:root {
    /* Color Palette - Premium Dark Theme */
    --primary: #6366f1;
    --primary-glow: rgba(99, 102, 241, 0.4);
    --secondary: #a855f7;
    --background: #0f172a;
    --surface: #1e293b;
    --surface-light: #334155;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --success: #22c55e;
    --error: #ef4444;

    /* Spacing & Layout */
    --header-height: 60px;
    --nav-height: 60px;
    /* Safe area for bottom nav */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;

    /* Transitions */
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

body {
    font-family: 'Inter', 'Noto Sans KR', sans-serif;
    background-color: var(--background);
    color: var(--text-primary);
    line-height: 1.5;
    overflow-x: hidden;
    height: 100vh;
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 6px;
}

::-webkit-scrollbar-track {
    background: transparent;
}

::-webkit-scrollbar-thumb {
    background: var(--surface-light);
    border-radius: 10px;
}

#app {
    width: 100%;
    height: 100%;
    position: relative;
    overflow: hidden;
}

/* Screens */
.screen {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--background);
    opacity: 0;
    pointer-events: none;
    transform: scale(0.95);
    transition: var(--transition);
    display: flex;
    flex-direction: column;
}

.screen.active {
    opacity: 1;
    pointer-events: auto;
    transform: scale(1);
    z-index: 10;
}

/* Auth Screen Styles */
.auth-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 2rem;
    z-index: 2;
    position: relative;
    max-width: 480px;
    margin: 0 auto;
    width: 100%;
}

.logo {
    text-align: center;
    margin-bottom: 2.5rem;
    animation: fadeInDown 0.8s ease;
}

.logo i {
    font-size: 4rem;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    background-clip: text;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    filter: drop-shadow(0 0 15px var(--primary-glow));
}

.logo h1 {
    font-size: 2rem;
    font-weight: 800;
    letter-spacing: -0.5px;
    margin-top: 0.5rem;
}

.logo p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.auth-box {
    width: 100%;
    background: rgba(30, 41, 59, 0.7);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    padding: 2rem;
    border-radius: var(--radius-lg);
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    animation: fadeInUp 0.8s ease;
}

/* Auth Tabs */
.auth-tabs {
    display: flex;
    margin-bottom: 1.5rem;
    background: var(--background);
    padding: 4px;
    border-radius: var(--radius-md);
}

.auth-tab {
    flex: 1;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    padding: 10px;
    font-weight: 600;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
}

.auth-tab.active {
    background: var(--surface-light);
    color: var(--text-primary);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

/* Forms */
.auth-form {
    display: none;
}

.auth-form.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

.input-group {
    position: relative;
    margin-bottom: 1rem;
}

.input-group i {
    position: absolute;
    left: 15px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
}

input {
    width: 100%;
    padding: 14px 14px 14px 45px;
    background: var(--background);
    border: 1px solid var(--surface-light);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 1rem;
    outline: none;
    transition: var(--transition);
}

input:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-glow);
}

.btn-primary {
    width: 100%;
    padding: 14px;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    border: none;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    margin-top: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    transition: var(--transition);
}

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

.btn-primary:hover {
    box-shadow: 0 0 20px var(--primary-glow);
}

/* Background Shapes */
.background-shapes .shape {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    z-index: 1;
    opacity: 0.5;
}

.shape-1 {
    width: 300px;
    height: 300px;
    background: var(--primary);
    top: -10%;
    right: -10%;
}

.shape-2 {
    width: 400px;
    height: 400px;
    background: var(--secondary);
    bottom: -10%;
    left: -20%;
}

.shape-3 {
    width: 200px;
    height: 200px;
    background: var(--success);
    top: 40%;
    left: 40%;
    opacity: 0.2;
}

/* Main Screen Layout */
.app-header {
    height: var(--header-height);
    background: rgba(15, 23, 42, 0.9);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--surface);
    display: flex;
    align-items: center;
    padding: 0 1.5rem;
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 20;
}

.header-content {
    width: 100%;
    max-width: 800px;
    /* Max width for desktop */
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.brand {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 700;
    font-size: 1.1rem;
    color: var(--text-primary);
}

.brand i {
    color: var(--primary);
}

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

.icon-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 1.2rem;
    cursor: pointer;
    padding: 4px;
}

