.custom-checkbox svg {
  display: none;
  width: 11px;
  height: 11px;
  stroke: #c8d4ff;
  stroke-width: 2.5;
  stroke-linecap: round;
  stroke-linejoin: round;
  fill: none;
}

.checkbox-group label {
  font-size: 0.83rem;
  font-weight: 400;
  text-transform: none;
  letter-spacing: 0;
  color: var(--muted);
  cursor: pointer;
  margin: 0;
  flex: 1;
  display: flex;
  align-items: flex-start;
  gap: 10px;
}

/* ── Footer ── */
footer.landing__footer {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 24px 16px max(24px, env(safe-area-inset-bottom));
  border-top: 1px solid var(--border-color);
  font-size: 0.78rem;
  color: var(--muted);
}

footer.landing__footer p { margin: 0; opacity: 0.7; }

/* ── Login modal ── */
#loginModal {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 1000;
  align-items: center;
  justify-content: center;
  padding: max(16px, env(safe-area-inset-top)) max(16px, env(safe-area-inset-right)) max(16px, env(safe-area-inset-bottom)) max(16px, env(safe-area-inset-left));
  background: rgba(0, 0, 0, 0.65);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

#loginModal.is-open { display: flex; }

.login-modal__card.signup-card {
  max-width: 400px;
  width: 100%;
  max-height: min(90dvh, 100%);
  overflow-y: auto;
}

.login-modal__head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
  gap: 12px;
}

.login-modal__head h2 {
  margin: 0;
  font-size: 1.15rem;
  font-weight: 700;
}

.login-modal__close {
  background: transparent;
  border: 1px solid var(--border-color);
  color: var(--muted);
  font-size: 1.1rem;
  cursor: pointer;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: color 0.15s, border-color 0.15s;
}

.login-modal__close:hover { color: var(--text); border-color: var(--border-strong); }

/* ── Responsive ── */
@media (max-width: 640px) {
  .form-row-two { grid-template-columns: 1fr; }
  .landing__nav-actions .landing__link:first-of-type { display: none; }
  .landing__features { border-radius: var(--radius-md); }
}

@media (max-width: 480px) {
  .landing__cta { flex-direction: column; width: 100%; max-width: 260px; margin-left: auto; margin-right: auto; }
  .landing__btn { width: 100%; }
  .landing__features { grid-template-columns: 1fr; }
}