:root {
    --bg-dark: #0B0F14;
    --text-light: #E5E7EB;
    --scrollbar-thumb: rgba(229, 231, 235, 0.3);
    --scrollbar-thumb-hover: rgba(229, 231, 235, 0.5);
}

body {
    background-color: var(--bg-dark);
    color: var(--text-light);
    font-family: 'Inter', sans-serif;
    margin: 0;
    min-height: 100vh;
}

.app-container {
    display: flex;
    flex-direction: row; /* Left-right on large screens */
    width: 100vw;
    height: 100vh;
}

/* Custom scrollbar */
::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb {
    background: var(--scrollbar-thumb);
    border-radius: 5px;
}
::-webkit-scrollbar-thumb:hover {
    background: var(--scrollbar-thumb-hover);
}

/* Sidebar (Left) */
.sidebar {
    width: 350px;
    background-color: var(--bg-dark);
    border-right: 1px solid var(--text-light);
    padding: 40px;
    display: flex;
    flex-direction: column;
    gap: 20px;
    overflow-y: auto;
}

.logo {
    font-size: 1.5rem;
    letter-spacing: 5px;
    border-bottom: 2px solid var(--text-light);
    padding-bottom: 10px;
    margin-bottom: 20px;
    text-align: center;
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

label {
    font-size: 0.8rem;
    text-transform: uppercase;
    opacity: 0.8;
}

input, select, textarea {
    background: transparent;
    border: 1px solid var(--text-light);
    color: var(--text-light);
    padding: 12px;
    border-radius: 4px;
    outline: none;
}

/* Transparent dropdowns */
select {
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
    background: rgba(229, 231, 235, 0.05);
}

select option {
    background: var(--bg-dark);
    color: var(--text-light);
}

.time-picker { display: flex; gap: 10px; }
.time-picker .input-group { flex: 1; }

button {
    background-color: var(--text-light);
    color: var(--bg-dark);
    border: none;
    padding: 15px;
    font-weight: bold;
    cursor: pointer;
    transition: 0.3s;
    margin-top: 10px;
}
button:hover { opacity: 0.8; }
button.secondary {
    background: transparent;
    border: 1px solid var(--text-light);
    color: var(--text-light);
}

/* Preview Area (Right) */
.preview-area {
    flex: 1;
    background-color: #161b22;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    padding: 50px;
    overflow-y: auto;
}

.planner-page {
    width: 100%;
    max-width: 600px;
    background-color: var(--bg-dark);
    border: 1px solid var(--text-light);
    min-height: 800px;
    padding: 60px;
    box-shadow: 0 20px 50px rgba(0,0,0,0.5);
}

.page-header h2 { font-size: 2rem; margin: 0; }
.line { width: 50px; height: 3px; background: var(--text-light); margin: 20px 0; }

.schedule-item {
    display: flex;
    border-bottom: 1px solid rgba(229, 231, 235, 0.2);
    padding: 15px 0;
    align-items: baseline;
}

.item-time { width: 120px; font-weight: bold; }
.item-task { flex: 1; font-family: 'Courier New', monospace; }

.placeholder-text { opacity: 0.3; text-align: center; margin-top: 100px; }

/* Responsive: Stack vertically on smaller screens */
@media (max-width: 1024px) {
    .app-container {
        flex-direction: column;
    }
    .sidebar {
        width: 100%;
        max-width: none;
        border-right: none;
        border-bottom: 1px solid var(--text-light);
        padding: 30px;
    }
    .preview-area {
        padding: 30px;
    }
    .planner-page {
        padding: 40px;
        min-height: 600px;
    }
}

@media (max-width: 480px) {
    .sidebar { padding: 20px; }
    .time-picker { flex-direction: column; }
    .preview-area { padding: 20px; }
    .planner-page { padding: 30px; }
    .page-header h2 { font-size: 1.8rem; }
}