:root {
    --nhs-blue: #005EB8;
    --nhs-dark-blue: #003087;
    --nhs-light-blue: #41B6E6;
    --nhs-white: #FFFFFF;
    --nhs-pale-grey: #F0F4F5;
    --nhs-mid-grey: #D8DDE0;
    --nhs-dark-grey: #425563;
    --nhs-black: #231F20;
    --nhs-green: #007F3B;
    --nhs-red: #DA291C;
    --nhs-yellow: #FFB81C;
    --nhs-warm-yellow: #FFD600;
    --sidebar-width: 320px;
    --border-radius: 12px;
    --transition-speed: 0.3s;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
}

body {
    background-color: var(--nhs-pale-grey);
    height: 100vh;
    overflow: hidden;
}

/* ========================================
   CHAT APP CONTAINER
   ======================================== */
.chat-app {
    display: flex;
    height: 100vh;
    width: 100%;
    background-color: var(--nhs-white);
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
}

/* ========================================
   SIDEBAR STYLES
   ======================================== */
.sidebar {
    width: var(--sidebar-width);
    background: linear-gradient(180deg, var(--nhs-white) 0%, #F8FAFC 100%);
    border-right: 1px solid var(--nhs-mid-grey);
    display: flex;
    flex-direction: column;
    height: 100vh;
    position: relative;
    box-shadow: 2px 0 10px rgba(0, 0, 0, 0.05);
}

.sidebar-header {
    padding: 24px;
    border-bottom: 2px solid var(--nhs-mid-grey);
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 20px;
}

    .logo i {
        font-size: 32px;
        color: var(--nhs-blue);
        background: rgba(0, 94, 184, 0.1);
        padding: 10px;
        border-radius: 12px;
    }

    .logo span {
        font-size: 20px;
        font-weight: 600;
        color: var(--nhs-black);
        letter-spacing: -0.5px;
    }

.btn-new-chat {
    width: 100%;
    padding: 14px;
    background: linear-gradient(135deg, var(--nhs-blue), var(--nhs-dark-blue));
    color: var(--nhs-white);
    border: none;
    border-radius: var(--border-radius);
    font-size: 15px;
    font-weight: 500;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    transition: all var(--transition-speed);
    box-shadow: 0 4px 12px rgba(0, 94, 184, 0.3);
}

    .btn-new-chat:hover {
        transform: translateY(-2px);
        box-shadow: 0 6px 16px rgba(0, 94, 184, 0.4);
    }

    .btn-new-chat i {
        font-size: 16px;
    }

.sidebar-section {
    padding: 20px 16px;
    border-bottom: 1px solid var(--nhs-mid-grey);
}

.section-title {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 15px;
    color: var(--nhs-dark-grey);
    font-size: 13px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

    .section-title i {
        font-size: 14px;
        color: var(--nhs-blue);
    }

    .section-title .btn-upload {
        margin-left: auto;
        background: none;
        border: none;
        color: var(--nhs-blue);
        cursor: pointer;
        padding: 6px;
        border-radius: 6px;
        transition: all var(--transition-speed);
    }

        .section-title .btn-upload:hover {
            background-color: rgba(0, 94, 184, 0.1);
            transform: scale(1.1);
        }

/* Conversations List */
.conversations-list {
    max-height: 250px;
    overflow-y: auto;
    scrollbar-width: thin;
    scrollbar-color: var(--nhs-mid-grey) transparent;
}

    .conversations-list::-webkit-scrollbar {
        width: 5px;
    }

    .conversations-list::-webkit-scrollbar-thumb {
        background-color: var(--nhs-mid-grey);
        border-radius: 10px;
    }

.conversation-item {
    padding: 12px 12px;
    margin: 4px 0;
    border-radius: 10px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 12px;
    transition: all var(--transition-speed);
    position: relative;
    background-color: var(--nhs-white);
    border: 1px solid transparent;
}

    .conversation-item:hover {
        background-color: var(--nhs-pale-grey);
        border-color: var(--nhs-mid-grey);
        transform: translateX(2px);
    }

    .conversation-item.active {
        background: linear-gradient(135deg, rgba(0, 94, 184, 0.08), rgba(0, 48, 135, 0.12));
        border-left: 4px solid var(--nhs-blue);
    }

