:root {
    --bg-color: #ffffff;
    --text-color: #0f1419;
    --accent-color: #0f1419;
    --secondary-bg: #eff3f4;
    --border-color: #eff3f4;
    --system-msg-color: #536471;
    --my-msg-bg: #0f1419;
    --my-msg-text: #ffffff;
    --partner-msg-bg: #eff3f4;
    --partner-msg-text: #0f1419;
    --error-color: #f4212e;
    --warning-color: #ffd400;
    --header-bg: rgba(255, 255, 255, 0.9);
    --btn-text-on-accent: #ffffff;
    --hover-bg: #dbe0e2;
    --accent-hover: #272c30;
}

body.dark-mode {
    --bg-color: #000000;
    --text-color: #e7e9ea;
    --accent-color: #e7e9ea;
    --secondary-bg: #202327;
    --border-color: #2f3336;
    --system-msg-color: #71767b;
    --my-msg-bg: #e7e9ea;
    --my-msg-text: #000000;
    --partner-msg-bg: #202327;
    --partner-msg-text: #e7e9ea;
    --header-bg: rgba(0, 0, 0, 0.8);
    --btn-text-on-accent: #000000;
    --hover-bg: rgba(239, 243, 244, 0.1);
    --accent-hover: #d7dbdc;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-font-smoothing: antialiased;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    height: 100dvh; /* Dynamic viewport height */
    width: 100vw;
    overflow: hidden;
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* Screen Management */
.screen {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: none;
    flex-direction: column;
    opacity: 0;
    transition: opacity 0.4s ease;
    background: var(--bg-color);
    z-index: 1;
}

.screen.active {
    display: flex;
    opacity: 1;
    z-index: 10;
}

/* Loading Screen */
#loading-screen {
    justify-content: center;
    align-items: center;
}

.logo-container {
    text-align: center;
}

.pulsing-logo {
    width: 80px;
    height: auto;
    margin: 0 auto 20px;
    animation: pulse 1.5s infinite ease-in-out;
    display: block;
}

@keyframes pulse {
    0% { transform: scale(0.8); opacity: 0.5; }
    50% { transform: scale(1.1); opacity: 1; }
    100% { transform: scale(0.8); opacity: 0.5; }
}

h1 {
    font-weight: 600;
    letter-spacing: -0.5px;
}

/* Landing Screen */
#landing-screen {
    justify-content: center;
    align-items: center;
    padding: 20px;
}

.content-wrapper {
    text-align: center;
    max-width: 400px;
    width: 100%;
}

/* Home Logo */
.home-logo {
    width: 64px;
    height: auto;
    margin-bottom: 24px;
    animation: fadeIn 0.8s ease-out;
}

.hero-text h1 {
    font-size: 2.8rem;
    margin-bottom: 12px;
    letter-spacing: -1px;
    font-weight: 800;
}

.hero-text p {
    color: var(--system-msg-color);
    margin-bottom: 48px;
    font-size: 1.1rem;
    font-weight: 500;
}

/* Button Loading State */
.btn-loader {
    width: 20px;
    height: 20px;
    border: 2px solid rgba(255,255,255,0.3);
    border-radius: 50%;
    border-top-color: #fff;
    animation: spin 0.8s linear infinite;
    display: inline-block;
}

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

.btn-primary.loading {
    pointer-events: none;
    opacity: 0.8;
}

.btn-primary.loading .btn-text {
    display: none;
}

.btn-primary.loading .btn-loader {
    display: inline-block !important; /* Override hidden class */
}

.btn {
    border: none;
    cursor: pointer;
    font-family: inherit;
    font-weight: 500;
    transition: transform 0.1s ease, opacity 0.2s ease;
    display: inline-flex;
    justify-content: center;
    align-items: center;
}

.btn:active {
    transform: scale(0.98);
}

.btn-primary {
    background-color: var(--accent-color);
    color: var(--btn-text-on-accent);
    padding: 16px 40px;
    font-size: 1.1rem;
    font-weight: 700;
    width: 100%;
    transition: background-color 0.2s;
}

.btn-primary:hover {
    background-color: var(--accent-hover);
}

.btn-pill {
    border-radius: 9999px;
}

.btn-outline {
    background: transparent;
    border: 1px solid #cfd9de;
    color: var(--text-color);
    padding: 8px 16px;
    border-radius: 9999px;
    font-weight: 700;
}

.btn-outline:hover {
    background: rgba(15, 20, 25, 0.1);
}

.terms {
    margin-top: 40px;
    font-size: 0.8rem;
    color: var(--border-color);
}

/* Chat Screen */
#chat-screen {
    background: var(--bg-color);
}

.chat-header {
    height: 60px;
    padding: 0 16px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border-color);
    background-color: var(--header-bg);
    backdrop-filter: blur(10px);
}

.header-right {
    display: flex;
    gap: 8px;
}

.header-left {
    display: flex;
    align-items: center;
    gap: 12px;
}

.chat-logo {
    width: 40px;
    height: auto;
    cursor: pointer;
}

.partner-status {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 700;
    font-size: 0.95rem;
}

.btn-icon-soft {
    width: 40px;
    height: 40px;
    padding: 0;
    border-radius: 50%;
    border: none;
    background: var(--secondary-bg);
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    transition: background-color 0.2s ease, transform 0.2s ease;
}

.btn-icon-soft:hover {
    background-color: var(--hover-bg);
}

.btn-icon-soft:active {
    transform: scale(0.96);
}

.status-dot {
    width: 8px;
    height: 8px;
    background-color: #ccc;
    border-radius: 50%;
}

