/* ========================================
   SHARED STYLES - Boolean Algebra Learning Hub
   ======================================== */

/* Reset & Base */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

/* ========================================
   COLOR VARIABLES (as CSS custom properties)
   ======================================== */
:root {
    --primary-start: #667eea;
    --primary-end: #764ba2;
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --success: #28a745;
    --success-light: #d4edda;
    --success-border: #c3e6cb;
    --danger: #dc3545;
    --danger-light: #f8d7da;
    --danger-border: #f5c6cb;
    --warning: #ffc107;
    --warning-light: #fff3cd;
    --info: #17a2b8;
    --gray-light: #f8f9fa;
    --gray-border: #e0e0e0;
    --text-dark: #333;
    --text-muted: #666;
}

/* ========================================
   TYPOGRAPHY
   ======================================== */
h1 {
    color: var(--primary-start);
    font-size: 48px;
    margin-bottom: 20px;
}

h2 {
    color: var(--primary-end);
    font-size: 32px;
    margin-bottom: 20px;
}

h3 {
    color: var(--primary-start);
    font-size: 24px;
    margin-bottom: 15px;
}

p, li {
    font-size: 18px;
    line-height: 1.6;
    color: var(--text-dark);
}

/* ========================================
   BUTTONS
   ======================================== */
.btn {
    background: var(--primary-gradient);
    color: white;
    border: none;
    padding: 15px 30px;
    border-radius: 8px;
    font-size: 18px;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s ease;
    margin: 5px;
    display: inline-block;
    text-decoration: none;
    text-align: center;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 20px rgba(102, 126, 234, 0.4);
}

.btn:active {
    transform: translateY(0);
}

.btn:disabled {
    background: linear-gradient(135deg, #ccc 0%, #999 100%);
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.btn-secondary {
    background: linear-gradient(135deg, #6c757d 0%, #495057 100%);
}

.btn-success {
    background: linear-gradient(135deg, #28a745 0%, #218838 100%);
}

.btn-danger {
    background: linear-gradient(135deg, #dc3545 0%, #c82333 100%);
}

/* ========================================
   TRUTH TABLES
   ======================================== */
.truth-table {
    margin: 20px auto;
    border-collapse: collapse;
    background: white;
    box-shadow: 0 8px 25px rgba(0,0,0,0.15);
    border-radius: 12px;
    overflow: hidden;
}

.truth-table th {
    background: var(--primary-start);
    color: white;
    padding: 15px 25px;
    font-size: 18px;
    font-weight: bold;
}

.truth-table td {
    padding: 12px 25px;
    text-align: center;
    border: 1px solid var(--gray-border);
    font-size: 18px;
    font-weight: bold;
}

.truth-table tr:nth-child(even) {
    background: var(--gray-light);
}

/* ========================================
   CARDS
   ======================================== */
.card {
    background: white;
    border: 3px solid var(--primary-start);
    border-radius: 15px;
    padding: 25px;
    box-shadow: 0 6px 20px rgba(0,0,0,0.1);
    transition: all 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 35px rgba(102, 126, 234, 0.3);
    border-color: var(--primary-end);
}

/* ========================================
   INFO & RESULT BOXES
   ======================================== */
.info-box {
    background: var(--warning-light);
    border-left: 5px solid var(--warning);
    padding: 15px 20px;
    border-radius: 8px;
    margin: 15px 0;
}

.example-box {
    background: linear-gradient(135deg, #f0f4ff 0%, #e8f0ff 100%);
    border-left: 6px solid var(--primary-start);
    padding: 20px;
    margin: 15px 0;
    border-radius: 10px;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.2);
}

.key-point {
    background: linear-gradient(135deg, var(--success-light) 0%, var(--success-border) 100%);
    border-left: 6px solid var(--success);
    padding: 20px;
    margin: 15px 0;
    border-radius: 8px;
    box-shadow: 0 4px 15px rgba(40, 167, 69, 0.2);
}

.result-box {
    background: linear-gradient(135deg, var(--success-light) 0%, var(--success-border) 100%);
    border-left: 5px solid var(--success);
    padding: 20px;
    border-radius: 10px;
    margin-top: 20px;
}

.result-box h3 {
    color: var(--success);
    margin-bottom: 10px;
}

.result-box.error {
    background: linear-gradient(135deg, var(--danger-light) 0%, var(--danger-border) 100%);
    border-left-color: var(--danger);
}

.result-box.error h3 {
    color: var(--danger);
}

/* ========================================
   FORM ELEMENTS
   ======================================== */
select,
input[type="text"],
textarea {
    width: 100%;
    padding: 12px;
    border: 2px solid #ddd;
    border-radius: 8px;
    font-size: 16px;
    transition: all 0.3s;
}

select:focus,
input:focus,
textarea:focus {
    outline: none;
    border-color: var(--primary-start);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

/* ========================================
   GRID LAYOUTS
   ======================================== */
.grid-2 {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
    margin: 20px 0;
}

