:root {
    --bg-dark: #0b0f19;
    --panel-bg: rgba(30, 41, 59, 0.7);
    --border-color: rgba(255, 255, 255, 0.1);
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --accent-primary: #3b82f6;
    --accent-glow: rgba(59, 130, 246, 0.5);
    --btn-success: #10b981;
    --btn-warning: #f59e0b;
    --btn-danger: #ef4444;
    --btn-purple: #8b5cf6;
    --border-radius: 16px;
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Poppins', sans-serif;
    background-color: var(--bg-dark);
    color: var(--text-main);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 20px;
    background-image: 
        radial-gradient(circle at 15% 50%, rgba(59, 130, 246, 0.15), transparent 25%),
        radial-gradient(circle at 85% 30%, rgba(139, 92, 246, 0.15), transparent 25%);
    background-attachment: fixed;
}

.tool-container {
    max-width: 800px;
    width: 100%;
    padding: 35px;
    border-radius: 24px;
    background: var(--panel-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--border-color);
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
}

.header-section {
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 35px;
    position: relative;
}

.logo-area {
    display: flex;
    align-items: center;
    gap: 15px;
}

.logo-icon {
    width: 55px;
    height: 55px;
    border-radius: 14px;
    background: linear-gradient(135deg, #3b82f6, #8b5cf6);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5em;
    color: #fff;
    box-shadow: 0 10px 20px var(--accent-glow);
}

.logo-text {
    font-size: 1.6em;
    font-weight: 800;
    letter-spacing: 1px;
}

.logo-text span {
    color: var(--accent-primary);
    text-shadow: 0 0 15px var(--accent-glow);
}

.label {
    font-weight: 600;
    font-size: 0.9em;
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.label i {
    color: var(--accent-primary);
}

textarea, input[type="text"] {
    width: 100%;
    padding: 16px;
    margin-bottom: 25px;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    background: rgba(15, 23, 42, 0.6);
    color: var(--text-main);
    font-family: 'Fira Code', 'Courier New', monospace;
    font-size: 0.9em;
    outline: none;
    resize: vertical;
    transition: var(--transition);
}

textarea:focus, input[type="text"]:focus {
    border-color: var(--accent-primary);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.25);
}

#inputHtml { min-height: 200px; }
#outputEncrypted { min-height: 160px; color: #a5b4fc; }

input[type="text"] {
    font-family: 'Poppins', sans-serif;
    margin-bottom: 0;
}

.button-row {
    display: flex;
    gap: 15px;
    margin-bottom: 25px;
    flex-wrap: wrap;
}

.btn {
    flex: 1;
    min-width: 120px;
    padding: 14px 20px;
    border: none;
    border-radius: 12px;
    cursor: pointer;
    font-weight: 600;
    font-size: 0.9em;
    font-family: 'Poppins', sans-serif;
    letter-spacing: 0.5px;
    color: #fff;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    text-decoration: none;
}

.btn:hover {
    transform: translateY(-2px);
    background: rgba(255, 255, 255, 0.1);
}

.btn:active {
    transform: translateY(0);
}

.btn-primary { background: linear-gradient(135deg, #3b82f6, #2563eb); border: none; box-shadow: 0 8px 15px rgba(37, 99, 235, 0.3); }
.btn-primary:hover { box-shadow: 0 12px 20px rgba(37, 99, 235, 0.4); background: linear-gradient(135deg, #60a5fa, #3b82f6); }

.btn-success:hover { background: var(--btn-success); border-color: var(--btn-success); }
.btn-warning:hover { background: var(--btn-warning); border-color: var(--btn-warning); }
.btn-purple:hover { background: var(--btn-purple); border-color: var(--btn-purple); }
.btn-danger:hover { background: var(--btn-danger); border-color: var(--btn-danger); }

.filename-wrap {
    margin-bottom: 25px;
}

.preview-section {
    margin-top: 10px;
    margin-bottom: 25px;
}

.preview-box {
    width: 100%;
    height: 400px;
    border-radius: var(--border-radius);
    background: #ffffff;
    border: 2px solid var(--border-color);
    overflow: hidden;
    position: relative;
}

