/* ===================================================
   AI Gakufu — Apple-inspired Design System
   =================================================== */

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

/* ----- Tokens ----- */
:root {
  --bg:          #000000;
  --bg2:         #0a0a0a;
  --glass:       rgba(255,255,255,0.05);
  --glass-hover: rgba(255,255,255,0.08);
  --border:      rgba(255,255,255,0.10);
  --border-s:    rgba(255,255,255,0.16);
  --text:        #f5f5f7;
  --text-2:      #a1a1a6;
  --text-3:      #6e6e73;
  --blue:        #0071e3;
  --blue-hover:  #0077ed;
  --green:       #30d158;
  --red:         #ff453a;
  --radius-lg:   20px;
  --radius-md:   14px;
  --radius-sm:   10px;
  --shadow:      0 2px 40px rgba(0,0,0,.6);
}

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display",
               "SF Pro Text", "Helvetica Neue", Arial, sans-serif;
  font-size: 17px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* ===== Nav ===== */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(0,0,0,.72);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  max-width: 980px;
  margin: 0 auto;
  padding: 0 1.5rem;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text);
  text-decoration: none;
  letter-spacing: -.02em;
}

.nav-links {
  display: flex;
  gap: 1.5rem;
}

.nav-links a {
  color: var(--text-2);
  text-decoration: none;
  font-size: .8rem;
  transition: color .2s;
}

.nav-links a:hover { color: var(--text); }

/* ===== Hero ===== */
.hero {
  text-align: center;
  padding: 7rem 1.5rem 5rem;
  background: radial-gradient(ellipse 80% 60% at 50% -10%,
    rgba(0,113,227,.18) 0%, transparent 70%);
}

.hero-eyebrow {
  display: inline-block;
  font-size: .75rem;
  font-weight: 600;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--blue);
  margin-bottom: 1.25rem;
  background: rgba(0,113,227,.12);
  border: 1px solid rgba(0,113,227,.3);
  border-radius: 99px;
  padding: .3rem .9rem;
}

.hero-title {
  font-size: clamp(2.8rem, 7vw, 5.5rem);
  font-weight: 700;
  letter-spacing: -.04em;
  line-height: 1.05;
  margin-bottom: 1.25rem;
  background: linear-gradient(160deg, #ffffff 40%, #86868b 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-sub {
  font-size: clamp(1rem, 2.5vw, 1.25rem);
  color: var(--text-2);
  margin-bottom: 2.5rem;
  line-height: 1.6;
}

/* ===== CTA button ===== */
.btn-cta {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  background: var(--blue);
  color: #fff;
  text-decoration: none;
  font-size: 1rem;
  font-weight: 500;
  padding: .75rem 1.75rem;
  border-radius: 99px;
  border: none;
  cursor: pointer;
  transition: background .2s, transform .15s;
}

.btn-cta:hover { background: var(--blue-hover); transform: scale(1.02); }
.btn-cta:active { transform: scale(.98); }

/* ===== Feature pills ===== */
.features {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: .75rem;
  padding: 0 1.5rem 4rem;
}

.feature-pill {
  display: flex;
  align-items: center;
  gap: .5rem;
  background: var(--glass);
  border: 1px solid var(--border);
  border-radius: 99px;
  padding: .5rem 1.1rem;
  font-size: .85rem;
  color: var(--text-2);
}

.feature-icon { font-size: 1rem; }

/* ===== Ad banner ===== */
.ad-banner-top {
  background: var(--bg2);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  padding: .75rem 1rem;
  text-align: center;
  min-height: 90px;
}

/* ===== Container ===== */
.container {
  max-width: 640px;
  margin: 3rem auto;
  padding: 0 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

/* ===== Glass card ===== */
.glass-card {
  background: var(--glass);
  backdrop-filter: blur(40px);
  -webkit-backdrop-filter: blur(40px);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2.5rem 2rem;
  box-shadow: var(--shadow);
  transition: border-color .25s;
}

.glass-card:hover { border-color: var(--border-s); }

.card-label {
  font-size: .7rem;
  font-weight: 700;
  letter-spacing: .12em;
  color: var(--blue);
  margin-bottom: .6rem;
}

.error-label { color: var(--red); }

.card-title {
  font-size: 1.5rem;
  font-weight: 600;
  letter-spacing: -.02em;
  margin-bottom: 1.75rem;
  color: var(--text);
}

/* ===== Drop zone ===== */
.drop-zone {
  border: 1.5px dashed var(--border-s);
  border-radius: var(--radius-md);
  padding: 2.5rem 1.5rem;
  text-align: center;
  cursor: pointer;
  transition: border-color .2s, background .2s;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: .5rem;
}

.drop-zone:hover,
.drop-zone.drag-over {
  border-color: var(--blue);
  background: rgba(0,113,227,.04);
}

