* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Light mode colors */
    --bg-color: #ffffff;
    --text-color: #222222;
    --text-muted: #666666;
    --border-color: #cccccc;
    --border-hover: #999999;
    --container-bg: #ffffff;
    --container-border: #dddddd;
    --input-bg: #ffffff;
    --button-bg: #ffffff;
    --button-hover: #f9f9f9;
    --accent-bg: #f9f9f9;
    --accent-border: #cccccc;
    --server-info-bg: #f0f8ff;
    --server-info-border: #b0d4f1;
    --code-bg: #e6f3ff;
    --file-label-bg: #fafafa;
    --file-label-hover: #f0f0f0;
    --progress-bg: #f0f0f0;
    --progress-track: #cccccc;
    --mobile-warning-bg: #fff3cd;
    --mobile-warning-border: #ffeaa7;
    --mobile-warning-text: #856404;
}

[data-theme="dark"] {
    /* Dark mode colors */
    --bg-color: #1a1a1a;
    --text-color: #e0e0e0;
    --text-muted: #a0a0a0;
    --border-color: #404040;
    --border-hover: #606060;
    --container-bg: #252525;
    --container-border: #404040;
    --input-bg: #2a2a2a;
    --button-bg: #2a2a2a;
    --button-hover: #353535;
    --accent-bg: #222222;
    --accent-border: #404040;
    --server-info-bg: #1e2832;
    --server-info-border: #2a4a5a;
    --code-bg: #2a3540;
    --file-label-bg: #252525;
    --file-label-hover: #2a2a2a;
    --progress-bg: #333333;
    --progress-track: #404040;
    --mobile-warning-bg: #332a1a;
    --mobile-warning-border: #4a3a2a;
    --mobile-warning-text: #d4b464;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
    max-width: 600px;
    margin: 0 auto;
    padding: 40px 20px;
    color: var(--text-color);
    line-height: 1.5;
    background-color: var(--bg-color);
    transition: background-color 0.3s ease, color 0.3s ease;
}

.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 40px;
}

.header h1 {
    margin: 0;
}

.header-tagline {
    font-size: 12px;
    color: var(--text-muted);
    font-weight: 400;
    text-align: right;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-top: 40px;
    padding: 20px 0;
}

.footer-links .how-link {
    font-size: 12px;
    color: var(--text-muted);
    text-decoration: none;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 1px;
}

.footer-links .how-link:hover {
    color: var(--text-color);
    border-bottom-color: var(--border-hover);
}

.dark-mode-toggle {
    background: none;
    border: none;
    font-size: 16px;
    cursor: pointer;
    padding: 4px;
    border-radius: 4px;
    opacity: 0.6;
    transition: opacity 0.2s ease, background-color 0.2s ease;
    margin-left: 10px;
}

.dark-mode-toggle:hover {
    opacity: 1;
    background-color: var(--accent-bg);
}

[data-theme="dark"] .dark-mode-toggle {
    /* Switch to sun icon in dark mode */
}

[data-theme="dark"] .dark-mode-toggle::before {
    content: "☀️";
}

[data-theme="light"] .dark-mode-toggle::before,
.dark-mode-toggle::before {
    content: "🌙";
}

.header-links {
    display: flex;
    gap: 15px;
    align-items: center;
}

.how-link {
    font-size: 12px;
    color: var(--text-muted);
    text-decoration: none;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 1px;
}

.how-link:hover {
    color: var(--text-color);
    border-bottom-color: var(--border-hover);
}

h1 {
    font-size: 24px;
    font-weight: 500;
    text-align: center;
    color: var(--text-color);
}

h2 {
    font-size: 18px;
    font-weight: 500;
    margin-bottom: 20px;
    color: var(--text-color);
}

h3 {
    font-size: 16px;
    font-weight: 500;
    margin-bottom: 15px;
    color: var(--text-color);
}

.container {
    border: 1px solid var(--container-border);
    border-radius: 4px;
    padding: 30px;
    margin-bottom: 20px;
    background-color: var(--container-bg);
}

.relay-config {
    border: 1px solid var(--container-border);
    border-radius: 4px;
    padding: 20px;
    margin-bottom: 30px;
    position: relative;
    background-color: var(--container-bg);
}

.relay-config-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
}

.relay-config-header h3 {
    margin: 0;
}

.close-btn {
    background: none;
    border: none;
    font-size: 18px;
    color: var(--text-muted);
    cursor: pointer;
    padding: 5px;
    line-height: 1;
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 3px;
}

.close-btn:hover {
    background: var(--accent-bg);
    color: var(--text-color);
}

.relay-config h4 {
    font-size: 14px;
    font-weight: 500;
    margin-bottom: 10px;
    color: var(--text-color);
}

.relay-select {
    width: 100%;
    padding: 8px 12px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 14px;
    font-family: inherit;
    margin-bottom: 15px;
    color: var(--text-color);
    background-color: var(--input-bg);
}

.relay-select:focus {
    outline: none;
    border-color: #666;
}

.custom-relay {
    display: flex;
    gap: 10px;
    margin-bottom: 15px;
}

.relay-status {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 14px;
    color: var(--text-color);
}

