:root {
    /* Light theme (default) */
    --bg-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --container-bg: #ffffff;
    --header-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --header-text: #ffffff;
    --text-primary: #333333;
    --text-secondary: #666666;
    --tab-bg: #f8f9fa;
    --tab-text: #666666;
    --tab-active-text: #667eea;
    --tab-active-bg: #ffffff;
    --tab-border: #667eea;
    --input-border: #e1e5e9;
    --input-bg: #ffffff;
    --input-text: #333333;
    --input-focus-border: #667eea;
    --input-focus-shadow: rgba(102, 126, 234, 0.1);
    --button-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --button-text: #ffffff;
    --button-hover-shadow: rgba(102, 126, 234, 0.3);
    --button-disabled-bg: #cccccc;
    --user-info-bg: #f8f9fa;
    --user-details-bg: #ffffff;
    --section-bg: #f8f9fa;
    --section-border: #667eea;
    --message-success-bg: #d4edda;
    --message-success-text: #155724;
    --message-success-border: #c3e6cb;
    --message-error-bg: #f8d7da;
    --message-error-text: #721c24;
    --message-error-border: #f5c6cb;
    --logout-btn-bg: #dc3545;
    --logout-btn-hover: #c82333;
    --border-color: #e1e5e9;
}

/* Dark theme */
[data-theme="dark"] {
    --bg-gradient: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
    --container-bg: #2d3748;
    --header-gradient: linear-gradient(135deg, #4a5568 0%, #2d3748 100%);
    --header-text: #f7fafc;
    --text-primary: #f7fafc;
    --text-secondary: #cbd5e0;
    --tab-bg: #4a5568;
    --tab-text: #cbd5e0;
    --tab-active-text: #90cdf4;
    --tab-active-bg: #2d3748;
    --tab-border: #90cdf4;
    --input-border: #4a5568;
    --input-bg: #1a202c;
    --input-text: #f7fafc;
    --input-focus-border: #90cdf4;
    --input-focus-shadow: rgba(144, 205, 244, 0.1);
    --button-gradient: linear-gradient(135deg, #4299e1 0%, #3182ce 100%);
    --button-text: #ffffff;
    --button-hover-shadow: rgba(66, 153, 225, 0.3);
    --button-disabled-bg: #4a5568;
    --user-info-bg: #4a5568;
    --user-details-bg: #2d3748;
    --section-bg: #4a5568;
    --section-border: #90cdf4;
    --message-success-bg: #22543d;
    --message-success-text: #9ae6b4;
    --message-success-border: #38a169;
    --message-error-bg: #742a2a;
    --message-error-text: #feb2b2;
    --message-error-border: #e53e3e;
    --logout-btn-bg: #e53e3e;
    --logout-btn-hover: #c53030;
    --border-color: #4a5568;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: var(--bg-gradient);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.3s ease;
}

.container {
    background: var(--container-bg);
    border-radius: 15px;
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    width: 100%;
    max-width: 400px;
    margin: 20px;
    transition: background 0.3s ease;
}

.header {
    background: var(--header-gradient);
    color: var(--header-text);
    text-align: center;
    padding: 30px 20px;
    position: relative;
    transition: background 0.3s ease, color 0.3s ease;
}

.header h1 {
    font-size: 1.8rem;
    margin-bottom: 10px;
}

.header p {
    opacity: 0.9;
    font-size: 0.9rem;
}

/* Theme toggle button styles */
.theme-toggle {
    position: absolute;
    top: 20px;
    right: 20px;
    background: rgba(255, 255, 255, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.3s ease;
    backdrop-filter: blur(10px);
}

/* When theme toggle is in header controls (admin page) */
.header-controls .theme-toggle {
    position: relative;
    top: auto;
    right: auto;
}

.theme-toggle:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: scale(1.1);
}

.theme-icon {
    width: 18px;
    height: 18px;
    color: var(--header-text);
    transition: opacity 0.3s ease;
}

/* Show sun icon in light theme (default) */
.sun-icon {
    opacity: 1;
}

.moon-icon {
    opacity: 0;
    position: absolute;
}

/* Show moon icon in dark theme */
[data-theme="dark"] .sun-icon {
    opacity: 0;
}

[data-theme="dark"] .moon-icon {
    opacity: 1;
}

.tab-container {
    display: flex;
    background: var(--tab-bg);
    transition: background 0.3s ease;
}

.tab {
    flex: 1;
    padding: 15px;
    text-align: center;
    cursor: pointer;
    font-weight: 500;
    color: var(--tab-text);
    border-bottom: 3px solid transparent;
    transition: all 0.3s ease;
}

.tab.active {
    color: var(--tab-active-text);
    border-bottom-color: var(--tab-border);
    background: var(--tab-active-bg);
}

.form-container {
    padding: 40px 30px;
}

.form {
    display: none;
}

.form.active {
    display: block;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: var(--text-primary);
    font-weight: 500;
    transition: color 0.3s ease;
}

