/* Material Design 3 Color System with CSS Variables */
:root {
    /* Light Mode Colors */
    --md-primary: #6750A4;
    --md-on-primary: #FFFFFF;
    --md-primary-container: #EADDFF;
    --md-on-primary-container: #21005D;

    /* Secondary Colors */
    --md-secondary: #625B71;
    --md-on-secondary: #FFFFFF;
    --md-secondary-container: #E8DEF8;
    --md-on-secondary-container: #1D192B;

    /* Error Colors */
    --md-error: #B3261E;
    --md-on-error: #FFFFFF;
    --md-error-container: #F9DEDC;
    --md-on-error-container: #410E0B;

    /* Surface Colors */
    --md-surface: #FFFBFE;
    --md-on-surface: #1C1B1F;
    --md-surface-variant: #E7E0EC;
    --md-on-surface-variant: #49454F;

    /* Outline */
    --md-outline: #79747E;
    --md-outline-variant: #CAC4D0;

    /* Shadows */
    --md-shadow: rgba(0, 0, 0, 0.3);
    --md-shadow-light: rgba(0, 0, 0, 0.1);

    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-2xl: 48px;

    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-full: 9999px;

    /* Typography */
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.5rem;
    --font-size-2xl: 2rem;

    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-base: 250ms ease-in-out;
}

/* Dark Mode - Follows System Preference */
@media (prefers-color-scheme: dark) {
    :root {
        /* Primary Colors - Dark Mode */
        --md-primary: #D0BCFF;
        --md-on-primary: #381E72;
        --md-primary-container: #4F378B;
        --md-on-primary-container: #EADDFF;

        /* Secondary Colors - Dark Mode */
        --md-secondary: #CCC2DC;
        --md-on-secondary: #332D41;
        --md-secondary-container: #4A4458;
        --md-on-secondary-container: #E8DEF8;

        /* Error Colors - Dark Mode */
        --md-error: #F2B8B5;
        --md-on-error: #601410;
        --md-error-container: #8C1D18;
        --md-on-error-container: #F9DEDC;

        /* Surface Colors - Dark Mode */
        --md-surface: #1C1B1F;
        --md-on-surface: #E6E1E5;
        --md-surface-variant: #49454F;
        --md-on-surface-variant: #CAC4D0;

        /* Outline - Dark Mode */
        --md-outline: #938F99;
        --md-outline-variant: #49454F;

        /* Shadows - Dark Mode */
        --md-shadow: rgba(0, 0, 0, 0.6);
        --md-shadow-light: rgba(0, 0, 0, 0.3);
    }
}

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

body {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    line-height: 1.6;
    color: var(--md-on-surface);
    background: linear-gradient(135deg, var(--md-primary-container) 0%, var(--md-surface) 100%);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Container */
.container {
    max-width: 600px;
    width: 100%;
    margin: 0 auto;
    padding: var(--spacing-lg);
    flex: 1;
    display: flex;
    flex-direction: column;
}

/* Header */
header {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
    padding-top: var(--spacing-xl);
}

h1 {
    font-size: var(--font-size-2xl);
    font-weight: 600;
    color: var(--md-primary);
    margin-bottom: var(--spacing-sm);
}

.subtitle {
    font-size: var(--font-size-lg);
    color: var(--md-on-surface-variant);
}

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

/* Form Styles */
.url-form {
    background: var(--md-surface);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    box-shadow: 0 4px 6px var(--md-shadow-light), 0 1px 3px var(--md-shadow-light);
    margin-bottom: var(--spacing-lg);
}

.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-label {
    display: block;
    font-size: var(--font-size-base);
    font-weight: 500;
    color: var(--md-on-surface);
    margin-bottom: var(--spacing-sm);
}

.input-wrapper {
    position: relative;
}

.url-input {
    width: 100%;
    padding: var(--spacing-md);
    font-size: var(--font-size-base);
    font-family: var(--font-family);
    color: var(--md-on-surface);
    background: var(--md-surface);
    border: 2px solid var(--md-outline-variant);
    border-radius: var(--radius-md);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.url-input:focus {
    outline: none;
    border-color: var(--md-primary);
    box-shadow: 0 0 0 3px rgba(103, 80, 164, 0.1);
}

.url-input:invalid:not(:placeholder-shown) {
    border-color: var(--md-error);
}

.url-input::placeholder {
    color: var(--md-on-surface-variant);
    opacity: 0.6;
}

/* Error Message */
.error-message {
    color: var(--md-error);
    font-size: var(--font-size-sm);
    margin-top: var(--spacing-xs);
    min-height: 20px;
    display: block;
}

.error-message:empty {
    display: none;
}

/* Buttons */
.btn-primary,
.btn-secondary,
.btn-copy {
    font-family: var(--font-family);
    font-size: var(--font-size-base);
    font-weight: 500;
    border: none;
    border-radius: var(--radius-full);
    cursor: pointer;
    transition: background-color var(--transition-fast), transform var(--transition-fast), box-shadow var(--transition-fast);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
}

