/* === Google Font Import === */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;700&family=Source+Serif+Pro:wght@400;600&display=swap');

/* === Design System Variables === */
:root {
    /* === Colors - 来自我们确认的设计方案 === */
    --color-primary: #0D6EFD;
    --color-secondary: #6C757D;
    --color-accent: #198754;
    --color-background: #F8F9FA;
    --color-text: #212529;
    --color-white: #FFFFFF;
    --color-border: #DEE2E6;

    /* === Typography - 来自我们确认的设计方案 === */
    --font-heading: 'Inter', sans-serif;
    --font-body: 'Source Serif Pro', serif;

    /* === Spacing & Radius === */
    --spacing-md: 1rem;
    --spacing-lg: 2rem;
    --border-radius: 0.5rem;
}

/* === Global Resets & Base Styles === */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: var(--font-heading); /* 默认使用UI字体 */
    color: var(--color-text);
    background-color: var(--color-background);
    line-height: 1.6;
    display: flex;
    justify-content: center;
    padding: var(--spacing-md);
}

.app-container {
    width: 100%;
    max-width: 720px;
    margin: 0 auto;
}

/* === Header === */
.header {
    text-align: center;
    padding: var(--spacing-lg) 0;
    border-bottom: 1px solid var(--color-border);
    margin-bottom: var(--spacing-lg);
}

.header__title {
    font-size: 2.25rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.header__subtitle {
    font-size: 1.1rem;
    color: var(--color-secondary);
    font-weight: 400;
}

/* === Citation Generator === */
.citation-generator__form {
    display: flex;
    gap: var(--spacing-md);
}

.citation-generator__input {
    flex-grow: 1;
    padding: 0.75rem var(--spacing-md);
    font-size: 1rem;
    font-family: var(--font-heading);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    transition: box-shadow 0.2s ease, border-color 0.2s ease;
}

.citation-generator__input:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(13, 110, 253, 0.25);
}

.citation-generator__button {
    font-family: var(--font-heading);
    font-size: 1rem;
    font-weight: 500;
    color: var(--color-white);
    background-color: var(--color-primary);
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: background-color 0.2s ease;
}

.citation-generator__button:hover {
    background-color: #0B5ED7; /* A slightly darker primary color */
}

/* === Results Section === */
.citation-results {
    margin-top: var(--spacing-lg);
}

/* === Footer === */
.footer {
    text-align: center;
    margin-top: var(--spacing-lg);
    padding: var(--spacing-md) 0;
    color: var(--color-secondary);
    font-size: 0.9rem;
}
/* === ADD THIS TO THE END OF style.css === */

/* === Result Card Styles === */
.result-card {
    background-color: var(--color-white);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    margin-bottom: var(--spacing-lg);
    padding: var(--spacing-lg);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

.result-card__title {
    font-family: var(--font-heading);
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--color-text);
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid var(--color-border);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.result-card__content {
    font-family: var(--font-body); /* 使用我们指定的衬线字体 */
    font-size: 1.1rem;
    line-height: 1.7;
    margin-bottom: var(--spacing-md);
}

.result-card__content p {
    margin: 0;
}

.result-card__copy-btn {
    font-family: var(--font-heading);
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--color-primary);
    background-color: transparent;
    border: 1px solid var(--color-primary);
    padding: 0.3rem 0.8rem;
    border-radius: 1rem; /* pill shape */
    cursor: pointer;
    transition: all 0.2s ease;
}

.result-card__copy-btn:hover {
    background-color: var(--color-primary);
    color: var(--color-white);
}

.result-card__copy-btn.copied {
    background-color: var(--color-accent);
    color: var(--color-white);
    border-color: var(--color-accent);
    cursor: default;
}

.error-message {
    color: #DC3545; /* A standard error red */
    font-weight: 500;
}
/* === ADD THIS TO THE END OF style.css === */

/* === View Switcher === */
.view-switcher {
    display: flex;
    justify-content: center;
    gap: 0.5rem;
    margin-bottom: var(--spacing-lg);
}

.view-switcher__button {
    font-family: var(--font-heading);
    font-size: 1rem;
    font-weight: 500;
    padding: 0.5rem 1.5rem;
    border: 1px solid var(--color-border);
    background-color: var(--color-white);
    color: var(--color-secondary);
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: all 0.2s ease;
}

.view-switcher__button:hover {
    background-color: var(--color-background);
    color: var(--color-primary);
}

.view-switcher__button.active {
    background-color: var(--color-primary);
    color: var(--color-white);
    border-color: var(--color-primary);
}

.view {
    display: none; /* Hide views by default */
}

.view.active {
    display: block; /* Show the active view */
}


/* === Textarea specific styles === */
.citation-generator__textarea {
    flex-grow: 1;
    padding: 0.75rem var(--spacing-md);
    font-size: 1rem;
    font-family: var(--font-heading);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    transition: box-shadow 0.2s ease, border-color 0.2s ease;
    resize: vertical;
    width: 100%;
}

