:root {
    --bg-color: #0d1117;
    --card-bg: #161b22;
    --border-color: #30363d;
    --text-primary: #c9d1d9;
    --text-secondary: #8b949e;
    --accent-color: #58a6ff;
    --success-color: #238636;
    --glass-bg: rgba(22, 27, 34, 0.8);
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
    --font-mono: 'IBM Plex Mono', SFMono-Regular, Consolas, "Liberation Mono", Menlo, monospace;
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-family: var(--font-sans);
    line-height: 1.6;
    overflow-x: hidden;
}

/* --- Layout --- */
.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 2rem;
}

header {
    margin-bottom: 3rem;
    text-align: center;
}

header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    letter-spacing: -0.05rem;
    margin-bottom: 0.5rem;
}

header p {
    color: var(--text-secondary);
}

.step-card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 2.5rem;
    box-shadow: 0 4px 24px rgba(0, 0, 0, 0.2);
    transition: transform 0.3s ease;
    display: none; /* Initial state */
}

.step-card.active {
    display: block;
    animation: fadeIn 0.4s ease-out;
}

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

/* --- Typography (MD Style) --- */
h2 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.md-label {
    background: var(--border-color);
    color: var(--text-secondary);
    font-family: var(--font-mono);
    font-size: 0.8rem;
    padding: 0.2rem 0.6rem;
    border-radius: 4px;
    margin-right: 0.5rem;
}

/* --- Form Elements --- */
.input-group {
    margin-bottom: 1.5rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    font-size: 0.9rem;
}

input, select, textarea {
    width: 100%;
    background-color: transparent;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 0.8rem 1rem;
    color: var(--text-primary);
    font-family: var(--font-sans);
    font-size: 1rem;
    transition: border-color 0.2s;
}

input:focus, select:focus, textarea:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(88, 166, 255, 0.1);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.8rem 1.5rem;
    border-radius: 6px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    border: none;
    font-size: 1rem;
}

.btn-primary {
    background-color: var(--accent-color);
    color: #fff;
}

.btn-primary:hover {
    filter: brightness(1.1);
}

.btn-ghost {
    background: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
}

.btn-ghost:hover {
    border-color: var(--text-secondary);
    color: var(--text-primary);
}

/* --- Special Components --- */
.script-editor {
    background-color: #010409;
    font-family: var(--font-mono);
    padding: 1rem;
    border-radius: 6px;
    border: 1px solid var(--border-color);
    min-height: 200px;
    white-space: pre-wrap;
    font-size: 0.9rem;
}

.preview-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    gap: 1rem;
    margin-top: 1.5rem;
}

.thumb-card {
    border: 1px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
    position: relative;
}

.thumb-img {
    width: 100%;
    aspect-ratio: 9/16;
    background-color: #30363d;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.progress-bar {
    width: 100%;
    height: 8px;
    background-color: var(--border-color);
    border-radius: 4px;
    margin: 1.5rem 0;
    overflow: hidden;
}

.progress-fill {
    width: 0%;
    height: 100%;
    background-color: var(--success-color);
    transition: width 0.3s ease;
}

.script-editor.loading {
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: rgba(1, 4, 9, 0.7);
    border-style: dashed;
}

.generating-text {
    color: var(--accent-color);
    font-weight: 600;
    font-family: var(--font-sans);
    animation: pulse 1.5s infinite;
}

@keyframes pulse {
    0% { opacity: 0.5; transform: scale(0.98); }
    50% { opacity: 1; transform: scale(1); }
    100% { opacity: 0.5; transform: scale(0.98); }
}

/* Footer / Navigation */
.nav-footer {
    display: flex;
    justify-content: space-between;
    margin-top: 2rem;
}