:root {
    --won: #16a34a;
    --won-bg: #f0fdf4;
    --won-border: #86efac;
    --planned: #2563eb;
    --planned-bg: #eff6ff;
    --planned-border: #93c5fd;
    --locked: #94a3b8;
    --locked-bg: #f8fafc;
    --available: #f59e0b;
    --available-bg: #fffbeb;
    --available-border: #fcd34d;
}
* { font-family: 'IBM Plex Sans', sans-serif; }
code, .mono { font-family: 'IBM Plex Mono', monospace; }

.course-card { transition: all 0.15s ease; cursor: default; }
.locked { opacity: 0.38; filter: grayscale(0.8); }
.prerequisite-highlight { outline: 2px solid #ef4444 !important; transform: scale(1.03); z-index: 10; }
.semester-col { min-width: 195px; }

/* Tabs */
.tab-btn { transition: all 0.15s; }
.tab-btn.active { background: #1e293b; color: #fff; }
.tab-btn:not(.active):hover { background: #e2e8f0; }

/* Plan cards */
.plan-period {
    border: 1px solid #e2e8f0;
    border-radius: 12px;
    background: #fff;
    overflow: hidden;
    box-shadow: 0 1px 4px rgba(0,0,0,0.06);
}
.plan-period-header {
    padding: 12px 16px;
    font-weight: 700;
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.plan-course-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 8px 16px;
    border-top: 1px solid #f1f5f9;
    font-size: 12px;
}
.plan-course-item:hover { background: #f8fafc; }
.credit-bar {
    height: 6px;
    border-radius: 3px;
    background: #e2e8f0;
    overflow: hidden;
}
.credit-bar-fill {
    height: 100%;
    border-radius: 3px;
    transition: width 0.4s ease;
}

/* Scrollbar */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: #cbd5e1; border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: #94a3b8; }

/* Drag & drop */
.drop-zone { transition: all 0.15s; }
.drop-zone.drag-over { background: #eff6ff !important; border-color: #3b82f6 !important; }

/* Modal */
#addCourseModal { transition: opacity 0.2s; }

.badge-won { background: var(--won-bg); color: var(--won); border: 1px solid var(--won-border); }
.badge-planned { background: var(--planned-bg); color: var(--planned); border: 1px solid var(--planned-border); }
.badge-available { background: var(--available-bg); color: var(--available); border: 1px solid var(--available-border); }

.animate-fade-in { animation: fadeIn 0.2s ease; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(4px); } to { opacity: 1; transform: translateY(0); } }

/* Grades modal */
#gradesModal { transition: opacity 0.2s; }
.grade-input { width: 70px; border: 1px solid #e2e8f0; border-radius: 6px; padding: 3px 6px; font-size: 12px; text-align: center; font-family: 'IBM Plex Mono', monospace; }
.grade-input:focus { outline: none; border-color: #3b82f6; box-shadow: 0 0 0 2px #bfdbfe; }
.obligatory-badge { display: inline-flex; align-items: center; gap: 3px; font-size: 9px; font-weight: 700; color: #1d4ed8; background: #dbeafe; border: 1px solid #93c5fd; border-radius: 4px; padding: 1px 5px; letter-spacing: 0.03em; }
.plan-course-item.obligatory-course { border-left: 3px solid #3b82f6; }

/* Course tree modal */
#treeModal { transition: opacity 0.2s; }
.tree-node { transition: all 0.15s; }
.tree-node:hover { transform: translateY(-1px); }
.tree-connector { stroke: #cbd5e1; stroke-width: 2; fill: none; }
.tree-connector.unlocks { stroke: #93c5fd; stroke-dasharray: 5 3; }


/* Schedule */
.schedule-block { border-radius: 6px; font-size: 10px; padding: 3px 5px; line-height: 1.3; overflow: hidden; cursor: default; }
.cal-header-cell { background: #f8fafc; font-size: 10px; font-weight: 700; color: #94a3b8; text-transform: uppercase; letter-spacing: 0.05em; padding: 8px 4px; text-align: center; border-right: 1px solid #e2e8f0; }
.cal-time-cell { font-size: 9px; color: #cbd5e1; font-family: 'IBM Plex Mono', monospace; padding: 0 6px; text-align: right; border-right: 1px solid #e2e8f0; white-space: nowrap; width: 44px; }
.cal-day-cell { border-right: 1px solid #f1f5f9; position: relative; }
.cal-row { border-top: 1px solid #f1f5f9; display: contents; }