:root {
  --color-primary: #0f766e;
  --color-primary-deep: #0b4f4a;
  --color-secondary: #2dd4bf;
  --color-accent: #e8910f;
  --color-accent-hover: #c9780a;
  --color-bg: #071c1a;
  --color-bg-elevated: #0d2e2a;
  --color-surface: #123a35;
  --color-fg: #ecfdf8;
  --color-fg-muted: #9fc5be;
  --color-border: rgba(94, 234, 212, 0.22);
  --color-ring: #2dd4bf;
  --font-display: "Space Grotesk", system-ui, sans-serif;
  --font-body: "DM Sans", system-ui, sans-serif;
  --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: 4.5rem;
  --radius: 0.35rem;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --duration: 200ms;
  --header-h: 4rem;
  --max: 68rem;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-body);
  font-size: 1.0625rem;
  line-height: 1.55;
  color: var(--color-fg);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}

img,
svg {
  display: block;
  max-width: 100%;
}

a {
  color: var(--color-secondary);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.18em;
  transition: color var(--duration) var(--ease);
}

a:hover {
  color: #99f6e4;
}

a:focus-visible,
button:focus-visible,
input:focus-visible,
.dropzone:focus-within {
  outline: 2px solid var(--color-ring);
  outline-offset: 3px;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-4);
  z-index: 100;
  padding: var(--space-2) var(--space-4);
  background: var(--color-accent);
  color: #111;
  font-weight: 600;
  text-decoration: none;
  border-radius: var(--radius);
}

.skip-link:focus {
  top: var(--space-3);
}

/* ——— Header ——— */
.site-header {
  position: fixed;
  inset: 0 0 auto;
  z-index: 40;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-h);
  padding: 0 clamp(1.25rem, 4vw, 2.5rem);
  background: linear-gradient(180deg, rgba(7, 28, 26, 0.92), rgba(7, 28, 26, 0.55) 70%, transparent);
  backdrop-filter: blur(8px);
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  color: var(--color-fg);
  text-decoration: none;
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.logo:hover {
  color: var(--color-fg);
}

.logo-mark {
  width: 0.85rem;
  height: 0.85rem;
  border-radius: 2px;
  background: linear-gradient(160deg, var(--color-secondary), var(--color-accent));
  box-shadow: 0 0 18px rgba(45, 212, 191, 0.45);
}

.logo-text {
  font-size: 1.15rem;
}

.site-nav {
  display: flex;
  gap: 1.25rem;
}

.site-nav a {
  color: var(--color-fg-muted);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
}

.site-nav a:hover {
  color: var(--color-fg);
}

/* ——— Hero ——— */
.hero {
  position: relative;
  isolation: isolate;
  min-height: 100vh;
  min-height: 100dvh;
  display: grid;
  place-items: end start;
  padding:
    calc(var(--header-h) + 2rem)
    clamp(1.25rem, 5vw, 3.5rem)
    clamp(3rem, 10vh, 5.5rem);
  overflow: hidden;
}

.hero-atmosphere {
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
}

.hero-wash {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 90% 70% at 18% 20%, rgba(45, 212, 191, 0.28), transparent 55%),
    radial-gradient(ellipse 70% 55% at 88% 78%, rgba(232, 145, 15, 0.18), transparent 50%),
    radial-gradient(ellipse 60% 45% at 55% 40%, rgba(15, 118, 110, 0.35), transparent 60%),
    linear-gradient(165deg, #041412 0%, #0a2f2a 42%, #123f38 72%, #071c1a 100%);
}

.hero-grid {
  position: absolute;
  inset: 0;
  opacity: 0.22;
  background-image:
    linear-gradient(rgba(236, 253, 248, 0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(236, 253, 248, 0.06) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(ellipse 75% 65% at 50% 40%, #000 20%, transparent 75%);
}

.stream {
  position: absolute;
  width: 2px;
  height: 42%;
  border-radius: 999px;
  opacity: 0.55;
  filter: blur(0.4px);
}

.stream-up {
  left: 22%;
  bottom: 8%;
  background: linear-gradient(180deg, transparent, var(--color-secondary), transparent);
  animation: drift-up 7.5s var(--ease) infinite;
}

.stream-down {
  right: 18%;
  top: 12%;
  background: linear-gradient(0deg, transparent, var(--color-accent), transparent);
  animation: drift-down 8.5s var(--ease) infinite;
  animation-delay: 0.8s;
}

.orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(40px);
  opacity: 0.5;
}

.orb-a {
  width: min(42vw, 28rem);
  height: min(42vw, 28rem);
  top: -8%;
  right: -6%;
  background: rgba(15, 118, 110, 0.55);
  animation: pulse-orb 9s ease-in-out infinite;
}