.grid-3 {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin: 20px 0;
}

/* ========================================
   TOGGLE SWITCH
   ======================================== */
.toggle-switch {
    width: 60px;
    height: 30px;
    background: var(--danger);
    border-radius: 15px;
    cursor: pointer;
    position: relative;
    transition: all 0.3s;
    display: inline-block;
    margin: 0 10px;
}

.toggle-switch.on {
    background: var(--success);
}

.toggle-switch::after {
    content: '';
    position: absolute;
    width: 26px;
    height: 26px;
    background: white;
    border-radius: 50%;
    top: 2px;
    left: 2px;
    transition: all 0.3s;
}

.toggle-switch.on::after {
    left: 32px;
}

/* ========================================
   HIGHLIGHT
   ======================================== */
.highlight {
    background: linear-gradient(120deg, var(--warning-light) 0%, #ffeaa7 100%);
    padding: 4px 10px;
    border-radius: 5px;
    font-weight: bold;
}

/* ========================================
   CODE BLOCKS
   ======================================== */
.code-block {
    background: #282c34;
    color: #abb2bf;
    padding: 25px;
    border-radius: 10px;
    font-family: 'Courier New', monospace;
    font-size: 16px;
    overflow-x: auto;
    margin: 20px 0;
    line-height: 1.8;
    box-shadow: 0 8px 25px rgba(0,0,0,0.3);
}

.code-comment { color: #5c6370; }
.code-keyword { color: #c678dd; }
.code-string { color: #98c379; }
.code-function { color: #61afef; }

/* ========================================
   ANIMATIONS
   ======================================== */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

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

@keyframes fadeInLeft {
    from { opacity: 0; transform: translateX(-50px); }
    to { opacity: 1; transform: translateX(0); }
}

@keyframes slideIn {
    from { opacity: 0; transform: translateX(-20px); }
    to { opacity: 1; transform: translateX(0); }
}

@keyframes slideInRight {
    from { opacity: 0; transform: translateX(50px); }
    to { opacity: 1; transform: translateX(0); }
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(100px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes scaleIn {
    from { opacity: 0; transform: scale(0.8); }
    to { opacity: 1; transform: scale(1); }
}

@keyframes bounceIn {
    0% { opacity: 0; transform: scale(0.3); }
    50% { opacity: 1; transform: scale(1.05); }
    70% { transform: scale(0.9); }
    100% { transform: scale(1); }
}

@keyframes popIn {
    0% { opacity: 0; transform: scale(0); }
    50% { transform: scale(1.1); }
    100% { opacity: 1; transform: scale(1); }
}

@keyframes zoomIn {
    from { opacity: 0; transform: scale(0.5); }
    to { opacity: 1; transform: scale(1); }
}

@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-20px); }
}

@keyframes glow {
    0%, 100% { box-shadow: 0 0 5px rgba(102, 126, 234, 0.5); }
    50% { box-shadow: 0 0 20px rgba(102, 126, 234, 0.8), 0 0 30px rgba(118, 75, 162, 0.6); }
}

@keyframes pulse {
    0%, 100% { box-shadow: 0 0 0 0 rgba(255, 243, 205, 0.7); }
    50% { box-shadow: 0 0 0 10px rgba(255, 243, 205, 0); }
}

@keyframes flip {
    from { transform: perspective(400px) rotateY(90deg); opacity: 0; }
    to { transform: perspective(400px) rotateY(0deg); opacity: 1; }
}

@keyframes swing {
    20% { transform: rotate(15deg); }
    40% { transform: rotate(-10deg); }
    60% { transform: rotate(5deg); }
    80% { transform: rotate(-5deg); }
    100% { transform: rotate(0deg); }
}

@keyframes rotateIn {
    from { opacity: 0; transform: rotate(-200deg) scale(0); }
    to { opacity: 1; transform: rotate(0) scale(1); }
}

/* Animation Classes */
.floating { animation: float 3s ease-in-out infinite; }
.glow { animation: glow 2s ease-in-out infinite; }
.zoom-in { animation: zoomIn 0.6s ease-out both; }
.slide-up { animation: slideUp 0.6s ease-out both; }
.flip { animation: flip 0.6s ease-out both; }
.swing { animation: swing 1s ease-in-out both; }
.bounce-in { animation: bounceIn 0.8s ease-out; }
.fade-in { animation: fadeIn 0.5s ease-out; }
.fade-in-up { animation: fadeInUp 0.6s ease-out both; }
.scale-in { animation: scaleIn 0.5s ease-out both; }

/* ========================================
   RESPONSIVE
   ======================================== */
@media (max-width: 768px) {
    h1 { font-size: 32px; }
    h2 { font-size: 24px; }

    .grid-2,
    .grid-3 {
        grid-template-columns: 1fr;
    }

    .btn {
        padding: 12px 20px;
        font-size: 16px;
    }
}