:root {
    --primary-color: #ffd700; 
    --secondary-color: #00aaff; 
    --background-color: #1a1a2e; 
    --card-background: #16213e;
    --text-color: #e0e0e0;
    --success-color: #4caf50;
    --disabled-color: #555;
    --font-family: 'Poppins', sans-serif;
}

body {
    font-family: var(--font-family);
    background-color: var(--background-color);
    color: var(--text-color);
    margin: 0;
    padding: 20px;
    display: flex;
    justify-content: center;
    align-items: flex-start;
}

#game-container {
    width: 100%;
    max-width: 900px;
    display: grid;
    grid-template-areas:
        "header header"
        "main aside"
        "footer footer";
    grid-template-columns: 2fr 1fr;
    gap: 20px;
}

header { grid-area: header; text-align: center; }
main { grid-area: main; }
aside { grid-area: aside; }
footer { grid-area: footer; text-align: center; font-size: 0.8em; opacity: 0.7; }

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

.card {
    background-color: var(--card-background);
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.4);
    margin-bottom: 20px;
}

h2 {
    color: var(--secondary-color);
    border-bottom: 2px solid var(--secondary-color);
    padding-bottom: 10px;
    margin-top: 0;
}

#stats-section p {
    font-size: 1.1em;
}

#stats-section span {
    color: var(--primary-color);
    font-weight: 600;
}

.battery-bar {
    width: 100%;
    height: 25px;
    background-color: #333;
    border-radius: 5px;
    overflow: hidden;
    border: 2px solid #555;
    margin-top: 10px;
}

#battery-fill {
    width: 0%;
    height: 100%;
    background: linear-gradient(90deg, #ffc107, #ffd700);
    border-radius: 3px;
    transition: width 0.2s linear;
}

#client-request {
    background-color: rgba(0, 0, 0, 0.2);
    padding: 15px;
    border-radius: 8px;
    min-height: 120px;
}

.upgrade-item, .request-button {
    display: flex;
    flex-direction: column;
    background-color: rgba(255, 255, 255, 0.05);
    padding: 15px;
    margin-bottom: 10px;
    border-radius: 8px;
    border-left: 5px solid var(--secondary-color);
    transition: transform 0.2s ease, background-color 0.2s ease;
}

.upgrade-item:hover {
    transform: scale(1.02);
}

.upgrade-cost, .request-reward {
    font-weight: 600;
    color: var(--primary-color);
}

.upgrade-bonus {
    color: var(--success-color);
}

button {
    background: linear-gradient(45deg, var(--secondary-color), #0077cc);
    color: white;
    border: none;
    padding: 10px 15px;
    border-radius: 5px;
    cursor: pointer;
    font-family: var(--font-family);
    font-size: 1em;
    font-weight: 600;
    margin-top: 10px;
    transition: transform 0.1s ease, box-shadow 0.2s ease;
}

button:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 10px rgba(0, 170, 255, 0.4);
}

button:active {
    transform: translateY(0);
}

button:disabled {
    background: var(--disabled-color);
    color: #999;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

#game-management-section button {
    background: var(--primary-color);
    color: var(--background-color);
    width: 100%;
    margin-top: 0; 
}
#game-management-section button:hover {
    box-shadow: 0 4px 10px rgba(255, 215, 0, 0.4);
}

#save-modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.7);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    backdrop-filter: blur(5px);
}

#save-modal.modal-hidden {
    display: none;
}

.modal-content {
    background-color: var(--card-background);
    padding: 30px;
    border-radius: 15px;
    width: 90%;
    max-width: 500px;
    text-align: center;
    border: 1px solid var(--secondary-color);
}

.modal-content h3 {
    color: var(--primary-color);
    margin-top: 0;
}

.modal-content textarea {
    width: 100%;
    box-sizing: border-box;
    margin: 15px 0;
    background-color: var(--background-color);
    color: var(--text-color);
    border: 1px solid var(--disabled-color);
    border-radius: 5px;
    padding: 10px;
    font-family: monospace;
}

.modal-buttons {
    display: flex;
    justify-content: center;
    gap: 10px;
}