/* ==========================================================================
   Smart Learning Buddy - Global Navigation Hamburger & Drawer Styles
   ========================================================================== */

:root {
    --nav-drawer-width: min(340px, 86vw);
}

/* Floating Hamburger Trigger Button */
.slb-nav-toggle {
    position: fixed;
    top: max(0.9rem, env(safe-area-inset-top));
    right: max(1rem, env(safe-area-inset-right));
    width: 46px;
    height: 46px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.94);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    border: 2px solid var(--primary, #E67E22);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.12);
    cursor: pointer;
    z-index: 9999;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 5px;
    padding: 0;
    transition: transform 0.2s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.2s ease, background-color 0.2s ease;
}

.slb-nav-toggle:hover {
    transform: scale(1.06);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.16);
    background: #FFFFFF;
}

.slb-nav-toggle:active {
    transform: scale(0.95);
}

.slb-nav-toggle:focus-visible {
    outline: 3px solid var(--primary, #E67E22);
    outline-offset: 3px;
}

/* Morphing Hamburger Bars */
.slb-nav-toggle .bar {
    width: 22px;
    height: 2.5px;
    background-color: var(--primary, #E67E22);
    border-radius: 2px;
    transition: transform 0.28s ease, opacity 0.2s ease;
    transform-origin: center;
}

.slb-nav-toggle.open .bar:nth-child(1) {
    transform: translateY(7.5px) rotate(45deg);
}

.slb-nav-toggle.open .bar:nth-child(2) {
    opacity: 0;
    transform: scaleX(0);
}

.slb-nav-toggle.open .bar:nth-child(3) {
    transform: translateY(-7.5px) rotate(-45deg);
}

/* Backdrop Scrim Overlay */
.slb-nav-backdrop {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(0, 0, 0, 0.38);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    z-index: 9997;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.28s ease;
}

.slb-nav-backdrop.open {
    opacity: 1;
    pointer-events: auto;
}

/* Off-Canvas Slide Drawer */
.slb-nav-drawer {
    position: fixed;
    top: 0;
    right: calc(-1 * var(--nav-drawer-width) - 20px);
    width: var(--nav-drawer-width);
    height: 100vh;
    height: 100dvh;
    background: var(--card-bg, #FFFFFF);
    color: var(--text, #2B2D42);
    box-shadow: -8px 0 32px rgba(0, 0, 0, 0.16);
    z-index: 9998;
    display: flex;
    flex-direction: column;
    transition: right 0.32s cubic-bezier(0.16, 1, 0.3, 1);
    font-family: 'Poppins', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    box-sizing: border-box;
}

.slb-nav-drawer.open {
    right: 0;
}

/* Drawer Header */
.slb-drawer-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1.25rem 1.25rem 1rem;
    border-bottom: 2px solid rgba(0, 0, 0, 0.06);
    background: var(--background, #FAFAFA);
}

.slb-drawer-title {
    margin: 0;
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--primary, #E67E22);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.slb-drawer-close {
    background: none;
    border: none;
    font-size: 1.3rem;
    color: var(--text-light, #6C757D);
    cursor: pointer;
    padding: 0.3rem 0.6rem;
    border-radius: 8px;
    transition: background 0.15s ease, color 0.15s ease;
}

.slb-drawer-close:hover {
    background: rgba(0, 0, 0, 0.06);
    color: var(--text, #2B2D42);
}

/* Drawer Sections */
.slb-drawer-body {
    padding: 1rem 1.25rem;
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
    flex: 1;
}

.slb-drawer-section-label {
    font-size: 0.78rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-light, #6C757D);
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    gap: 0.4rem;
}

.slb-nav-list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.slb-nav-item {
    margin: 0;
    padding: 0;
}

.slb-nav-link {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.65rem 0.85rem;
    color: var(--text, #2B2D42);
    text-decoration: none;
    border-radius: 10px;
    font-size: 0.95rem;
    font-weight: 500;
    background: transparent;
    transition: all 0.18s ease;
    border: 1px solid transparent;
}

.slb-nav-link-left {
    display: flex;
    align-items: center;
    gap: 0.65rem;
}

.slb-nav-link-icon {
    font-size: 1.15rem;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 24px;
}

.slb-nav-link:hover {
    background: rgba(0, 0, 0, 0.04);
    transform: translateX(3px);
}

/* Active Page Indicator */
.slb-nav-link.active-page {
    background: rgba(230, 126, 34, 0.1);
    color: var(--primary, #E67E22);
    font-weight: 600;
    border-color: rgba(230, 126, 34, 0.25);
}

.slb-active-pill {
    font-size: 0.7rem;
    background: var(--primary, #E67E22);
    color: white;
    padding: 0.15rem 0.45rem;
    border-radius: 10px;
    font-weight: 600;
    letter-spacing: 0.02em;
}

/* In-Page Jumper Items */
.slb-jumper-link {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.55rem 0.8rem;
    color: var(--text, #2B2D42);
    text-decoration: none;
    border-radius: 8px;
    font-size: 0.9rem;
    transition: all 0.18s ease;
    cursor: pointer;
    border: 1px solid transparent;
}

.slb-jumper-link:hover:not(.disabled) {
    background: rgba(0, 0, 0, 0.04);
    color: var(--primary, #E67E22);
    transform: translateX(3px);
}

.slb-jumper-link.disabled {
    opacity: 0.45;
    cursor: not-allowed;
    pointer-events: none;
}

.slb-jumper-tag {
    font-size: 0.72rem;
    color: var(--text-light, #6C757D);
    background: rgba(0, 0, 0, 0.05);
    padding: 0.12rem 0.4rem;
    border-radius: 6px;
}

/* Drawer Footer */
.slb-drawer-footer {
    padding: 0.85rem 1.25rem;
    border-top: 1px solid rgba(0, 0, 0, 0.06);
    background: var(--background, #FAFAFA);
    font-size: 0.78rem;
    color: var(--text-light, #6C757D);
    text-align: center;
}

/* Highlight Target Pulse on Jump */
@keyframes slbSectionPulse {
    0% {
        box-shadow: 0 0 0 0 rgba(230, 126, 34, 0.6);
        border-color: var(--primary, #E67E22);
    }
    50% {
        box-shadow: 0 0 0 8px rgba(230, 126, 34, 0.2);
        border-color: var(--primary, #E67E22);
    }
    100% {
        box-shadow: none;
    }
}

.slb-jump-pulse {
    animation: slbSectionPulse 1.2s ease-out;
}