* {
    box-sizing: border-box;
}

button, .task-card, .slot.filled, .nav-btn, .switch {
    cursor: pointer;
}

:root {
    --bg-color: #fafafa;
    --card-bg: #ffffff;
    --input-bg: #ffffff;
    --task-bg: #f9fafb;
    --task-hover: #ffffff;
    --completed-bg: #f3f4f6;
    --text-primary: #111827; 
    --text-secondary: #6b7280;
    --text-tertiary: #9ca3af;
    --accent: #2563eb; 
    --accent-soft: #eff6ff;
    --border: #e5e7eb;
    --slider-bg: #e5e7eb;
    --radius: 16px; 
    --shadow-soft: 0 4px 20px -2px rgba(0, 0, 0, 0.05);
    --shadow-hover: 0 10px 25px -5px rgba(0, 0, 0, 0.08);
    --z-overlay: 100;
    --z-drawer: 200;
    --z-modal: 300;
    --z-toast: 400;
    
    --slot-avail-bg: #f9fafb;
    --slot-avail-border: #bfdbfe;
    --slot-avail-text: #60a5fa;
    --slot-drag-bg: #eff6ff;
    --slot-drag-border: #2563eb;
    --slot-drag-text: #2563eb;
}

[data-theme="dark"] {
    --bg-color: #050505;
    --card-bg: #121212;
    --input-bg: #121212;
    --task-bg: #1e1e1e;
    --task-hover: #2a2a2a;
    --completed-bg: #0a0a0a;
    
    --text-primary: #ffffff;
    --text-secondary: #d4d4d4;
    --text-tertiary: #737373;
    
    --accent: #3b82f6;
    --accent-soft: rgba(59, 130, 246, 0.15);
    --border: #262626;
    --slider-bg: #262626;
    
    --shadow-soft: 0 4px 20px -2px rgba(0, 0, 0, 0.7);
    --shadow-hover: 0 10px 25px -5px rgba(0, 0, 0, 0.9);

    --slot-avail-bg: #0a0a0a;
    --slot-avail-border: #1e40af;
    --slot-avail-text: #60a5fa;
    --slot-drag-bg: #172554;
    --slot-drag-border: #3b82f6;
    --slot-drag-text: #60a5fa;
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-primary);
    margin: 0;
    overflow-x: hidden; 
    transition: background-color 0.3s ease, color 0.3s ease;
}

.app-wrapper {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    position: relative;
    transition: filter 0.3s ease;
}

.top-nav {
    width: 100%;
    padding: 2rem 2.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: absolute; 
    top: 0;
    left: 0;
    right: 0;
}

.spacer { flex-grow: 1; }

.nav-btn {
    background: var(--card-bg); 
    border: 1px solid transparent;
    color: var(--text-secondary);
    padding: 10px 18px; 
    border-radius: 30px; 
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px; 
    transition: all 0.2s ease;
    position: relative;
    box-shadow: 0 2px 5px rgba(0,0,0,0.03);
    font-size: 0.9rem;
    font-weight: 500;
}

.nav-btn:hover {
    background-color: var(--card-bg);
    border-color: var(--border);
    color: var(--text-primary);
    transform: translateY(-1px);
    box-shadow: var(--shadow-soft);
}

.nav-icon {
    display: flex;
    align-items: center;
}

.badge {
    position: absolute;
    top: -5px;
    right: -5px;
    background: var(--accent);
    color: white;
    font-size: 0.65rem;
    font-weight: 700;
    min-width: 18px;
    height: 18px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 9px;
    border: 2px solid var(--bg-color);
    z-index: 10;
}

.floating-settings-btn {
    position: fixed;
    bottom: 2rem;
    left: 2rem; 
    background: var(--card-bg);
    border: 1px solid transparent;
    color: var(--text-secondary);
    padding: 10px 18px;
    border-radius: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    box-shadow: var(--shadow-soft);
    font-size: 0.9rem;
    font-weight: 500;
    z-index: 50; 
    transition: all 0.2s ease;
}

.floating-settings-btn:hover {
    border-color: var(--border);
    color: var(--text-primary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

.container {
    width: 100%;
    max-width: 480px;
    padding: 0 2rem 2rem;
    display: flex;
    flex-direction: column;
    margin-top: 8rem; 
    flex-grow: 1; 
}

.credits {
    width: 100%;
    text-align: center;
    padding: 2rem;
    font-size: 0.85rem;
    color: var(--text-tertiary);
    margin-top: auto; 
}

.credits a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
}

.credits a:hover {
    color: var(--accent);
    text-decoration: underline;
}

header { 
    text-align: center; 
    margin-bottom: 2.5rem; 
}

h1 { 
    margin: 0; 
    margin-bottom: 0.5rem; 
    letter-spacing: -1.5px; 
    line-height: 1.1;
    font-size: 2.5rem;
    color: var(--text-primary);
}

