/**
 * Little Search Index (lsi.gr) - Modern Dark Theme
 * ROBIS Lab - Laboratory of Robotics, Embedded & Integrated Systems
 * Department of Electrical & Computer Engineering, University of Western Macedonia
 */

:root {
    --lsi-bg: #0d1117;
    --lsi-card-bg: #161b22;
    --lsi-card-hover: #1c2128;
    --lsi-card-header: #1f242c;
    --lsi-border: #30363d;
    --lsi-border-hover: #484f58;
    --lsi-text-primary: #f0f6fc;
    --lsi-text-secondary: #8b949e;
    --lsi-text-muted: #6e7681;
    --lsi-accent: #38bdf8;
    --lsi-accent-hover: #0ea5e9;
    --lsi-cyan: #00d2d3;
    --lsi-cyan-glow: rgba(0, 210, 211, 0.25);
    --lsi-success: #238636;
    --lsi-success-hover: #2ea043;
    --lsi-danger: #da3633;
    --lsi-danger-hover: #f85149;
    --lsi-warning: #d29922;
    --lsi-info: #58a6ff;
    --lsi-purple: #a855f7;
    --lsi-shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
    --lsi-shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.6);
    --lsi-radius: 12px;
    --lsi-radius-sm: 8px;
    --lsi-radius-lg: 16px;
    --lsi-transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

/* Base resets & typography */
html, body {
    background-color: var(--lsi-bg) !important;
    color: var(--lsi-text-primary) !important;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji";
    margin: 0;
    padding: 0;
    min-height: 100vh;
    overflow-x: hidden;
}

a {
    color: var(--lsi-accent);
    text-decoration: none;
    transition: var(--lsi-transition);
}

a:hover {
    color: var(--lsi-accent-hover);
    text-decoration: underline;
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}
::-webkit-scrollbar-track {
    background: var(--lsi-bg);
}
::-webkit-scrollbar-thumb {
    background: var(--lsi-border);
    border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
    background: var(--lsi-border-hover);
}

/* ==========================================================================
   1. Student View / PIN Entry Screen
   ========================================================================== */
.student-viewport {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    background: radial-gradient(circle at 50% 20%, #161b22 0%, #0d1117 70%);
    position: relative;
}

.student-navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.25rem 2rem;
    border-bottom: 1px solid rgba(48, 54, 61, 0.6);
    background: rgba(22, 27, 34, 0.7);
    backdrop-filter: blur(12px);
}

.student-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.25rem;
    font-weight: 700;
    color: #ffffff !important;
    text-decoration: none !important;
}

.student-brand .logo-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: var(--lsi-radius-sm);
    background: linear-gradient(135deg, #0ea5e9 0%, #00d2d3 100%);
    color: #ffffff;
    box-shadow: 0 0 15px var(--lsi-cyan-glow);
}

.student-brand .brand-sub {
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--lsi-text-secondary);
    display: block;
    margin-top: -2px;
}

.instructor-login-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--lsi-accent) !important;
    background: rgba(56, 189, 248, 0.08);
    border: 1px solid rgba(56, 189, 248, 0.3);
    text-decoration: none !important;
    transition: var(--lsi-transition);
}

.instructor-login-btn:hover {
    background: rgba(56, 189, 248, 0.18);
    border-color: var(--lsi-accent);
    color: #ffffff !important;
    box-shadow: 0 0 16px rgba(56, 189, 248, 0.3);
}

.student-hero {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem 1rem;
    flex: 1;
}

.pin-card {
    background: var(--lsi-card-bg);
    border: 1px solid var(--lsi-border);
    border-radius: var(--lsi-radius-lg);
    box-shadow: var(--lsi-shadow-lg);
    width: 100%;
    max-width: 520px;
    padding: 2.75rem 2.25rem;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.pin-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, #38bdf8, #00d2d3, #a855f7);
}

.pin-card-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.35rem 0.85rem;
    border-radius: 20px;
    background: rgba(0, 210, 211, 0.1);
    color: var(--lsi-cyan);
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.5px;
    text-transform: uppercase;
    margin-bottom: 1.25rem;
    border: 1px solid rgba(0, 210, 211, 0.2);
}

.pin-card h1 {
    font-size: 1.75rem;
    font-weight: 800;
    color: #ffffff;
    margin-bottom: 0.5rem;
    letter-spacing: -0.5px;
}

.pin-card p.subtitle {
    color: var(--lsi-text-secondary);
    font-size: 0.95rem;
    margin-bottom: 2rem;
    line-height: 1.5;
}

