/* =================================
SECTION PREVIEW
================================= */

.section--preview{
  background: var(--bg-books);
  position: relative;
}

.section--preview .container{
  max-width: 1120px;
  margin: 0 auto;
}

.section--preview .centered-text{
  max-width: 760px;
  margin: 0 auto 42px;
}

/* leichtes Ambient Light, passend zu vocab / hero */
.section--preview::after{
  content:"";
  position:absolute;
  inset:0;
  pointer-events:none;
  background:
    radial-gradient(
      circle at 20% 10%,
      rgba(0,113,227,0.06),
      transparent 42%
    ),
    radial-gradient(
      circle at 82% 24%,
      rgba(0,0,0,0.035),
      transparent 40%
    );
  opacity:.9;
  z-index:0;
}

.section--preview > *{
  position:relative;
  z-index:1;
}

/* =================================
PREVIEW GRID
================================= */

.preview-grid{
  display:grid;
  grid-template-columns:repeat(3,minmax(0,1fr));
  gap:20px;
  align-items:stretch;
  max-width:980px;
  margin:0 auto;
}


/* =================================
PREVIEW CARD
================================= */

.preview-card{
  position:relative;
  display:flex;
  flex-direction:column;
  min-width:0;

  background:var(--card);
  border:1px solid var(--line);
  border-radius:24px;

  backdrop-filter:blur(16px);
  -webkit-backdrop-filter:blur(16px);

  box-shadow:var(--shadow-soft);
  overflow:hidden;

  transition:
    transform .3s ease,
    box-shadow .3s ease,
    border-color .3s ease,
    background .3s ease;
}

.preview-card:hover{
  transform:translateY(-6px);
  box-shadow:0 26px 70px rgba(0,0,0,0.14);
}

/* =================================
PREVIEW IMAGE
================================= */

.preview-image{
  position:relative;
  aspect-ratio: 16 / 9.5;
  overflow:hidden;
  background:var(--card-strong);
}

.preview-image img{
  width:100%;
  height:100%;
  object-fit:cover;
  display:block;
  transition:transform .55s ease;
}

.preview-card:hover .preview-image img{
  transform:scale(1.04);
}

/* optionaler leichter Verlauf oben aufs Bild */
.preview-image::after{
  content:"";
  position:absolute;
  inset:0;
  pointer-events:none;
  background:
    linear-gradient(
      to bottom,
      rgba(0,0,0,0.04) 0%,
      transparent 36%,
      transparent 100%
    );
}

/* =================================
PREVIEW CONTENT
================================= */

.preview-content{
  display:flex;
  flex-direction:column;
  flex:1;
  padding:16px 16px 18px;
}

.preview-kicker{
  display:inline-flex;
  align-self:flex-start;
  margin-bottom:8px;
  padding:5px 10px;
  border-radius:999px;
  background:rgba(0,113,227,0.08);
  color:var(--primary);
  font-size:0.74rem;
  font-weight:600;
  letter-spacing:-0.01em;
}

.preview-card h3{
  font-size:1.06rem;
  line-height:1.14;
  letter-spacing:-0.03em;
  font-weight:700;
}

.preview-card p{
  margin-top:6px;
  color:var(--text-soft);
  font-size:0.9rem;
  line-height:1.45;
}

.preview-meta{
  margin-top:auto;
  padding-top:12px;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:12px;
}

.preview-link{
  display:inline-flex;
  align-items:center;
  gap:7px;
  font-size:0.86rem;
  font-weight:600;
  color:var(--primary);
  transition:transform .2s ease, opacity .2s ease;
}

.preview-card:hover .preview-link{
  transform:translateX(3px);
}

/* =================================
DARK MODE
================================= */

@media (prefers-color-scheme: dark){

  .section--preview{
    background:var(--bg-books);
  }

  .section--preview::after{
    background:
      radial-gradient(
        circle at 20% 10%,
        rgba(80,120,180,0.12),
        transparent 46%
      ),
      radial-gradient(
        circle at 82% 24%,
        rgba(255,255,255,0.03),
        transparent 38%
      );
    opacity:1;
  }

  .preview-card{
    background:rgba(255,255,255,0.04);
    border:1px solid rgba(255,255,255,0.08);
    box-shadow:0 18px 50px rgba(0,0,0,0.45);
  }

