:root {
    --primary-color: #007AFF; /* Apple Blue */
    --secondary-color: #F2F2F7; /* Light Gray Background for iOS */
    --text-color: #000000; /* Darker text for better contrast */
    --light-text-color: #8E8E93; /* Gray for secondary text */
    --border-color: #C6C6C8;
    --card-background: #FFFFFF;
    --shadow-color: rgba(0, 0, 0, 0.08);
    --border-radius: 10px;
    --spacing-unit: 15px;
    --header-height: 44px; /* Standard iOS header height */
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
    background-color: var(--secondary-color);
    color: var(--text-color);
    margin: 0;
    padding-top: var(--header-height); /* Space for fixed header */
    padding-bottom: calc(var(--spacing-unit) + 60px); /* Adjust for fixed footer */
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.main-content.container {
    max-width: 768px;
    margin: 0 auto;
    padding: var(--spacing-unit);
    padding-bottom: calc(var(--spacing-unit) + 60px); /* Ensure content is not hidden by fixed footer */
    box-sizing: border-box;
}

.header.sticky {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    text-align: center;
    height: var(--header-height);
    line-height: var(--header-height);
    background-color: var(--card-background);
    border-bottom: 0.5px solid var(--border-color); /* Finer border */
    z-index: 1000;
    box-shadow: none; /* Remove shadow for cleaner iOS look */
}

.header-title {
    margin: 0;
    font-size: 17px; /* Standard iOS navigation title size */
    font-weight: 600;
    color: var(--text-color);
}

.intro-text {
    font-size: 15px;
    color: var(--light-text-color);
    text-align: center;
}

/* Help Page Specific Styles */
.help-section {
    background-color: var(--card-background);
    border-radius: var(--border-radius);
    margin-bottom: var(--spacing-unit);
    padding: var(--spacing-unit);
    box-shadow: 0 1px 3px var(--shadow-color);
}

.help-section h2 {
    font-size: 20px;
    color: var(--text-color);
    margin-top: 0;
    margin-bottom: 10px;
    font-weight: 600;
}

.help-section p {
    font-size: 15px;
    color: var(--text-color);
    margin-bottom: 10px;
    line-height: 1.5;
}

.help-section ul {
    list-style: none; /* Remove default bullet points */
    padding: 0;
    margin-top: 5px;
    margin-bottom: 10px;
}

.help-section li {
    line-height: 1.5;
    margin-bottom: 8px; /* Slightly more spacing */
    font-size: 15px;
    color: var(--text-color);
    position: relative;
    padding-left: 15px; /* Space for custom bullet */
}

.help-section li::before {
    content: '•'; /* Custom bullet point */
    color: var(--primary-color);
    position: absolute;
    left: 0;
    top: 0;
}

.help-section li button {
    background-color: var(--primary-color);
    color: var(--card-background);
    font-size: 14px;
    padding: 5px 10px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    margin-left: 10px;
    transition: background-color 0.2s ease-in-out;
}

.help-section li button.copy-success {
    background-color: #28a745; /* Green on success */
}

.help-section li button.copy-fail {
    background-color: #FF3B30; /* Red on failure */
}

.help-section a {
    color: var(--primary-color);
    text-decoration: none;
    font-size: 15px;
}

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

/* Rate Page Specific Styles */
.input-group-container {
    display: flex;
    margin-bottom: var(--spacing-unit);
    background-color: var(--card-background);
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: 0 1px 3px var(--shadow-color);
}

.input-group-container .text-input {
    flex-grow: 1;
    border: none;
    padding: 12px var(--spacing-unit);
    font-size: 16px;
    background-color: transparent;
    color: var(--text-color);
    outline: none;
    -webkit-appearance: none; /* Remove default iOS styling */
    appearance: none;
}

.input-group-container .text-input::placeholder {
    color: var(--light-text-color);
}

.input-group-container .action-button {
    padding: 12px var(--spacing-unit);
    font-size: 16px;
    background-color: var(--primary-color);
    color: var(--card-background);
    border: none;
    border-radius: 0 var(--border-radius) var(--border-radius) 0;
    cursor: pointer;
    transition: background-color 0.3s ease;
    font-weight: 500;
    flex-shrink: 0;
}

.input-group-container .action-button:hover {
    background-color: #0056b3;
}

.info-section {
    background-color: var(--card-background);
    border-radius: var(--border-radius);
    margin-bottom: 10px; /* Slightly less margin for info sections */
    padding: var(--spacing-unit);
    box-shadow: 0 1px 3px var(--shadow-color);
    font-size: 15px;
    color: var(--text-color);
    line-height: 1.4;
}

.table-container {
    background-color: var(--card-background);
    border-radius: var(--border-radius);
    margin-top: var(--spacing-unit);
    overflow: hidden; /* Ensures rounded corners for table */
    box-shadow: 0 1px 3px var(--shadow-color);
}

.data-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 15px;
    color: var(--text-color);
}

.data-table th,
.data-table td {
    padding: 12px var(--spacing-unit);
    text-align: left;
    border-bottom: 0.5px solid var(--border-color);
}