    .conversation-item i {
        color: var(--nhs-blue);
        font-size: 16px;
    }

.conversation-info {
    flex: 1;
    overflow: hidden;
}

.conversation-title {
    font-size: 14px;
    font-weight: 500;
    color: var(--nhs-black);
    margin-bottom: 4px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.conversation-date {
    font-size: 11px;
    color: var(--nhs-dark-grey);
    display: flex;
    align-items: center;
    gap: 8px;
}

.conversation-actions {
    display: none;
    gap: 6px;
    position: absolute;
    right: 10px;
    background: inherit;
    padding: 4px;
    border-radius: 6px;
}

.conversation-item:hover .conversation-actions {
    display: flex;
}

.conversation-actions button {
    background: none;
    border: none;
    color: var(--nhs-dark-grey);
    cursor: pointer;
    padding: 4px 6px;
    border-radius: 4px;
    font-size: 12px;
    transition: all var(--transition-speed);
}

    .conversation-actions button:hover {
        background-color: var(--nhs-white);
        color: var(--nhs-blue);
    }

    .conversation-actions button.delete:hover {
        color: var(--nhs-red);
    }

/* Documents List */
.documents-list {
    max-height: 150px;
    overflow-y: auto;
}

.document-item {
    padding: 10px 12px;
    margin: 4px 0;
    border-radius: 8px;
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 13px;
    background-color: var(--nhs-white);
    border: 1px solid var(--nhs-mid-grey);
    transition: all var(--transition-speed);
}

    .document-item:hover {
        background-color: var(--nhs-pale-grey);
        border-color: var(--nhs-blue);
    }

    .document-item i {
        color: var(--nhs-blue);
        font-size: 14px;
    }

    .document-item .file-info {
        flex: 1;
        overflow: hidden;
    }

    .document-item .file-name {
        font-weight: 500;
        color: var(--nhs-black);
        overflow: hidden;
        text-overflow: ellipsis;
        white-space: nowrap;
    }

    .document-item .file-meta {
        font-size: 10px;
        color: var(--nhs-dark-grey);
    }

    .document-item .document-actions {
        display: flex;
        gap: 6px;
    }

        .document-item .document-actions button {
            background: none;
            border: none;
            color: var(--nhs-dark-grey);
            cursor: pointer;
            padding: 4px;
            border-radius: 4px;
            font-size: 11px;
        }

            .document-item .document-actions button:hover {
                color: var(--nhs-red);
            }

    .document-item.placeholder {
        background-color: var(--nhs-pale-grey);
        border: 2px dashed var(--nhs-mid-grey);
        justify-content: center;
        color: var(--nhs-dark-grey);
    }

        .document-item.placeholder i {
            color: var(--nhs-mid-grey);
        }

/* Sidebar Footer */
.sidebar-footer {
    margin-top: auto;
    padding: 20px 16px;
    border-top: 2px solid var(--nhs-mid-grey);
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: linear-gradient(180deg, transparent, rgba(0, 94, 184, 0.02));
}

.user-info {
    display: flex;
    align-items: center;
    gap: 12px;
}

.user-avatar {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--nhs-blue), var(--nhs-dark-blue));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--nhs-white);
    box-shadow: 0 2px 8px rgba(0, 94, 184, 0.3);
}

.user-info span {
    font-weight: 500;
    color: var(--nhs-black);
}

.btn-icon {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: 1px solid var(--nhs-mid-grey);
    background: var(--nhs-white);
    color: var(--nhs-dark-grey);
    cursor: pointer;
    transition: all var(--transition-speed);
    display: flex;
    align-items: center;
    justify-content: center;
}

    .btn-icon:hover {
        background-color: var(--nhs-blue);
        color: var(--nhs-white);
        border-color: var(--nhs-blue);
        transform: rotate(5deg);
    }

/* ========================================
   MAIN CHAT AREA
   ======================================== */
.main-chat {
    flex: 1;
    display: flex;
    flex-direction: column;
    background: linear-gradient(135deg, var(--nhs-white) 0%, #FAFCFE 100%);
    height: 100vh;
    position: relative;
}

