/* Responsive — mobile first refinements + tablet
   Rules below progressively tighten layout for narrow viewports. */

/* Tablet ≤ 1024px */
@media (max-width: 1024px) {
    .shell { padding: 24px clamp(18px, 4vw, 40px) 70px; }
    .letters-grid { gap: 22px; }
    .moments-grid { grid-auto-rows: 100px; }
}

/* Mobile-large ≤ 760px */
@media (max-width: 760px) {
    .topbar { padding: 8px 10px 8px 14px; gap: 8px; }
    .brand-name      { font-size: 0.92rem; }
    .brand-name small{ display: none; }
    .user-chip span:not(.avatar) { display: none; }
    .user-chip { padding: 4px; }
    .topbar-actions { gap: 6px; }
    .lang-toggle button { padding: 6px 10px; }

    .hero-rose { display: none; }
    .hero { padding: 18px 0 48px; }
    .hero .lead { margin-top: 18px; }

    .vault-head { align-items: flex-start; }
    .letters-grid { grid-template-columns: 1fr; gap: 18px; }

    .modal-paper { padding: 28px 20px 26px; max-height: 92dvh; border-radius: 20px; }
    .modal-controls { padding-bottom: 12px; }
    .letter-view .letter-title { font-size: clamp(1.6rem, 6vw, 2rem); }
    .letter-body { font-size: 1.12rem; line-height: 1.72; }
    .letter-body p:first-of-type::first-letter { font-size: 2.6rem; padding: 4px 8px 0 0; }

    .thread-modal-paper { max-height: 94dvh; }
    .thread-head { padding: 16px 18px 14px; }
    .thread-list { padding: 18px 14px 24px; gap: 14px; }
    .thread-msg {
        grid-template-columns: 32px 1fr;
        column-gap: 12px;
        padding: 14px 16px 16px 16px;
        border-radius: 14px;
    }
    .thread-msg .avatar { width: 32px; height: 32px; font-size: 0.86rem; }
    .thread-list::before { left: 28px; }
    .thread-msg .from-line .badge { margin-left: 0; }
    .thread-msg .body { font-size: 1rem; }

    /* Moments — collapse mosaic into a 6-col grid */
    .moments { margin-top: 70px; }
    .moments-grid { grid-template-columns: repeat(6, 1fr); grid-auto-rows: 86px; gap: 8px; }
    .moments-grid .frame:nth-child(1)  { grid-column: span 6; grid-row: span 3; }
    .moments-grid .frame:nth-child(2)  { grid-column: span 3; grid-row: span 2; }
    .moments-grid .frame:nth-child(3)  { grid-column: span 3; grid-row: span 2; }
    .moments-grid .frame:nth-child(4)  { grid-column: span 3; grid-row: span 2; }
    .moments-grid .frame:nth-child(5)  { grid-column: span 3; grid-row: span 2; }
    .moments-grid .frame:nth-child(6)  { grid-column: span 6; grid-row: span 3; }
    .moments-grid .frame:nth-child(7)  { grid-column: span 3; grid-row: span 2; }
    .moments-grid .frame:nth-child(8)  { grid-column: span 3; grid-row: span 2; }
    .moments-grid .frame:nth-child(9)  { grid-column: span 6; grid-row: span 2; }
    .moments-grid .frame:nth-child(10) { grid-column: span 3; grid-row: span 2; }
    .moments-grid .frame:nth-child(11) { grid-column: span 3; grid-row: span 2; }
    .moments-grid .frame:nth-child(12) { grid-column: span 6; grid-row: span 2; }
}

/* Mobile-small ≤ 420px */
@media (max-width: 420px) {
    .shell { padding: 20px 14px 60px; }
    .topbar { top: 8px; }
    .login-card { padding: 36px 24px 28px; }
    .envelope { aspect-ratio: 5 / 3.6; }
    .envelope .stamp-holder { width: 42px; height: 50px; top: 10px; right: 10px; }
    .envelope .seal { width: 28px; height: 28px; bottom: 12px; right: 14px; font-size: 0.74rem; }
    .envelope .address { left: 16px; right: 50px; bottom: 14px; }
    .envelope h3 { font-size: 1rem; }
    .envelope .address-lines { display: none; }

    .moments-grid { grid-auto-rows: 76px; }
}