.form-group input {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid var(--input-border);
    border-radius: 8px;
    font-size: 1rem;
    background: var(--input-bg);
    color: var(--input-text);
    transition: all 0.3s ease;
}

.form-group input:focus {
    outline: none;
    border-color: var(--input-focus-border);
    box-shadow: 0 0 0 3px var(--input-focus-shadow);
}

.submit-btn {
    width: 100%;
    padding: 12px;
    background: var(--button-gradient);
    color: var(--button-text);
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.submit-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px var(--button-hover-shadow);
}

.submit-btn:disabled {
    background: var(--button-disabled-bg);
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

.message {
    margin-top: 15px;
    padding: 10px;
    border-radius: 5px;
    text-align: center;
    font-weight: 500;
}

.message.success {
    background: var(--message-success-bg);
    color: var(--message-success-text);
    border: 1px solid var(--message-success-border);
    transition: all 0.3s ease;
}

.message.error {
    background: var(--message-error-bg);
    color: var(--message-error-text);
    border: 1px solid var(--message-error-border);
    transition: all 0.3s ease;
}

#userSection .user-info {
    display: none;
    padding: 20px;
    background: var(--user-info-bg);
    border-top: 1px solid var(--border-color);
    transition: all 0.3s ease;
}

#userSection .user-info.active {
    display: block;
}

.user-details {
    background: var(--user-details-bg);
    padding: 15px;
    border-radius: 8px;
    margin-bottom: 15px;
    transition: background 0.3s ease;
}

.user-details h3 {
    color: var(--text-primary);
    margin-bottom: 10px;
    transition: color 0.3s ease;
}

.user-details p {
    margin: 5px 0;
    color: var(--text-secondary);
    transition: color 0.3s ease;
}

.change-password-section {
    background: var(--user-details-bg);
    padding: 20px;
    border-radius: 8px;
    margin-bottom: 15px;
    transition: background 0.3s ease;
}

.change-password-section h3 {
    color: var(--text-primary);
    margin-bottom: 15px;
    font-size: 1.1rem;
    transition: color 0.3s ease;
}

.action-buttons {
    margin-bottom: 15px;
}

.action-btn {
    width: 100%;
    padding: 12px;
    background: var(--button-gradient);
    color: var(--button-text);
    border: none;
    border-radius: 8px;
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
}

.action-btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px var(--button-hover-shadow);
}

.form-buttons {
    display: flex;
    gap: 10px;
    margin-top: 15px;
}

.form-buttons .submit-btn {
    flex: 1;
    margin: 0;
}

.logout-btn {
    width: 100%;
    padding: 10px;
    background: var(--logout-btn-bg);
    color: var(--button-text);
    border: none;
    border-radius: 8px;
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.3s ease;
}

.logout-btn:hover {
    background: var(--logout-btn-hover);
}

.loading {
    display: inline-block;
    width: 16px;
    height: 16px;
    border: 2px solid #ffffff;
    border-radius: 50%;
    border-top-color: transparent;
    animation: spin 1s ease-in-out infinite;
    margin-right: 8px;
}

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

.profile-section, .security-section {
    margin-bottom: 25px;
    padding: 15px;
    background: var(--section-bg);
    border-radius: 8px;
    border-left: 3px solid var(--section-border);
    transition: all 0.3s ease;
}

.profile-section h4, .security-section h4 {
    margin: 0 0 15px 0;
    color: var(--text-primary);
    font-size: 1rem;
    font-weight: 600;
    transition: color 0.3s ease;
}

.forgot-password-link {
    margin-top: 10px;
    text-align: center;
}

.forgot-password-link a {
    color: var(--tab-active-text);
    text-decoration: none;
    font-size: 0.9rem;
    transition: all 0.3s ease;
}

.forgot-password-link a:hover {
    color: var(--input-focus-border);
    text-decoration: underline;
}

/* Action buttons section */
.action-buttons {
    display: flex;
    gap: 10px;
    justify-content: center;
    margin-bottom: 15px;
}

.action-btn-circular {
    background: var(--section-bg);
    border: 2px solid var(--border-color);
    border-radius: 50%;
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.3s ease;
    color: var(--tab-active-text);
}

.action-btn-circular:hover {
    background: var(--tab-border);
    border-color: var(--tab-border);
    color: white;
    transform: scale(1.1);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.3);
}

.action-icon {
    transition: all 0.3s ease;
}

/* Active state for edit profile button */
.action-btn-circular.active {
    background: var(--tab-border);
    border-color: var(--tab-border);
    color: white;
    transform: scale(1.05);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.3);
}

/* Mobile responsiveness for action buttons */
@media (max-width: 480px) {
    .action-btn-circular {
        width: 44px;
        height: 44px;
    }

    .action-icon {
        width: 16px;
        height: 16px;
    }
}