.subtitle { 
    color: var(--text-secondary); 
    margin: 0; 
    font-size: 1.1rem;
    font-weight: 400;
}

.input-group { 
    display: flex; 
    gap: 12px; 
    margin-bottom: 2rem; 
    position: relative;
}

input {
    flex-grow: 1; 
    padding: 1.2rem 1.2rem; 
    border: 1px solid transparent;
    border-radius: var(--radius); 
    outline: none; 
    -webkit-appearance: none;
    transition: all 0.3s ease; 
    background: var(--input-bg); 
    color: var(--text-primary); 
    box-shadow: var(--shadow-soft);
    font-size: 1rem;
    cursor: text;
    caret-color: var(--text-secondary); 
}

input:hover { box-shadow: var(--shadow-hover); }
input:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

button#addBtn {
    background: var(--text-primary); 
    color: var(--bg-color); 
    border: 1px solid var(--border);
    width: 56px;
    border-radius: var(--radius); 
    display: flex;
    align-items: center;
    justify-content: center;
    transition: transform 0.2s, background 0.2s;
}
button#addBtn:hover { 
    transform: scale(1.05);
    opacity: 0.9;
}
button#addBtn:active { transform: scale(0.95); }

h2 {
    font-size: 0.8rem; 
    text-transform: uppercase; 
    letter-spacing: 0.1em;
    color: var(--text-tertiary); 
    margin-bottom: 1.2rem; 
    display: flex; 
    justify-content: space-between;
    font-weight: 600;
}

.focus-grid { display: flex; flex-direction: column; gap: 16px; }

.slot {
    min-height: 80px;
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

.slot.filled {
    background: var(--card-bg);
    border: 1px solid var(--border);
    box-shadow: var(--shadow-soft);
    justify-content: space-between;
    padding: 1.2rem;
    border-left: 5px solid var(--accent);
    color: var(--text-primary);
}

.slot.filled:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

.slot.empty {
    border: 2px dashed var(--border);
    background: transparent;
    color: var(--text-tertiary);
    font-size: 0.95rem;
    user-select: none;
    text-align: center;
    padding: 0 20px;
}

.slot.empty.available {
    background-color: var(--slot-avail-bg); 
    border-color: var(--slot-avail-border);     
    color: var(--slot-avail-text);           
}

.slot.empty.drag-over {
    background-color: var(--slot-drag-bg) !important; 
    border-color: var(--slot-drag-border) !important; 
    color: var(--slot-drag-text) !important;       
    transform: scale(1.02); 
}

.focus-message {
    text-align: center;
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-top: 20px;
    font-style: italic;
    opacity: 0.8;
}
.focus-message.hidden { display: none; }

.drawer {
    position: fixed;
    top: 0;
    bottom: 0;
    width: 320px;
    background: var(--card-bg);
    z-index: var(--z-drawer);
    padding: 2rem;
    transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1);
    box-shadow: 0 0 30px rgba(0,0,0,0.1);
    display: flex;
    flex-direction: column;
}

.drawer-left {
    left: 0;
    transform: translateX(-100%);
    border-right: 1px solid var(--border);
}

.drawer-right {
    right: 0;
    transform: translateX(100%);
    border-left: 1px solid var(--border);
}

.drawer.open {
    transform: translateX(0);
}

.drawer-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
}

.drawer-header h2 { margin: 0; color: var(--text-primary); }

.drawer-content {
    flex-grow: 1;
    overflow-y: auto;
    padding-bottom: 2rem;
}

.drawer-content::-webkit-scrollbar { width: 6px; }
.drawer-content::-webkit-scrollbar-track { background: transparent; }
.drawer-content::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }

.task-list { 
    display: flex; 
    flex-direction: column; 
    gap: 12px; 
}

.task-card {
    background: var(--task-bg); 
    padding: 1rem; 
    border-radius: var(--radius);
    border: 1px solid transparent; 
    display: flex; 
    justify-content: space-between;
    align-items: center;
    color: var(--text-primary);
    transition: all 0.2s;
    font-size: 0.9rem;
}

.task-card:hover {
    background: var(--task-hover);
    border-color: var(--border);
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}

.task-card.completed-task {
    background: var(--completed-bg);
    color: var(--text-tertiary);
    text-decoration: line-through;
}

.overlay {
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(0, 0, 0, 0.2);
    backdrop-filter: blur(2px);
    z-index: var(--z-overlay);
    opacity: 1;
    transition: opacity 0.3s;
}
.overlay.hidden {
    opacity: 0;
    pointer-events: none;
}