.pin-input-group {
    position: relative;
    margin-bottom: 1.5rem;
}

.pin-input {
    width: 100%;
    font-size: 1.6rem;
    font-weight: 700;
    text-align: center;
    padding: 1.1rem 1.25rem;
    border-radius: var(--lsi-radius);
    border: 2px solid var(--lsi-border);
    background: #0d1117;
    color: #ffffff;
    outline: none;
    letter-spacing: 2px;
    transition: var(--lsi-transition);
    box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.5);
    box-sizing: border-box;
}

.pin-input::placeholder {
    color: #484f58;
    font-weight: 500;
    letter-spacing: normal;
    font-size: 1.15rem;
}

.pin-input:focus {
    border-color: var(--lsi-cyan);
    background: #111822;
    box-shadow: 0 0 0 4px var(--lsi-cyan-glow), inset 0 2px 4px rgba(0, 0, 0, 0.5);
}

.pin-submit-btn {
    width: 100%;
    padding: 1rem 1.5rem;
    font-size: 1.1rem;
    font-weight: 700;
    border-radius: var(--lsi-radius);
    background: linear-gradient(135deg, #0ea5e9 0%, #00d2d3 100%);
    border: none;
    color: #ffffff;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    transition: var(--lsi-transition);
    box-shadow: 0 4px 15px rgba(14, 165, 233, 0.35);
}

.pin-submit-btn:hover {
    background: linear-gradient(135deg, #0284c7 0%, #00b4b6 100%);
    box-shadow: 0 6px 20px rgba(14, 165, 233, 0.5);
    transform: translateY(-1px);
}

.pin-submit-btn:active {
    transform: translateY(1px);
}

.pin-card-footer {
    margin-top: 1.5rem;
    font-size: 0.8rem;
    color: var(--lsi-text-muted);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.4rem;
}

.student-footer {
    text-align: center;
    padding: 1.5rem;
    font-size: 0.8rem;
    color: var(--lsi-text-muted);
    border-top: 1px solid rgba(48, 54, 61, 0.4);
}

/* ==========================================================================
   2. Admin View / Dashboard Navigation
   ========================================================================== */
.admin-navbar {
    background: rgba(22, 27, 34, 0.95);
    border-bottom: 1px solid var(--lsi-border);
    backdrop-filter: blur(12px);
    position: sticky;
    top: 0;
    z-index: 1020;
    padding: 0.75rem 1.5rem;
}

.admin-nav-container {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    flex-wrap: wrap;
}

.admin-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.15rem;
    font-weight: 800;
    color: #ffffff !important;
    text-decoration: none !important;
}

.admin-nav-tabs {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: #0d1117;
    padding: 0.3rem;
    border-radius: 30px;
    border: 1px solid var(--lsi-border);
    list-style: none;
    margin: 0;
}

.admin-tab-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.45rem;
    padding: 0.45rem 1.1rem;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--lsi-text-secondary);
    background: transparent;
    border: none;
    cursor: pointer;
    transition: var(--lsi-transition);
    text-decoration: none !important;
}

.admin-tab-btn:hover {
    color: var(--lsi-text-primary);
    background: rgba(255, 255, 255, 0.05);
}

.admin-tab-btn.active {
    color: #ffffff;
    background: linear-gradient(135deg, #0ea5e9 0%, #0284c7 100%);
    box-shadow: 0 2px 8px rgba(14, 165, 233, 0.35);
}

.admin-tab-btn .badge {
    font-size: 0.7rem;
    padding: 0.2rem 0.5rem;
    border-radius: 10px;
    background: rgba(0, 0, 0, 0.25);
}

.admin-user-controls {
    display: flex;
    align-items: center;
    gap: 0.6rem;
}

/* ==========================================================================
   3. Metric Strip (Overview Cards)
   ========================================================================== */
.metrics-strip {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.metric-card {
    background: var(--lsi-card-bg);
    border: 1px solid var(--lsi-border);
    border-radius: var(--lsi-radius);
    padding: 1.25rem 1.5rem;
    display: flex;
    align-items: center;
    gap: 1.25rem;
    transition: var(--lsi-transition);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.25);
}

.metric-card.clickable {
    cursor: pointer;
    user-select: none;
}

.metric-card.clickable:hover {
    border-color: var(--lsi-accent);
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(0, 210, 211, 0.18);
}

.metric-card.active {
    border-color: var(--lsi-accent);
    background: rgba(0, 210, 211, 0.06);
}

