html, body {
    margin: 0;
    padding: 0;
    width: 100%;
    overflow-x: hidden; /* prevents tiny horizontal shift */
}

body {
    min-height: 100vh;
    margin: 0;
    display: flex;
    flex-direction: column;

    font-family: Arial, sans-serif;
    background: #f6f7fb;
}

/* MAIN LAYOUT */
.container {
    padding: 14px;
    flex: 1;
}

/* STUDY WRAPPER */
#study {
    display: flex;
    flex-direction: column;
    align-items: center;
}

/* FILTERS WRAPPER */
.deck-filters {
  display: flex;
  gap: 8px;
  justify-content: center;
  margin: 0 0 20px;
  flex-wrap: wrap;
}

@media (max-width: 600px) {
    .deck-filters {
        margin: 0 0 0px;
        gap: 6px;
    }
}

/* =========================
   TITLES
   ========================= */
#study h1 {
    font-size: 22px;
    font-weight: 600;
    text-align: center;

    color: #222;
    letter-spacing: 0.3px;
}

#study h1::after {
    content: "";
    display: block;
    width: 40px;
    height: 3px;
    margin: 10px auto 0;

    background: #ddd;
    border-radius: 2px;
}

#study h2 {
    font-size: 16px;
    font-weight: 500;
    text-align: center;
    color: #666;
}

/* =========================
   FOOTER
   ========================= */
.app-footer {
    width: 100%;
    box-sizing: border-box;

    padding: 8px 18px;

    background: rgba(20,20,20,0.9);
    color: rgba(255,255,255,0.75);

    backdrop-filter: blur(8px);

    margin-top: 30px;
}

.footer-content {
    display: flex;
    justify-content: flex-end;
    align-items: center;

    font-size: 12px;
    letter-spacing: 0.3px;
}

.footer-content span:hover {
    cursor: default;
    color: rgba(255,255,255,0.95);
}