/* Global Styles */
:root {
    --primary: #3b82f6;       /* Brighter blue (was #2563eb) */
    --primary-dark: #2563eb;  /* Less dark blue (was #1e40af) */
    --secondary: #10b981;     /* Success green */
    --accent: #f59e0b;        /* Warning/Attention orange */
    --dark: #1e293b;          /* Dark slate */
    --light: #f8fafc;         /* Very light grey/blue */
    --white: #ffffff;
    --text-main: #334155;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Poppins', sans-serif;
    line-height: 1.6;
    color: var(--text-main);
    background-color: var(--light);
    scroll-behavior: smooth;
}

/* Navbar */
.navbar {
    background-color: var(--white);
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
    flex-wrap: wrap; /* Allow wrapping for mobile menu */
}

.menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 30px;
    height: 21px;
    background: none;
    border: none;
    cursor: pointer;
}

.menu-toggle .bar {
    height: 3px;
    width: 100%;
    background-color: var(--primary);
    border-radius: 3px;
}

.logo {
    font-weight: 700;
    font-size: 1.5rem;
    color: var(--primary);
}

.nav-links {
    list-style: none;
    display: flex;
    gap: 2rem;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-main);
    font-weight: 500;
    transition: color 0.3s;
}

.nav-links a:hover {
    color: var(--primary);
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: var(--white);
    padding: 6rem 2rem;
    text-align: center;
    border-bottom-right-radius: 50px;
    border-bottom-left-radius: 50px;
}

.hero h1 {
    font-size: 3.5rem;
    margin-bottom: 1rem;
    font-weight: 700;
}

.hero p {
    font-size: 1.2rem;
    opacity: 0.9;
    margin-bottom: 2rem;
}

/* Buttons */
.btn {
    display: inline-block;
    background-color: var(--accent);
    color: var(--white);
    padding: 0.8rem 2rem;
    border-radius: 30px;
    text-decoration: none;
    font-weight: 600;
    transition: transform 0.2s, box-shadow 0.2s;
    border: none;
    cursor: pointer;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

.hidden {
    display: none;
}

/* Sections */
.section {
    padding: 4rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.alt-bg {
    background-color: #e2e8f0;
    border-radius: 20px;
    margin-top: 2rem;
    margin-bottom: 2rem;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: var(--dark);
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background-color: var(--primary);
    margin: 10px auto 0;
    border-radius: 2px;
}

/* Goals Section (Green) */
.goals-list {
    list-style: none;
    font-size: 1.2rem;
    font-weight: 500;
}

.goals-list li {
    margin-bottom: 1rem;
    display: flex;
    align-items: center;
    gap: 10px;
}

.check-icon {
    color: #22c55e; /* Bright Green */
    font-weight: bold;
    font-size: 1.5rem;
}

.goals-container {
    background: #f0fdf4; /* Very light green background */
    padding: 2rem;
    border-radius: 10px;
    box-shadow: var(--shadow);
    max-width: 800px;
    margin: 0 auto;
}

/* Cards */
.card-grid {
    display: flex; /* Changed from grid to flex for vertical stack */
    flex-direction: column;
    gap: 2rem;
    max-width: 800px; /* Limit width so they don't stretch too far */
    margin: 0 auto; /* Center the stack */
}

.card {
    background: var(--white);
    padding: 3rem; /* Bigger padding */
    border-radius: 15px;
    box-shadow: var(--shadow);
    transition: transform 0.3s;
    text-align: center;
    border: 1px solid #e2e8f0; /* Slight border for definition */
}

.card:hover {
    transform: translateY(-5px);
    border-color: var(--primary); /* Highlight on hover */
}

.card .icon {
    font-size: 4rem; /* Bigger icon */
    margin-bottom: 1.5rem;
}

.card h3 {
    margin-bottom: 1rem;
    font-size: 2rem; /* Bigger title */
    color: var(--primary-dark);
}

.card p {
    font-size: 1.2rem; /* Bigger text */
    line-height: 1.8;
}

/* Steps (EVA) */
.steps-container {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 1rem;
}