.metric-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--lsi-radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.35rem;
    flex-shrink: 0;
}

.metric-icon.blue { background: rgba(56, 189, 248, 0.12); color: #38bdf8; border: 1px solid rgba(56, 189, 248, 0.25); }
.metric-icon.green { background: rgba(35, 134, 54, 0.15); color: #2ea043; border: 1px solid rgba(35, 134, 54, 0.3); }
.metric-icon.amber { background: rgba(210, 153, 34, 0.15); color: #d29922; border: 1px solid rgba(210, 153, 34, 0.3); }
.metric-icon.purple { background: rgba(168, 85, 247, 0.15); color: #a855f7; border: 1px solid rgba(168, 85, 247, 0.3); }

.metric-details {
    display: flex;
    flex-direction: column;
}

.metric-num {
    font-size: 1.7rem;
    font-weight: 800;
    color: #ffffff;
    line-height: 1.2;
}

.metric-label {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--lsi-text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-top: 0.15rem;
}

/* ==========================================================================
   4. Links Table & Search
   ========================================================================== */
.admin-card {
    background: var(--lsi-card-bg);
    border: 1px solid var(--lsi-border);
    border-radius: var(--lsi-radius);
    margin-bottom: 2rem;
    overflow: hidden;
    box-shadow: var(--lsi-shadow);
}

.admin-card-header {
    background: var(--lsi-card-header);
    border-bottom: 1px solid var(--lsi-border);
    padding: 1rem 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.admin-card-header h2 {
    font-size: 1.15rem;
    font-weight: 700;
    color: #ffffff;
    margin: 0;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.search-toolbar {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    flex-wrap: wrap;
    width: 100%;
    margin-top: 0.5rem;
}

.search-input-wrapper {
    position: relative;
    flex: 1 1 300px;
}

.search-input-wrapper .search-icon {
    position: absolute;
    left: 14px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--lsi-text-muted);
    font-size: 0.95rem;
    pointer-events: none;
}

.search-input {
    width: 100%;
    background: #0d1117;
    border: 1px solid var(--lsi-border);
    border-radius: var(--lsi-radius-sm);
    color: #ffffff;
    padding: 0.65rem 1rem 0.65rem 2.4rem;
    font-size: 0.9rem;
    outline: none;
    transition: var(--lsi-transition);
    box-sizing: border-box;
}

.search-input:focus {
    border-color: var(--lsi-accent);
    box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.2);
    background: #111822;
}

.filter-pills {
    display: flex;
    align-items: center;
    gap: 0.4rem;
}

.filter-pill {
    padding: 0.4rem 0.85rem;
    border-radius: 16px;
    font-size: 0.8rem;
    font-weight: 600;
    background: #0d1117;
    border: 1px solid var(--lsi-border);
    color: var(--lsi-text-secondary);
    cursor: pointer;
    transition: var(--lsi-transition);
}

.filter-pill:hover {
    color: #ffffff;
    border-color: var(--lsi-border-hover);
}

.filter-pill.active {
    background: rgba(56, 189, 248, 0.15);
    border-color: var(--lsi-accent);
    color: #ffffff;
}

.table-responsive-wrapper {
    overflow-x: auto;
    width: 100%;
}

.lsi-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.88rem;
    color: var(--lsi-text-primary);
}

.lsi-table th {
    background: #161b22;
    border-bottom: 2px solid var(--lsi-border);
    color: var(--lsi-text-secondary);
    font-size: 0.8rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    padding: 0.85rem 1rem;
    text-align: left;
    white-space: nowrap;
}

.lsi-table th a {
    color: var(--lsi-text-secondary);
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
}

.lsi-table th a:hover {
    color: #ffffff;
    text-decoration: none;
}

.lsi-table td {
    border-bottom: 1px solid var(--lsi-border);
    padding: 0.85rem 1rem;
    vertical-align: middle;
}

.lsi-table tbody tr {
    transition: var(--lsi-transition);
}

.lsi-table tbody tr:hover {
    background: var(--lsi-card-hover);
}

/* Badges */
.hash-pill {
    font-family: SFMono-Regular, Menlo, Monaco, Consolas, monospace;
    font-size: 0.95rem;
    font-weight: 700;
    color: #38bdf8;
    background: rgba(56, 189, 248, 0.1);
    border: 1px solid rgba(56, 189, 248, 0.3);
    padding: 0.25rem 0.6rem;
    border-radius: 6px;
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
}