.drop-icon-wrap {
  width: 56px;
  height: 56px;
  border-radius: 14px;
  background: rgba(255,255,255,.06);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-2);
  margin-bottom: .25rem;
}

.drop-primary { font-size: .95rem; font-weight: 500; }
.drop-secondary { font-size: .82rem; color: var(--text-3); }
.drop-hint { font-size: .75rem; color: var(--text-3); margin-top: .25rem; }

/* ===== File info ===== */
.file-info {
  display: flex;
  align-items: center;
  gap: .75rem;
  background: rgba(255,255,255,.04);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: .75rem 1rem;
  margin-top: 1rem;
}

.file-icon-sm { font-size: 1.2rem; }
.file-name { flex: 1; font-size: .88rem; word-break: break-all; color: var(--text-2); }

.btn-remove {
  background: none;
  border: none;
  color: var(--text-3);
  cursor: pointer;
  font-size: .9rem;
  padding: .2rem;
  transition: color .15s;
  line-height: 1;
}
.btn-remove:hover { color: var(--red); }

/* ===== Form ===== */
.form-group {
  margin-top: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: .4rem;
}

.form-group label {
  font-size: .82rem;
  color: var(--text-3);
  font-weight: 500;
}

.form-group input {
  background: rgba(255,255,255,.05);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  font-size: .95rem;
  font-family: inherit;
  padding: .75rem 1rem;
  outline: none;
  transition: border-color .2s, background .2s;
}

.form-group input:focus {
  border-color: var(--blue);
  background: rgba(255,255,255,.07);
}

.form-group input::placeholder { color: var(--text-3); }

/* ===== Buttons ===== */
.btn-primary-pill {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .5rem;
  background: var(--blue);
  color: #fff;
  border: none;
  border-radius: 99px;
  font-size: .95rem;
  font-weight: 500;
  font-family: inherit;
  padding: .8rem 1.75rem;
  cursor: pointer;
  width: 100%;
  margin-top: 1.5rem;
  transition: background .2s, transform .15s, opacity .2s;
}

.btn-primary-pill:hover:not(:disabled) { background: var(--blue-hover); }
.btn-primary-pill:active:not(:disabled) { transform: scale(.98); }
.btn-primary-pill:disabled { opacity: .3; cursor: not-allowed; }

.btn-outline-pill {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .4rem;
  background: transparent;
  color: var(--blue);
  border: 1.5px solid var(--blue);
  border-radius: 99px;
  font-size: .9rem;
  font-weight: 500;
  font-family: inherit;
  padding: .65rem 1.5rem;
  cursor: pointer;
  text-decoration: none;
  transition: background .2s, color .2s;
}

.btn-outline-pill:hover { background: rgba(0,113,227,.1); }

.btn-ghost {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  color: var(--text-3);
  border: none;
  border-radius: 99px;
  font-size: .88rem;
  font-family: inherit;
  padding: .6rem 1.25rem;
  cursor: pointer;
  transition: color .2s, background .2s;
}

.btn-ghost:hover { color: var(--text-2); background: rgba(255,255,255,.05); }

/* ===== Progress ===== */
.progress-track {
  background: rgba(255,255,255,.07);
  border-radius: 99px;
  height: 4px;
  overflow: hidden;
  margin-bottom: 1rem;
}

.progress-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--blue), #34aadc);
  border-radius: 99px;
  transition: width .4s ease;
}

.progress-message {
  color: var(--text-3);
  font-size: .85rem;
  margin-bottom: 1.5rem;
}

.steps {
  display: flex;
  flex-direction: column;
  gap: .9rem;
}

.step {
  display: flex;
  align-items: center;
  gap: .9rem;
  font-size: .88rem;
  color: var(--text-3);
  transition: color .3s;
}

.step-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--border-s);
  flex-shrink: 0;
  transition: background .3s;
}

.step.active .step-dot  { background: var(--blue); box-shadow: 0 0 8px var(--blue); }
.step.active            { color: var(--text); }
.step.done .step-dot    { background: var(--green); }
.step.done              { color: var(--green); }

/* ===== Result ===== */
.result-meta {
  color: var(--text-3);
  font-size: .85rem;
  margin-top: -.75rem;
  margin-bottom: 1.5rem;
}

.download-grid {
  display: flex;
  flex-direction: column;
  gap: .75rem;
}

.download-card {
  display: flex;
  align-items: center;
  gap: 1rem;
  background: rgba(255,255,255,.04);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.25rem 1.5rem;
  transition: border-color .2s, background .2s;
}

.download-card:hover {
  border-color: var(--border-s);
  background: rgba(255,255,255,.06);
}

.dl-icon { font-size: 2rem; flex-shrink: 0; }

.dl-info { flex: 1; }
.dl-info h3 { font-size: .95rem; font-weight: 600; margin-bottom: .15rem; }
.dl-info p  { font-size: .78rem; color: var(--text-3); }

