@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

:root {
    --primary: #1d9bf0; /* Twitter Blue */
    --primary-hover: #1a8cd8;
    --bg-dark: #0f172a;
    --bg-card: #1e293b;
    --text-white: #f8fafc;
    --text-gray: #94a3b8;
    --accent: #8b5cf6;
    --error: #ef4444;
    --success: #10b981;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', sans-serif;
}

body {
    background-color: var(--bg-dark);
    color: var(--text-white);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 20px;
    overflow-x: hidden;
}

.container {
    width: 100%;
    max-width: 600px;
    background: var(--bg-card);
    padding: 40px;
    border-radius: 24px;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    border: 1px solid rgba(255, 255, 255, 0.05);
    animation: fadeIn 0.6s ease-out;
}

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

header {
    text-align: center;
    margin-bottom: 32px;
}

h1 {
    font-size: 2.5rem;
    font-weight: 800;
    background: linear-gradient(135deg, #fff 0%, #94a3b8 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 8px;
}

p.subtitle {
    color: var(--text-gray);
    font-size: 1rem;
}

.input-group {
    position: relative;
    margin-bottom: 24px;
}

input[type="text"] {
    width: 100%;
    padding: 16px 20px;
    background: rgba(15, 23, 42, 0.6);
    border: 2px solid rgba(255, 255, 255, 0.1);
    border-radius: 14px;
    color: #fff;
    font-size: 1rem;
    outline: none;
    transition: var(--transition);
}

input[type="text"]:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(29, 155, 240, 0.15);
}

button#download-btn {
    width: 100%;
    padding: 16px;
    margin-top: 12px;
    background: var(--primary);
    color: #fff;
    border: none;
    border-radius: 14px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 8px;
}

button#download-btn:hover {
    background: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 10px 20px -5px rgba(29, 155, 240, 0.4);
}

button#download-btn:active {
    transform: translateY(0);
}

button#download-btn:disabled {
    background: var(--text-gray);
    cursor: not-allowed;
    opacity: 0.7;
}

/* Response Area */
#result-area {
    margin-top: 32px;
    display: none;
    animation: slideUp 0.5s ease-out;
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.video-container {
    width: 100%;
    background: #000;
    border-radius: 16px;
    overflow: hidden;
    margin-bottom: 20px;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

video {
    width: 100%;
    display: block;
}

.actions {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.btn-secondary {
    padding: 14px;
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-white);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 12px;
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
    text-align: center;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 8px;
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.1);
}

.btn-primary-action {
    padding: 14px;
    background: var(--success);
    color: #fff;
    border: none;
    border-radius: 12px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
    text-align: center;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 8px;
}

.btn-primary-action:hover {
    background: #059669;
    box-shadow: 0 5px 15px -3px rgba(16, 185, 129, 0.3);
}

/* Loading Spinner */
.spinner {
    width: 24px;
    height: 24px;
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: #fff;
    animation: spin 1s linear infinite;
    display: none;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Mobile Adjustments */
@media (max-width: 480px) {
    .container {
        padding: 24px;
    }
    h1 {
        font-size: 2rem;
    }
}