.badge-perm {
    background: rgba(35, 134, 54, 0.15);
    color: #3fb950;
    border: 1px solid rgba(35, 134, 54, 0.3);
    padding: 0.2rem 0.55rem;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 600;
}

.badge-temp {
    background: rgba(210, 153, 34, 0.15);
    color: #d29922;
    border: 1px solid rgba(210, 153, 34, 0.3);
    padding: 0.2rem 0.55rem;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 600;
}

.clicks-badge {
    font-size: 0.85rem;
    font-weight: 700;
    color: #ffffff;
    background: #0d1117;
    border: 1px solid var(--lsi-border);
    padding: 0.2rem 0.6rem;
    border-radius: 12px;
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
}

.url-truncate {
    max-width: 320px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    display: block;
}

.actions-cell {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    white-space: nowrap;
}

.action-btn {
    width: 32px;
    height: 32px;
    border-radius: 6px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border: 1px solid var(--lsi-border);
    background: #0d1117;
    color: var(--lsi-text-secondary);
    cursor: pointer;
    transition: var(--lsi-transition);
    text-decoration: none !important;
}

.action-btn:hover {
    color: #ffffff;
    border-color: var(--lsi-border-hover);
}

.action-btn.edit:hover { background: rgba(56, 189, 248, 0.15); color: #38bdf8; border-color: #38bdf8; }
.action-btn.delete:hover { background: rgba(218, 54, 51, 0.15); color: #f85149; border-color: #da3633; }
.action-btn.qr:hover { background: rgba(168, 85, 247, 0.15); color: #c084fc; border-color: #a855f7; }
.action-btn.copy:hover { background: rgba(35, 134, 54, 0.15); color: #3fb950; border-color: #238636; }

/* ==========================================================================
   5. Modern Create / Edit URL Form
   ========================================================================== */
.form-container {
    max-width: 860px;
    margin: 0 auto;
}

.edit-active-banner {
    background: rgba(210, 153, 34, 0.12);
    border: 1px solid rgba(210, 153, 34, 0.4);
    border-radius: var(--lsi-radius-sm);
    padding: 0.85rem 1.25rem;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    color: #e3b341;
    font-weight: 600;
}

.lsi-form-group {
    margin-bottom: 1.25rem;
}

.lsi-form-group label {
    display: block;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--lsi-text-secondary);
    margin-bottom: 0.45rem;
}

.lsi-form-control {
    width: 100%;
    background: #0d1117;
    border: 1px solid var(--lsi-border);
    border-radius: var(--lsi-radius-sm);
    color: #ffffff;
    padding: 0.75rem 1rem;
    font-size: 0.95rem;
    outline: none;
    transition: var(--lsi-transition);
    box-sizing: border-box;
}

.lsi-form-control:focus {
    border-color: var(--lsi-accent);
    background: #111822;
    box-shadow: 0 0 0 3px rgba(56, 189, 248, 0.2);
}

.lsi-form-control:disabled, .lsi-form-control[readonly] {
    background: rgba(22, 27, 34, 0.6);
    color: var(--lsi-text-muted);
    border-color: rgba(48, 54, 61, 0.6);
    cursor: not-allowed;
}

.lsi-form-help {
    font-size: 0.78rem;
    color: var(--lsi-text-muted);
    margin-top: 0.35rem;
}

.form-grid-2 {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.btn-primary-lsi {
    background: linear-gradient(135deg, #0ea5e9 0%, #0284c7 100%);
    color: #ffffff;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: var(--lsi-radius-sm);
    font-weight: 700;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: var(--lsi-transition);
    box-shadow: 0 4px 12px rgba(14, 165, 233, 0.3);
}

.btn-primary-lsi:hover {
    background: linear-gradient(135deg, #0284c7 0%, #0369a1 100%);
    box-shadow: 0 6px 16px rgba(14, 165, 233, 0.45);
    transform: translateY(-1px);
}

.btn-secondary-lsi {
    background: #161b22;
    color: var(--lsi-text-primary);
    border: 1px solid var(--lsi-border);
    padding: 0.75rem 1.25rem;
    border-radius: var(--lsi-radius-sm);
    font-weight: 600;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: var(--lsi-transition);
}

.btn-secondary-lsi:hover {
    background: #1c2128;
    border-color: var(--lsi-border-hover);
    color: #ffffff;
}

/* Result Toast / Card */
.result-card {
    background: rgba(35, 134, 54, 0.1);
    border: 1px solid rgba(35, 134, 54, 0.4);
    border-radius: var(--lsi-radius);
    padding: 1.5rem;
    margin-bottom: 2rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 1rem;
}

