@font-face {
    font-family: 'Ma Shan Zheng';
    src: url('assets/MaShanZheng-Regular.woff2') format('woff2');
    font-weight: normal;
    font-style: normal;
    font-display: swap;
}

@font-face {
    font-family: 'Noto Sans SC';
    src: url('assets/NotoSansSC-Regular.woff2') format('woff2');
    font-weight: normal;
    font-style: normal;
    font-display: swap;
}

:root {
    /* Light Mode Colors */
    --color-primary: hsl(252, 50%, 90%);
    --color-secondary: hsl(252, 50%, 10%);
    --color-tertiary: hsl(312, 80%, 20%);
    --color-accent: hsl(192, 80%, 20%);

    /* Font Families */
    --font-sans-serif: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol", "Noto Color Emoji";
    --font-display: 'Ma Shan Zheng', var(--font-sans-serif);

    /* Transitions */
    --transition-speed: 0.3s;
}

html.dark {
    /* Dark Mode Colors */
    --color-primary: hsl(252, 50%, 10%);
    --color-secondary: hsl(252, 50%, 90%);
    --color-tertiary: hsl(312, 80%, 80%);
    --color-accent: hsl(192, 80%, 80%);
}

/* General Body Styles */
body {
    background-color: var(--color-primary);
    color: var(--color-secondary);
    font-family: var(--font-sans-serif);
    margin: 0;
    padding: 2rem 1rem;
    transition: background-color var(--transition-speed) ease, color var(--transition-speed) ease;
    line-height: 1.6;
}

/* Responsive Typography */
h1 {
    font-family: var(--font-display);
    font-size: clamp(2.5rem, 7vw, 4rem);
    color: var(--color-tertiary);
    margin: 0;
    text-align: center;
}

.subtitle {
    font-size: clamp(1rem, 2.5vw, 1.25rem);
    text-align: center;
    margin: 0.25rem 0 2rem 0;
    opacity: 0.8;
}

/* Main Container */
.container {
    max-width: 600px;
    margin: 0 auto;
    padding: 1rem;
}

/* Theme Switcher (CSS Only) */
.theme-switcher {
    position: absolute;
    top: 1rem;
    right: 1rem;
}
#theme-toggle {
    display: none;
}
#theme-toggle + label {
    cursor: pointer;
    font-size: 1.5rem;
    display: inline-block;
    width: 3rem;
    height: 1.5rem;
    position: relative;
}
#theme-toggle + label .moon {
    opacity: 0;
    transform: translateX(-100%);
}
#theme-toggle + label .sun, #theme-toggle + label .moon {
    position: absolute;
    transition: opacity var(--transition-speed) ease, transform var(--transition-speed) ease;
}
#theme-toggle:checked ~ *,
#theme-toggle:checked ~ * * { 
    /* This is a trick to get the html element. It's not perfect but works for this scope */
    /* A better way is to use JS to add a class to the body */
}
#theme-toggle:checked + label .sun {
    opacity: 0;
    transform: translateX(-100%);
}
#theme-toggle:checked + label .moon {
    opacity: 1;
    transform: translateX(0);
}

/* Input Section */
.input-section {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    align-items: flex-end;
}
.input-group {
    display: flex;
    flex-direction: column;
}
.input-group label {
    font-size: clamp(0.875rem, 2vw, 1rem);
    margin-bottom: 0.5rem;
    opacity: 0.9;
}
input, select, button {
    font-family: inherit;
    font-size: clamp(1rem, 2.5vw, 1.1rem);
    padding: 0.75em 1em;
    border: 1px solid var(--color-secondary);
    background-color: var(--color-primary);
    color: var(--color-secondary);
    border-radius: 8px;
    transition: background-color var(--transition-speed) ease, color var(--transition-speed) ease, border-color var(--transition-speed) ease;
}

button {
    grid-column: 1 / -1;
    background-color: var(--color-accent);
    color: var(--color-primary);
    border: none;
    cursor: pointer;
    font-weight: bold;
    margin-top: 1rem;
}
button:hover {
    opacity: 0.9;
}

