/* ==========================================================================
   MHENT STUDY - GLOBAL LAYOUT & COMPONENT STYLES
   ========================================================================== */

/* Top Navigation Bar */
.study-navbar {
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
    background: var(--bg-glass);
    border-bottom: 1px solid var(--border-color);
    padding: 0.85rem 1.75rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    transition: all var(--transition-normal);
}

.brand-group {
    display: flex;
    align-items: center;
    gap: 0.85rem;
}

.brand-logo-badge {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    background: linear-gradient(135deg, #0284c7, #0ea5e9, #38bdf8);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-weight: 900;
    font-size: 1.2rem;
    box-shadow: 0 4px 16px var(--accent-edu-glow);
}

.brand-text {
    display: flex;
    flex-direction: column;
}

.brand-title {
    font-size: 1.15rem;
    font-weight: 800;
    letter-spacing: -0.02em;
    display: flex;
    align-items: center;
    gap: 0.4rem;
}

.brand-title span.highlight {
    background: linear-gradient(135deg, #0ea5e9, #38bdf8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.brand-sub {
    font-size: 0.72rem;
    color: var(--text-muted);
    font-weight: 600;
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

/* Nav Actions */
.nav-actions {
    display: flex;
    align-items: center;
    gap: 0.85rem;
}

.streak-pill {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.4rem 0.85rem;
    background: rgba(249, 115, 22, 0.12);
    border: 1px solid rgba(249, 115, 22, 0.3);
    border-radius: var(--radius-full);
    font-weight: 700;
    font-size: 0.85rem;
    color: #f97316;
}

.btn-icon {
    width: 38px;
    height: 38px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-subtle);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    transition: all var(--transition-fast);
}

.btn-icon:hover {
    background: var(--accent-edu);
    color: #fff;
    border-color: var(--accent-edu);
    transform: translateY(-2px);
}

.btn-primary {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.55rem 1.15rem;
    border-radius: var(--radius-md);
    background: linear-gradient(135deg, #0284c7, #0ea5e9);
    color: #ffffff;
    font-weight: 600;
    font-size: 0.9rem;
    box-shadow: 0 4px 14px var(--accent-edu-glow);
    transition: all var(--transition-fast);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px var(--accent-edu-glow);
    filter: brightness(1.08);
}

.btn-ghost {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.55rem 1.15rem;
    border-radius: var(--radius-md);
    background: var(--bg-subtle);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    font-weight: 600;
    font-size: 0.9rem;
    transition: all var(--transition-fast);
}

.btn-ghost:hover {
    background: var(--border-color);
    transform: translateY(-2px);
}

/* Breadcrumb Sub-bar */
.study-subbar {
    padding: 0.75rem 1.75rem;
    background: var(--bg-surface);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.breadcrumb-list {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.85rem;
    color: var(--text-muted);
}

.breadcrumb-list a:hover {
    color: var(--accent-edu);
}

.breadcrumb-sep {
    opacity: 0.5;
}

.breadcrumb-current {
    font-weight: 700;
    color: var(--text-primary);
}

/* Modals & Overlays */
.mhent-overlay {
    position: fixed;
    inset: 0;
    background: rgba(3, 7, 18, 0.65);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    z-index: 9999;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-normal);
}

.mhent-overlay.active {
    opacity: 1;
    pointer-events: auto;
}

.mhent-modal {
    width: 100%;
    max-width: 520px;
    background: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    overflow: hidden;
    transform: translateY(20px) scale(0.96);
    transition: transform var(--transition-normal);
}

.mhent-overlay.active .mhent-modal {
    transform: translateY(0) scale(1);
}

.modal-header {
    padding: 1.25rem 1.5rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.modal-body {
    padding: 1.5rem;
}

.modal-footer {
    padding: 1rem 1.5rem;
    background: var(--bg-subtle);
    border-top: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: flex-end;
    gap: 0.75rem;
}

/* Toast Notification */
#study-toast-container {
    position: fixed;
    bottom: 24px;
    right: 24px;
    z-index: 10000;
    display: flex;
    flex-direction: column;
    gap: 10px;
    pointer-events: none;
}

.study-toast {
    pointer-events: auto;
    min-width: 280px;
    max-width: 420px;
    padding: 0.85rem 1.15rem;
    border-radius: var(--radius-md);
    background: var(--bg-glass-strong);
    backdrop-filter: blur(16px);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-md);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 0.88rem;
    font-weight: 600;
    color: var(--text-primary);
    animation: toastSlideUp 0.3s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

.study-toast.success { border-left: 4px solid var(--success); }
.study-toast.error { border-left: 4px solid var(--error); }
.study-toast.info { border-left: 4px solid var(--accent-edu); }

@keyframes toastSlideUp {
    from {
        opacity: 0;
        transform: translateY(16px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}