:root {
    --bg-color: #0f172a;
    --primary: #6366f1;
    --primary-hover: #4f46e5;
    --success: #22c55e;
    --success-hover: #16a34a;
    --secondary: rgba(255, 255, 255, 0.1);
    --secondary-hover: rgba(255, 255, 255, 0.2);
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --glass-bg: rgba(15, 23, 42, 0.75);
    --glass-border: rgba(255, 255, 255, 0.1);
    --input-bg: rgba(0,0,0,0.3);
    --header-gradient: linear-gradient(to right, #fff, #a5b4fc);
    --bg-gradient: radial-gradient(circle at 15% 50%, rgba(99, 102, 241, 0.15), transparent 25%),
                   radial-gradient(circle at 85% 30%, rgba(139, 92, 246, 0.15), transparent 25%);
}

:root[data-theme="light"] {
    --bg-color: #f1f5f9;
    --primary: #4f46e5;
    --primary-hover: #4338ca;
    --success: #16a34a;
    --success-hover: #15803d;
    --secondary: rgba(0, 0, 0, 0.15);
    --secondary-hover: rgba(0, 0, 0, 0.25);
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --glass-bg: rgba(255, 255, 255, 0.85);
    --glass-border: rgba(0, 0, 0, 0.1);
    --input-bg: rgba(255, 255, 255, 0.5);
    --header-gradient: linear-gradient(to right, #1e293b, #4f46e5);
    --bg-gradient: radial-gradient(circle at 15% 50%, rgba(99, 102, 241, 0.1), transparent 25%),
                   radial-gradient(circle at 85% 30%, rgba(139, 92, 246, 0.1), transparent 25%);
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    overflow: hidden; /* Hide outer scroll */
    transition: background-color 0.3s ease, color 0.3s ease;
    user-select: none;
    -webkit-user-select: none;
    overscroll-behavior: none;
}

img {
    -webkit-user-drag: none;
}

.app-bg {
    position: fixed; top: 0; left: 0; width: 100vw; height: 100vh;
    background: var(--bg-gradient);
    z-index: -1;
    transition: background 0.3s ease;
}

.glass {
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
}

.main-workspace {
    height: 100vh; /* Full viewport height, user scrolls workspace */
    overflow-y: auto;
    padding: 2rem;
    padding-bottom: 350px; /* Space for the bottom panels */
}

/* Scrollbar styling */
::-webkit-scrollbar { width: 8px; height: 8px; }
::-webkit-scrollbar-track { background: rgba(0,0,0,0.1); }
::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.2); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: rgba(255,255,255,0.4); }

.app-header {
    text-align: center;
    margin-bottom: 2rem;
}

.app-header h2 {
    font-size: 2.2rem;
    background: var(--header-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    font-weight: 700;
}

.preview-workspace {
    display: flex;
    gap: 2rem;
    justify-content: center;
    align-items: flex-start;
    flex-wrap: wrap;
}

.preview-card, .a4-card {
    padding: 1.5rem;
    border-radius: 16px;
    box-shadow: 0 8px 32px rgba(0,0,0,0.3);
    display: flex;
    flex-direction: column;
    align-items: center;
}

.preview-card h3, .a4-card h3 {
    margin-bottom: 1.5rem;
    color: var(--text-secondary);
    font-size: 1rem;
    text-transform: uppercase;
    letter-spacing: 1px;
}

#previewCanvas {
    max-width: 100%;
    border-radius: 8px;
    box-shadow: 0 4px 15px rgba(0,0,0,0.5);
    touch-action: none;
    background: #000;
}

#a4Sheet {
    width: 794px;
    height: 1123px;
    background: white;
    border-radius: 4px;
    display: flex;
    flex-wrap: wrap;
    align-content: flex-start;
    justify-content: center;
    overflow: hidden;
    gap: 12px;
    padding: 20px 20px 10px 20px;
    transform-origin: top center;
    transform: scale(0.5);
    margin-bottom: -561px; /* Correct height for scaled element */
    box-shadow: 0 10px 40px rgba(0,0,0,0.5);
}

.photoBox canvas {
    border-radius: 0;
    box-shadow: none;
}

/* Bottom Tab Navigation */
.bottom-tab-bar {
    position: fixed;
    bottom: 0; left: 0; width: 100%;
    display: flex;
    justify-content: space-around;
    padding: 0.5rem 0;
    z-index: 101;
    background: var(--glass-bg);
    border-top: 1px solid var(--glass-border);
    backdrop-filter: blur(12px);
    transition: background 0.3s ease;
}

.tab-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.4rem;
    font-size: 0.75rem;
    cursor: pointer;
    padding: 0.5rem;
    width: 25%;
    transition: all 0.3s ease;
    font-family: 'Inter', sans-serif;
}