.chat-header {
    padding: 20px 30px;
    border-bottom: 1px solid var(--nhs-mid-grey);
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: var(--nhs-white);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.02);
}

.chat-title {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 18px;
    font-weight: 600;
    color: var(--nhs-black);
}

    .chat-title i {
        color: var(--nhs-blue);
        font-size: 22px;
    }

.chat-actions {
    display: flex;
    gap: 10px;
}

/* Chat Messages Area */
.chat-messages {
    flex: 1;
    overflow-y: auto;
    padding: 30px;
    scroll-behavior: smooth;
}

    .chat-messages::-webkit-scrollbar {
        width: 6px;
    }

    .chat-messages::-webkit-scrollbar-track {
        background: transparent;
    }

    .chat-messages::-webkit-scrollbar-thumb {
        background: var(--nhs-mid-grey);
        border-radius: 10px;
    }

/* Welcome Message */
.welcome-message {
    text-align: center;
    max-width: 600px;
    margin: 60px auto;
    animation: fadeIn 0.5s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.welcome-icon {
    width: 100px;
    height: 100px;
    background: linear-gradient(135deg, rgba(0, 94, 184, 0.1), rgba(0, 48, 135, 0.05));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 25px;
    border: 2px solid var(--nhs-light-blue);
}

    .welcome-icon i {
        font-size: 48px;
        color: var(--nhs-blue);
    }

.welcome-message h2 {
    font-size: 28px;
    color: var(--nhs-black);
    margin-bottom: 12px;
    font-weight: 600;
}

.welcome-message p {
    color: var(--nhs-dark-grey);
    margin-bottom: 30px;
    font-size: 16px;
    line-height: 1.6;
}

.welcome-suggestions {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
    margin-top: 30px;
}

.suggestion-btn {
    padding: 15px 20px;
    background: var(--nhs-white);
    border: 2px solid var(--nhs-mid-grey);
    border-radius: var(--border-radius);
    color: var(--nhs-dark-grey);
    cursor: pointer;
    transition: all var(--transition-speed);
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 14px;
    text-align: left;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.02);
}

    .suggestion-btn:hover {
        border-color: var(--nhs-blue);
        background: linear-gradient(135deg, var(--nhs-white), rgba(0, 94, 184, 0.02));
        transform: translateY(-2px);
        box-shadow: 0 10px 20px rgba(0, 94, 184, 0.1);
    }

    .suggestion-btn i {
        color: var(--nhs-blue);
        font-size: 18px;
    }

/* Message Bubbles */
.message {
    margin-bottom: 25px;
    max-width: 80%;
    animation: slideIn 0.3s ease;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.message.user {
    margin-left: auto;
}

.message.assistant {
    margin-right: auto;
}

.message-wrapper {
    position: relative;
    display: flex;
    align-items: flex-start;
    gap: 12px;
}

.message.user .message-wrapper {
    flex-direction: row-reverse;
}

.message-avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.message.user .message-avatar {
    background: linear-gradient(135deg, var(--nhs-blue), var(--nhs-dark-blue));
    color: var(--nhs-white);
}

.message.assistant .message-avatar {
    background: linear-gradient(135deg, var(--nhs-light-blue), var(--nhs-blue));
    color: var(--nhs-white);
}

.message-content {
    padding: 15px 20px;
    border-radius: 18px;
    line-height: 1.6;
    font-size: 15px;
    position: relative;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.message.user .message-content {
    background: linear-gradient(135deg, var(--nhs-blue), var(--nhs-dark-blue));
    color: var(--nhs-white);
    border-bottom-right-radius: 4px;
}

.message.assistant .message-content {
    background: var(--nhs-white);
    color: var(--nhs-black);
    border: 1px solid var(--nhs-mid-grey);
    border-bottom-left-radius: 4px;
}

.message-metadata {
    font-size: 12px;
    margin-top: 8px;
    margin-left: 48px;
    display: flex;
    align-items: center;
    gap: 12px;
    color: var(--nhs-dark-grey);
}