.btn-primary {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-xl);
    background: var(--md-primary);
    color: var(--md-on-primary);
    box-shadow: 0 2px 4px var(--md-shadow-light);
}

.btn-primary:hover:not(:disabled) {
    background: #5a3f94;
    box-shadow: 0 4px 8px var(--md-shadow-light);
    transform: translateY(-1px);
}

.btn-primary:active:not(:disabled) {
    transform: translateY(0);
}

.btn-primary:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.btn-primary.loading .btn-text {
    opacity: 0;
}

.btn-primary.loading .btn-loader {
    display: block;
}

.btn-loader {
    display: none;
    width: 20px;
    height: 20px;
    border: 2px solid var(--md-on-primary);
    border-top-color: transparent;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    position: absolute;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

.btn-secondary {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-xl);
    background: var(--md-secondary-container);
    color: var(--md-on-secondary-container);
}

.btn-secondary:hover {
    background: #d5cbe8;
    transform: translateY(-1px);
}

.btn-copy {
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--md-primary-container);
    color: var(--md-on-primary-container);
    border-radius: var(--radius-md);
    white-space: nowrap;
}

.btn-copy:hover {
    background: #d5c4f7;
}

.btn-copy.copied {
    background: var(--md-primary);
    color: var(--md-on-primary);
}

/* Loading Indicator */
.loading-indicator {
    background: var(--md-surface);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    box-shadow: 0 4px 6px var(--md-shadow-light);
    text-align: center;
    display: none;
}

.loading-indicator[aria-hidden="false"] {
    display: block;
}

.spinner {
    width: 48px;
    height: 48px;
    border: 4px solid var(--md-outline-variant);
    border-top-color: var(--md-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin: 0 auto var(--spacing-md);
}

/* Error Container */
.error-container {
    background: var(--md-error-container);
    padding: var(--spacing-lg);
    border-radius: var(--radius-xl);
    border-left: 4px solid var(--md-error);
    display: none;
    margin-bottom: var(--spacing-lg);
}

.error-container[aria-hidden="false"] {
    display: flex;
    gap: var(--spacing-md);
}

.error-icon {
    font-size: var(--font-size-xl);
    flex-shrink: 0;
}

.error-content {
    flex: 1;
}

.error-title {
    font-size: var(--font-size-lg);
    font-weight: 600;
    color: var(--md-on-error-container);
    margin-bottom: var(--spacing-xs);
}

.error-text {
    color: var(--md-on-error-container);
    font-size: var(--font-size-base);
}

/* Result Container */
.result-container {
    display: none;
}

.result-container[aria-hidden="false"] {
    display: block;
}

.result-card {
    background: var(--md-surface);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    box-shadow: 0 4px 6px var(--md-shadow-light), 0 1px 3px var(--md-shadow-light);
}

.result-title {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--md-primary);
    margin-bottom: var(--spacing-lg);
    text-align: center;
}

.result-url-wrapper {
    display: flex;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-lg);
}

.result-url {
    flex: 1;
    padding: var(--spacing-md);
    font-size: var(--font-size-base);
    font-family: monospace;
    color: var(--md-primary);
    background: var(--md-primary-container);
    border: 2px solid var(--md-outline-variant);
    border-radius: var(--radius-md);
    font-weight: 500;
}

.result-url:focus {
    outline: none;
    border-color: var(--md-primary);
}

.result-details {
    background: var(--md-surface-variant);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-lg);
}

.result-detail {
    display: flex;
    justify-content: space-between;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
}

.result-detail:last-child {
    margin-bottom: 0;
}

.detail-label {
    font-weight: 500;
    color: var(--md-on-surface-variant);
}

.detail-value {
    color: var(--md-on-surface);
    word-break: break-all;
    text-align: right;
}

/* Footer */
footer {
    text-align: center;
    padding: var(--spacing-lg) 0;
    color: var(--md-on-surface-variant);
    font-size: var(--font-size-sm);
    margin-top: auto;
}

/* Responsive Breakpoints */
@media (max-width: 640px) {
    .container {
        padding: var(--spacing-md);
    }

    header {
        padding-top: var(--spacing-lg);
        margin-bottom: var(--spacing-xl);
    }

    h1 {
        font-size: var(--font-size-xl);
    }

    .subtitle {
        font-size: var(--font-size-base);
    }

    .url-form,
    .result-card {
        padding: var(--spacing-lg);
    }

    .result-url-wrapper {
        flex-direction: column;
    }

    .btn-copy {
        width: 100%;
    }

    .result-detail {
        flex-direction: column;
        gap: var(--spacing-xs);
    }

    .detail-value {
        text-align: left;
    }
}

/* Accessibility - Focus Visible */
*:focus-visible {
    outline: 2px solid var(--md-primary);
    outline-offset: 2px;
}

/* Accessibility - Reduced Motion */
@media (prefers-reduced-motion: reduce) {

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Hidden Elements */
[aria-hidden="true"] {
    display: none !important;
}