.modal {
    position: fixed;
    top: 50%; left: 50%;
    transform: translate(-50%, -50%);
    background: var(--card-bg);
    width: 90%;
    max-width: 400px;
    border-radius: 20px;
    padding: 1.5rem;
    box-shadow: 0 20px 50px rgba(0,0,0,0.15);
    z-index: var(--z-modal);
    transition: all 0.3s;
    opacity: 1;
    color: var(--text-primary);
}
.modal.hidden {
    opacity: 0;
    pointer-events: none;
    transform: translate(-50%, -40%);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.modal-header h3 { margin: 0; font-size: 1.1rem; color: var(--text-primary); }

.setting-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    gap: 24px; 
}

.setting-text { display: flex; flex-direction: column; gap: 4px; }
.setting-title { font-weight: 500; font-size: 0.95rem; color: var(--text-primary); }
.setting-desc { font-size: 0.8rem; color: var(--text-secondary); }

.divider { border: 0; border-top: 1px solid var(--border); margin: 1.5rem 0; }

.text-btn {
    background: none; border: none; color: #ef4444; font-weight: 600; font-size: 0.9rem;
}
.text-btn:hover { text-decoration: underline; }

.icon-btn-plain {
    background: none; border: none; font-size: 1.2rem; color: var(--text-secondary); opacity: 0.7;
}
.icon-btn-plain:hover { opacity: 1; transform: rotate(90deg); transition: 0.3s; color: var(--text-primary); }

.task-actions { display: flex; gap: 8px; align-items: center; }

.icon-btn {
    background: var(--card-bg); border: 1px solid var(--border); 
    border-radius: 6px; width: 28px; height: 28px; 
    display: flex; align-items: center; justify-content: center;
    color: var(--text-secondary);
    font-size: 0.8rem;
    transition: all 0.2s;
}
.icon-btn:hover { border-color: var(--accent); color: var(--accent); }

.custom-checkbox {
    width: 24px; height: 24px;
    border: 2px solid var(--border);
    border-radius: 8px; 
    display: flex; align-items: center; justify-content: center;
    transition: all 0.2s ease;
}
.check-icon { width: 14px; height: 14px; stroke: var(--accent); opacity: 0; }
.custom-checkbox:hover { border-color: var(--accent); }
.custom-checkbox:hover .check-icon { opacity: 0.5; }
.custom-checkbox.checked { background-color: var(--accent); border-color: var(--accent); transform: scale(0.9); }
.custom-checkbox.checked .check-icon { stroke: white; opacity: 1; }

.switch {
    position: relative;
    display: inline-block;
    width: 110px; 
    height: 32px;
    flex-shrink: 0; 
}
.switch input { opacity: 0; width: 0; height: 0; }

.slider {
    position: absolute; cursor: pointer; top: 0; left: 0; right: 0; bottom: 0;
    background-color: var(--slider-bg); 
    transition: .4s; border-radius: 34px;
    overflow: hidden; 
}

.slider:before {
    position: absolute; content: ""; 
    height: 24px; width: 24px; 
    left: 4px; bottom: 4px;
    background-color: white; 
    transition: .4s; 
    border-radius: 50%; 
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    z-index: 2;
}

.slider::after {
    content: "OFF"; 
    position: absolute;
    right: 18px; 
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
    font-size: 11px;
    font-weight: 700;
    text-transform: uppercase;
    transition: all 0.4s ease;
}

#modeToggle + .slider::after { content: "Manual"; }
#modeToggle:checked + .slider::after { content: "Auto"; }

#themeToggle + .slider::after { content: "Light"; }
#themeToggle:checked + .slider::after { content: "Dark"; }


input:checked + .slider { background-color: var(--accent); }
input:checked + .slider:before { 
    transform: translateX(78px); 
} 

input:checked + .slider::after {
    right: auto;
    left: 18px; 
    color: white;
}

.dragging { opacity: 0.5; transform: scale(0.98); }

#toast {
    position: fixed; bottom: 30px; left: 50%; transform: translateX(-50%);
    background: var(--text-primary); color: var(--bg-color); 
    padding: 12px 24px; border-radius: 30px;
    font-size: 0.9rem; box-shadow: 0 10px 30px rgba(0,0,0,0.2);
    opacity: 0; transition: opacity 0.3s; pointer-events: none; z-index: var(--z-toast);
}
#toast.show { opacity: 1; transform: translateX(-50%) translateY(-10px); }

@media (max-width: 600px) {
    .drawer { width: 85%; }
    
    .nav-label { display: none; }
    
    .nav-btn {
        padding: 10px;
        border-radius: 50%;
    }
    
    .floating-settings-btn .nav-label { display: none; }
    .floating-settings-btn {
        padding: 10px;
        border-radius: 50%;
    }
}