.message.user .message-metadata {
    justify-content: flex-end;
}

.message-time {
    font-size: 11px;
    color: var(--nhs-dark-grey);
}

.message-source {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    padding: 3px 10px;
    background: var(--nhs-pale-grey);
    border-radius: 20px;
    font-size: 10px;
    font-weight: 600;
    color: var(--nhs-blue);
}

.message-actions {
    display: flex;
    gap: 8px;
    margin-left: auto;
}

    .message-actions button {
        background: none;
        border: none;
        color: var(--nhs-dark-grey);
        cursor: pointer;
        padding: 5px;
        border-radius: 4px;
        font-size: 12px;
        transition: all var(--transition-speed);
    }

        .message-actions button:hover {
            background-color: rgba(0, 94, 184, 0.1);
            color: var(--nhs-blue);
        }

        .message-actions button.delete-msg:hover {
            color: var(--nhs-red);
        }

/* Chat Input Area */
.chat-input-area {
    padding: 20px 30px;
    background: var(--nhs-white);
    border-top: 1px solid var(--nhs-mid-grey);
    box-shadow: 0 -4px 20px rgba(0, 0, 0, 0.02);
}

.input-container {
    display: flex;
    gap: 15px;
    align-items: flex-end;
    background: var(--nhs-pale-grey);
    border-radius: 24px;
    padding: 8px 8px 8px 20px;
    border: 2px solid transparent;
    transition: all var(--transition-speed);
}

    .input-container:focus-within {
        border-color: var(--nhs-blue);
        background: var(--nhs-white);
        box-shadow: 0 0 0 4px rgba(0, 94, 184, 0.1);
    }

textarea {
    flex: 1;
    border: none;
    background: none;
    padding: 12px 0;
    font-size: 15px;
    outline: none;
    resize: none;
    max-height: 150px;
    font-family: inherit;
}

.btn-send {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--nhs-blue), var(--nhs-dark-blue));
    color: var(--nhs-white);
    border: none;
    cursor: pointer;
    transition: all var(--transition-speed);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 12px rgba(0, 94, 184, 0.3);
}

    .btn-send:hover:not(:disabled) {
        transform: scale(1.05) rotate(5deg);
        box-shadow: 0 6px 16px rgba(0, 94, 184, 0.4);
    }

    .btn-send:disabled {
        background: var(--nhs-mid-grey);
        cursor: not-allowed;
        box-shadow: none;
    }

.input-hints {
    display: flex;
    align-items: center;
    gap: 20px;
    margin-top: 12px;
    font-size: 12px;
    color: var(--nhs-dark-grey);
}

    .input-hints span {
        display: flex;
        align-items: center;
        gap: 6px;
        cursor: pointer;
        padding: 4px 8px;
        border-radius: 16px;
        transition: all var(--transition-speed);
    }

        .input-hints span:hover {
            background-color: var(--nhs-pale-grey);
            color: var(--nhs-blue);
        }

    .input-hints i {
        font-size: 14px;
        color: var(--nhs-blue);
    }

.shortcut {
    margin-left: auto;
    background: var(--nhs-pale-grey);
    padding: 4px 12px;
    border-radius: 20px;
    font-weight: 500;
}

/* Typing Indicator */
.typing-indicator {
    position: fixed;
    bottom: 100px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--nhs-white);
    padding: 15px 25px;
    border-radius: 30px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    border: 1px solid var(--nhs-mid-grey);
    z-index: 1000;
    animation: slideUp 0.3s ease;
}

@keyframes slideUp {
    from {
        bottom: 0;
        opacity: 0;
    }

    to {
        bottom: 100px;
        opacity: 1;
    }
}

.typing-bubble {
    display: flex;
    gap: 5px;
}

    .typing-bubble span {
        width: 8px;
        height: 8px;
        background: var(--nhs-blue);
        border-radius: 50%;
        animation: bounce 1.5s infinite;
    }

        .typing-bubble span:nth-child(2) {
            animation-delay: 0.2s;
        }

        .typing-bubble span:nth-child(3) {
            animation-delay: 0.4s;
        }

@keyframes bounce {
    0%, 60%, 100% {
        transform: translateY(0);
    }

    30% {
        transform: translateY(-10px);
    }
}

/* Loading Overlay */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(5px);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    color: var(--nhs-white);
}