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

.app-content {
    flex: 1;
    margin-top: var(--header-height);
    margin-bottom: calc(var(--nav-height) + 10px);
    overflow-y: auto;
    width: 100%;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

/* Tabs Content */
.tab-content {
    display: none;
    height: 100%;
    padding: 1rem;
    animation: fadeIn 0.3s ease;
}

.tab-content.active {
    display: block;
}

/* Bottom Nav */
.bottom-nav {
    height: var(--nav-height);
    background: rgba(30, 41, 59, 0.95);
    backdrop-filter: blur(10px);
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    display: flex;
    justify-content: space-around;
    align-items: center;
    position: fixed;
    bottom: 0;
    width: 100%;
    z-index: 20;
    padding-bottom: env(safe-area-inset-bottom);
}

.nav-item {
    background: none;
    border: none;
    color: var(--text-secondary);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 4px;
    cursor: pointer;
    flex: 1;
    height: 100%;
    position: relative;
    transition: var(--transition);
}

.nav-item span {
    font-size: 0.7rem;
    font-weight: 500;
}

.nav-item i {
    font-size: 1.4rem;
    transition: var(--transition);
}

.nav-item .active-icon {
    display: none;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -100%);
    /* Adjust icon position */
}

.nav-item .ri-home-4-line,
.nav-item .ri-chat-3-line,
.nav-item .ri-apps-line,
.nav-item .ri-user-line {
    /* Show line icons by default */
    display: block;
}

/* Nav Active State */
.nav-item.active {
    color: var(--primary);
}

.nav-item.active .ri-home-4-line,
.nav-item.active .ri-chat-3-line,
.nav-item.active .ri-apps-line,
.nav-item.active .ri-user-line {
    display: none;
}

.nav-item.active .active-icon {
    display: block;
    position: static;
    transform: none;
}

/* Empty State */
.empty-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 80%;
    color: var(--text-secondary);
    text-align: center;
}

.empty-state i {
    font-size: 4rem;
    margin-bottom: 1rem;
    opacity: 0.5;
}

.empty-state h3 {
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.btn-secondary {
    margin-top: 1rem;
    padding: 10px 20px;
    background: var(--surface-light);
    color: var(--text-primary);
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    font-weight: 500;
}

/* Chat Styling */
.chat-container {
    display: flex;
    flex-direction: column;
    height: 100%;
    position: relative;
}

.chat-messages {
    flex: 1;
    overflow-y: auto;
    padding-bottom: 80px;
    /* Space for input area */
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.message {
    max-width: 80%;
    padding: 10px 14px;
    border-radius: 18px;
    font-size: 0.95rem;
    position: relative;
    animation: slideUp 0.3s ease;
    word-break: break-all;
}

.message.system {
    align-self: center;
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-secondary);
    padding: 5px 15px;
    border-radius: 15px;
    font-size: 0.8rem;
    max-width: 90%;
    margin: 10px 0;
}

.message.system-announcement {
    align-self: center;
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.2), rgba(168, 85, 247, 0.2));
    border: 1px solid rgba(99, 102, 241, 0.3);
    color: var(--primary-light);
    padding: 8px 16px;
    border-radius: 12px;
    font-size: 0.85rem;
    font-weight: 600;
    text-align: center;
    margin: 10px 0;
    width: 100%;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.message.system-announcement i {
    margin-right: 5px;
}

.message.self {
    align-self: flex-end;
    background: var(--primary);
    color: white;
    border-bottom-right-radius: 4px;
}

.message.other {
    align-self: flex-start;
    background: var(--surface-light);
    color: var(--text-primary);
    border-bottom-left-radius: 4px;
}

.message-meta {
    font-size: 0.7rem;
    margin-top: 4px;
    opacity: 0.7;
    text-align: right;
    display: flex;
    justify-content: space-between;
    gap: 8px;
}

.sender-name {
    font-weight: 700;
    margin-bottom: 2px;
    display: block;
    font-size: 0.75rem;
    color: var(--secondary);
}

.self .sender-name {
    display: none;
}

.chat-input-area {
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    padding: 12px;
    background: var(--background);
    border-top: 1px solid var(--surface);
    display: flex;
    gap: 10px;
}

.chat-input-area input {
    flex: 1;
    background: var(--surface);
    border: none;
    padding: 12px;
}

#send-btn {
    width: 50px;
    background: var(--primary);
    border: none;
    border-radius: var(--radius-md);
    color: white;
    font-size: 1.2rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

