/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Light Theme Colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f5f5f5;
    --text-primary: #212121;
    --text-secondary: #757575;
    --accent-color: #2196f3;
    --accent-hover: #1976d2;
    --border-color: #e0e0e0;
    --shadow: rgba(0, 0, 0, 0.1);
    --input-bg: #ffffff;
    --footer-bg: #f5f5f5;
}

/* Dark Theme - Based on OS Preference */
@media (prefers-color-scheme: dark) {
    :root {
        --bg-primary: #121212;
        --bg-secondary: #1e1e1e;
        --text-primary: #e0e0e0;
        --text-secondary: #b0b0b0;
        --accent-color: #64b5f6;
        --accent-hover: #42a5f5;
        --border-color: #333333;
        --shadow: rgba(0, 0, 0, 0.3);
        --input-bg: #2c2c2c;
        --footer-bg: #1e1e1e;
    }
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.container {
    max-width: 600px;
    width: 100%;
    margin: 0 auto;
    padding: 1rem;
    flex: 1;
    display: flex;
    flex-direction: column;
}

/* Header */
header {
    text-align: center;
    margin-bottom: 2rem;
    padding: 1.5rem 0;
}

h1 {
    font-size: 1.75rem;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.subtitle {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* Privacy Notice */
.privacy-notice {
    margin-top: 1rem;
    padding: 0.75rem 1rem;
    background-color: var(--bg-secondary);
    border-left: 3px solid var(--accent-color);
    border-radius: 4px;
    display: flex;
    align-items: flex-start;
    gap: 0.5rem;
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

.privacy-icon {
    flex-shrink: 0;
    margin-top: 0.1rem;
    color: var(--accent-color);
}

.privacy-notice span {
    flex: 1;
}

/* Main Content */
main {
    flex: 1;
}

/* Type Selector */
.type-selector {
    margin-bottom: 1.5rem;
}

.type-selector label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-primary);
}

/* Form Styles */
.qr-form {
    display: none;
    animation: fadeIn 0.3s ease-in;
}

.qr-form.active {
    display: block;
}

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

.form-group {
    margin-bottom: 1rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.4rem;
    font-weight: 500;
    color: var(--text-primary);
    font-size: 0.9rem;
}

.form-input,
.form-select {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    background-color: var(--input-bg);
    color: var(--text-primary);
    transition: border-color 0.3s, box-shadow 0.3s;
}

.form-input:focus,
.form-select:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(33, 150, 243, 0.15);
}

textarea.form-input {
    resize: vertical;
    font-family: inherit;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
    user-select: none;
}

.checkbox-label input[type="checkbox"] {
    width: 1.2rem;
    height: 1.2rem;
    cursor: pointer;
}

/* Button Group */
.button-group {
    display: flex;
    gap: 0.75rem;
    margin: 1.5rem 0;
    flex-wrap: wrap;
}

.btn {
    flex: 1;
    min-width: 140px;
    padding: 0.875rem 1.5rem;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    text-align: center;
}

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

.btn-primary:hover:not(:disabled) {
    background-color: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px var(--shadow);
}

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

.btn-secondary:hover:not(:disabled) {
    background-color: var(--border-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px var(--shadow);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* QR Code Output */
.qr-output {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 200px;
    margin: 1.5rem 0;
    padding: 1.5rem;
    background-color: var(--bg-secondary);
    border-radius: 12px;
    border: 2px dashed var(--border-color);
}

#qr-canvas {
    display: flex;
    justify-content: center;
    align-items: center;
}

#qr-canvas .qr-wrapper {
    padding: 20px;
    background-color: #ffffff;
    border-radius: 8px;
    display: inline-block;
}

#qr-canvas canvas,
#qr-canvas img {
    max-width: 100%;
    height: auto;
    border-radius: 4px;
}

/* Footer */
footer {
    margin-top: auto;
    padding: 1.5rem 0;
    text-align: center;
    background-color: var(--footer-bg);
    border-top: 1px solid var(--border-color);
}

.footer-privacy {
    margin-bottom: 1rem;
    padding: 1rem;
    background-color: var(--bg-secondary);
    border-radius: 6px;
    text-align: left;
}

.footer-privacy p {
    color: var(--text-primary);
    font-size: 0.85rem;
    line-height: 1.6;
    margin: 0;
}

.footer-privacy strong {
    color: var(--accent-color);
    display: block;
    margin-bottom: 0.25rem;
}

footer p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

footer a {
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
}

footer a:hover {
    color: var(--accent-hover);
    text-decoration: underline;
}

/* Responsive Design - Tablet */
@media (min-width: 640px) {
    .container {
        padding: 1.5rem;
    }

    h1 {
        font-size: 2.25rem;
    }

    .subtitle {
        font-size: 1rem;
    }

    .button-group {
        gap: 1rem;
    }

    .btn {
        padding: 1rem 2rem;
    }
}

/* Responsive Design - Desktop */
@media (min-width: 1024px) {
    .container {
        max-width: 700px;
        padding: 2rem;
    }

    h1 {
        font-size: 2.5rem;
    }

    header {
        margin-bottom: 2.5rem;
        padding: 2rem 0;
    }

    .form-input,
    .form-select {
        padding: 0.875rem;
        font-size: 1rem;
    }

    .qr-output {
        min-height: 250px;
        padding: 2rem;
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Print Styles */
@media print {
    body {
        background-color: white;
        color: black;
    }

    .button-group,
    .type-selector,
    .qr-form,
    footer a {
        display: none;
    }

    .qr-output {
        border: 1px solid black;
    }
}