/* ========================================
   App Container - Seamless Dark Surface
======================================== */
.app-container {
    height: 100vh;
    width: 100vw;
    display: flex;
    flex-direction: row;
    background: var(--bg-base);
    background-image:
        radial-gradient(circle at top left, rgba(245, 184, 0, 0.06), transparent 24%),
        radial-gradient(circle at 80% 0%, rgba(96, 165, 250, 0.06), transparent 22%);
    overflow: hidden;
}

.app-main {
    flex: 1;
    display: flex;
    flex-direction: column;
    min-width: 0;
    overflow: hidden;
}

/* ========================================
   Header - Floating Navigation
======================================== */
.header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-4) var(--space-6);
    min-height: 72px;
    background: linear-gradient(180deg, var(--bg-glass), transparent);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    flex-shrink: 0;
    position: relative;
    z-index: 100;
    gap: var(--space-4);
}

/* Subtle gradient fade at bottom */
.header::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, 
        transparent 0%, 
        var(--bg-hover) 20%, 
        var(--bg-hover) 80%, 
        transparent 100%
    );
    opacity: 0.5;
}

/* ========================================
   Back to Landing Button
======================================== */
.back-to-landing {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-3);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-size: 13px;
    font-weight: 500;
    transition: var(--transition-fast);
    flex-shrink: 0;
}

.back-to-landing:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
    transform: translateY(-1px);
}

.back-to-landing svg {
    width: 16px;
    height: 16px;
}

/* ========================================
   Logo
======================================== */
.logo {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2);
    border-radius: var(--radius-md);
    transition: var(--transition-fast);
}

.logo:hover {
    background: var(--bg-hover);
}

/* ========================================
   App Content Wrapper - Full Width
   ======================================== */
.app-content-wrapper {
    flex: 1;
    display: flex;
    overflow: hidden;
    min-height: 0;
    background: transparent;
}

.app-content {
    width: 100%;
    background: transparent;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    flex: 1;
    min-height: 0;
}

/* ========================================
   Header Right Actions
   ======================================== */
.header-right {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    margin-left: auto;
}

/* Icon Buttons - Ghost Style */
.theme-toggle,
.history-toggle-btn {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-md);
    background: var(--bg-glass);
    border: 1px solid var(--border-default);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition-spring);
    color: var(--text-secondary);
    touch-action: manipulation;
    -webkit-tap-highlight-color: transparent;
    cursor: pointer;
}

.theme-toggle:hover,
.history-toggle-btn:hover {
    background: var(--bg-hover);
    color: var(--text-primary);
    transform: translateY(-1px);
}

.theme-toggle svg,
.history-toggle-btn svg {
    width: 18px;
    height: 18px;
}

.theme-toggle .sun-icon { display: block; }
.theme-toggle .moon-icon { display: none; }
[data-theme="dark"] .theme-toggle .sun-icon { display: none; }
[data-theme="dark"] .theme-toggle .moon-icon { display: block; }

/* ========================================
   User Menu - Floating Card
======================================== */
.user-menu {
    position: relative;
}

.user-menu-btn {
    display: flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-1) var(--space-2) var(--space-1) var(--space-1);
    border-radius: var(--radius-md);
    background: var(--bg-glass);
    border: 1px solid var(--border-default);
    transition: var(--transition-spring);
}

.user-menu-btn:hover {
    background: var(--bg-hover);
    transform: translateY(-1px);
}

.user-avatar {
    width: 32px;
    height: 32px;
    border-radius: var(--radius-md);
    background: linear-gradient(135deg, var(--accent) 0%, var(--accent-hover) 100%);
    color: var(--accent-text);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    font-weight: 700;
}

.user-name {
    font-size: 13px;
    font-weight: 500;
    color: var(--text-primary);
    max-width: 100px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.pro-badge {
    font-size: 9px;
    font-weight: 700;
    letter-spacing: 0.06em;
    padding: 2px 5px;
    border-radius: 4px;
    background: var(--accent);
    color: var(--accent-text);
    line-height: 1;
    flex-shrink: 0;
}

.pro-badge.hidden {
    display: none;
}

.dropdown-icon {
    width: 14px;
    height: 14px;
    color: var(--text-tertiary);
    transition: var(--transition-fast);
}

.user-menu-btn:hover .dropdown-icon {
    color: var(--text-secondary);
}

/* Dropdown Panel */
.user-dropdown {
    position: absolute;
    top: calc(100% + var(--space-2));
    right: 0;
    min-width: 220px;
    background: var(--bg-panel);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-floating);
    z-index: 300;
    overflow: hidden;
    animation: scaleIn 0.15s ease;
    transform-origin: top right;
}

.user-dropdown.hidden {
    display: none;
}

.user-dropdown-header {
    padding: var(--space-4);
    background: var(--bg-hover);
}

.user-dropdown-email {
    font-size: 12px;
    color: var(--text-secondary);
    word-break: break-all;
}

.user-dropdown-divider {
    height: var(--space-2);
    background: transparent;
}

.user-dropdown-item {
    width: 100%;
    display: flex;
    align-items: center;
    gap: var(--space-3);
    padding: var(--space-3) var(--space-4);
    background: transparent;
    font-size: 13px;
    font-weight: 500;
    color: var(--text-primary);
    transition: var(--transition-fast);
}

.user-dropdown-item:hover {
    background: var(--bg-hover);
}

.user-dropdown-item svg {
    width: 16px;
    height: 16px;
    color: var(--text-tertiary);
}

/* ========================================
   Main Content Area
======================================== */
.main-content {
    flex: 1;
    display: flex;
    min-height: 0;
    position: relative;
    overflow: hidden;
    padding: 0 var(--space-4) var(--space-4) 0;
    gap: 0;
}

/* ========================================
   Mode Back Button (top-right of viktorina / flashcard modes)
======================================== */
.mode-back-btn {
    position: absolute;
    top: var(--space-3);
    right: var(--space-3);
    z-index: 50;
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
    padding: var(--space-2) var(--space-3);
    background: var(--bg-glass);
    border: 1px solid var(--border-default);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-spring);
    box-shadow: var(--shadow-sm);
}

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

.mode-back-btn svg {
    flex-shrink: 0;
}

/* ========================================
   Responsive Layout
======================================== */
@media (max-width: 900px) {
    .header {
        padding: var(--space-3) var(--space-4);
        gap: var(--space-2);
    }

    .back-to-landing span {
        display: none;
    }

    .back-to-landing {
        padding: var(--space-2);
    }

    .user-name {
        display: none;
    }
}

@media (max-width: 600px) {
    .header {
        min-height: 56px;
        padding: var(--space-2) var(--space-3);
    }

    .header::after {
        display: none;
    }

    .theme-toggle,
    .history-toggle-btn {
        width: 44px;
        height: 44px;
    }

    .main-content {
        padding: 0;
    }

    .user-menu-btn {
        min-height: 44px;
    }

    .user-dropdown-item {
        padding: var(--space-3) var(--space-4);
        min-height: 44px;
    }
}