/* ExpertSYS - Modern Light Theme */

/* ========== Reset & Base ========== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Primary Colors */
    --primary-blue: #2563eb;
    --primary-blue-light: #3b82f6;
    --primary-blue-dark: #1d4ed8;

    /* Background Colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-tertiary: #f1f5f9;
    --bg-hover: #f1f5f9;

    /* Text Colors */
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-tertiary: #94a3b8;

    /* Border Colors */
    --border-light: #e2e8f0;
    --border-medium: #cbd5e1;
    --border-dark: #94a3b8;

    /* Accent Colors */
    --success: #10b981;
    --success-light: #d1fae5;
    --warning: #f59e0b;
    --warning-light: #fef3c7;
    --danger: #ef4444;
    --danger-light: #fee2e2;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;

    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-full: 9999px;

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 200ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 300ms cubic-bezier(0.4, 0, 0.2, 1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    line-height: 1.6;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ========== Layout ========== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--spacing-lg);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* ========== Header ========== */
.header {
    background: var(--bg-primary);
    padding: var(--spacing-lg) var(--spacing-xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-sm);
    margin-bottom: var(--spacing-xl);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--spacing-lg);
}

.header h1 {
    font-size: 28px;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.025em;
}

.header-buttons {
    display: flex;
    gap: var(--spacing-sm);
    align-items: center;
}

.icon-btn {
    background: transparent;
    border: 1px solid var(--border-light);
    font-size: 18px;
    cursor: pointer;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    color: var(--text-secondary);
}

.icon-btn:hover {
    background-color: var(--bg-hover);
    border-color: var(--border-medium);
    color: var(--text-primary);
    transform: translateY(-1px);
}

.subtitle {
    font-size: 14px;
    color: var(--text-secondary);
    margin-top: var(--spacing-sm);
    font-weight: 500;
}

/* ========== Chat Container ========== */
.chat-container {
    flex: 1;
    overflow-y: auto;
    padding: var(--spacing-md) 0;
}

.welcome-message {
    padding: var(--spacing-xl) 0;
}

.welcome-message h2 {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: var(--spacing-lg);
    color: var(--text-primary);
}

.suggested-questions {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.suggested-question-btn {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-light);
    color: var(--text-primary);
    font-size: 15px;
    font-weight: 500;
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all var(--transition-fast);
    text-align: left;
    width: 100%;
    box-shadow: var(--shadow-sm);
}

.suggested-question-btn:hover {
    background-color: var(--bg-primary);
    border-color: var(--primary-blue);
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

/* ========== Messages ========== */
.message {
    margin-bottom: var(--spacing-lg);
    padding: var(--spacing-lg);
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.message-role {
    font-weight: 700;
    font-size: 14px;
    margin-bottom: var(--spacing-sm);
    color: var(--primary-blue);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.message-content {
    font-size: 15px;
    line-height: 1.7;
    color: var(--text-primary);
    white-space: pre-wrap;
}

.message.user .message-role {
    color: var(--success);
}

.message img {
    max-width: 600px;
    width: 100%;
    height: auto;
    border-radius: var(--radius-lg);
    margin: var(--spacing-lg) 0;
    box-shadow: var(--shadow-md);
}

.youtube-embed {
    margin: var(--spacing-lg) 0;
    border-radius: var(--radius-lg);
    overflow: hidden;
    max-width: 100%;
    box-shadow: var(--shadow-md);
}

.youtube-embed iframe {
    max-width: 100%;
    width: 100%;
    height: 400px;
    border: none;
}

/* ========== Related FAQ Section ========== */
.related-faq-section {
    margin: var(--spacing-lg) 0;
    padding: var(--spacing-lg);
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.related-faq-section h3 {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.related-questions-scroll {
    max-height: 400px;
    overflow-y: auto;
    padding: var(--spacing-sm);
}

.related-question-btn {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-light);
    color: var(--text-primary);
    font-size: 14px;
    font-weight: 500;
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    text-align: left;
    width: 100%;
    margin-bottom: var(--spacing-sm);
}

.related-question-btn:hover {
    background-color: var(--bg-hover);
    border-color: var(--primary-blue);
    transform: translateX(4px);
}

/* ========== Feedback Section ========== */
.feedback-section {
    margin: var(--spacing-lg) 0;
    padding: var(--spacing-lg);
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.feedback-section h3 {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.feedback-buttons {
    display: flex;
    gap: var(--spacing-md);
}

.feedback-btn {
    font-size: 28px;
    width: 56px;
    height: 56px;
    border-radius: var(--radius-full);
    background-color: var(--bg-secondary);
    border: 2px solid var(--border-light);
    cursor: pointer;
    transition: all var(--transition-base);
    display: flex;
    align-items: center;
    justify-content: center;
}

.feedback-btn:hover {
    transform: scale(1.1);
    box-shadow: var(--shadow-md);
}

