@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');

:root {
    --primary: #10B981;
    --primary-dark: #059669;
    --secondary: #34D399;
    --bg: #F3F4F6;
    --card: rgba(255, 255, 255, 0.9);
    --text-main: #1F2937;
    --text-muted: #6B7280;
    --success: #10B981;
    --warning: #F59E0B;
    --danger: #EF4444;
    --info: #3B82F6;
    
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    
    --radius: 16px;
    --spacing: 8px;
    --glass-border: 1px solid rgba(255, 255, 255, 0.2);
}

body.dark {
    --bg: #111827;
    --card: rgba(31, 41, 55, 0.8);
    --text-main: #F9FAFB;
    --text-muted: #9CA3AF;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3);
    --glass-border: 1px solid rgba(255, 255, 255, 0.05);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Inter', sans-serif;
}

body {
    background-color: var(--bg);
    background-image: radial-gradient(at 0% 0%, hsla(152,100%,74%,0.15) 0px, transparent 50%),
                      radial-gradient(at 100% 0%, hsla(189,100%,56%,0.15) 0px, transparent 50%);
    background-attachment: fixed;
    color: var(--text-main);
    -webkit-tap-highlight-color: transparent;
    line-height: 1.5;
}

a { text-decoration: none; color: inherit; }

#app {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    padding-bottom: 80px; 
}

/* App Bar */
.app-bar {
    background: var(--card);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    padding: calc(var(--spacing) * 2);
    border-bottom: var(--glass-border);
    position: sticky;
    top: 0;
    z-index: 10;
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.app-bar h1 {
    font-size: 1.25rem;
    font-weight: 700;
    background: linear-gradient(to right, var(--primary), var(--info));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

/* Layout */
.container {
    padding: calc(var(--spacing) * 2.5);
    flex: 1;
    animation: fadeIn 0.15s ease-out;
}

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

/* Cards */
.card {
    background: var(--card);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: var(--glass-border);
    border-radius: var(--radius);
    padding: calc(var(--spacing) * 2.5);
    box-shadow: var(--shadow);
    margin-bottom: calc(var(--spacing) * 2.5);
    transition: transform 0.2s, box-shadow 0.2s;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: calc(var(--spacing) * 1.5) calc(var(--spacing) * 2);
    border-radius: var(--radius);
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    border: none;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    width: 100%;
    text-align: center;
    box-shadow: var(--shadow-sm);
    position: relative;
    overflow: hidden;
}
.btn:active {
    transform: scale(0.92);
    opacity: 0.85;
}
.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    box-shadow: 0 4px 12px rgba(16, 185, 129, 0.3);
}
.btn-primary:hover {
    box-shadow: 0 6px 16px rgba(16, 185, 129, 0.4);
}
.btn-secondary {
    background-color: transparent;
    color: var(--primary);
    border: 2px solid var(--primary);
}
.btn-text {
    background-color: transparent;
    color: var(--primary);
    padding: var(--spacing);
    box-shadow: none;
}

/* Loading States */
.btn.is-loading,
form.is-loading button[type="submit"] {
    color: transparent !important;
    pointer-events: none;
}
.btn.is-loading::after,
form.is-loading button[type="submit"]::after {
    content: "";
    position: absolute;
    width: 1.25rem;
    height: 1.25rem;
    top: calc(50% - 0.625rem);
    left: calc(50% - 0.625rem);
    border: 3px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.8s cubic-bezier(0.4, 0, 0.2, 1) infinite;
}
.btn-secondary.is-loading::after,
form.is-loading .btn-secondary[type="submit"]::after {
    border-color: rgba(16, 185, 129, 0.2);
    border-top-color: var(--primary);
}
.btn-secondary.text-danger.is-loading::after {
    border-color: rgba(239, 68, 68, 0.2);
    border-top-color: var(--danger);
}
@keyframes spin {
    to { transform: rotate(360deg); }
}

/* HTMX Top Progress Bar */
body.htmx-request::before {
    content: "";
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 3px;
    background: var(--primary);
    animation: htmx-progress 1s ease-in-out infinite;
    z-index: 9999;
}
@keyframes htmx-progress {
    0% { transform: translateX(-100%); }
    50% { transform: translateX(0); }
    100% { transform: translateX(100%); }
}

/* Forms */
input, select, textarea {
    width: 100%;
    padding: calc(var(--spacing) * 1.5);
    border-radius: 12px;
    border: 1px solid var(--text-muted);
    background-color: transparent;
    color: var(--text-main);
    font-size: 1rem;
    margin-bottom: calc(var(--spacing) * 2);
    transition: border-color 0.2s, box-shadow 0.2s;
}
input:focus, select:focus, textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.1);
}
select option {
    background-color: var(--card);
    color: var(--text-main);
}