.step {
    flex: 1;
    min-width: 200px;
    text-align: center;
    position: relative;
    background: white;
    padding: 2rem;
    border-radius: 15px;
    box-shadow: var(--shadow);
}

.step-number {
    width: 60px;
    height: 60px;
    background-color: var(--primary);
    color: var(--white);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    font-weight: bold;
    margin: 0 auto 1rem;
}

.small-text {
    font-size: 0.9rem;
    color: #64748b;
    margin-top: 0.5rem;
}

/* Interactive Simulation (EVA Traffic Light) */
.simulation-container {
    background: var(--white);
    padding: 3rem;
    border-radius: 15px;
    box-shadow: var(--shadow);
    text-align: center;
}

.circuit-diagram {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 2rem;
    flex-wrap: wrap;
    margin-bottom: 2rem;
}

.circuit-control, .circuit-power {
    border: 3px solid #cbd5e1;
    padding: 1.5rem;
    border-radius: 15px;
    width: 220px;
    height: 300px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: space-around;
    background-color: #f8fafc;
}

.component-wrapper {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
}

.label {
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--text-main);
}

/* Button / Taster Symbol */
.sim-button {
    background-color: #ef4444;
    border: none;
    padding: 0;
    border-radius: 50%;
    width: 80px;
    height: 80px;
    cursor: pointer;
    box-shadow: 0 4px 0 #b91c1c;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.1s;
}

.sim-button:active, .sim-button.active {
    transform: translateY(4px);
    box-shadow: none;
}

.symbol-taster {
    width: 40px;
    height: 40px;
    position: relative;
}

.button-head {
    width: 30px;
    height: 10px;
    background: white;
    position: absolute;
    top: 15px;
    left: 5px;
    border-radius: 2px;
}

.line-top, .line-bottom {
    width: 4px;
    height: 12px;
    background: white;
    position: absolute;
    left: 18px;
}
.line-top { top: 3px; }
.line-bottom { bottom: 3px; }


/* Logic Processing Animation */
.coil#sim-logic {
    background: white;
    border: 2px solid #cbd5e1;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s;
}

.coil#sim-logic.processing {
    border-color: var(--accent);
    background-color: #fffbeb;
    box-shadow: 0 0 15px var(--accent);
    animation: pulseLogic 0.5s infinite alternate;
}

@keyframes pulseLogic {
    from { transform: scale(1); }
    to { transform: scale(1.1); }
}

/* Traffic Light */
.traffic-light {
    width: 80px;
    height: 160px;
    background-color: #333;
    border-radius: 10px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: space-around;
    padding: 10px;
}

.light {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background-color: #555;
    transition: background-color 0.3s, box-shadow 0.3s;
}

.light.red.active {
    background-color: #ef4444;
    box-shadow: 0 0 20px #ef4444;
}

.light.green.active {
    background-color: #10b981;
    box-shadow: 0 0 20px #10b981;
}

.circuit-arrow {
    font-weight: bold;
    color: var(--primary);
    font-size: 1.2rem;
}

.status-text {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--dark);
}

/* Accordion */
.accordion {
    max-width: 800px;
    margin: 0 auto;
}

.accordion-item {
    background: var(--white);
    border-radius: 8px;
    margin-bottom: 1rem;
    box-shadow: var(--shadow);
    overflow: hidden;
}

.accordion-header {
    width: 100%;
    padding: 1.5rem;
    text-align: left;
    border: none;
    background-color: #f1f5f9; /* Light grey background to make it visible */
    color: #1e293b; /* Dark text explicitly */
    font-weight: 600;
    font-size: 1.1rem;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: background-color 0.2s;
}

.accordion-header:hover {
    background-color: #e2e8f0; /* Darker on hover */
    color: var(--primary); /* Blue text on hover */
}

.accordion-header:after {
    content: '+';
    font-size: 1.5rem;
}

.accordion-content {
    padding: 0 1.5rem;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease, padding 0.3s ease;
}