  .preview-card:hover{
    background:rgba(255,255,255,0.06);
    box-shadow:0 26px 70px rgba(0,0,0,0.55);
  }

  .preview-kicker{
    background:rgba(125,182,255,0.10);
    color:#8cc0ff;
  }

  .preview-image::after{
    background:
      linear-gradient(
        to bottom,
        rgba(0,0,0,0.16) 0%,
        transparent 40%,
        transparent 100%
      );
  }
}

/* =================================
TABLET
================================= */

@media (min-width:740px) and (max-width:1100px){

  .preview-grid{
    grid-template-columns:repeat(2,minmax(0,1fr));
    gap:22px;
  }

  .preview-card h3{
    font-size:1.2rem;
  }
}

/* =================================
MOBILE
================================= */

@media (max-width:740px){

  .section--preview .centered-text{
    margin-bottom:36px;
  }

  .preview-grid{
    grid-template-columns:repeat(2,minmax(0,1fr));
    gap:14px;
    max-width:100%;
    margin:0 auto;
  }

  .preview-card{
    border-radius:20px;
  }

  .preview-image{
    aspect-ratio:1 / 1;
  }

  .preview-content{
    padding:12px 12px 14px;
  }

  .preview-kicker{
    margin-bottom:6px;
    padding:4px 8px;
    font-size:0.68rem;
  }

  .preview-card h3{
    font-size:0.96rem;
    line-height:1.15;
  }

  .preview-card p{
    margin-top:5px;
    font-size:0.82rem;
    line-height:1.4;
  }

  .preview-meta{
    padding-top:10px;
  }

  .preview-link{
    font-size:0.8rem;
  }

  .preview-card:hover{
    transform:none;
    box-shadow:var(--shadow-soft);
  }
}

.hybrid-visual--four{
  display:grid;
  grid-template-columns:1fr;
  gap:20px;
  justify-items:center;
  align-items:start;
}

.hybrid-visual--four .flip-card{
  width:min(100%, 340px);
}

.hybrid-visual--four .card-front,
.hybrid-visual--four .card-back{
  width:100%;
  display:block;
}

.hybrid-visual--four .hybrid-plus{
  display:none;
}

/* TABLET + DESKTOP: 2 pro Reihe */
@media (min-width:740px){

  .hybrid-visual--four{
    grid-template-columns:repeat(2,minmax(280px, 360px));
    gap:28px 28px;
    justify-content:center;
  }

  .hybrid-visual--four .flip-card{
    width:100%;
    max-width:360px;
  }
}

/* DESKTOP etwas größer */
@media (min-width:1024px){

  .hybrid-visual--four{
    grid-template-columns:repeat(2,minmax(300px, 390px));
    gap:34px 34px;
  }

  .hybrid-visual--four .flip-card{
    max-width:390px;
  }
}

/* =================================
Intro Vorschau zentrieren
================================= */
/* Intro Block zentrieren */
.vocab-intro .vocab-layout{
  display:block;
}

.vocab-intro .vocab-content{
  max-width:760px;
  margin:0 auto;
  text-align:center;
}

.vocab-intro .mini-info{
  max-width:680px;
  margin-left:auto;
  margin-right:auto;
}

/* ================================
PASSWORT OVERLAY
================================ */

#password-overlay{
position:fixed;
inset:0;
z-index:99999;

display:flex;
align-items:center;
justify-content:center;

padding:24px;

background:
linear-gradient(180deg,#f3f7ff 0%,#f7f9ff 50%,#faf8f3 100%);
backdrop-filter:blur(14px);
-webkit-backdrop-filter:blur(14px);
}

#password-overlay::before{
content:"";
position:absolute;
inset:0;
pointer-events:none;
background:
radial-gradient(circle at 20% 20%, rgba(255,255,255,0.75) 0%, transparent 30%),
radial-gradient(circle at 80% 80%, rgba(186,210,255,0.22) 0%, transparent 28%);
}

