:root {
    --primary-color: #1877F2;
    --secondary-color: #2C3E50;
    --background-color: #F0F2F5;
    --card-background: #FFFFFF;
    --text-color: #2C3E50;
    --border-radius: 12px;
    --spacing: 20px;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --input-border-color: #D9DBE0;
}

[data-theme="dark"] {
    --primary-color: #4a90e2;
    --secondary-color: #AAB8C5;
    --background-color: #1A1A1A;
    --card-background: #2A2A2A;
    --text-color: #E0E0E0;
    --shadow-color: rgba(255, 255, 255, 0.1);
    --input-border-color: #444444;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    line-height: 1.6;
    transition: background-color 0.3s, color 0.3s;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing);
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

header h1 {
    color: var(--primary-color);
    font-size: 1.8rem;
    line-height: 1;
}

.theme-switcher .switch {
    position: relative;
    display: inline-block;
    width: 60px;
    height: 34px;
}

.theme-switcher .switch input { 
    opacity: 0;
    width: 0;
    height: 0;
}

.theme-switcher .slider {
    position: absolute;
    cursor: pointer;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: #ccc;
    transition: .4s;
    border-radius: 34px;
}

.theme-switcher .slider:before {
    position: absolute;
    content: "";
    height: 26px;
    width: 26px;
    left: 4px;
    bottom: 4px;
    background-color: white;
    transition: .4s;
    border-radius: 50%;
}

.theme-switcher input:checked + .slider {
    background-color: var(--primary-color);
}

.theme-switcher input:checked + .slider:before {
    transform: translateX(26px);
}

.theme-switcher .slider-icon {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    color: white;
    pointer-events: none;
}

.theme-switcher .sun {
    left: 8px;
}

.theme-switcher .moon {
    right: 8px;
}

main {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing);
}

@media (min-width: 768px) {
    main {
        grid-template-columns: 1fr 1fr;
    }
    header h1 {
        font-size: 2.5rem;
    }
}

.input-section, .output-section {
    background-color: var(--card-background);
    padding: var(--spacing);
    border-radius: var(--border-radius);
    box-shadow: 0 4px 12px var(--shadow-color);
}

.section-header h2 {
    margin-bottom: 1rem;
}

.input-group, #dynamic-inputs .input-group {
    margin-bottom: 1.5rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.modern-select, .modern-textarea, .modern-input {
    width: 100%;
    padding: 0.8rem;
    border: 1px solid var(--input-border-color);
    border-radius: var(--border-radius);
    background-color: var(--background-color);
    color: var(--text-color);
    font-size: 1rem;
}

.options-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
}

@media (min-width: 576px) {
    .options-grid {
        grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    }
}

.option-card {
    background-color: var(--background-color);
    padding: 1rem;
    border-radius: var(--border-radius);
}

.option-card h3 {
    margin-bottom: 1rem;
}

.form-row {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
}

.form-group {
    flex: 1;
    min-width: 150px;
}

.custom-size-wrapper {
    display: flex;
    gap: 0.5rem;
}

.custom-size-wrapper input {
    width: 100%;
}

.color-picker {
    width: 100%;
}

.generate-btn {
    width: 100%;
    padding: 1rem;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1.2rem;
    cursor: pointer;
    transition: all 0.3s;
}

.qr-display {
    position: relative;
    width: 100%;
    padding-top: 100%; /* 1:1 Aspect Ratio */
    background-color: var(--background-color);
    border-radius: var(--border-radius);
    overflow: hidden;
}

.qr-display > * {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: contain;
    padding: 1rem;
}

.qr-placeholder {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

.generate-section {
    margin-top: 1.5rem;
    display: grid;
    grid-template-columns: 1fr;
    gap: 1rem;
}

.reset-btn {
    width: 100%;
    padding: 1rem;
    background-color: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
    border-radius: var(--border-radius);
    font-size: 1.2rem;
    cursor: pointer;
    transition: all 0.3s;
}

.qr-placeholder i {
    font-size: 4rem;
    color: var(--secondary-color);
}

.actions {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
    margin-top: 1.5rem;
}

.action-btn {
    background-color: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
    border-radius: var(--border-radius);
    padding: 0.8rem;
    cursor: pointer;
    transition: all 0.3s;
}

.action-btn:disabled {
    background-color: #999;
    cursor: not-allowed;
    border-color: #999;
    color: white;
}

footer {
    text-align: center;
    margin-top: 2rem;
    padding: 1rem;
    color: var(--secondary-color);
}

/* Pickr styles */
.pickr .pcr-button {
    width: 100%;
    height: 40px;
    border-radius: var(--border-radius);
    border: 1px solid var(--input-border-color);
}

.pcr-app .pcr-interaction .pcr-result {
    flex-grow: 1;
}

@media (hover: hover) {
  .generate-btn:hover {
    filter: brightness(1.1);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.2);
  }

  .reset-btn:hover, .action-btn:hover:not(:disabled) {
    background-color: var(--primary-color);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.2);
  }
}