/* Switch Toggle */
.switch {
  position: relative;
  display: inline-block;
  width: 50px;
  height: 28px;
}
.switch input {
  opacity: 0;
  width: 0;
  height: 0;
}
.slider {
  position: absolute;
  cursor: pointer;
  top: 0; left: 0; right: 0; bottom: 0;
  background-color: var(--text-muted);
  transition: .4s;
}
.slider.round {
  border-radius: 34px;
}
.slider.round:before {
  border-radius: 50%;
}
.slider:before {
  position: absolute;
  content: "";
  height: 20px;
  width: 20px;
  left: 4px;
  bottom: 4px;
  background-color: white;
  transition: .4s;
}
input:checked + .slider {
  background-color: var(--primary);
}
input:checked + .slider:before {
  transform: translateX(22px);
}

/* Bottom Nav */
.bottom-nav {
    position: fixed;
    bottom: 0;
    width: 100%;
    background: var(--card);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-top: var(--glass-border);
    display: flex;
    justify-content: space-around;
    padding: 12px 0 calc(12px + env(safe-area-inset-bottom));
    z-index: 100;
}
.bottom-nav a {
    display: flex;
    flex-direction: column;
    align-items: center;
    color: var(--text-muted);
    font-size: 0.75rem;
    flex: 1;
    transition: color 0.2s, transform 0.2s;
}
.bottom-nav a:active {
    transform: scale(0.9);
}
.bottom-nav a.active {
    color: var(--primary);
    font-weight: 600;
}
.bottom-nav .icon {
    font-size: 1.5rem;
    margin-bottom: 4px;
    transition: transform 0.2s;
}
.bottom-nav a.active .icon {
    transform: translateY(-2px);
}

/* Toast */
.toast {
    position: fixed;
    bottom: 90px;
    left: 50%;
    transform: translateX(-50%) translateY(0);
    background: rgba(31, 41, 55, 0.95);
    backdrop-filter: blur(8px);
    color: white;
    padding: 12px 24px;
    border-radius: 30px;
    font-size: 0.875rem;
    font-weight: 500;
    z-index: 1000;
    opacity: 1;
    transition: all 0.3s cubic-bezier(0.68, -0.55, 0.265, 1.55);
    box-shadow: var(--shadow-lg);
}
.toast.hidden {
    opacity: 0;
    transform: translateX(-50%) translateY(20px);
    pointer-events: none;
}

/* Utilities */
.text-center { text-align: center; }
.mb-1 { margin-bottom: var(--spacing); }
.mb-2 { margin-bottom: calc(var(--spacing) * 2); }
.mt-2 { margin-top: calc(var(--spacing) * 2); }
.d-flex { display: flex; }
.align-center { align-items: center; }
.justify-between { justify-content: space-between; }
.text-primary { color: var(--primary); }
.text-muted { color: var(--text-muted); }
.text-success { color: var(--success); }
.text-warning { color: var(--warning); }
.text-info { color: var(--info); }
.text-danger { color: var(--danger); }

/* Progress Ring */
.progress-ring {
    position: relative;
    width: 120px;
    height: 120px;
}
.progress-ring svg {
    transform: rotate(-90deg);
    filter: drop-shadow(0 4px 6px rgba(16, 185, 129, 0.2));
}
.progress-ring circle {
    fill: none;
    stroke-width: 8;
}
.progress-ring .bg { stroke: rgba(16, 185, 129, 0.1); }
.progress-ring .progress {
    stroke: url(#gradient);
    stroke-linecap: round;
    transition: stroke-dashoffset 1s cubic-bezier(0.4, 0, 0.2, 1);
}
.progress-ring .text {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--primary);
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: calc(var(--spacing) * 6) calc(var(--spacing) * 2);
}
.empty-state .icon {
    font-size: 5rem;
    margin-bottom: calc(var(--spacing) * 2);
    opacity: 0.8;
}

/* Flashcard Specific */
.flashcard-container {
    perspective: 1000px;
    height: 350px;
    margin-bottom: calc(var(--spacing) * 3);
}
.flashcard {
    width: 100%;
    height: 100%;
    position: relative;
    transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    transform-style: preserve-3d;
    cursor: pointer;
}
.flashcard.is-flipped {
    transform: rotateY(180deg);
}
.flashcard-face {
    position: absolute;
    width: 100%;
    height: 100%;
    backface-visibility: hidden;
    background: var(--card);
    border: var(--glass-border);
    border-radius: 24px;
    box-shadow: var(--shadow-lg);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: calc(var(--spacing) * 3);
    text-align: center;
}
.flashcard-back {
    transform: rotateY(180deg);
    background: linear-gradient(135deg, var(--card) 0%, rgba(16, 185, 129, 0.05) 100%);
}
.flashcard-word { 
    font-size: 3rem; 
    font-weight: 700; 
    margin-bottom: var(--spacing);
    color: var(--text-main);
}
.flashcard-reading { 
    font-size: 1.25rem; 
    color: var(--text-muted); 
    margin-bottom: calc(var(--spacing) * 2);
    font-weight: 500;
}
.flashcard-meaning { 
    font-size: 1.75rem; 
    color: var(--primary); 
    font-weight: 700;
}