.tab-btn.active {
    color: var(--primary);
}

.tab-btn i {
    font-size: 1.3rem;
    transition: transform 0.2s ease;
}

.tab-btn.active i {
    transform: translateY(-2px);
}

/* Bottom Panels */
.bottom-panels {
    position: fixed;
    bottom: 65px;
    left: 0; width: 100%;
    background: var(--glass-bg);
    border-top: 1px solid var(--glass-border);
    z-index: 100;
    transition: background 0.3s ease;
    max-height: 40vh;
    overflow-y: auto;
    backdrop-filter: blur(12px);
    box-shadow: 0 -10px 30px rgba(0,0,0,0.3);
}

.tab-panel {
    display: none;
    padding: 1rem 1.5rem;
}

.tab-panel.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

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

.panel-scroll-x {
    display: flex;
    gap: 1.25rem;
    overflow-x: auto;
    padding-bottom: 0.5rem;
    align-items: center;
}

.prop-btn {
    background: var(--secondary);
    color: var(--text-secondary);
    border: 1px solid transparent;
}
.prop-btn.active {
    background: rgba(99, 102, 241, 0.2);
    color: var(--text-primary);
    border-color: var(--primary);
}

.control-item {
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.control-item label {
    font-size: 0.7rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    font-weight: 600;
    white-space: nowrap;
}

input, select {
    background: var(--input-bg);
    border: 1px solid var(--glass-border);
    color: var(--text-primary);
    padding: 0.5rem 0.75rem;
    border-radius: 6px;
    font-family: inherit;
    font-size: 0.9rem;
    transition: all 0.3s ease;
    user-select: auto;
    -webkit-user-select: auto;
}

input:focus, select:focus {
    outline: none;
    border-color: var(--primary);
}

input[type="number"] { width: 80px; }
input[type="text"] { width: 160px; }
select { width: auto; cursor: pointer; }
input[type="color"] {
    padding: 2px 4px;
    height: 35px;
    width: 60px;
    cursor: pointer;
}
input[type="range"] {
    width: 100%;
    cursor: pointer;
}

.btn {
    padding: 0.6rem 1.25rem;
    border-radius: 8px;
    border: none;
    cursor: pointer;
    font-weight: 600;
    font-family: 'Inter', sans-serif;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.3s ease;
    white-space: nowrap;
    font-size: 0.9rem;
}

.btn-primary { background: var(--primary); color: white; box-shadow: 0 4px 12px rgba(99, 102, 241, 0.3); }
.btn-primary:hover { background: var(--primary-hover); transform: translateY(-2px); }
.btn-success { background: var(--success); color: white; box-shadow: 0 4px 12px rgba(34, 197, 94, 0.3); }
.btn-success:hover { background: var(--success-hover); transform: translateY(-2px); }
.btn-secondary { background: var(--secondary); color: var(--text-primary); border: 1px solid var(--glass-border); }
.btn-secondary:hover { background: var(--secondary-hover); transform: translateY(-2px); }

/* Hide file input and style label as button */
input[type="file"] { display: none; }
.upload-label {
    background: transparent;
    border: 1px dashed var(--primary);
    color: var(--primary);
    padding: 0.5rem 1rem;
    border-radius: 6px;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
    font-weight: 600;
    transition: all 0.3s ease;
    margin-top: 0.2rem;
}
.upload-label:hover { background: rgba(99, 102, 241, 0.1); }
/* Modal Styles */
.modal-overlay {
    position: fixed;
    top: 0; left: 0; width: 100vw; height: 100vh;
    background: rgba(0,0,0,0.8);
    backdrop-filter: blur(5px);
    z-index: 1000;
    display: flex;
    justify-content: center;
    align-items: center;
}
.modal-overlay.hidden { display: none; }

.modal-content {
    width: 90%;
    max-width: 800px;
    background: var(--bg-color);
    padding: 2rem;
    border-radius: 16px;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    border: 1px solid var(--glass-border);
    box-shadow: 0 10px 40px rgba(0,0,0,0.5);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.modal-header h3 { margin: 0; font-size: 1.4rem; color: #fff; }
.btn-icon { background: transparent; border: none; color: #fff; font-size: 1.5rem; cursor: pointer; }

.cropper-wrapper {
    width: 100%;
    height: 40vh;
    background: var(--bg-color);
    border-radius: 8px;
    overflow: hidden;
}

.editor-controls {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
}
.editor-controls .control-item {
    background: rgba(255,255,255,0.05);
    padding: 1rem;
    border-radius: 8px;
}
.modal-actions {
    display: flex;
    justify-content: flex-end;
    gap: 1rem;
    margin-top: 1rem;
}

@media print {
    body * { visibility: hidden; }
    #a4Sheet, #a4Sheet * { visibility: visible; }
    #a4Sheet {
        position: absolute;
        left: 0; top: 0;
        transform: scale(1);
        margin: 0;
        box-shadow: none;
    }
}