.feedback-btn.good:hover {
    background-color: var(--success-light);
    border-color: var(--success);
}

.feedback-btn.bad:hover {
    background-color: var(--danger-light);
    border-color: var(--danger);
}

.feedback-message {
    margin-top: var(--spacing-md);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    font-size: 14px;
    font-weight: 500;
}

.feedback-message.success {
    background-color: var(--success-light);
    color: var(--success);
    border: 1px solid var(--success);
}

.feedback-message.info {
    background-color: #dbeafe;
    color: var(--primary-blue);
    border: 1px solid var(--primary-blue-light);
}

/* ========== Input Area ========== */
.input-area {
    padding: var(--spacing-lg) 0;
    border-top: 1px solid var(--border-light);
    background: var(--bg-secondary);
    margin: 0 calc(-1 * var(--spacing-lg));
    padding: var(--spacing-lg);
}

.composer {
    display: flex;
    align-items: flex-end;
    gap: var(--spacing-md);
    width: 100%;
    max-width: 900px;
    margin: 0 auto;
}

.composer textarea {
    flex: 1 1 auto;
    min-width: 0;
    min-height: 100px;
    max-height: 300px;
    resize: vertical;
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-lg);
    border: 2px solid var(--border-light);
    background: var(--bg-primary);
    color: var(--text-primary);
    font-size: 15px;
    font-family: inherit;
    outline: none;
    transition: all var(--transition-fast);
    box-shadow: var(--shadow-sm);
}

.composer textarea:focus {
    border-color: var(--primary-blue);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.composer textarea::placeholder {
    color: var(--text-tertiary);
}

.composer .actions {
    display: flex;
    gap: var(--spacing-sm);
    flex: 0 0 auto;
}

.composer .btn {
    width: 56px;
    height: 56px;
    border-radius: var(--radius-lg);
    border: 2px solid var(--border-light);
    background: var(--bg-primary);
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    cursor: pointer;
    transition: all var(--transition-fast);
    box-shadow: var(--shadow-sm);
}

.composer .btn:hover {
    background: var(--bg-hover);
    border-color: var(--border-medium);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.composer .btn.send {
    background: var(--primary-blue);
    color: white;
    border: none;
}

.composer .btn.send:hover {
    background: var(--primary-blue-dark);
    box-shadow: var(--shadow-lg);
}

/* ========== Modal ========== */
.modal {
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(15, 23, 42, 0.7);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    animation: fadeIn 0.2s ease-in-out;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.modal-content {
    background-color: var(--bg-primary);
    padding: var(--spacing-2xl);
    border-radius: var(--radius-xl);
    max-width: 500px;
    width: 90%;
    position: relative;
    box-shadow: var(--shadow-xl);
    animation: slideUp 0.3s ease-out;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.close {
    color: var(--text-tertiary);
    float: right;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    line-height: 1;
    transition: color var(--transition-fast);
}

.close:hover {
    color: var(--text-primary);
}

.modal-content h2 {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: var(--spacing-lg);
    color: var(--text-primary);
}

.settings-section {
    margin-bottom: var(--spacing-lg);
}

.settings-section h3 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
    color: var(--text-primary);
}

.settings-section select {
    width: 100%;
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    border: 2px solid var(--border-light);
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-size: 15px;
    outline: none;
    transition: all var(--transition-fast);
}

.settings-section select:focus {
    border-color: var(--primary-blue);
}

.settings-section p {
    color: var(--text-secondary);
    font-size: 14px;
    line-height: 1.6;
}

/* ========== Scrollbar ========== */
::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}

::-webkit-scrollbar-track {
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
}

::-webkit-scrollbar-thumb {
    background: var(--border-medium);
    border-radius: var(--radius-sm);
    transition: background var(--transition-fast);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--border-dark);
}

/* ========== Utilities ========== */
hr {
    border: none;
    border-top: 1px solid var(--border-light);
    margin: var(--spacing-lg) 0;
}

/* ========== Related FAQ Selector ========== */
.related-faq-item {
    display: flex;
    flex-direction: row;
    align-items: flex-start;
    padding: 0.75rem;
    margin-bottom: 0.5rem;
    cursor: pointer;
    border-radius: 6px;
    transition: background-color 0.15s;
    writing-mode: horizontal-tb;
    direction: ltr;
}

.related-faq-item:hover {
    background-color: #3c4043;
}

.related-faq-item.selected {
    background-color: #3c4043;
}

.related-faq-checkbox {
    margin: 0.25rem 0.75rem 0 0;
    cursor: pointer;
    min-width: 16px;
    flex-shrink: 0;
}

.related-faq-text {
    flex: 1;
    min-width: 0;
    writing-mode: horizontal-tb;
    direction: ltr;
}

.related-faq-question {
    font-size: 14px;
    color: #e3e3e3;
    font-weight: 500;
    line-height: 1.4;
    word-wrap: break-word;
    white-space: normal;
    overflow-wrap: break-word;
    writing-mode: horizontal-tb;
    direction: ltr;
}