.password-box{
position:relative;
z-index:1;

width:min(100%, 440px);
padding:32px 28px;

border-radius:28px;
text-align:center;

background:rgba(255,255,255,0.78);
border:1px solid rgba(255,255,255,0.7);

box-shadow:
0 24px 60px rgba(15,23,42,0.12),
0 10px 24px rgba(15,23,42,0.08);

backdrop-filter:blur(18px);
-webkit-backdrop-filter:blur(18px);
}

.password-box h2{
margin:0 0 10px;
font-size:clamp(1.55rem,2vw,2rem);
line-height:1.15;
letter-spacing:-0.03em;
color:#111827;
}

.password-box p{
margin:0 0 18px;
font-size:1rem;
line-height:1.55;
color:#4b5563;
}

#pw-input{
width:100%;
height:54px;
margin-bottom:12px;
padding:0 16px;

border-radius:16px;
border:1px solid rgba(17,24,39,0.10);
outline:none;

background:rgba(255,255,255,0.95);
color:#111827;
font-size:1rem;

transition:
border-color .22s ease,
box-shadow .22s ease,
transform .22s ease;
}

#pw-input::placeholder{
color:#9ca3af;
}

#pw-input:focus{
border-color:rgba(59,130,246,0.32);
box-shadow:0 0 0 4px rgba(59,130,246,0.10);
transform:translateY(-1px);
}

#pw-btn{
width:100%;
height:54px;
padding:0 18px;

border:none;
border-radius:999px;
cursor:pointer;

font-size:0.98rem;
font-weight:600;
letter-spacing:-0.01em;

color:#ffffff;
background:linear-gradient(135deg,#111827 0%,#1f2937 100%);

box-shadow:
0 14px 30px rgba(17,24,39,0.18),
0 6px 14px rgba(17,24,39,0.10);

transition:
transform .22s ease,
box-shadow .22s ease,
opacity .22s ease;
}

#pw-btn:hover{
transform:translateY(-2px);
box-shadow:
0 18px 34px rgba(17,24,39,0.22),
0 8px 18px rgba(17,24,39,0.12);
}

#pw-btn:active{
transform:translateY(0);
}

#pw-error{
margin-top:12px !important;
margin-bottom:0 !important;
font-size:0.95rem;
font-weight:500;
color:#c62828 !important;
}

/* Mobil */
@media (max-width:680px){

  #password-overlay{
    padding:16px;
  }

  .password-box{
    width:100%;
    padding:24px 18px;
    border-radius:24px;
  }

  .password-box h2{
    font-size:1.4rem;
  }

  .password-box p{
    font-size:0.96rem;
    margin-bottom:16px;
  }

  #pw-input,
  #pw-btn{
    height:50px;
    font-size:0.96rem;
  }
}

/* Dark Mode */
body.dark-mode #password-overlay{
background:
radial-gradient(circle at 20% 20%,#0e1a2a 0%,#0a111a 70%) fixed;
}

body.dark-mode #password-overlay::before{
background:
radial-gradient(circle at 18% 18%, rgba(110,168,255,0.14) 0%, transparent 30%),
radial-gradient(circle at 82% 78%, rgba(255,255,255,0.05) 0%, transparent 26%);
}

body.dark-mode .password-box{
background:rgba(15,23,42,0.72);
border:1px solid rgba(255,255,255,0.08);

box-shadow:
0 24px 60px rgba(0,0,0,0.34),
0 10px 24px rgba(0,0,0,0.18);
}

body.dark-mode .password-box h2{
color:#f9fafb;
}

body.dark-mode .password-box p{
color:#cbd5e1;
}

body.dark-mode #pw-input{
background:rgba(255,255,255,0.06);
border:1px solid rgba(255,255,255,0.10);
color:#f9fafb;
}

body.dark-mode #pw-input::placeholder{
color:#94a3b8;
}

body.dark-mode #pw-input:focus{
border-color:rgba(147,197,253,0.30);
box-shadow:0 0 0 4px rgba(147,197,253,0.12);
}

body.dark-mode #pw-btn{
background:linear-gradient(135deg,#f8fafc 0%,#dbe6f3 100%);
color:#0f172a;

box-shadow:
0 16px 30px rgba(0,0,0,0.24),
0 8px 18px rgba(0,0,0,0.16);
}

body.dark-mode #pw-error{
color:#ff8a80 !important;
}