.preview-box iframe {
    width: 100%;
    height: 100%;
    border: none;
}

.preview-placeholder {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: #475569;
    font-size: 1em;
    font-weight: 500;
    text-align: center;
    pointer-events: none;
}

.preview-placeholder i {
    display: block;
    font-size: 2.5em;
    margin-bottom: 10px;
    color: #94a3b8;
}

.whatsapp-btn {
    width: 100%;
    background: #25D366;
    color: #fff;
    border: none;
    font-size: 1em;
    box-shadow: 0 8px 15px rgba(37, 211, 102, 0.2);
}

.whatsapp-btn:hover {
    background: #128C7E;
    box-shadow: 0 12px 20px rgba(37, 211, 102, 0.4);
}

.footer {
    text-align: center;
    margin-top: 30px;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
    color: var(--text-muted);
}

.footer p { font-size: 0.8em; letter-spacing: 1px; margin-bottom: 5px; }
.footer h3 { font-size: 1em; font-weight: 700; color: #fff; letter-spacing: 2px; }

@media (max-width: 600px) {
    .tool-container { padding: 20px; }
    .logo-text { font-size: 1.3em; }
    .preview-box { height: 300px; }
    .btn { min-width: calc(50% - 8px); }
}

/* ========== PWA INSTALL POPUP CSS ========== */
.popup-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    display: flex;
    justify-content: center;
    align-items: center;
    animation: fadeIn 0.3s ease;
    padding: 20px;
    box-sizing: border-box;
}

.popup-content {
    background: rgba(30, 41, 59, 0.95);
    border: 1px solid var(--border-color);
    border-radius: 24px;
    padding: 30px;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.6);
    position: relative;
    width: 100%;
    max-width: 400px;
    animation: slideUp 0.3s ease;
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
}

.popup-close-btn {
    position: absolute;
    top: 12px;
    right: 12px;
    background: rgba(255, 255, 255, 0.1);
    border: none;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    cursor: pointer;
    color: #fff;
    font-size: 1em;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.popup-close-btn:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: rotate(90deg);
}

/* Tailwind-like utility classes for popup */
.max-w-sm { max-width: 24rem; }
.text-center { text-align: center; }
.w-20 { width: 5rem; }
.h-20 { height: 5rem; }
.rounded-2xl { border-radius: 1rem; }
.mx-auto { margin-left: auto; margin-right: auto; }
.shadow-lg { box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05); }
.mb-2 { margin-bottom: 0.5rem; }
.mb-4 { margin-bottom: 1rem; }
.mb-6 { margin-bottom: 1.5rem; }
.w-full { width: 100%; }
.text-sm { font-size: 0.875rem; }
.text-lg { font-size: 1.125rem; }
.text-xl { font-size: 1.25rem; }
.text-gray-500 { color: #6b7280; }
.font-bold { font-weight: 700; }

.btn-premium {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 14px 20px;
    border: none;
    border-radius: 12px;
    cursor: pointer;
    font-weight: 600;
    font-size: 1em;
    font-family: 'Poppins', sans-serif;
    letter-spacing: 0.5px;
    color: #fff;
    background: linear-gradient(135deg, #3b82f6, #2563eb);
    box-shadow: 0 8px 15px rgba(37, 99, 235, 0.3);
    transition: var(--transition);
    margin-bottom: 12px;
}

.btn-premium:hover {
    transform: translateY(-2px);
    box-shadow: 0 12px 20px rgba(37, 99, 235, 0.4);
    background: linear-gradient(135deg, #60a5fa, #3b82f6);
}

.not-now-btn {
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    font-size: 0.9em;
    font-weight: 500;
    text-decoration: underline;
    transition: var(--transition);
    padding: 5px 10px;
    font-family: 'Poppins', sans-serif;
}

.not-now-btn:hover {
    color: #fff;
}

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

@keyframes slideUp {
    from { transform: translateY(30px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}