.spinner {
    width: 50px;
    height: 50px;
    border: 4px solid var(--nhs-white);
    border-top-color: var(--nhs-blue);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 20px;
}

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

/* Modals */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10000;
    animation: fadeIn 0.3s ease;
}

.modal {
    background: var(--nhs-white);
    border-radius: 20px;
    width: 400px;
    max-width: 90%;
    padding: 30px;
    animation: slideDown 0.3s ease;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}

@keyframes slideDown {
    from {
        transform: translateY(-50px);
        opacity: 0;
    }

    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.modal h3 {
    color: var(--nhs-black);
    margin-bottom: 15px;
    font-size: 20px;
    display: flex;
    align-items: center;
    gap: 10px;
}

    .modal h3 i {
        color: var(--nhs-blue);
    }

.modal p {
    color: var(--nhs-dark-grey);
    margin-bottom: 20px;
    line-height: 1.6;
}

.modal input {
    width: 100%;
    padding: 14px;
    border: 2px solid var(--nhs-mid-grey);
    border-radius: 12px;
    font-size: 15px;
    margin-bottom: 20px;
    transition: all var(--transition-speed);
}

    .modal input:focus {
        border-color: var(--nhs-blue);
        outline: none;
        box-shadow: 0 0 0 4px rgba(0, 94, 184, 0.1);
    }

.modal-actions {
    display: flex;
    gap: 12px;
    justify-content: flex-end;
}

    .modal-actions button {
        padding: 12px 24px;
        border-radius: 30px;
        border: none;
        cursor: pointer;
        font-size: 14px;
        font-weight: 500;
        transition: all var(--transition-speed);
    }

    .modal-actions .cancel-btn {
        background: var(--nhs-pale-grey);
        color: var(--nhs-dark-grey);
    }

        .modal-actions .cancel-btn:hover {
            background: var(--nhs-mid-grey);
        }

    .modal-actions .save-btn {
        background: linear-gradient(135deg, var(--nhs-blue), var(--nhs-dark-blue));
        color: var(--nhs-white);
    }

        .modal-actions .save-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 6px 16px rgba(0, 94, 184, 0.3);
        }

    .modal-actions .delete-btn {
        background: linear-gradient(135deg, var(--nhs-red), #B22222);
        color: var(--nhs-white);
    }

        .modal-actions .delete-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 6px 16px rgba(218, 41, 28, 0.3);
        }

/* Toast Notifications */
.toast {
    position: fixed;
    bottom: 30px;
    right: 30px;
    background: var(--nhs-white);
    border-radius: 12px;
    padding: 15px 25px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
    display: flex;
    align-items: center;
    gap: 15px;
    z-index: 10001;
    animation: slideInRight 0.3s ease;
    border-left: 4px solid var(--nhs-blue);
}

    .toast.success {
        border-left-color: var(--nhs-green);
    }

    .toast.error {
        border-left-color: var(--nhs-red);
    }

    .toast.warning {
        border-left-color: var(--nhs-yellow);
    }

    .toast i {
        font-size: 20px;
    }

    .toast.success i {
        color: var(--nhs-green);
    }

    .toast.error i {
        color: var(--nhs-red);
    }

    .toast.warning i {
        color: var(--nhs-yellow);
    }

.toast-message {
    flex: 1;
    color: var(--nhs-black);
}

.toast-close {
    background: none;
    border: none;
    color: var(--nhs-dark-grey);
    cursor: pointer;
    padding: 5px;
    font-size: 16px;
}

@keyframes slideInRight {
    from {
        transform: translateX(100%);
        opacity: 0;
    }

    to {
        transform: translateX(0);
        opacity: 1;
    }
}

/* Responsive Design */
@media (max-width: 768px) {
    .sidebar {
        position: fixed;
        left: -100%;
        z-index: 1000;
        transition: left var(--transition-speed);
    }

        .sidebar.active {
            left: 0;
        }

    .message {
        max-width: 90%;
    }

    .welcome-suggestions {
        grid-template-columns: 1fr;
    }

    .chat-header {
        padding: 15px 20px;
    }

    .chat-messages {
        padding: 20px;
    }

    .input-hints {
        flex-wrap: wrap;
    }
}