body {
    font-family: 'Segoe UI', Arial, sans-serif;
    margin: 0;
    padding: 0;
    background: linear-gradient(135deg, #18191a 0%, #23272f 100%);
    color: #fff;
    min-height: 100vh;
}

.main-grid {
    display: flex;
    min-height: 100vh;
    gap: 0;
}

.options-panel, .preview-panel {
    padding: 40px 32px;
    box-sizing: border-box;
}

.options-panel {
    flex: 1;
    background: rgba(36,37,38,0.98);
    display: flex;
    flex-direction: column;
    gap: 32px;
    min-width: 340px;
    max-width: 420px;
    border-top-right-radius: 24px;
    border-bottom-right-radius: 24px;
    box-shadow: 2px 0 24px 0 rgba(0,0,0,0.10);
}

.preview-panel {
    flex: 2;
    background: transparent;
    display: flex;
    flex-direction: column;
    gap: 32px;
    justify-content: flex-start;
}

h2 {
    font-size: 1.15rem;
    letter-spacing: 1px;
    margin-bottom: 18px;
    color: #b0b3b8;
    font-weight: 600;
}

form {
    display: flex;
    flex-direction: column;
    gap: 18px;
}

label {
    font-size: 1rem;
    color: #b0b3b8;
    margin-bottom: 4px;
    font-weight: 500;
}

input[type="url"], input[type="text"] {
    background: rgba(58,59,60,0.95);
    color: #fff;
    border: 1.5px solid #23272f;
    border-radius: 8px;
    padding: 14px 16px;
    font-size: 1.05rem;
    margin-bottom: 8px;
    transition: 
        background 0.2s,
        border 0.2s,
        box-shadow 0.2s;
    box-shadow: 0 2px 8px rgba(79,140,255,0.04);
}

input[type="url"]:focus, input[type="text"]:focus {
    background: #23272f;
    border: 1.5px solid #4f8cff;
    outline: none;
    box-shadow: 0 0 0 2px #4f8cff33;
}

button[type="submit"], #copy-btn {
    background: linear-gradient(90deg, #4f8cff 60%, #3574e6 100%);
    color: #fff;
    border: none;
    border-radius: 8px;
    padding: 14px 0;
    font-size: 1.08rem;
    font-weight: 600;
    cursor: pointer;
    transition: 
        background 0.2s,
        transform 0.18s cubic-bezier(.4,2,.6,1),
        box-shadow 0.2s;
    margin-top: 10px;
    box-shadow: 0 2px 12px rgba(79,140,255,0.10);
    min-width: 120px;
    padding-left: 32px;
    padding-right: 32px;
    text-align: center;
    letter-spacing: 0.5px;
    position: relative;
    overflow: hidden;
}

button[type="submit"]:hover, #copy-btn:hover {
    background: linear-gradient(90deg, #3574e6 0%, #4f8cff 100%);
    transform: scale(1.045) translateY(-2px);
    box-shadow: 0 6px 24px rgba(79,140,255,0.18);
}

button[type="submit"]:active, #copy-btn:active {
    background: #285bb5;
    transform: scale(0.98);
    box-shadow: 0 1px 4px rgba(79,140,255,0.10);
}

#copy-btn.copied {
    background: linear-gradient(90deg, #22c55e 60%, #16a34a 100%);
    color: #fff;
    animation: copiedPop 0.5s;
}

@keyframes copiedPop {
    0% { transform: scale(1); }
    30% { transform: scale(1.15); }
    60% { transform: scale(0.95);}
    100% { transform: scale(1);}
}

.iframe-preview {
    background: none;
    border-radius: 0;
    display: block;
    align-items: unset;
    justify-content: unset;
    margin-bottom: 24px;
    box-shadow: none;
    overflow: visible;
    min-height: unset;
    min-width: unset;
    padding: 0;
}

.iframe-preview video, .iframe-preview iframe {
    border: none;
    border-radius: 12px;
    background: #18191a;
    box-shadow: 0 4px 24px rgba(0,0,0,0.18);
    transition: width 0.3s, height 0.3s, box-shadow 0.3s;
    display: block;
    margin: 0 auto;
}

.output {
    background: rgba(36,37,38,0.98);
    border-radius: 14px;
    padding: 22px 18px 18px 18px;
    margin-top: 0;
    box-shadow: 0 2px 16px rgba(0,0,0,0.18);
    display: flex;
    flex-direction: column;
    gap: 16px;
    animation: fadeIn 0.5s;
}

.output h2 {
    color: #b0b3b8;
    font-size: 1.05rem;
    font-weight: 600;
    margin-bottom: 8px;
    letter-spacing: 1px;
}

#embed-code {
    width: 100%;
    min-width: 320px;
    max-width: 100%;
    height: 130px;
    min-height: 110px;
    max-height: 220px;
    resize: none;
    font-size: 1.08rem;
    padding: 14px;
    box-sizing: border-box;
    background: #18191a;
    color: #4f8cff;
    border: 1.5px solid #3a3b3c;
    border-radius: 8px;
    transition: border 0.2s, box-shadow 0.2s;
    font-family: 'Fira Mono', 'Consolas', 'Menlo', monospace;
    box-shadow: 0 2px 8px rgba(79,140,255,0.04);
}

#embed-code:focus {
    border: 1.5px solid #4f8cff;
    outline: none;
    box-shadow: 0 0 0 2px #4f8cff33;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px);}
    to { opacity: 1; transform: translateY(0);}
}