.orb-b {
  width: min(36vw, 22rem);
  height: min(36vw, 22rem);
  bottom: -10%;
  left: -4%;
  background: rgba(232, 145, 15, 0.22);
  animation: pulse-orb 11s ease-in-out infinite reverse;
}

.hero-content {
  max-width: 36rem;
  animation: rise-in 0.9s var(--ease) both;
}

.hero-brand {
  margin: 0 0 var(--space-3);
  font-family: var(--font-display);
  font-size: clamp(3.4rem, 12vw, 6.75rem);
  font-weight: 700;
  line-height: 0.92;
  letter-spacing: -0.055em;
  color: var(--color-fg);
  text-shadow: 0 12px 40px rgba(0, 0, 0, 0.35);
}

.hero-title {
  margin: 0 0 var(--space-4);
  font-family: var(--font-display);
  font-size: clamp(1.35rem, 3.2vw, 1.85rem);
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--color-secondary);
}

.hero-lede {
  margin: 0 0 var(--space-6);
  max-width: 28rem;
  color: var(--color-fg-muted);
  font-size: 1.08rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
}

/* ——— Buttons ——— */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.85rem;
  padding: 0.7rem 1.35rem;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font-family: var(--font-body);
  font-size: 0.98rem;
  font-weight: 600;
  line-height: 1;
  text-decoration: none;
  cursor: pointer;
  transition:
    background var(--duration) var(--ease),
    color var(--duration) var(--ease),
    border-color var(--duration) var(--ease),
    transform var(--duration) var(--ease);
}

.btn:active {
  transform: translateY(1px);
}

.btn-accent {
  background: var(--color-accent);
  color: #14110c;
}

.btn-accent:hover {
  background: var(--color-accent-hover);
  color: #14110c;
}

.btn-primary {
  background: var(--color-primary);
  color: var(--color-fg);
}

.btn-primary:hover {
  background: #0d9488;
  color: var(--color-fg);
}

.btn-ghost {
  background: transparent;
  color: var(--color-fg);
  border-color: var(--color-border);
}

.btn-ghost:hover {
  background: rgba(236, 253, 248, 0.06);
  color: var(--color-fg);
  border-color: rgba(94, 234, 212, 0.45);
}

.btn-block {
  width: 100%;
}

/* ——— Sections ——— */
.transfer,
.how {
  padding: var(--space-8) clamp(1.25rem, 5vw, 3.5rem);
  max-width: var(--max);
  margin: 0 auto;
}

.section-intro {
  max-width: 34rem;
  margin-bottom: var(--space-7);
  animation: rise-in 0.7s var(--ease) both;
}

.section-intro h2 {
  margin: 0 0 var(--space-3);
  font-family: var(--font-display);
  font-size: clamp(1.85rem, 4vw, 2.4rem);
  font-weight: 700;
  letter-spacing: -0.03em;
}

.section-intro p {
  margin: 0;
  color: var(--color-fg-muted);
}

.transfer-panels {
  display: grid;
  gap: var(--space-6);
}

@media (min-width: 840px) {
  .transfer-panels {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-7);
  }
}

.panel {
  padding: 0;
  animation: rise-in 0.75s var(--ease) both;
}

.panel:nth-child(2) {
  animation-delay: 0.08s;
}

.panel h3 {
  margin: 0 0 var(--space-5);
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.panel-notice {
  margin: -0.5rem 0 var(--space-4);
  padding: 0.65rem 0.85rem;
  border: 1px solid rgba(252, 165, 165, 0.35);
  border-radius: var(--radius);
  background: rgba(252, 165, 165, 0.1);
  color: #fecaca;
  font-size: 0.9rem;
  line-height: 1.45;
}

.panel.is-disabled .transfer-form {
  opacity: 0.55;
}

.dropzone.is-disabled {
  cursor: not-allowed;
  pointer-events: none;
}

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

.dropzone {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  min-height: 11.5rem;
  padding: var(--space-5);
  border: 1.5px dashed var(--color-border);
  border-radius: var(--radius);
  background: linear-gradient(160deg, rgba(18, 58, 53, 0.65), rgba(13, 46, 42, 0.4));
  color: var(--color-fg-muted);
  text-align: center;
  cursor: pointer;
  transition:
    border-color var(--duration) var(--ease),
    background var(--duration) var(--ease),
    color var(--duration) var(--ease);
}