.citation-generator__textarea:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(13, 110, 253, 0.25);
}

.citation-generator__form {
    flex-direction: column;
}

/* === Batch Results and Actions === */
.batch-result-item {
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    margin-bottom: var(--spacing-lg);
    background-color: var(--color-white);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

.batch-result-item__title {
    font-family: var(--font-heading);
    font-weight: 700;
    padding: var(--spacing-md);
    background-color: var(--color-background);
    border-bottom: 1px solid var(--color-border);
    border-top-left-radius: var(--border-radius);
    border-top-right-radius: var(--border-radius);
}

.batch-result-item .result-card {
    border: none;
    box-shadow: none;
    margin-bottom: 0;
}

.bulk-actions {
    display: flex;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.bulk-actions__button {
    font-family: var(--font-heading);
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--color-white);
    background-color: var(--color-secondary);
    border: none;
    padding: 0.5rem 1rem;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: background-color 0.2s ease;
}

.bulk-actions__button:hover {
    background-color: #5A6268;
}

/* === History View === */
.history-list {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.history-item {
    display: block;
    padding: var(--spacing-md);
    background-color: var(--color-white);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    text-decoration: none;
    color: var(--color-text);
    font-family: var(--font-heading);
    cursor: pointer;
    transition: all 0.2s ease;
}

.history-item:hover {
    border-color: var(--color-primary);
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    transform: translateY(-2px);
}

.history-item__title {
    font-weight: 700;
    margin: 0;
}

.history-item__date {
    font-size: 0.85rem;
    color: var(--color-secondary);
}
/* === ADD THIS TO THE END OF style.css === */

/* === Generator Controls & Actions === */
.generator-controls {
    display: flex;
    justify-content: flex-start;
    align-items: center;
    margin-bottom: var(--spacing-md);
    gap: var(--spacing-lg);
}

.generator-controls__group {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.generator-controls__label {
    font-family: var(--font-heading);
    font-size: 0.9rem;
    color: var(--color-secondary);
}

.generator-controls__select {
    font-family: var(--font-heading);
    padding: 0.4rem 0.6rem;
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    background-color: var(--color-white);
}

.generator-actions {
    display: flex;
    justify-content: flex-end;
    gap: var(--spacing-md);
    width: 100%;
    margin-top: var(--spacing-md);
}

.citation-generator__button--secondary {
    font-family: var(--font-heading);
    font-size: 1rem;
    font-weight: 500;
    color: var(--color-text);
    background-color: var(--color-white);
    border: 1px solid var(--color-border);
    padding: 0.75rem 1.5rem;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: all 0.2s ease;
}

.citation-generator__button--secondary:hover {
    background-color: var(--color-background);
    border-color: #ced4da;
}
/* === ADD THIS TO THE END OF style.css === */

/* === UI/UX Refinements === */

/* Loading Spinner */
.loading-spinner-container {
    display: flex;
    justify-content: center;
    align-items: center;
    padding: var(--spacing-lg);
}

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

.loading-spinner {
    display: inline-block;
    width: 40px;
    height: 40px;
    border: 4px solid rgba(0, 0, 0, 0.1);
    border-left-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

/* Custom Scrollbar */
/* Works on Firefox */
* {
  scrollbar-width: thin;
  scrollbar-color: var(--color-secondary) var(--color-background);
}

/* Works on Chrome, Edge, and Safari */
::-webkit-scrollbar {
  width: 10px;
}

::-webkit-scrollbar-track {
  background: var(--color-background);
}

::-webkit-scrollbar-thumb {
  background-color: #ced4da; /* A slightly lighter secondary color */
  border-radius: 20px;
  border: 3px solid var(--color-background);
}

::-webkit-scrollbar-thumb:hover {
    background-color: var(--color-secondary);
}
/* === ADD THIS TO THE END OF style.css === */

/* === Accordion (Collapsible) Results === */
.batch-result-item__title {
    cursor: pointer;
    position: relative;
    transition: background-color 0.2s ease;
}

.batch-result-item__title:hover {
    background-color: #e9ecef; /* A slightly darker background */
}

.batch-result-item__title::after {
    content: '▼';
    position: absolute;
    right: var(--spacing-md);
    top: 50%;
    transform: translateY(-50%) rotate(0deg);
    transition: transform 0.3s ease;
    color: var(--color-secondary);
}

.batch-result-item.active .batch-result-item__title::after {
    transform: translateY(-50%) rotate(180deg);
}

.batch-result-item__content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease-out;
    background-color: var(--color-white);
}

.batch-result-item.active .batch-result-item__content {
    max-height: 1000px; /* A large enough value to show content */
    transition: max-height 0.5s ease-in;
}


/* === Hanging Indent for Full References === */
.result-card[data-type="full-reference"] .result-card__content p {
    /* This creates the hanging indent */
    padding-left: 2em;
    text-indent: -2em;
}