#send-btn:active {
    transform: scale(0.9);
}

/* Profile Card */
.profile-card {
    background: linear-gradient(135deg, var(--surface), var(--surface-light));
    border-radius: var(--radius-lg);
    padding: 2rem;
    text-align: center;
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.profile-avatar {
    width: 100px;
    height: 100px;
    background: linear-gradient(135deg, var(--primary), #ec4899);
    border-radius: 50%;
    margin: 0 auto 1.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3rem;
    color: white;
    box-shadow: 0 10px 25px -5px rgba(236, 72, 153, 0.5);
}

.profile-stats {
    display: flex;
    justify-content: center;
    gap: 2rem;
    margin: 2rem 0;
    padding: 1.5rem 0;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.stat-item {
    display: flex;
    flex-direction: column;
}

.stat-value {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

.stat-label {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.detail-item {
    display: flex;
    justify-content: space-between;
    padding: 10px 0;
    color: var(--text-secondary);
}

.detail-item .value {
    color: var(--text-primary);
    font-weight: 500;
}

/* Toast */
#toast-container {
    position: fixed;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 100;
    display: flex;
    flex-direction: column;
    gap: 10px;
    width: 90%;
    max-width: 400px;
    pointer-events: none;
}

.toast {
    background: rgba(30, 41, 59, 0.95);
    backdrop-filter: blur(5px);
    color: white;
    padding: 12px 20px;
    border-radius: 50px;
    font-size: 0.9rem;
    box-shadow: 0 10px 30px -10px rgba(0, 0, 0, 0.5);
    animation: slideDown 0.3s ease;
    display: flex;
    align-items: center;
    gap: 10px;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.toast.success {
    border-left: 4px solid var(--success);
}

.toast.error {
    border-left: 4px solid var(--error);
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

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

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

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

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

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

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

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

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

/* Desktop Responsive Adjustments */
@media (min-width: 800px) {
    .bottom-nav {
        max-width: 800px;
        left: 50%;
        transform: translateX(-50%);
        position: fixed;
        border-radius: var(--radius-lg) var(--radius-lg) 0 0;
    }
}

/* Feed Styling */
.feed-list {
    padding-bottom: 80px;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.feed-card {
    background: var(--surface);
    border-radius: var(--radius-md);
    padding: 1.5rem;
    position: relative;
    border: 1px solid rgba(255, 255, 255, 0.05);
    animation: fadeInUp 0.5s ease;
}

.feed-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 1rem;
    font-size: 0.9rem;
}

.feed-author {
    font-weight: 700;
    color: var(--secondary);
    display: flex;
    align-items: center;
    gap: 6px;
}

.feed-time {
    color: var(--text-secondary);
    font-size: 0.8rem;
}

.feed-content {
    white-space: pre-wrap;
    color: var(--text-primary);
    line-height: 1.6;
    margin-bottom: 1rem;
}

.feed-actions {
    display: flex;
    gap: 1rem;
    padding-top: 1rem;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.action-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 6px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: var(--transition);
}

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

.action-btn.liked {
    color: #f43f5e;
}

.action-btn i {
    font-size: 1.2rem;
}

.comments-section {
    margin-top: 1rem;
    padding-top: 1rem;
    border-top: 1px dashed rgba(255, 255, 255, 0.1);
    animation: fadeIn 0.3s ease;
}

.comments-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin-bottom: 1rem;
}

.comment-item {
    font-size: 0.9rem;
    color: var(--text-secondary);
    background: rgba(255, 255, 255, 0.03);
    padding: 8px 12px;
    border-radius: var(--radius-sm);
}

.comment-item strong {
    color: var(--text-primary);
    margin-right: 6px;
}

.comment-input-wrapper {
    display: flex;
    gap: 8px;
}

.comment-input {
    flex: 1;
    padding: 8px 12px;
    font-size: 0.9rem;
    border: 1px solid rgba(255, 255, 255, 0.1);
    background: rgba(0, 0, 0, 0.2);
    border-radius: var(--radius-sm);
}

.comment-send-btn {
    background: var(--primary);
    color: white;
    border: none;
    width: 36px;
    border-radius: var(--radius-sm);
    cursor: pointer;
}

