/* --- 全局与基础样式 --- */
:root {
    --primary-color: #007bff;
    --primary-color-dark: #0056b3;
    --secondary-color: #6c757d;
    --success-color: #28a745;
    --danger-color: #dc3545;
    --warning-color: #ffc107;
    --info-color: #17a2b8;
    --light-color: #f8f9fa;
    --dark-color: #343a40;
    --border-color: #dee2e6;
    --card-bg: #ffffff;
    --body-bg: #eef2f7;
    --text-color: #495057;
    --font-family-sans-serif: -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";
    --border-radius: 0.3rem;
    --box-shadow: 0 0.5rem 1rem rgba(0, 0, 0, 0.1);
    --box-shadow-sm: 0 0.125rem 0.25rem rgba(0, 0, 0, 0.075);
}

body {
    font-family: var(--font-family-sans-serif);
    line-height: 1.6;
    margin: 0;
    background-color: var(--body-bg);
    color: var(--text-color);
    font-size: 16px;
}

.page-wrapper {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.container {
    width: 90%;
    max-width: 1140px;
    margin-left: auto;
    margin-right: auto;
    padding-left: 15px;
    padding-right: 15px;
}

.app-header {
    background-color: var(--primary-color);
    color: white;
    padding: 1.5rem 0;
    text-align: center;
    box-shadow: var(--box-shadow-sm);
}

.app-header h1 {
    margin: 0 0 0.5rem 0;
    font-size: 2.2rem;
    font-weight: 600;
}

.app-header .tagline {
    font-size: 1rem;
    opacity: 0.9;
    margin: 0;
}

.app-header i {
    margin-right: 0.5rem;
}

.app-main {
    flex-grow: 1;
    padding: 2rem 0;
}

.card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow-sm);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}

.search-panel .search-input-group {
    display: flex;
    align-items: center;
    margin-bottom: 1rem;
    position: relative;
}

.search-panel .search-icon {
    position: absolute;
    left: 15px;
    color: var(--secondary-color);
    font-size: 1.1rem;
}

#emailInput {
    flex-grow: 1;
    padding: 0.75rem 0.75rem 0.75rem 2.8rem;
    font-size: 1rem;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    transition: border-color 0.15s ease-in-out, box-shadow 0.15s ease-in-out;
}

#emailInput:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 0.2rem rgba(0, 123, 255, 0.25);
    outline: none;
}

.button-primary {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 0.75rem 1.25rem;
    font-size: 1rem;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: background-color 0.15s ease-in-out;
    margin-left: 0.5rem;
    display: inline-flex;
    align-items: center;
}

.button-primary i {
    margin-right: 0.4rem;
}

.button-primary:hover {
    background-color: var(--primary-color-dark);
}

.search-panel .controls-group {
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 0.9rem;
    color: var(--secondary-color);
}

.controls-group label {
    margin-right: 0.5rem;
}

.custom-select {
    padding: 0.5rem 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    background-color: white;
    font-size: 0.9rem;
}

.total-results-info {
    font-style: italic;
}

.message-area {
    padding: 1rem;
    margin-bottom: 1.5rem;
    border-radius: var(--border-radius);
    text-align: center;
    font-weight: 500;
    display: none;
}

.message-area.loading {
    background-color: var(--info-color);
    color: white;
    border: 1px solid var(--info-color);
}

.message-area.error {
    background-color: #f8d7da;
    color: var(--danger-color);
    border: 1px solid #f5c6cb;
}

.message-area.info {
    background-color: #e2e3e5;
    color: var(--dark-color);
    border: 1px solid #d6d8db;
}

.email-list .email-item {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    padding: 1rem 1.25rem;
    margin-bottom: 1rem;
    border-radius: var(--border-radius);
    transition: box-shadow 0.2s ease-in-out;
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 0.5rem 1rem;
}

.email-list .email-item:hover {
    box-shadow: var(--box-shadow-sm);
}

.email-item .email-info {
    overflow: hidden;
}

.email-item .email-subject {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--primary-color);
    margin: 0 0 0.3rem 0;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.email-item .email-meta {
    font-size: 0.85rem;
    color: var(--secondary-color);
    display: flex;
    flex-wrap: wrap;
    gap: 0.2rem 1rem;
    margin-bottom: 0.2rem;
}

.email-item .email-meta span {
    display: inline-flex;
    align-items: center;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.email-item .email-meta i {
    margin-right: 0.3rem;
    color: #999;
}

.email-item .view-button-container {
    display: flex;
    align-items: center;
    justify-content: flex-end;
}