.accordion-content.open {
    padding-bottom: 1.5rem;
    max-height: 200px; /* Adjust based on content */
}

/* Quiz */
.quiz-container {
    background: var(--white);
    padding: 3rem;
    border-radius: 15px;
    box-shadow: var(--shadow);
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.quiz-question {
    font-size: 1.5rem;
    margin-bottom: 2rem;
    font-weight: 600;
}

.quiz-options {
    display: grid;
    gap: 1rem;
}

.option-btn {
    padding: 1rem;
    border: 2px solid #e2e8f0;
    border-radius: 10px;
    background: #f8fafc; /* Light background for visibility */
    color: #1e293b; /* Dark text */
    cursor: pointer;
    font-size: 1.1rem;
    transition: all 0.2s;
    font-weight: 500;
}

.option-btn:hover {
    background-color: #e2e8f0;
    border-color: var(--primary);
    color: #1e293b;
}

.option-btn.correct {
    background-color: var(--secondary);
    color: white;
    border-color: var(--secondary);
}

.option-btn.wrong {
    background-color: #ef4444;
    color: white;
    border-color: #ef4444;
}

.quiz-result {
    margin-top: 1.5rem;
    font-weight: bold;
    font-size: 1.2rem;
    min-height: 1.5rem;
}

/* Responsive */
@media (max-width: 768px) {
    .navbar {
        padding: 1rem;
    }

    .menu-toggle {
        display: flex; /* Show hamburger on mobile */
    }

    .nav-links {
        display: none; /* Hide default menu */
        width: 100%;
        position: absolute;
        top: 100%;
        left: 0;
        background-color: var(--white);
        flex-direction: column;
        padding: 1rem;
        box-shadow: var(--shadow);
        text-align: center;
        gap: 1.5rem;
    }

    .nav-links.active {
        display: flex; /* Show when active */
    }

    .time-counter {
        display: none; /* Hide timer on very small screens or move it */
    }
    
    .hero {
        padding: 3rem 1rem;
    }

    .hero h1 {
        font-size: 2rem;
    }
    
    .section {
        padding: 2rem 1rem;
    }

    /* Cards - Ensure they fit on small screens */
    .card {
        padding: 1.5rem;
        width: 100%; /* Ensure full width usage */
    }

    .card .icon {
        font-size: 3rem;
    }

    .card h3 {
        font-size: 1.5rem;
    }

    /* Simulation - Ensure it fits */
    .simulation-container {
        padding: 1.5rem; /* Reduce padding */
    }

    .circuit-diagram {
        flex-direction: column;
        gap: 1.5rem;
    }
    
    .circuit-arrow {
        transform: rotate(90deg);
        margin: 0.5rem 0;
    }

    .circuit-control, .circuit-power {
        width: 100%;
        max-width: 100%; /* Use full width */
        height: auto; /* Auto height to fit content */
        min-height: 250px;
    }

    /* Steps */
    .steps-container {
        flex-direction: column;
    }

    .step {
        width: 100%;
        margin-bottom: 1rem;
    }

    .watermark {
        font-size: 0.6rem;
        bottom: 10px;
        right: 10px;
        background-color: rgba(255, 255, 255, 0.9);
        padding: 3px 8px;
    }
}

/* Small Phones (iPhone SE, etc.) */
@media (max-width: 380px) {
    .hero h1 {
        font-size: 1.5rem;
    }
    
    .section-title {
        font-size: 1.8rem;
    }

    .card {
        padding: 1rem;
    }
    
    .circuit-control, .circuit-power {
        padding: 1rem;
    }
}

/* Watermark */
.watermark {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background-color: rgba(255, 255, 255, 0.8);
    padding: 5px 10px;
    border-radius: 5px;
    font-size: 0.8rem;
    color: #64748b;
    font-weight: 600;
    pointer-events: none; /* Allows clicking through it */
    z-index: 1000;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    border: 1px solid rgba(0,0,0,0.1);
}