.data-table th {
    background-color: #F9F9F9;
    font-weight: 600;
    color: var(--light-text-color);
    font-size: 13px; /* Smaller font for table headers */
    text-transform: uppercase;
}

.data-table tbody tr:last-child td {
    border-bottom: none;
}

.data-table tbody tr:hover {
    background-color: #F9F9F9;
}

/* Override default error-message for specific context if needed */
.result-section .error-message {
    background-color: #FFF0F0;
    color: #FF3B30;
    border-radius: var(--border-radius);
    padding: var(--spacing-unit);
    margin: var(--spacing-unit) 0;
    text-align: center;
}

/* Styles for rate info spans in index.html */
.rate-info-container {
    display: flex; /* 使用 Flexbox 布局 */
    justify-content: center; /* 水平居中 */
    gap: 10px; /* 两个 span 之间的间距 */
    margin-top: 5px;
    margin-bottom: 5px;
    flex-wrap: nowrap; /* 强制不换行 */
}

.info-span,
.info-spanplus {
    font-size: 0.6em; /* 字体再小点 */
    color: var(--light-text-color); /* 灰色，使用主题变量 */
    white-space: nowrap; /* 防止文本换行 */
    text-align: center; /* 居中显示 */
    flex-shrink: 0; /* 防止缩小 */
}

.settings-group .setting-title {
    font-size: 17px; /* Slightly smaller for group titles */
    font-weight: 600;
    color: var(--text-color);
    margin: 0;
    padding: var(--spacing-unit);
    border-bottom: 0.5px solid var(--border-color);
    background-color: #F9F9F9; /* Light background for title section */
}

.settings-group p {
    font-size: 15px;
    color: var(--text-color);
    margin: 0;
    padding: 0;
    line-height: 1.5;
}

.settings-group ul.setup-steps {
    list-style: decimal; /* Use decimal for steps */
    padding: 0 var(--spacing-unit) var(--spacing-unit) calc(var(--spacing-unit) * 2); /* Indent for list numbers */
    margin: 0;
}

.settings-group ul.setup-steps li {
    font-size: 15px;
    color: var(--text-color);
    line-height: 1.5;
    padding: 5px 0;
}

.setting-item {
    display: flex;
    align-items: center;
    padding: var(--spacing-unit);
    text-decoration: none;
    color: var(--text-color);
    border-bottom: 0.5px solid var(--border-color); /* Finer border */
    transition: background-color 0.2s ease;
}

.setting-item:last-child {
    border-bottom: none;
}

.setting-item:hover {
    background-color: #F9F9F9;
}

.setting-item span {
    flex-grow: 1;
    font-size: 16px; /* Slightly smaller for general text */
}

.download-button {
    display: inline-block;
    background-color: var(--primary-color);
    color: var(--card-background);
    padding: 8px 15px;
    border-radius: 8px; /* Slightly more rounded */
    text-decoration: none;
    font-size: 16px;
    font-weight: 500;
    transition: background-color 0.2s ease;
}

.download-button:hover {
    background-color: #0056b3; /* Darker blue on hover */
    text-decoration: none;
}

.unavailable-text {
    color: var(--light-text-color);
    font-style: italic;
    font-size: 15px;
}

.info-item {
    display: flex;
    align-items: center;
    padding: 10px var(--spacing-unit); /* Adjusted padding */
    font-size: 15px;
    border-bottom: 0.5px solid var(--border-color); /* Finer border */
    background-color: var(--card-background);
}

.info-item:last-child {
    border-bottom: none;
}

.info-item span:first-child {
    color: var(--light-text-color);
    width: 80px; /* Adjusted width for labels */
    flex-shrink: 0;
}

.info-item span.copy-target {
    flex-grow: 1;
    color: var(--text-color);
    word-break: break-all;
    padding-right: 10px; /* Space before copy button */
}

.copy-button {
    background: none;
    border: none;
    color: var(--primary-color);
    font-size: 15px; /* Slightly smaller icon */
    cursor: pointer;
    margin-left: auto; /* Push to the right */
    padding: 5px 8px;
    border-radius: 5px;
    transition: background-color 0.2s ease;
    flex-shrink: 0;
}

.copy-button:hover {
    background-color: rgba(0, 122, 255, 0.1);
}

.copy-button.copy-success {
    color: #28a745; /* Green on success */
}

.error-message {
    color: #FF3B30; /* iOS Red for errors */
    font-size: 14px;
    padding: 8px var(--spacing-unit);
    background-color: #FFF0F0; /* Light red background */
    border-radius: var(--border-radius);
    margin: 5px var(--spacing-unit);
}

/* Collapsible settings group styles */
.settings-group .setting-header {
    display: flex;
    align-items: center;
    padding: var(--spacing-unit);
    background-color: #F9F9F9; /* Light background for header */
    border-bottom: 0.5px solid var(--border-color);
    cursor: pointer;
    transition: background-color 0.2s ease;
}