.button-view-content {
    background-color: var(--success-color);
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    font-size: 0.9rem;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: background-color 0.15s ease-in-out;
    white-space: nowrap;
}

.button-view-content:hover {
    background-color: #1e7e34;
}

.button-view-content:disabled {
    background-color: #a3cfbb;
    cursor: not-allowed;
}

.pagination-nav {
    display: flex;
    justify-content: center;
    margin-top: 2rem;
}

.pagination {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    gap: 0.3rem;
}

.pagination .page-item .page-link {
    display: block;
    padding: 0.6rem 0.9rem;
    color: var(--primary-color);
    background-color: white;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    text-decoration: none;
    transition: background-color 0.15s ease-in-out, color 0.15s ease-in-out;
    font-size: 0.9rem;
}

.pagination .page-item.disabled .page-link {
    color: var(--secondary-color);
    pointer-events: none;
    background-color: var(--light-color);
    border-color: var(--border-color);
}

.pagination .page-item.active .page-link {
    z-index: 1;
    color: white;
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}

.pagination .page-item:not(.disabled) .page-link:hover {
    background-color: #e9ecef;
    border-color: #adb5bd;
}

.modal {
    display: none;
    position: fixed;
    z-index: 1050;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow-x: hidden;
    overflow-y: auto;
    background-color: rgba(0, 0, 0, 0.6);
}

.modal-dialog {
    position: relative;
    width: auto;
    margin: 1.75rem;
    pointer-events: none;
    max-width: 800px;
}

@media (min-width: 576px) {
    .modal-dialog {
        margin-left: auto;
        margin-right: auto;
    }
}

.modal-content {
    position: relative;
    display: flex;
    flex-direction: column;
    width: 100%;
    pointer-events: auto;
    background-color: var(--card-bg);
    background-clip: padding-box;
    border: 1px solid rgba(0, 0, 0, 0.2);
    border-radius: var(--border-radius);
    outline: 0;
    box-shadow: var(--box-shadow);
    max-height: calc(100vh - 3.5rem);
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 1.25rem;
    border-bottom: 1px solid var(--border-color);
    background-color: var(--light-color);
}

.modal-title {
    margin: 0;
    font-size: 1.25rem;
    font-weight: 500;
    color: var(--dark-color);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
    max-width: calc(100% - 30px);
}

.close-button {
    padding: 0.5rem;
    margin: -0.5rem -0.5rem -0.5rem auto;
    background-color: transparent;
    border: 0;
    font-size: 1.5rem;
    font-weight: 700;
    line-height: 1;
    color: var(--secondary-color);
    text-shadow: 0 1px 0 #fff;
    opacity: 0.7;
    cursor: pointer;
}

.close-button:hover {
    opacity: 1;
}

.modal-body {
    position: relative;
    flex: 1 1 auto;
    padding: 1.25rem;
    overflow-y: auto;
}

.email-meta-modal {
    font-size: 0.9rem;
    color: var(--text-color);
    margin-bottom: 1rem;
}

.email-meta-modal p {
    margin: 0.3rem 0;
}

.email-meta-modal strong {
    color: var(--dark-color);
}

.modal-body hr {
    margin-top: 1rem;
    margin-bottom: 1rem;
    border: 0;
    border-top: 1px solid var(--border-color);
}

#emailBodyFrame {
    width: 100%;
    min-height: 400px;
    border: none;
}

.app-footer {
    background-color: var(--dark-color);
    color: rgba(255, 255, 255, 0.7);
    padding: 1.5rem 0;
    text-align: center;
    font-size: 0.85rem;
    margin-top: auto;
}

.warning-footer {
    color: rgba(255, 193, 7, 0.9);
    margin: 0;
}

.warning-footer i {
    margin-right: 0.3rem;
}

.loading-spinner {
    border: 4px solid #f3f3f3;
    border-top: 4px solid var(--primary-color);
    border-radius: 50%;
    width: 30px;
    height: 30px;
    animation: spin 1s linear infinite;
    margin: 20px auto;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

@media (max-width: 768px) {
    .search-panel .controls-group {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }

    .search-panel .search-input-group {
        flex-direction: column;
        align-items: stretch;
    }

    #emailInput {
        margin-bottom: 0.5rem;
    }

    .button-primary {
        margin-left: 0;
        width: 100%;
    }

    .email-list .email-item {
        grid-template-columns: 1fr;
        gap: 0.5rem;
    }

    .email-item .view-button-container {
        justify-content: flex-start;
        margin-top: 0.5rem;
    }

    .modal-dialog {
        margin: 0.5rem;
    }

    .modal-content {
         max-height: calc(100vh - 1rem);
    }
}