.related-faq-category {
    font-size: 12px;
    color: #9aa0a6;
    margin-top: 0.25rem;
    writing-mode: horizontal-tb;
    direction: ltr;
}

/* ========== Responsive ========== */
@media (max-width: 768px) {
    .container {
        padding: var(--spacing-md);
    }

    .header {
        padding: var(--spacing-sm) var(--spacing-md);
    }

    .header h1 {
        font-size: 18px;
    }

    .subtitle {
        font-size: 12px !important;
        margin-top: 2px !important;
    }

    .composer textarea {
        min-height: 40px;
    }

    .modal-content {
        width: 95%;
        padding: var(--spacing-lg);
    }

    .message img {
        max-width: 100%;
    }

    .welcome-message {
        padding: var(--spacing-md) 0;
    }

    .welcome-message h2 {
        font-size: 18px;
    }

    .suggested-question-btn {
        padding: var(--spacing-md);
        font-size: 13px;
    }
}

/* Answer branch buttons */
.answer-branch-btn {
    display: block;
    padding: 1rem;
    background-color: #2d2d2d;
    border: 1px solid #3c4043;
    border-radius: 8px;
    color: #e3e3e3;
    text-decoration: none;
    transition: all 0.2s;
}

.answer-branch-btn:hover {
    background-color: #3c4043;
    border-color: #8ab4f8;
    transform: translateX(4px);
}

/* ========== Login Styles ========== */
.login-form {
    margin-top: var(--spacing-lg);
}

.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-group label {
    display: block;
    margin-bottom: var(--spacing-sm);
    font-weight: 600;
    color: var(--text-primary);
    font-size: 14px;
}

.form-group input {
    width: 100%;
    padding: var(--spacing-md);
    border: 2px solid var(--border-light);
    border-radius: var(--radius-md);
    font-size: 15px;
    box-sizing: border-box;
    background: var(--bg-primary);
    color: var(--text-primary);
    transition: all var(--transition-fast);
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary-blue);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.login-message {
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-md);
    text-align: center;
    font-size: 14px;
    font-weight: 500;
}

.login-message.error {
    background: var(--danger-light);
    color: var(--danger);
    border: 1px solid var(--danger);
}

.login-message.success {
    background: var(--success-light);
    color: var(--success);
    border: 1px solid var(--success);
}

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

.btn-primary {
    flex: 1;
    padding: var(--spacing-md);
    background: var(--primary-blue);
    color: white;
    border: none;
    border-radius: var(--radius-md);
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-fast);
    box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
    background: var(--primary-blue-dark);
    box-shadow: var(--shadow-md);
    transform: translateY(-1px);
}

.guest-info {
    padding: var(--spacing-lg);
    background: var(--bg-secondary);
    border-radius: var(--radius-md);
    border-left: 3px solid var(--primary-blue);
}

.info-text {
    font-size: 14px;
    color: var(--text-secondary);
    margin: 0 0 var(--spacing-xs) 0;
}

.remaining-text {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
    margin: 0;
}

.trial-notice {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-lg);
    text-align: center;
}

.trial-notice p {
    margin: 0;
    font-size: 14px;
    font-weight: 600;
}

.register-link, .login-link {
    text-align: center;
    margin-top: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.register-link p, .login-link p {
    font-size: 14px;
    color: var(--text-secondary);
    margin: 0;
}

.register-link a, .login-link a {
    color: var(--primary-blue);
    text-decoration: none;
    font-weight: 600;
}

.register-link a:hover, .login-link a:hover {
    text-decoration: underline;
}

.required {
    color: var(--danger);
    font-weight: 700;
}

.register-form {
    margin-top: var(--spacing-lg);
}

.register-message {
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-md);
    text-align: center;
    font-size: 14px;
    font-weight: 500;
}

.register-message.error {
    background: var(--danger-light);
    color: var(--danger);
    border: 1px solid var(--danger);
}

.register-message.success {
    background: var(--success-light);
    color: var(--success);
    border: 1px solid var(--success);
}

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

/* ========== Forgot Password Styles ========== */
.forgot-password-link {
    text-align: center;
    margin-bottom: var(--spacing-sm);
}

.forgot-password-link p {
    font-size: 13px;
    margin: 0;
}

.forgot-password-link a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
}

.forgot-password-link a:hover {
    color: var(--primary-blue);
    text-decoration: underline;
}

.forgot-password-form {
    margin-top: var(--spacing-lg);
}

.forgot-password-message {
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-md);
    text-align: center;
    font-size: 14px;
    font-weight: 500;
}

.forgot-password-message.error {
    background: var(--danger-light);
    color: var(--danger);
    border: 1px solid var(--danger);
}

.forgot-password-message.success {
    background: var(--success-light);
    color: var(--success);
    border: 1px solid var(--success);
}