.settings-group .setting-header:hover {
    background-color: #EFEFF4;
}

.settings-group .setting-header .setting-title {
    flex-grow: 1;
    margin: 0;
    padding: 0; /* Reset padding from general .setting-title */
    border-bottom: none; /* Remove border from general .setting-title */
    background-color: transparent; /* Reset background from general .setting-title */
}

.indicator-icon {
    font-size: 14px;
    color: var(--light-text-color);
    transition: transform 0.3s ease;
}

.indicator-icon.rotated {
    transform: rotate(180deg);
}

.setting-content {
    max-height: 1000px; /* Arbitrarily large value for transition */
    overflow: hidden;
    transition: max-height 0.3s ease-out;
}

.setting-content.collapsed {
    max-height: 0;
}

/* Footer styles */
.footer {
    position: fixed;
    bottom: 0;
    left: 0;
    width: 100%;
    background-color: var(--card-background);
    border-top: 0.5px solid var(--border-color); /* Finer border */
    box-shadow: none; /* Remove shadow for cleaner iOS look */
    z-index: 9999;
    padding-bottom: env(safe-area-inset-bottom); /* For iPhone X notch */
}

.footer-nav {
    list-style-type: none;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: space-around;
}

.footer-nav li {
    flex: 1;
    text-align: center;
}

.footer-nav .nav-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-decoration: none;
    color: var(--light-text-color);
    font-size: 10px; /* Smaller font for tab labels */
    padding: 8px 0;
    transition: color 0.2s ease;
}

.footer-nav .nav-item.active {
    color: var(--primary-color);
}

.footer-nav .nav-item i {
    font-size: 22px; /* Slightly larger icons */
    margin-bottom: 2px; /* Reduced margin */
}

.footer-nav .nav-item:hover {
    color: var(--primary-color);
}

/* Responsive adjustments */
@media (max-width: 480px) {
    .main-content.container {
        padding: var(--spacing-unit) 10px;
    }

    .header.sticky {
        /* No specific adjustments needed here as it's fixed width 100% */
    }

    .settings-group .setting-title {
        padding: var(--spacing-unit) 10px;
    }

    .setting-item {
        padding: var(--spacing-unit) 10px;
    }

    .info-item {
        padding: 10px 10px;
    }

    .error-message {
        margin: 5px 10px;
    }
}

/* CDR Page Specific Styles */
.query-section {
    background-color: var(--card-background);
    border-radius: var(--border-radius);
    margin-bottom: var(--spacing-unit);
    padding: var(--spacing-unit);
    box-shadow: 0 1px 3px var(--shadow-color);
    display: flex;
    flex-direction: column;
    align-items: center;
}

.query-section label {
    font-size: 16px;
    color: var(--text-color);
    margin-bottom: 10px;
}

.date-input {
    width: 100%;
    padding: 10px;
    margin-bottom: 15px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 16px;
    box-sizing: border-box;
    -webkit-appearance: none; /* Remove default iOS styling */
    appearance: none;
}

.action-button {
    display: block;
    width: 100%;
    padding: 12px;
    font-size: 18px;
    background-color: var(--primary-color);
    color: var(--card-background);
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.3s ease;
    font-weight: 500;
}

.action-button:hover {
    background-color: #0056b3;
}

.result-section {
    text-align: left;
    padding: 0;
    max-width: 100%;
    margin: 0 auto;
}

.call-list {
    list-style-type: none;
    padding: 0;
    margin: 0;
}

.call-item {
    background-color: var(--card-background);
    border-radius: var(--border-radius);
    margin-bottom: var(--spacing-unit);
    padding: var(--spacing-unit);
    box-shadow: 0 1px 3px var(--shadow-color);
    font-size: 16px;
    line-height: 1.4;
}

.call-info-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 5px;
}

.callee {
    font-weight: 600;
    font-size: 18px;
    color: var(--text-color);
    overflow: hidden;
    white-space: nowrap;
    text-overflow: ellipsis;
    flex-grow: 1;
}

.fee {
    color: var(--primary-color);
    font-weight: 600;
    font-size: 18px;
    text-align: right;
    flex-shrink: 0;
}

.call-type {
    color: var(--light-text-color);
    font-size: 14px;
    margin-bottom: 5px;
}

.memo {
    color: var(--light-text-color);
    font-size: 14px;
    margin-top: 5px;
    text-align: left;
    white-space: pre-wrap;
}

.call-time-details {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 10px;
    font-size: 14px;
    color: var(--light-text-color);
}

.call-duration {
    background-color: var(--primary-color);
    color: var(--card-background);
    padding: 4px 8px;
    border-radius: 5px;
    font-size: 14px;
    text-align: right;
    min-width: 70px;
}

.no-results {
    text-align: center;
    color: var(--light-text-color);
    font-size: 16px;
    padding: var(--spacing-unit);
}

/* Override default error-message for specific context if needed */
.result-section .error-message {
    background-color: #FFF0F0;
    color: #FF3B30;
    border-radius: var(--border-radius);
    padding: var(--spacing-unit);
    margin: var(--spacing-unit) 0;
    text-align: center;
}