/* ======= CSS Variables (Design System) ======= */
:root {
    /* Light Theme (Default) */
    --bg-color: #f3f6f9;
    --card-bg: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --primary-light: #eff6ff;
    --accent-color: #f43f5e;
    
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.05);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.05), 0 2px 4px -2px rgba(0,0,0,0.05);
    --shadow-lg: 0 10px 25px -3px rgba(0,0,0,0.05), 0 4px 6px -4px rgba(0,0,0,0.02);
    --shadow-qr: 0 20px 40px rgba(0,0,0,0.08);

    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-full: 9999px;

    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.dark-mode {
    --bg-color: #0f172a;
    --card-bg: #1e293b;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --border-color: #334155;
    --primary-color: #3b82f6;
    --primary-hover: #60a5fa;
    --primary-light: #1e3a8a;

    --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.4);
    --shadow-lg: 0 10px 25px -3px rgba(0,0,0,0.5);
    --shadow-qr: 0 20px 40px rgba(0,0,0,0.6);
}

/* ======= Global Reset ======= */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Outfit', sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    transition: background-color var(--transition), color var(--transition);
}

.d-none { display: none !important; }
.mt-2 { margin-top: 0.5rem; }
.mt-3 { margin-top: 1rem; }

/* ======= Layout ======= */
.app-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* ======= Header ======= */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 0;
    border-bottom: 1px solid var(--border-color);
    margin-bottom: 2rem;
}

.logo-link {
    text-decoration: none;
    color: inherit;
}

.logo-container {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.logo {
    width: 40px;
    height: 40px;
}

.app-name {
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -0.5px;
}
.app-name span { color: var(--primary-color); }

.header-actions {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.nav-link {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
}
.nav-link:hover { color: var(--primary-color); }

.icon-btn {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    width: 40px;
    height: 40px;
    border-radius: var(--radius-full);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
}
.icon-btn:hover {
    background: var(--primary-light);
    color: var(--primary-color);
    border-color: var(--primary-color);
    transform: translateY(-2px);
}

/* ======= Main Content ======= */
.main-content {
    display: grid;
    grid-template-columns: 1fr 400px;
    gap: 3rem;
    align-items: start;
    padding-bottom: 4rem;
}

/* ======= Configuration Panel ======= */
.config-panel {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.panel-section {
    background: var(--card-bg);
    padding: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.section-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--primary-color);
}

/* Type Buttons */
.type-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: 1rem;
}

.type-btn {
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    padding: 1rem;
    border-radius: var(--radius-md);
    font-weight: 500;
    font-size: 0.95rem;
    cursor: pointer;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    transition: var(--transition);
}

.type-btn i { font-size: 1.75rem; }

.type-btn:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
    background: var(--primary-light);
}

.type-btn.active {
    background: var(--primary-color);
    color: #fff;
    border-color: var(--primary-color);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

/* Forms */
.form-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}
.full-width { grid-column: 1 / -1; }

.input-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.input-group label {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.input-group input:not([type="color"]):not([type="range"]):not([type="file"]):not([type="checkbox"]),
.input-group textarea,
.input-group select {
    width: 100%;
    padding: 0.75rem 1rem;
    background: var(--bg-color);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    border-radius: var(--radius-md);
    font-size: 1rem;
    transition: var(--transition);
    outline: none;
}

.input-group textarea { resize: vertical; min-height: 80px; }

.input-group input:focus,
.input-group textarea:focus,
.input-group select:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px var(--primary-light);
}

option {
    background-color: var(--bg-color);
    color: var(--text-primary);
}

/* Accordion */
.accordion {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.accordion-item {
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.accordion-header {
    width: 100%;
    background: transparent;
    border: none;
    padding: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 1.05rem;
    font-weight: 500;
    color: var(--text-primary);
    cursor: pointer;
    transition: var(--transition);
}
.accordion-header:hover { background: var(--bg-color); }
.accordion-header i { transition: transform 0.3s ease; }
.accordion-header.active i { transform: rotate(180deg); }

.accordion-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out, padding 0.3s ease;
    padding: 0 1rem;
    background: var(--bg-color);
}
.accordion-content.open {
    max-height: 500px;
    padding: 1rem;
    border-top: 1px solid var(--border-color);
}

/* Color Pickers */
.color-pickers {
    display: flex;
    gap: 2rem;
}

.color-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.color-input-wrapper {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

input[type="color"] {
    -webkit-appearance: none;
    border: none;
    width: 40px;
    height: 40px;
    border-radius: var(--radius-full);
    cursor: pointer;
    overflow: hidden;
    padding: 0;
    background: none;
    box-shadow: var(--shadow-sm);
}
input[type="color"]::-webkit-color-swatch-wrapper { padding: 0; }
input[type="color"]::-webkit-color-swatch { border: 2px solid var(--border-color); border-radius: var(--radius-full); }

.color-hex {
    font-family: monospace;
    font-size: 1rem;
    color: var(--text-secondary);
    background: var(--card-bg);
    padding: 0.25rem 0.5rem;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
}

/* File Upload */
.logo-upload-container { display: flex; align-items: center; gap: 1rem; flex-wrap: wrap; }
.file-upload-label {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--primary-light);
    color: var(--primary-color);
    padding: 0.75rem 1.25rem;
    border-radius: var(--radius-md);
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    border: 1px dashed var(--primary-color);
}
.file-upload-label:hover { background: var(--primary-color); color: white; }
.file-name { font-size: 0.9rem; color: var(--text-secondary); }

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
    font-size: 0.9rem;
}

/* Buttons */
.btn {
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition);
    border: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.btn-primary {
    background: var(--primary-color);
    color: white;
    box-shadow: 0 4px 10px rgba(37, 99, 235, 0.2);
}
.btn-primary:hover {
    background: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 6px 15px rgba(37, 99, 235, 0.3);
}

.btn-outline {
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-primary);
}
.btn-outline:hover { background: var(--bg-color); }

.btn-small { padding: 0.5rem 1rem; font-size: 0.85rem; }

/* ======= Preview Panel ======= */
.sticky-container {
    position: sticky;
    top: 2rem;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.qr-preview-card {
    background: var(--card-bg);
    padding: 3rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-qr);
    display: flex;
    align-items: center;
    justify-content: center;
    aspect-ratio: 1;
    border: 1px solid var(--border-color);
}

.qr-container {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.qr-container svg { width: 100% !important; height: 100% !important; max-width: 300px; max-height: 300px; }
.qr-container canvas { width: 100% !important; height: 100% !important; max-width: 300px; max-height: 300px; }


.download-section {
    background: var(--card-bg);
    padding: 1.5rem;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-color);
    text-align: center;
}

.download-title {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.download-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.75rem;
}

.download-btn { width: 100%; }

/* Range Slider */
input[type="range"] {
    -webkit-appearance: none;
    width: 100%;
    height: 6px;
    background: var(--border-color);
    border-radius: var(--radius-full);
    outline: none;
}
input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
}

/* Responsiveness */
@media (max-width: 1024px) {
    .main-content {
        grid-template-columns: 1fr;
    }
    .sticky-container {
        position: static;
        max-width: 500px;
        margin: 0 auto;
    }
}

@media (max-width: 640px) {
    .header { flex-direction: column; gap: 1rem; text-align: center; }
    .form-grid { grid-template-columns: 1fr; }
    .download-grid { grid-template-columns: 1fr; }
}