.btn-dl {
  display: inline-flex;
  align-items: center;
  gap: .4rem;
  background: var(--blue);
  color: #fff;
  border: none;
  border-radius: 99px;
  font-size: .82rem;
  font-weight: 500;
  font-family: inherit;
  padding: .55rem 1.1rem;
  cursor: pointer;
  white-space: nowrap;
  flex-shrink: 0;
  transition: background .2s;
}

.btn-dl:hover { background: var(--blue-hover); }

/* ===== Error ===== */
.error-message {
  color: var(--text-2);
  font-size: .9rem;
  margin-bottom: 1.5rem;
  white-space: pre-wrap;
}

/* ===== Modal ===== */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,.8);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  padding: 1rem;
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
}

.modal-card {
  background: #1c1c1e;
  border: 1px solid var(--border-s);
  border-radius: var(--radius-lg);
  padding: 2rem 1.75rem;
  width: 100%;
  max-width: 380px;
  box-shadow: 0 24px 80px rgba(0,0,0,.8);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: .75rem;
  text-align: center;
}

.modal-card h3 {
  font-size: 1.1rem;
  font-weight: 600;
  letter-spacing: -.01em;
}

.ad-notice { font-size: .82rem; color: var(--text-3); }

.ad-unit-wrap {
  width: 100%;
  min-height: 100px;
  background: rgba(255,255,255,.03);
  border: 1px dashed var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

/* Countdown ring */
.countdown-wrap {
  position: relative;
  width: 64px;
  height: 64px;
  margin-top: .25rem;
}

.countdown-ring {
  width: 64px;
  height: 64px;
  transform: rotate(-90deg);
}

.ring-bg {
  fill: none;
  stroke: rgba(255,255,255,.08);
  stroke-width: 4;
}

#ring-progress {
  fill: none;
  stroke: var(--blue);
  stroke-width: 4;
  stroke-linecap: round;
  stroke-dasharray: 163.4;
  stroke-dashoffset: 0;
  transition: stroke-dashoffset .9s linear;
}

.countdown-number {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--text);
}

.countdown-msg { font-size: .8rem; color: var(--text-3); }

/* Locked download button */
.btn-locked {
  opacity: .3;
  pointer-events: none;
  cursor: not-allowed;
}

.btn-locked.unlocked {
  opacity: 1;
  pointer-events: auto;
  cursor: pointer;
  animation: pop .25s ease;
}

@keyframes pop {
  0%   { transform: scale(.95); }
  60%  { transform: scale(1.03); }
  100% { transform: scale(1); }
}

/* ===== Footer ===== */
.site-footer {
  text-align: center;
  padding: 3rem 1.5rem 2rem;
  border-top: 1px solid var(--border);
  margin-top: 2rem;
}

.footer-logo {
  font-size: 1.1rem;
  font-weight: 600;
  letter-spacing: -.02em;
  color: var(--text);
  margin-bottom: 1rem;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  margin-bottom: .75rem;
}

.footer-links a {
  color: var(--text-3);
  text-decoration: none;
  font-size: .8rem;
  transition: color .2s;
}

.footer-links a:hover { color: var(--text-2); }

.footer-copy {
  font-size: .75rem;
  color: var(--text-3);
}

/* ===== Utilities ===== */
.hidden { display: none !important; }

/* ===== Responsive ===== */
@media (max-width: 520px) {
  .hero { padding: 5rem 1.25rem 3rem; }
  .glass-card { padding: 1.75rem 1.25rem; }
  .download-card { flex-wrap: wrap; }
  .btn-dl { width: 100%; justify-content: center; }
}

/* ===== Legal pages ===== */
.legal-container { max-width: 720px; margin: 2rem auto; padding: 0 1.25rem; }
.legal-card { background: var(--glass); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 2.5rem; box-shadow: var(--shadow); }
.legal-card h1 { font-size: 1.8rem; font-weight: 700; letter-spacing: -.03em; margin-bottom: .4rem; }
.legal-card .updated { color: var(--text-3); font-size: .82rem; margin-bottom: 2rem; }
.legal-card h2 { font-size: 1rem; font-weight: 600; color: var(--text); margin: 1.75rem 0 .6rem; }
.legal-card p, .legal-card li { color: var(--text-2); font-size: .9rem; line-height: 1.8; }
.legal-card ul { padding-left: 1.4rem; margin-top: .4rem; }
.legal-card ul li { margin-bottom: .3rem; }
.legal-card a { color: var(--blue); text-decoration: none; }
.legal-card a:hover { text-decoration: underline; }
.back-link { display: inline-flex; align-items: center; gap: .4rem; color: var(--text-3); text-decoration: none; font-size: .85rem; margin-bottom: 1.25rem; transition: color .15s; }
.back-link:hover { color: var(--blue); }
.important { background: rgba(0,113,227,.08); border: 1px solid rgba(0,113,227,.2); border-radius: var(--radius-sm); padding: 1rem 1.25rem; margin-top: .5rem; }