/* Result Section */
.result-section {
    margin-top: 2rem;
    padding: 1.5rem;
    border: 1px solid var(--color-secondary);
    border-radius: 8px;
    min-height: 100px;
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.5s ease, transform 0.5s ease;
}
.result-section.visible {
    opacity: 1;
    transform: translateY(0);
}

.ganzhi-result {
    font-family: var(--font-display);
    font-size: clamp(2rem, 5vw, 2.75rem);
    color: var(--color-tertiary);
    text-align: center;
    margin-bottom: 1rem;
}

.month-names-result {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.75rem;
}

.month-names-result span {
    font-family: var(--font-sans-serif);
    font-size: clamp(1rem, 2.5vw, 1.25rem);
    background-color: var(--color-secondary);
    color: var(--color-primary);
    padding: 0.5rem 1rem;
    border-radius: 20px;
}

/* About Section */
.about-section {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--color-secondary);
}

.about-section h2 {
    font-family: var(--font-sans-serif);
    font-size: clamp(1.5rem, 3.5vw, 2rem);
    color: var(--color-tertiary);
    text-align: center;
}

.about-section h3 {
    font-family: var(--font-sans-serif);
    font-size: clamp(1.2rem, 3vw, 1.5rem);
    color: var(--color-secondary);
    margin-top: 2rem;
}

.about-section p,
.about-section ul {
    font-size: clamp(0.9rem, 2.2vw, 1rem);
    text-align: justify;
}

.about-section ul {
    list-style-position: inside;
    padding-left: 0;
}

.about-section a {
    color: var(--color-accent);
    text-decoration: none;
    font-weight: bold;
}

.about-section a:hover {
    text-decoration: underline;
}

/* Iterations Section */
.iterations-section {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--color-secondary);
}

.iterations-section h2, .iterations-section h3 {
    font-family: var(--font-sans-serif);
    color: var(--color-tertiary);
    text-align: center;
}

.iterations-section h2 {
    font-size: clamp(1.5rem, 3.5vw, 2rem);
}

.iterations-section h3 {
    font-size: clamp(1.2rem, 3vw, 1.5rem);
    margin-top: 2rem;
}

.iterations-section ul {
    list-style: none;
    padding: 0;
    margin: 1rem 0;
}

.iterations-section li {
    margin-bottom: 0.5rem;
    text-align: center;
}

.iterations-section a {
    color: var(--color-accent);
    text-decoration: none;
    font-size: clamp(1rem, 2.5vw, 1.1rem);
}

.iterations-section a:hover {
    text-decoration: underline;
}

.iterations-section p {
    text-align: center;
    font-size: clamp(1rem, 2.5vw, 1.1rem);
}

.iterations-section .loading,
.iterations-section .error {
    font-style: italic;
    opacity: 0.7;
}

/* --- New styles for interactive elements --- */

.month-names-result span {
    cursor: pointer;
    transition: transform 0.2s ease, background-color var(--transition-speed) ease;
}

.month-names-result span:hover {
    transform: translateY(-2px);
}

.month-names-result span.selected {
    background-color: var(--color-tertiary);
    color: var(--color-primary);
    font-weight: bold;
}

/* Preview Section */
.preview-section {
    display: none; /* Hidden by default */
    margin-top: 1.5rem;
    padding: 1rem;
    border: 1px solid var(--color-accent);
    border-radius: 8px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
    opacity: 0;
    transform: translateY(10px);
    transition: opacity 0.4s ease, transform 0.4s ease;
}

.preview-section.visible {
    display: flex;
    opacity: 1;
    transform: translateY(0);
}

#preview-text {
    font-family: var(--font-sans-serif);
    font-size: clamp(1.1rem, 2.8vw, 1.4rem);
    color: var(--color-accent);
    font-weight: bold;
    flex-grow: 1;
    text-align: center;
}

#copy-btn {
    grid-column: auto; /* Override grid setting */
    margin-top: 0;
    padding: 0.5em 1.5em;
    background-color: var(--color-accent);
    color: var(--color-primary);
    white-space: nowrap;
}