:root {
    --bg-color: #0b0e14;
    --card-bg: rgba(20, 24, 35, 0.85);
    --primary-color: #00f2ff;
    --secondary-color: #7000ff;
    --accent-color: #ff007a;
    --text-color: #e0e6ed;
    --success-color: #39ff14;
    --error-color: #ff3131;
    --font-main: 'Lexend', sans-serif;
    --blur: 10px;
}

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

body {
    font-family: var(--font-main);
    background-color: var(--bg-color);
    color: var(--text-color);
    overflow: hidden;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background-image: 
        radial-gradient(circle at 50% 50%, rgba(20, 24, 35, 0) 0%, rgba(11, 14, 20, 1) 100%),
        url('/bg-cyber.png');
    background-size: cover;
    background-position: center;
}

#app {
    width: 90%;
    max-width: 900px;
    height: 85vh;
    background: var(--card-bg);
    backdrop-filter: blur(var(--blur));
    border: 1px solid rgba(0, 242, 255, 0.2);
    border-radius: 20px;
    box-shadow: 0 0 30px rgba(0, 0, 0, 0.5), 0 0 15px rgba(0, 242, 255, 0.1);
    display: flex;
    flex-direction: column;
    position: relative;
    overflow: hidden;
}

header {
    padding: 20px;
    text-align: center;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.header-content h1 {
    font-size: 1.8rem;
    letter-spacing: 3px;
    font-weight: 700;
}

.header-content h1 span {
    color: var(--primary-color);
    text-shadow: 0 0 10px var(--primary-color);
}

#progress-container {
    width: 60%;
    height: 8px;
    background: rgba(255, 255, 255, 0.1);
    margin: 15px auto 0;
    border-radius: 4px;
    overflow: hidden;
}

#progress-bar {
    width: 0%;
    height: 100%;
    background: linear-gradient(90deg, var(--secondary-color), var(--primary-color));
    transition: width 0.5s ease;
    box-shadow: 0 0 10px var(--primary-color);
}

#game-container {
    flex-grow: 1;
    padding: 30px;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow-y: auto;
}

section {
    width: 100%;
    transition: transform 0.4s ease, opacity 0.4s ease;
}

.hidden {
    display: none !important;
}

.active {
    display: block;
    animation: fadeIn 0.5s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.intro-content, .ending-content {
    text-align: center;
}

.shield-icon {
    font-size: 5rem;
    margin-bottom: 20px;
    filter: drop-shadow(0 0 15px var(--primary-color));
}

.shield-icon.success {
    filter: drop-shadow(0 0 15px var(--success-color));
}

h2 {
    font-size: 2rem;
    margin-bottom: 20px;
    color: var(--primary-color);
}

p {
    line-height: 1.6;
    margin-bottom: 30px;
    font-size: 1.1rem;
}

.primary-btn, .secondary-btn {
    padding: 15px 40px;
    font-size: 1.2rem;
    font-weight: 700;
    border: none;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-family: var(--font-main);
    text-transform: uppercase;
    letter-spacing: 2px;
}

.primary-btn {
    background: linear-gradient(135deg, var(--secondary-color), var(--accent-color));
    color: white;
    box-shadow: 0 5px 15px rgba(112, 0, 255, 0.4);
}

.primary-btn:hover {
    transform: scale(1.05);
    box-shadow: 0 8px 25px rgba(112, 0, 255, 0.6);
}

.secondary-btn {
    background: transparent;
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
}

.secondary-btn:hover {
    background: var(--primary-color);
    color: var(--bg-color);
}

/* Level UI */
.level-content {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

#level-title {
    color: var(--accent-color);
    text-transform: uppercase;
    font-size: 1rem;
    letter-spacing: 2px;
}

#level-description {
    font-size: 1.3rem;
    font-weight: 400;
}

.options-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
}

.option-btn {
    padding: 20px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 12px;
    color: var(--text-color);
    font-family: var(--font-main);
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.2s ease;
}

.option-btn:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: var(--primary-color);
}

#feedback {
    padding: 15px;
    border-radius: 10px;
    text-align: center;
    font-weight: 700;
}

#feedback.success {
    background: rgba(57, 255, 20, 0.1);
    color: var(--success-color);
    border: 1px solid var(--success-color);
}

#feedback.error {
    background: rgba(255, 49, 49, 0.1);
    color: var(--error-color);
    border: 1px solid var(--error-color);
}

footer {
    padding: 15px;
    text-align: right;
    font-size: 0.9rem;
    opacity: 0.6;
}

@media (max-width: 600px) {
    .options-container {
        grid-template-columns: 1fr;
    }
    
    #app {
        width: 95%;
        height: 90vh;
    }
}