:root {
    --bg-primary: #0f0f23;
    --bg-card: rgba(255, 255, 255, 0.05);
    --accent-green: #00ff88;
    --accent-blue: #00d4ff;
    --accent-purple: #a855f7;
    --accent-gold: #f59e0b;
    --text-primary: #e0e0e0;
    --text-secondary: #888888;
}

body {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-family: 'Inter', sans-serif;
    scroll-behavior: smooth;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}
::-webkit-scrollbar-track {
    background: var(--bg-primary);
}
::-webkit-scrollbar-thumb {
    background: #333;
    border-radius: 3px;
}
::-webkit-scrollbar-thumb:hover {
    background: var(--accent-blue);
}

::selection {
    background-color: rgba(0, 212, 255, 0.3);
    color: #fff;
}

/* Hide Scrollbar util */
.hide-scrollbar::-webkit-scrollbar {
    display: none;
}
.hide-scrollbar {
    -ms-overflow-style: none;
    scrollbar-width: none;
}

/* Glass Components */
.glass-card {
    background: var(--bg-card);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 16px;
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
}

.glass-nav {
    background: rgba(15, 15, 35, 0.7);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.nav-link {
    color: var(--text-secondary);
    font-weight: 500;
    transition: color 0.2s ease, text-shadow 0.2s ease;
}
.nav-link:hover {
    color: #fff;
}
.nav-link.active {
    color: #fff;
    text-shadow: 0 0 10px rgba(255, 255, 255, 0.3);
}

/* Typography & Neon */
.neon-text-green {
    text-shadow: 0 0 15px rgba(0, 255, 136, 0.5);
}
.neon-text-blue {
    text-shadow: 0 0 15px rgba(0, 212, 255, 0.5);
}

.gradient-text {
    background: linear-gradient(135deg, #00ff88, #00d4ff);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Buttons */
.btn-green {
    background: linear-gradient(135deg, #00b35e, #00ff88);
    color: #000;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0, 255, 136, 0.2);
}
.btn-green:hover {
    box-shadow: 0 6px 25px rgba(0, 255, 136, 0.4);
    transform: translateY(-2px);
}

.btn-blue {
    background: linear-gradient(135deg, #0093b3, #00d4ff);
    color: #000;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0, 212, 255, 0.2);
}
.btn-blue:hover {
    box-shadow: 0 6px 25px rgba(0, 212, 255, 0.4);
    transform: translateY(-2px);
}

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

.fade-in-up {
    animation: fadeInUp 0.8s ease-out forwards;
    opacity: 0; /* Starts hidden until animation */
}

@keyframes shimmer {
    0% { transform: translateX(-100%); }
    100% { transform: translateX(100%); }
}
.shimmer-anim {
    animation: shimmer 2s infinite linear;
}

.hero-bg-animation {
    background: radial-gradient(circle at center, rgba(0,212,255,0.05) 0%, rgba(15,15,35,0) 70%);
    animation: pulse-glow 4s infinite alternate ease-in-out;
}

@keyframes pulse-glow {
    0% { opacity: 0.5; transform: scale(1); }
    100% { opacity: 1; transform: scale(1.1); }
}

@keyframes fillWater {
    0% { height: 0%; opacity: 0; }
    100% { height: 100%; opacity: 1; }
}

/* Water Tracker */
.water-glass {
    width: 40px;
    height: 50px;
    border: 2px solid rgba(255,255,255,0.2);
    border-radius: 4px 4px 12px 12px;
    position: relative;
    cursor: pointer;
    overflow: hidden;
    transition: border-color 0.3s ease;
}
.water-glass:hover {
    border-color: var(--accent-blue);
}
.water-glass.filled .water-fill {
    height: 100%;
    opacity: 1;
}
.water-fill {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 0%;
    background: linear-gradient(to top, #0093b3, #00d4ff);
    opacity: 0;
    transition: height 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275), opacity 0.3s;
}

/* Checkbox */
.exercise-checkbox {
    appearance: none;
    width: 24px;
    height: 24px;
    border: 2px solid #4b5563;
    border-radius: 6px;
    background: transparent;
    cursor: pointer;
    position: relative;
    transition: all 0.2s ease;
}
.exercise-checkbox:checked {
    background: var(--accent-green);
    border-color: var(--accent-green);
}
.exercise-checkbox:checked::after {
    content: '✓';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: #000;
    font-size: 14px;
    font-weight: bold;
}

/* Feature Cards */
.feature-card-green:hover { border-color: rgba(0, 255, 136, 0.3); }
.feature-card-blue:hover { border-color: rgba(0, 212, 255, 0.3); }

/* Timeline (Cyber path) */
.timeline-item {
    position: relative;
    padding-left: 2rem;
}
@media (min-width: 768px) {
    .timeline-item { padding-left: 3rem; }
}
.timeline-line {
    position: absolute;
    left: 11px; /* Center with the node dot */
    top: 2rem;
    bottom: -2rem;
    width: 2px;
    background: rgba(255,255,255,0.1);
}
.timeline-item:last-child .timeline-line {
    display: none;
}
.timeline-node {
    position: absolute;
    left: 0;
    top: 1rem;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--bg-primary);
    border: 2px solid #4b5563;
    z-index: 10;
    transition: all 0.3s;
}
.timeline-item.completed .timeline-node {
    background: var(--accent-blue);
    border-color: var(--accent-blue);
    box-shadow: 0 0 10px rgba(0, 212, 255, 0.5);
}
.timeline-item.active .timeline-node {
    border-color: var(--accent-blue);
    background: var(--bg-primary);
    box-shadow: 0 0 15px rgba(0, 212, 255, 0.5);
}
.lesson-card {
    cursor: pointer;
}
.lesson-card:hover {
    transform: translateX(10px);
    border-color: rgba(255,255,255,0.2);
}

/* Lesson Content Styles */
.lesson-content-prose h2 {
    font-size: 1.5rem;
    font-weight: 700;
    color: #fff;
    margin-top: 2rem;
    margin-bottom: 1rem;
}
.lesson-content-prose p {
    margin-bottom: 1rem;
    line-height: 1.6;
    color: var(--text-primary);
}
.lesson-content-prose ul {
    list-style-type: disc;
    padding-left: 1.5rem;
    margin-bottom: 1rem;
}
.lesson-content-prose li {
    margin-bottom: 0.5rem;
}
.lesson-content-prose pre {
    background: #1e1e2e;
    padding: 1rem;
    border-radius: 8px;
    overflow-x: auto;
    margin-bottom: 1.5rem;
    border: 1px solid rgba(255,255,255,0.1);
}
.lesson-content-prose code {
    font-family: monospace;
}

/* Quiz Option */
.quiz-option {
    display: block;
    padding: 1rem;
    border: 1px solid rgba(255,255,255,0.1);
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s;
    background: rgba(255,255,255,0.02);
}
.quiz-option:hover {
    background: rgba(255,255,255,0.05);
}
.quiz-option.selected {
    border-color: var(--accent-blue);
    background: rgba(0,212,255,0.1);
}
.quiz-option.correct {
    border-color: var(--accent-green);
    background: rgba(0,255,136,0.1);
}
.quiz-option.incorrect {
    border-color: #ef4444;
    background: rgba(239,68,68,0.1);
}