.status-dot.online { background-color: #34c759; }
.status-dot.searching { background-color: #ffcc00; animation: pulse 1s infinite; }
.status-dot.offline { background-color: #ff3b30; }

.messages-area {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.system-message {
    text-align: center;
    color: var(--system-msg-color);
    font-size: 0.85rem;
    margin: 10px auto;
    background-color: var(--secondary-bg);
    padding: 8px 16px;
    border-radius: 9999px;
    display: inline-block;
    max-width: 90%;
    align-self: center;
    font-weight: 500;
}

.system-action {
    align-self: center;
    margin: 10px 0;
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.message {
    max-width: 80%;
    padding: 12px 16px;
    border-radius: 24px;
    font-size: 1rem;
    line-height: 1.4;
    word-wrap: break-word;
    position: relative;
    animation: fadeIn 0.3s cubic-bezier(0.2, 0.8, 0.2, 1);
}

.message.mine {
    align-self: flex-end;
    background-color: var(--my-msg-bg);
    color: var(--my-msg-text);
    border-bottom-right-radius: 4px;
}

.message.partner {
    align-self: flex-start;
    background-color: var(--partner-msg-bg);
    color: var(--partner-msg-text);
    border-bottom-left-radius: 4px;
}

.message.error {
    align-self: center;
    background: #ffe5e5;
    color: var(--error-color);
    font-size: 0.9rem;
}

.message code {
    background: rgba(0,0,0,0.1);
    padding: 2px 4px;
    border-radius: 4px;
    font-family: monospace;
}

.message blockquote {
    border-left: 3px solid rgba(0,0,0,0.2);
    margin: 4px 0;
    padding-left: 8px;
    opacity: 0.8;
}

/* Reply Styles */
.reply-banner {
    background: var(--secondary-bg);
    padding: 8px 16px;
    font-size: 0.85rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border-color);
    animation: slideUp 0.2s ease;
}

.reply-banner .reply-content {
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: 80%;
    opacity: 0.8;
}

.reply-banner .close-reply {
    cursor: pointer;
    padding: 4px;
}

.message .reply-context {
    font-size: 0.75rem;
    opacity: 0.7;
    margin-bottom: 4px;
    padding-bottom: 4px;
    border-bottom: 1px solid rgba(0,0,0,0.1);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    display: block;
    cursor: pointer;
}

.message .reply-btn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    opacity: 0;
    cursor: pointer;
    padding: 8px;
    transition: opacity 0.2s;
}

.message:hover .reply-btn {
    opacity: 1;
}

.message.mine .reply-btn {
    left: -32px;
}

.message.partner .reply-btn {
    right: -32px;
}

.chat-input-area {
    padding: 0; /* Reset padding because wrapper handles it */
    border-top: 1px solid var(--border-color);
    background: var(--bg-color);
    display: flex;
    flex-direction: column;
}

.input-container-inner {
    padding: 15px 20px;
}

.input-wrapper {
    display: flex;
    gap: 10px;
    background: var(--secondary-bg);
    padding: 8px;
    border-radius: 9999px;
    align-items: center;
}

#message-input {
    flex: 1;
    border: none;
    background: transparent;
    padding: 8px 16px;
    font-size: 1rem;
    outline: none;
    color: var(--text-color);
}

.btn-icon {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: none;
    background: var(--accent-color);
    color: var(--btn-text-on-accent);
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    transition: opacity 0.2s;
}

.btn-icon:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.typing-indicator {
    padding: 0 20px 10px;
    display: flex;
    gap: 4px;
}

.typing-indicator span {
    width: 6px;
    height: 6px;
    background: #ccc;
    border-radius: 50%;
    animation: typing 1.4s infinite both;
}

.typing-indicator span:nth-child(1) { animation-delay: 0s; }
.typing-indicator span:nth-child(2) { animation-delay: 0.2s; }
.typing-indicator span:nth-child(3) { animation-delay: 0.4s; }

@keyframes typing {
    0%, 80%, 100% { transform: scale(0); }
    40% { transform: scale(1); }
}

/* Modal */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    opacity: 1;
    transition: opacity 0.2s ease;
}

.modal-overlay.hidden {
    opacity: 0;
    pointer-events: none;
    display: none; /* Keep display none to prevent clicks when hidden */
}

.modal-content {
    background: var(--bg-color);
    width: 90%;
    max-width: 500px;
    border-radius: 24px;
    padding: 32px;
    position: relative;
    box-shadow: 0 10px 40px rgba(0,0,0,0.2);
    animation: slideUp 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

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

.modal-close {
    position: absolute;
    top: 16px;
    right: 16px;
}

.modal-header h2 {
    margin-bottom: 24px;
    font-size: 1.5rem;
    font-weight: 800;
}

.modal-body p {
    color: var(--system-msg-color);
    line-height: 1.6;
    margin-bottom: 24px;
}

.modal-body h3 {
    font-size: 1.1rem;
    margin-bottom: 16px;
    font-weight: 700;
}

.rules-list {
    list-style-type: none;
}

.rules-list li {
    padding: 8px 0;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-color);
    font-size: 0.95rem;
    display: flex;
    align-items: center;
}

/* Invert logo in dark mode */
body.dark-mode .pulsing-logo,
body.dark-mode .home-logo,
body.dark-mode .chat-logo {
    filter: invert(1);
}

.rules-list li:last-child {
    border-bottom: none;
}

.hidden {
    display: none !important;
}