.server-info {
    background: var(--server-info-bg);
    border: 1px solid var(--server-info-border);
    border-radius: 4px;
    padding: 15px;
    font-size: 12px;
    color: var(--text-color);
}

.server-info h4 {
    margin: 0 0 8px 0;
    color: var(--text-color);
    font-size: 13px;
}

.server-info code {
    background: var(--code-bg);
    padding: 2px 4px;
    border-radius: 2px;
    font-family: 'SF Mono', 'Monaco', 'Inconsolata', 'Roboto Mono', 'Source Code Pro', 'Menlo', 'Consolas', monospace;
    color: var(--text-color);
}

.mode-selector {
    text-align: center;
    margin-bottom: 30px;
}

button {
    border: 1px solid var(--border-color);
    color: var(--text-color);
    padding: 12px 24px;
    border-radius: 4px;
    cursor: pointer;
    font-size: 14px;
    font-family: inherit;
    margin: 0 8px;
    background-color: var(--button-bg);
    transition: border-color 0.2s ease, background-color 0.2s ease;
}

button:hover {
    border-color: var(--border-hover);
    background-color: var(--button-hover);
}

button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

input[type="text"] {
    border: 1px solid var(--border-color);
    color: var(--text-color);
    padding: 12px 16px;
    border-radius: 4px;
    font-size: 14px;
    font-family: inherit;
    width: 100%;
    background-color: var(--input-bg);
}

input[type="text"]:focus {
    outline: none;
    border-color: #666;
}

input[type="file"] {
    display: none;
}

.file-label {
    display: block;
    border: 2px dashed var(--border-color);
    padding: 40px 20px;
    border-radius: 4px;
    text-align: center;
    cursor: pointer;
    margin: 20px 0;
    color: var(--text-color);
    background: var(--file-label-bg);
    transition: all 0.2s ease;
}

.file-label:hover {
    border-color: var(--border-hover);
    background: var(--file-label-hover);
}

.pin-display {
    font-size: 28px;
    font-weight: 600;
    text-align: center;
    padding: 20px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    margin: 20px 0;
    letter-spacing: 4px;
    color: var(--text-color);
    background: var(--accent-bg);
    /* Use a monospace font that clearly distinguishes O from 0 */
    font-family: 'SF Mono', 'Monaco', 'Inconsolata', 'Roboto Mono', 'Source Code Pro', 'Menlo', 'Consolas', monospace;
    /* Prevent confusion between similar characters */
    font-feature-settings: "zero" 1; /* Use slashed zero if available */
}

.share-url {
    border: 1px solid var(--container-border);
    border-radius: 4px;
    padding: 20px;
    margin: 20px 0;
    background: var(--accent-bg);
}

.url-container {
    display: flex;
    gap: 10px;
    margin-bottom: 10px;
}

.url-container input {
    flex: 1;
    padding: 12px 16px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 14px;
    font-family: 'SF Mono', 'Monaco', 'Inconsolata', 'Roboto Mono', 'Source Code Pro', 'Menlo', 'Consolas', monospace;
    color: var(--text-color);
    background-color: var(--input-bg);
}

.url-container button {
    padding: 12px 20px;
    white-space: nowrap;
}

.share-instruction {
    font-size: 14px;
    color: var(--text-muted);
    margin: 0;
    text-align: center;
}

.pin-input {
    text-align: center;
    padding: 20px 0;
}

.pin-input input {
    text-align: center;
    letter-spacing: 2px;
    font-size: 18px;
    max-width: 200px;
    margin-bottom: 20px;
    /* Use same monospace font for PIN input */
    font-family: 'SF Mono', 'Monaco', 'Inconsolata', 'Roboto Mono', 'Source Code Pro', 'Menlo', 'Consolas', monospace;
    font-weight: 600;
    /* Prevent confusion between similar characters */
    font-feature-settings: "zero" 1; /* Use slashed zero if available */
    background-color: var(--input-bg);
    color: var(--text-color);
    border: 1px solid var(--border-color);
}

.status {
    padding: 15px;
    margin: 15px 0;
    border-radius: 4px;
    border: 1px solid var(--border-color);
    font-size: 14px;
    color: var(--text-color);
    background: var(--accent-bg);
}

.progress {
    width: 100%;
    height: 8px;
    border-radius: 4px;
    overflow: hidden;
    margin: 15px 0;
    border: 1px solid var(--progress-track);
    background: var(--progress-bg);
}

.progress-bar {
    height: 100%;
    background: var(--text-color);
    width: 0%;
    transition: width 0.3s ease;
}

.hidden {
    display: none;
}

.file-input {
    margin: 20px 0;
}

#fileName {
    margin-top: 10px;
    font-size: 14px;
    color: var(--text-color);
}

/* Responsive design */
@media (max-width: 480px) {
    body {
        padding: 20px 15px;
    }
    
    .header {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }
    
    .header-tagline {
        text-align: left;
    }
    
    .mode-selector button {
        margin: 5px 4px;
    }
    
    .url-container {
        flex-direction: column;
    }
    
    .url-container button {
        margin-top: 10px;
    }
    
    .pin-display {
        font-size: 24px;
        letter-spacing: 3px;
    }
    
    .pin-input input {
        font-size: 16px;
        letter-spacing: 1px;
    }
}