.fab-btn {
    position: fixed;
    bottom: calc(var(--nav-height) + 20px);
    right: 20px;
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    border: none;
    font-size: 1.5rem;
    box-shadow: 0 10px 20px rgba(99, 102, 241, 0.4);
    cursor: pointer;
    z-index: 100;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.fab-btn:active {
    transform: scale(0.9);
}

@media (min-width: 800px) {
    .fab-btn {
        right: calc((100% - 800px) / 2 + 20px);
    }
}

/* Sponsorship Card */
.sponsorship-card {
    margin-top: 2rem;
    background: rgba(0, 0, 0, 0.2);
    border-radius: var(--radius-md);
    padding: 1.5rem;
    border: 1px solid rgba(255, 215, 0, 0.2);
}

.sponsorship-header {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 8px;
    margin-bottom: 1rem;
    color: #fbbf24;
}

.credit-amount {
    font-size: 2rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
    color: white;
}

.btn-primary.small {
    padding: 8px 16px;
    font-size: 0.9rem;
    width: auto;
    margin: 0 auto;
}

/* Modals */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(5px);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    pointer-events: none;
    transition: var(--transition);
    padding: 20px;
}

.modal-overlay.active {
    opacity: 1;
    pointer-events: auto;
}

.modal-content {
    background: var(--surface);
    width: 100%;
    max-width: 500px;
    border-radius: var(--radius-lg);
    border: 1px solid rgba(255, 255, 255, 0.1);
    transform: scale(0.9);
    transition: var(--transition);
}

.modal-overlay.active .modal-content {
    transform: scale(1);
}

.modal-header {
    padding: 1.2rem;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-close {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 1.5rem;
    cursor: pointer;
}

.modal-body {
    padding: 1.5rem;
}

.modal-footer {
    padding: 1.2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

textarea {
    width: 100%;
    background: var(--background);
    border: 1px solid var(--surface-light);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    padding: 1rem;
    font-family: inherit;
    resize: none;
    outline: none;
}

textarea:focus {
    border-color: var(--primary);
}

/* Sponsor Info */
.account-info {
    background: var(--background);
    padding: 1rem;
    border-radius: var(--radius-sm);
    text-align: center;
    margin-bottom: 1.5rem;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.account-info .bank {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.account-info .number {
    font-weight: 700;
    font-size: 1.1rem;
    color: var(--primary);
}

.btn-copy {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 1.1rem;
}

.sponsor-notice {
    list-style: none;
    font-size: 0.9rem;
    color: var(--text-secondary);
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.sponsor-notice li {
    padding-left: 14px;
    position: relative;
    text-align: left;
}

.sponsor-notice li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--primary);
}

.sponsor-notice strong {
    color: var(--secondary);
}

/* --- Level & XP Section --- */
.level-section {
    background: var(--surface);
    padding: 1.5rem;
    border-radius: var(--radius-lg);
    margin-bottom: 20px;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--surface-light);
}

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

.level-badge {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    padding: 5px 12px;
    border-radius: 20px;
    font-weight: 700;
    font-size: 0.9rem;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
}

.xp-text {
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
}

.xp-progress-bar {
    width: 100%;
    height: 10px;
    background: var(--background);
    border-radius: 10px;
    overflow: hidden;
    position: relative;
}

.xp-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    border-radius: 10px;
    transition: width 0.5s ease;
    box-shadow: 0 0 10px rgba(99, 102, 241, 0.5);
}

/* Toastify Custom override if needed */
.toastify {
    background: var(--surface) !important;
    color: var(--text-primary) !important;
    border: 1px solid var(--surface-light) !important;
    box-shadow: var(--shadow-lg) !important;
    border-radius: var(--radius-md) !important;
    font-family: 'Inter', sans-serif !important;
}

/* --- Contents Tab --- */
.content-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: 15px;
    padding: 10px 0;
}

.content-card {
    background: var(--surface);
    border-radius: var(--radius-md);
    overflow: hidden;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
    border: 1px solid var(--surface-light);
    display: flex;
    flex-direction: column;
}

.content-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
    border-color: var(--primary);
}

.content-thumb {
    width: 100%;
    aspect-ratio: 1/1;
    /* Square thumbnail */
    object-fit: cover;
    background: #000;
}

.content-info {
    padding: 12px;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.content-title {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 5px;
    color: var(--text-primary);
}

.content-desc {
    font-size: 0.8rem;
    color: var(--text-secondary);
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}