:root {
        /* Dark Theme (Default) */
        --bg-gradient-start: #0a0f1f;
        --bg-gradient-end: #0c002b;
        --text-color: #ffffff;
        --text-color-muted: rgba(255, 255, 255, 0.6);
        --glass-bg: rgba(40, 48, 87, 0.25);
        --glass-border: rgba(255, 255, 255, 0.15);
        --input-bg: rgba(0, 0, 0, 0.3);
        --shadow-color: rgba(0, 0, 0, 0.3);
        --primary-color: #0d6efd;
        --primary-hover: #0b5ed7;
        --danger-color: #dc3545;
    }

    body.light-theme {
        /* Light Theme */
        --bg-gradient-start: #f0f2f5;
        --bg-gradient-end: #e4e9f0;
        --text-color: #1a1a1a;
        --text-color-muted: rgba(0, 0, 0, 0.6);
        --glass-bg: rgba(255, 255, 255, 0.6);
        --glass-border: rgba(0, 0, 0, 0.1);
        --input-bg: rgba(255, 255, 255, 0.8);
        --shadow-color: rgba(0, 0, 0, 0.1);
        --primary-color: #007bff;
        --primary-hover: #0069d9;
    }

    /* Preloader Styles */
    #preloader {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background: var(--bg-gradient-start);
        z-index: 99999;
        display: flex;
        justify-content: center;
        align-items: center;
    }
    .loader {
        width: 50px;
        height: 50px;
        border: 5px solid var(--glass-border);
        border-top-color: var(--primary-color);
        border-radius: 50%;
        animation: spin 1s linear infinite;
    }
    @keyframes spin {
        to { transform: rotate(360deg); }
    }

    /* Welcome Popup Styles */
    .welcome-popup-overlay {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background: rgba(0, 0, 0, 0.5);
        backdrop-filter: blur(5px);
        -webkit-backdrop-filter: blur(5px);
        z-index: 10001;
        display: flex;
        justify-content: center;
        align-items: center;
    }
    .welcome-popup-message {
        padding: 2rem 3rem;
        background: var(--glass-bg);
        border-radius: 15px;
        border: 1px solid var(--glass-border);
        box-shadow: 0 8px 32px 0 var(--shadow-color);
        text-align: center;
        color: var(--text-color);
    }
    .welcome-popup-message h2 {
        font-weight: 600;
        margin-bottom: 0.5rem;
    }
    html {
        background-color: linear-gradient(135deg, var(--bg-gradient-start), var(--bg-gradient-end));

    }
    /* Base Styles */
    body {
        font-family: 'Poppins', sans-serif;
        background: linear-gradient(135deg, var(--bg-gradient-start), var(--bg-gradient-end));
        background-attachment: fixed;
        color: var(--text-color);
        text-align: center;
        min-height: 100vh;
        padding: 20px;
        overflow-x: hidden;
        transition: background 0.4s ease, color 0.4s ease;
    }
    
    .main-content {
        visibility: hidden;
        opacity: 0;
    }

    .glass-container { max-width: 650px; margin: 20px auto; padding: 2rem; background: var(--glass-bg); border-radius: 15px; border: 1px solid var(--glass-border); box-shadow: 0 8px 32px 0 var(--shadow-color); backdrop-filter: blur(15px); -webkit-backdrop-filter: blur(15px); transition: background 0.4s ease, border 0.4s ease; }
    .header-container { display: flex; justify-content: center; align-items: center; position: relative; max-width: 650px; margin: 0 auto; }
    .main-title { font-weight: 600; margin-bottom: 1.5rem; flex-grow: 1; }
    .theme-btn { position: absolute; right: 0; top: 50%; transform: translateY(-50%); font-size: 1.2rem; background: var(--glass-bg); border: 1px solid var(--glass-border); color: var(--text-color); width: 45px; height: 45px; border-radius: 50%; cursor: pointer; transition: all 0.3s ease; }
    .theme-btn:hover { color: var(--primary-color); }
    .language-controls { display: flex; align-items: center; justify-content: space-between; margin-bottom: 1rem; }
    .custom-select-wrapper { position: relative; width: 45%; font-size: 0.9rem; }
    .selected-language { background-color: var(--input-bg); border: 1px solid var(--glass-border); border-radius: 8px; padding: 10px 15px; cursor: pointer; display: flex; justify-content: space-between; align-items: center; transition: all 0.3s ease; }
    .selected-language:hover, .selected-language.active { border-color: var(--primary-color); }
    .options-container { display: none; position: absolute; top: 110%; left: 0; width: 100%; max-height: 250px; overflow-y: auto; background: var(--input-bg); border-radius: 8px; border: 1px solid var(--glass-border); z-index: 100; padding: 5px; backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px); }
    .search-box { width: 100%; background: transparent; border: none; border-bottom: 1px solid var(--glass-border); padding: 10px; color: var(--text-color); margin-bottom: 5px; }
    .search-box:focus { outline: none; border-bottom-color: var(--primary-color); }
    .option { padding: 10px 15px; cursor: pointer; border-radius: 5px; text-align: left; }
    .option:hover, .option.active { background-color: var(--primary-color); color: white; }
    .options-container::-webkit-scrollbar { width: 8px; }
    .options-container::-webkit-scrollbar-track { background: transparent; }
    .options-container::-webkit-scrollbar-thumb { background: var(--glass-border); border-radius: 10px; }
    textarea.form-control { min-height: 140px; background-color: var(--input-bg); color: var(--text-color); border: 1px solid var(--glass-border); }
    .input-area-group { position: relative; }
    .char-counter { position: absolute; bottom: 10px; right: 15px; font-size: 0.8rem; color: var(--text-color-muted); transition: color 0.3s ease; }
    .char-counter.limit-exceeded { color: var(--danger-color); font-weight: bold; }
    .translate-btn { position: relative; }
    .translate-btn .spinner-border { display: none; }
    .translate-btn.loading .btn-text { opacity: 0; }
    .translate-btn.loading .spinner-border { display: inline-block; position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%); }
    .popup { position: fixed; top: 20px; left: 50%; transform: translateX(-50%); min-width: 280px; padding: 15px 20px; border-radius: 10px; background: var(--glass-bg); border-left: 5px solid var(--primary-color); box-shadow: 0 5px 15px var(--shadow-color); backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px); display: flex; align-items: center; gap: 15px; font-weight: 600; z-index: 10000; opacity: 0; visibility: hidden; }
    .popup.success { border-left-color: #28a745; }
    .popup.error { border-left-color: #dc3545; }
    .popup-icon { font-size: 1.5rem; }
    #logo { width: 110px; height: auto; }
    .image-container { height: 130px; }