.rating-buttons {
    display: flex;
    gap: calc(var(--spacing) * 1.5);
}
.rating-buttons .btn { flex: 1; padding: calc(var(--spacing) * 2); border-radius: 20px; font-weight: 700; }
.btn-sulit { background: linear-gradient(135deg, #EF4444, #F87171); color: white; border: none; box-shadow: 0 4px 12px rgba(239, 68, 68, 0.3); }
.btn-lumayan { background: linear-gradient(135deg, #F59E0B, #FBBF24); color: white; border: none; box-shadow: 0 4px 12px rgba(245, 158, 11, 0.3); }
.btn-hafal { background: linear-gradient(135deg, #10B981, #34D399); color: white; border: none; box-shadow: 0 4px 12px rgba(16, 185, 129, 0.3); }

/* List Items */
.list-item {
    display: flex;
    align-items: center;
    padding: calc(var(--spacing) * 2);
    background: var(--card);
    backdrop-filter: blur(12px);
    border: var(--glass-border);
    border-radius: var(--radius);
    margin-bottom: calc(var(--spacing) * 1.5);
    box-shadow: var(--shadow-sm);
    color: var(--text-main);
    transition: transform 0.2s, box-shadow 0.2s;
}
.list-item:active {
    transform: scale(0.98);
}
.list-item .content { flex: 1; }
.list-item .title { font-weight: 700; font-size: 1.15rem; margin-bottom: 2px; }
.list-item .subtitle { font-size: 0.85rem; color: var(--text-muted); font-weight: 500; }

/* Progress Bar (Linear) */
.progress-bar-bg {
    background: rgba(16, 185, 129, 0.15);
    height: 8px;
    border-radius: 4px;
    width: 100%;
    margin-top: 8px;
    overflow: hidden;
}
.progress-bar-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    border-radius: 4px;
    transition: width 0.5s ease-out;
}

/* Badges */
.badge {
    display: inline-block;
    padding: 2px 8px;
    border-radius: 12px;
    font-size: 0.75rem;
    font-weight: 600;
    margin-right: 4px;
}
.badge-success { background: rgba(16, 185, 129, 0.1); color: var(--success); }
.badge-warning { background: rgba(245, 158, 11, 0.1); color: var(--warning); }
.badge-danger { background: rgba(239, 68, 68, 0.1); color: var(--danger); }
.badge-muted { background: rgba(107, 114, 128, 0.1); color: var(--text-muted); }

/* Table */
.table-wrapper {
    overflow-x: auto;
    border-radius: var(--radius);
    background: var(--card);
    box-shadow: var(--shadow-sm);
}
table {
    width: 100%;
    border-collapse: collapse;
    text-align: left;
}
th, td {
    padding: 12px 16px;
    border-bottom: 1px solid rgba(107, 114, 128, 0.1);
}
th {
    background: rgba(107, 114, 128, 0.05);
    font-weight: 600;
    color: var(--text-muted);
}
tr:last-child td { border-bottom: none; }
tr:hover { background: rgba(16, 185, 129, 0.05); }

/* Filter Tabs */
.filter-tabs {
    display: flex;
    overflow-x: auto;
    gap: 8px;
    margin-bottom: 16px;
    padding-bottom: 4px;
}
.filter-tabs::-webkit-scrollbar { display: none; }
.filter-tab {
    padding: 6px 16px;
    border-radius: 20px;
    background: var(--card);
    color: var(--text-muted);
    font-weight: 600;
    font-size: 0.85rem;
    white-space: nowrap;
    cursor: pointer;
    border: 1px solid rgba(107, 114, 128, 0.2);
    transition: all 0.2s;
}
.filter-tab.active {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
}

/* Furigana and Toggling Logic */
/* Furigana and Toggling Logic */
.jap-kana-mode { display: none; }
.jap-kanji-mode { display: inline; }
.jap-furigana { 
    display: ruby-text; 
    transform: translateY(-2px); 
}

/* Kanji OFF, Kana ON */
.hide-kanji:not(.hide-kana) .jap-kanji-mode { display: none !important; }
.hide-kanji:not(.hide-kana) .jap-kana-mode { display: inline !important; }

/* Kanji ON, Kana OFF */
.hide-kana .jap-furigana { display: none !important; }

/* Kanji OFF, Kana OFF */
.hide-kanji.hide-kana .jap-kanji-mode,
.hide-kanji.hide-kana .jap-kana-mode { display: none !important; }