.result-card .url-text {
    font-size: 1.25rem;
    font-weight: 800;
    color: #3fb950;
    font-family: SFMono-Regular, Menlo, Monaco, Consolas, monospace;
}

/* ==========================================================================
   6. Analytics View
   ========================================================================== */
.analytics-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
}

.progress-bar-container {
    width: 100%;
    height: 6px;
    background: rgba(48, 54, 61, 0.6);
    border-radius: 3px;
    overflow: hidden;
    margin-top: 4px;
}

.progress-bar-fill {
    height: 100%;
    background: linear-gradient(90deg, #38bdf8, #00d2d3);
    border-radius: 3px;
}

/* ==========================================================================
   7. Modals
   ========================================================================== */
.lsi-modal-backdrop {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.75);
    backdrop-filter: blur(4px);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 1050;
    padding: 1rem;
}

.lsi-modal-backdrop.show {
    display: flex;
}

.lsi-modal {
    background: var(--lsi-card-bg);
    border: 1px solid var(--lsi-border);
    border-radius: var(--lsi-radius-lg);
    box-shadow: var(--lsi-shadow-lg);
    width: 100%;
    max-width: 480px;
    overflow: hidden;
    animation: modalSlide 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes modalSlide {
    from { opacity: 0; transform: scale(0.95) translateY(-10px); }
    to { opacity: 1; transform: scale(1) translateY(0); }
}

.lsi-modal-header {
    background: var(--lsi-card-header);
    border-bottom: 1px solid var(--lsi-border);
    padding: 1.1rem 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.lsi-modal-header h3 {
    margin: 0;
    font-size: 1.1rem;
    color: #ffffff;
    font-weight: 700;
}

.lsi-modal-body {
    padding: 1.5rem;
    color: var(--lsi-text-primary);
}

.lsi-modal-footer {
    background: var(--lsi-card-header);
    border-top: 1px solid var(--lsi-border);
    padding: 0.9rem 1.5rem;
    display: flex;
    align-items: center;
    justify-content: flex-end;
    gap: 0.75rem;
}

.close-modal-btn {
    background: none;
    border: none;
    color: var(--lsi-text-muted);
    font-size: 1.3rem;
    cursor: pointer;
    padding: 0;
    line-height: 1;
}

.close-modal-btn:hover {
    color: #ffffff;
}

/* ==========================================================================
   8. Responsive Adjustments
   ========================================================================== */
@media (max-width: 768px) {
    .form-grid-2 {
        grid-template-columns: 1fr;
    }
    .metrics-strip {
        grid-template-columns: 1fr 1fr;
    }
    .admin-navbar {
        padding: 0.6rem 0.75rem;
    }
    .admin-nav-container {
        flex-direction: column;
        align-items: stretch;
        gap: 0.75rem;
    }
    .admin-nav-container nav {
        width: 100%;
        max-width: 100%;
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
        padding-bottom: 2px;
    }
    .admin-nav-tabs {
        width: max-content;
        min-width: 100%;
        overflow-x: auto;
        justify-content: flex-start;
        border-radius: var(--lsi-radius-sm);
        padding: 0.25rem;
    }
    .admin-tab-btn {
        white-space: nowrap;
        padding: 0.4rem 0.85rem;
        font-size: 0.8rem;
    }
    .student-navbar {
        padding: 1rem;
    }
    .pin-card {
        padding: 2rem 1.25rem;
    }
}

@media (max-width: 480px) {
    .metrics-strip {
        grid-template-columns: 1fr;
    }
}

/* Flash Alert Close Button */
.close-alert-btn {
    background: transparent;
    border: none;
    color: var(--lsi-text-muted);
    font-size: 1.25rem;
    cursor: pointer;
    padding: 0 0.5rem;
    line-height: 1;
    margin-left: auto;
    transition: color 0.15s ease;
}
.close-alert-btn:hover {
    color: #ffffff;
}

/* Floating Toast Notifications */
.lsi-toast-container {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    z-index: 9999;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    pointer-events: none;
}

.lsi-toast {
    pointer-events: auto;
    background: #161b22;
    border: 1px solid var(--lsi-border);
    border-left: 4px solid var(--lsi-accent);
    padding: 0.85rem 1.25rem;
    border-radius: var(--lsi-radius-sm);
    color: #f0f6fc;
    font-size: 0.9rem;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.45);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    animation: toastSlideIn 0.3s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

@keyframes toastSlideIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}