:root {
        --primary-color: #ffb347;
        --gradient: linear-gradient(to right, #ffcc33, #ff9966);
        --text-dark: #333;
        --text-light: #fff;
        --bg-light: #f5f7fa;
        --bg-white: #ffffff;
        --border-color: #ddd;
    }

    * {
        margin: 0;
        padding: 0;
        box-sizing: border-box;
        font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    }

    html, body {
        height: 100%;
        width: 100%;
        background: var(--bg-light);
        overflow: hidden;
    }

    .container {
        width: 100%;
        height: 100%;
        max-width: 480px; /* Max width for larger phone screens */
        margin: 0 auto;
        background: var(--bg-white);
        box-shadow: 0 5px 20px rgba(0,0,0,0.05);
        display: flex;
        flex-direction: column;
        overflow: hidden;
    }

    .screen {
        display: none;
        flex-direction: column;
        width: 100%;
        height: 100%;
        padding: 30px;
        animation: fadeIn 0.5s ease;
    }

    .screen.active {
        display: flex;
    }

    @keyframes fadeIn {
        from { opacity: 0; }
        to { opacity: 1; }
    }

    /* Common Styles */
    .main-button {
        padding: 15px;
        border: none;
        border-radius: 12px;
        background: var(--gradient);
        color: var(--text-light);
        font-size: 1.2rem; /* Increased font size */
        font-weight: bold;
        cursor: pointer;
        transition: 0.3s;
        width: 100%;
        margin-top: 20px;
        position: relative;
        min-height: 55px; /* Increased height */
    }
    .main-button:hover {
        opacity: 0.9;
        transform: translateY(-2px);
    }
    .main-button:disabled {
        opacity: 0.7;
        cursor: not-allowed;
    }

    .button-loader {
        display: none;
    }
    .main-button.loading .button-text {
        visibility: hidden;
    }
    .main-button.loading .button-loader {
        display: block;
        position: absolute;
        top: 50%;
        left: 50%;
        transform: translate(-50%, -50%);
        font-size: 1.5rem;
    }

    h1 {
        font-size: 2.5rem; /* Increased font size */
        color: var(--text-dark);
        text-align: center;
        margin-bottom: 10px;
    }
    h2 {
        font-size: 1.8rem; /* Increased font size */
        color: var(--text-dark);
        margin-bottom: 25px;
        text-align: center;
    }
    p {
        font-size: 1.2rem; /* Increased font size */
        color: #666;
        text-align: center;
        margin-bottom: 30px;
    }

    /* 1. Intro Screen */
    #introScreen {
        justify-content: center;
        align-items: center;
        text-align: center;
    }
    #introScreen img {
        width: 200px;
        height: 200px;
        border-radius: 50%;
        object-fit: cover;
        margin-bottom: 30px;
        box-shadow: 0 4px 15px rgba(0,0,0,0.1);
    }

    /* 2. User Info Screen */
    #userInfoScreen {
        justify-content: center;
    }
    .form-group {
        display: flex;
        flex-direction: column;
        gap: 15px;
    }
    .form-group input, .form-group select {
        padding: 15px;
        border: 1px solid var(--border-color);
        border-radius: 8px;
        font-size: 1.1rem; /* Increased font size */
        width: 100%;
    }

    /* 3. Fortune Selection Screen */
    #fortuneSelectionScreen {
        justify-content: center;
    }
    .fortune-group {
        margin-bottom: 20px;
    }
    .fortune-group h3 {
        color: #555;
        margin-bottom: 15px;
        border-bottom: 1px solid var(--border-color);
        padding-bottom: 10px;
    }
    .options-grid {
        display: grid;
        grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
        gap: 10px;
        align-items: stretch; /* Align items to stretch */
    }
    .options-grid label {
        padding: 15px 10px;
        border: 1px solid var(--border-color);
        border-radius: 8px;
        text-align: center;
        cursor: pointer;
        transition: 0.2s;
        display: flex;
        justify-content: center;
        align-items: center;
        height: 100%;
        font-size: 1.1rem;
    }
    .options-grid input[type="radio"], .options-grid input[type="checkbox"] {
        display: none;
    }
    .options-grid input[type="radio"]:checked + label, .options-grid input[type="checkbox"]:checked + label {
        background: var(--primary-color);
        color: var(--text-light);
        border-color: var(--primary-color);
        font-weight: bold;
    }
    .year-input-group {
        display: flex;
        gap: 10px;
        margin-top: 10px;
    }
    .year-input-group input {
        flex: 1;
        padding: 10px;
        border: 1px solid var(--border-color);
        border-radius: 8px;
        font-size: 1rem;
        text-align: center;
    }
    .year-input-group input:disabled {
        background: #eee;
    }
    .option-group {
        display: flex;
        flex-direction: column;
        height: 100%;
    }
    .option-group label {
        flex-grow: 1;
    }


    /* 4. Chat Screen */
    #chatScreen {
        padding: 0;
    }
    .chat-header {
        background: var(--gradient);
        color: var(--text-light);
        padding: 15px 20px;
        font-size: 1.2rem;
        font-weight: bold;
        display: flex;
        justify-content: space-between;
        align-items: center;
    }
    .chat-header button {
        background: none;
        border: 1px solid var(--text-light);
        color: var(--text-light);
        padding: 8px 12px; /* Increased padding */
        border-radius: 8px;
        font-size: 1rem; /* Increased font size */
        cursor: pointer;
    }
    .chat-messages {
        flex: 1;
        padding: 20px;
        overflow-y: auto;
        display: flex;
        flex-direction: column;
        gap: 12px;
    }
    .message {
        max-width: 85%;
        padding: 12px 18px;
        border-radius: 20px;
        word-wrap: break-word;
        line-height: 1.5;
        animation: fadeIn 0.3s ease;
        font-size: 1.1rem; /* Increased font size */
    }
    .user-message {
        background: #4da6ff;
        color: white;
        align-self: flex-end;
        border-bottom-right-radius: 5px;
    }
    .bot-message {
        background: #e5e5ea;
        color: #333;
        align-self: flex-start;
        border-bottom-left-radius: 5px;
    }
    .chat-input {
        display: flex;
        border-top: 1px solid var(--border-color);
        padding: 10px;
    }
    .chat-input input {
        flex: 1;
        padding: 15px; /* Increased padding */
        border: 1px solid var(--border-color);
        border-radius: 25px; /* More rounded */
        outline: none;
        font-size: 1.1rem; /* Increased font size */
        margin-right: 10px;
    }
    .chat-input button {
        padding: 15px 25px; /* Increased padding */
        border: none;
        border-radius: 25px; /* More rounded */
        background: var(--gradient);
        color: white;
        font-weight: bold;
        cursor: pointer;
    }