.dropzone:hover,
.dropzone.is-dragover {
  border-color: var(--color-secondary);
  background: linear-gradient(160deg, rgba(15, 118, 110, 0.35), rgba(13, 46, 42, 0.55));
  color: var(--color-fg);
}

.dropzone .icon {
  color: var(--color-secondary);
  margin-bottom: var(--space-1);
}

.dropzone-title {
  font-weight: 600;
  color: var(--color-fg);
}

.dropzone-hint {
  font-size: 0.9rem;
}

.dropzone-file {
  margin-top: var(--space-2);
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-secondary);
}

.field {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.field label {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-fg-muted);
}

.optional {
  font-weight: 400;
  opacity: 0.75;
}

.field input {
  width: 100%;
  min-height: 2.85rem;
  padding: 0.65rem 0.9rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: rgba(7, 28, 26, 0.65);
  color: var(--color-fg);
  font: inherit;
  transition: border-color var(--duration) var(--ease);
}

.field input::placeholder {
  color: rgba(159, 197, 190, 0.55);
}

.field input:hover {
  border-color: rgba(94, 234, 212, 0.4);
}

.form-status {
  min-height: 1.4em;
  margin: 0;
  font-size: 0.92rem;
  color: var(--color-secondary);
}

.form-status.is-error {
  color: #fca5a5;
}

.share-result {
  margin-top: var(--space-2);
  padding: var(--space-4);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: rgba(15, 118, 110, 0.2);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.share-result-label {
  margin: 0;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--color-fg-muted);
}

.share-code-value {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.45rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--color-secondary);
  word-break: break-all;
}

.share-link-wrap {
  margin: 0;
  font-size: 0.9rem;
  overflow-wrap: anywhere;
}

/* ——— How ——— */
.how {
  padding-bottom: var(--space-8);
}

.steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: var(--space-6);
}

@media (min-width: 840px) {
  .steps {
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-7);
  }
}

.steps li {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  animation: rise-in 0.7s var(--ease) both;
}

.steps li:nth-child(2) {
  animation-delay: 0.07s;
}

.steps li:nth-child(3) {
  animation-delay: 0.14s;
}

.step-index {
  font-family: var(--font-display);
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: var(--color-accent);
}

.steps strong {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.steps span:last-child {
  color: var(--color-fg-muted);
  font-size: 0.98rem;
}

/* ——— Footer ——— */
.site-footer {
  padding: var(--space-6) clamp(1.25rem, 5vw, 3.5rem) var(--space-7);
  border-top: 1px solid var(--color-border);
  color: var(--color-fg-muted);
  font-size: 0.92rem;
}

.site-footer p {
  margin: 0 0 var(--space-2);
}

.footer-brand {
  font-family: var(--font-display);
  font-weight: 700;
  color: var(--color-fg);
}

.footer-meta {
  opacity: 0.85;
}

/* ——— Toast ——— */
.toast {
  position: fixed;
  bottom: 1.5rem;
  left: 50%;
  z-index: 50;
  transform: translateX(-50%) translateY(120%);
  max-width: min(92vw, 24rem);
  padding: 0.85rem 1.15rem;
  border-radius: var(--radius);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  color: var(--color-fg);
  font-size: 0.95rem;
  font-weight: 500;
  box-shadow: 0 16px 40px rgba(0, 0, 0, 0.35);
  transition: transform 0.35s var(--ease);
}

.toast.is-visible {
  transform: translateX(-50%) translateY(0);
}

/* ——— Motion ——— */
@keyframes rise-in {
  from {
    opacity: 0;
    transform: translateY(18px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes drift-up {
  0%,
  100% {
    transform: translateY(12%);
    opacity: 0.25;
  }
  50% {
    transform: translateY(-18%);
    opacity: 0.7;
  }
}

@keyframes drift-down {
  0%,
  100% {
    transform: translateY(-10%);
    opacity: 0.25;
  }
  50% {
    transform: translateY(20%);
    opacity: 0.65;
  }
}

@keyframes pulse-orb {
  0%,
  100% {
    transform: scale(1);
    opacity: 0.45;
  }
  50% {
    transform: scale(1.08);
    opacity: 0.62;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .hero-content,
  .section-intro,
  .panel,
  .steps li {
    animation: none;
  }

  .stream,
  .orb {
    animation: none;
  }

  .btn,
  .dropzone,
  .toast,
  a {
    transition: none;
  }
}

@media (max-width: 560px) {
  .site-nav {
    gap: 0.85rem;
  }

  .site-nav a {
    font-size: 0.88rem;
  }

  .hero {
    place-items: center start;
  }

  .hero-actions {
    width: 100%;
  }

  .hero-actions .btn {
    flex: 1 1 auto;
  }
}